Searched +hist:4 +hist:b6f5d20 (Results 76 - 100 of 106) sorted by path

12345

/linux-master/fs/ocfs2/
H A Dfile.hdiff a528d35e Tue Jan 31 09:46:22 MST 2017 David Howells <dhowells@redhat.com> statx: Add a system call to make enhanced file info available

Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.

The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode. This change is propagated to the vfs_getattr*()
function.

Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.

========
OVERVIEW
========

The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.

A number of requests were gathered for features to be included. The
following have been included:

(1) Make the fields a consistent size on all arches and make them large.

(2) Spare space, request flags and information flags are provided for
future expansion.

(3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
__s64).

(4) Creation time: The SMB protocol carries the creation time, which could
be exported by Samba, which will in turn help CIFS make use of
FS-Cache as that can be used for coherency data (stx_btime).

This is also specified in NFSv4 as a recommended attribute and could
be exported by NFSD [Steve French].

(5) Lightweight stat: Ask for just those details of interest, and allow a
netfs (such as NFS) to approximate anything not of interest, possibly
without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
Dilger] (AT_STATX_DONT_SYNC).

(6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
its cached attributes are up to date [Trond Myklebust]
(AT_STATX_FORCE_SYNC).

And the following have been left out for future extension:

(7) Data version number: Could be used by userspace NFS servers [Aneesh
Kumar].

Can also be used to modify fill_post_wcc() in NFSD which retrieves
i_version directly, but has just called vfs_getattr(). It could get
it from the kstat struct if it used vfs_xgetattr() instead.

(There's disagreement on the exact semantics of a single field, since
not all filesystems do this the same way).

(8) BSD stat compatibility: Including more fields from the BSD stat such
as creation time (st_btime) and inode generation number (st_gen)
[Jeremy Allison, Bernd Schubert].

(9) Inode generation number: Useful for FUSE and userspace NFS servers
[Bernd Schubert].

(This was asked for but later deemed unnecessary with the
open-by-handle capability available and caused disagreement as to
whether it's a security hole or not).

(10) Extra coherency data may be useful in making backups [Andreas Dilger].

(No particular data were offered, but things like last backup
timestamp, the data version number and the DOS archive bit would come
into this category).

(11) Allow the filesystem to indicate what it can/cannot provide: A
filesystem can now say it doesn't support a standard stat feature if
that isn't available, so if, for instance, inode numbers or UIDs don't
exist or are fabricated locally...

(This requires a separate system call - I have an fsinfo() call idea
for this).

(12) Store a 16-byte volume ID in the superblock that can be returned in
struct xstat [Steve French].

(Deferred to fsinfo).

(13) Include granularity fields in the time data to indicate the
granularity of each of the times (NFSv4 time_delta) [Steve French].

(Deferred to fsinfo).

(14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
Note that the Linux IOC flags are a mess and filesystems such as Ext4
define flags that aren't in linux/fs.h, so translation in the kernel
may be a necessity (or, possibly, we provide the filesystem type too).

(Some attributes are made available in stx_attributes, but the general
feeling was that the IOC flags were to ext[234]-specific and shouldn't
be exposed through statx this way).

(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
Michael Kerrisk].

(Deferred, probably to fsinfo. Finding out if there's an ACL or
seclabal might require extra filesystem operations).

(16) Femtosecond-resolution timestamps [Dave Chinner].

(A __reserved field has been left in the statx_timestamp struct for
this - if there proves to be a need).

(17) A set multiple attributes syscall to go with this.

===============
NEW SYSTEM CALL
===============

The new system call is:

int ret = statx(int dfd,
const char *filename,
unsigned int flags,
unsigned int mask,
struct statx *buffer);

The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat(). There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.

Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):

(1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
respect.

(2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
its attributes with the server - which might require data writeback to
occur to get the timestamps correct.

(3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
network filesystem. The resulting values should be considered
approximate.

mask is a bitmask indicating the fields in struct statx that are of
interest to the caller. The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat(). It should be noted that asking for
more information may entail extra I/O operations.

buffer points to the destination for the data. This must be 256 bytes in
size.

======================
MAIN ATTRIBUTES RECORD
======================

The following structures are defined in which to return the main attribute
set:

struct statx_timestamp {
__s64 tv_sec;
__s32 tv_nsec;
__s32 __reserved;
};

struct statx {
__u32 stx_mask;
__u32 stx_blksize;
__u64 stx_attributes;
__u32 stx_nlink;
__u32 stx_uid;
__u32 stx_gid;
__u16 stx_mode;
__u16 __spare0[1];
__u64 stx_ino;
__u64 stx_size;
__u64 stx_blocks;
__u64 __spare1[1];
struct statx_timestamp stx_atime;
struct statx_timestamp stx_btime;
struct statx_timestamp stx_ctime;
struct statx_timestamp stx_mtime;
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major;
__u32 stx_dev_minor;
__u64 __spare2[14];
};

The defined bits in request_mask and stx_mask are:

STATX_TYPE Want/got stx_mode & S_IFMT
STATX_MODE Want/got stx_mode & ~S_IFMT
STATX_NLINK Want/got stx_nlink
STATX_UID Want/got stx_uid
STATX_GID Want/got stx_gid
STATX_ATIME Want/got stx_atime{,_ns}
STATX_MTIME Want/got stx_mtime{,_ns}
STATX_CTIME Want/got stx_ctime{,_ns}
STATX_INO Want/got stx_ino
STATX_SIZE Want/got stx_size
STATX_BLOCKS Want/got stx_blocks
STATX_BASIC_STATS [The stuff in the normal stat struct]
STATX_BTIME Want/got stx_btime{,_ns}
STATX_ALL [All currently available stuff]

stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.

Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution. Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.

The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does. The following
attributes map to FS_*_FL flags and are the same numerical value:

STATX_ATTR_COMPRESSED File is compressed by the fs
STATX_ATTR_IMMUTABLE File is marked immutable
STATX_ATTR_APPEND File is append-only
STATX_ATTR_NODUMP File is not to be dumped
STATX_ATTR_ENCRYPTED File requires key to decrypt in fs

Within the kernel, the supported flags are listed by:

KSTAT_ATTR_FS_IOC_FLAGS

[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]

New flags include:

STATX_ATTR_AUTOMOUNT Object is an automount trigger

These are for the use of GUI tools that might want to mark files specially,
depending on what they are.

Fields in struct statx come in a number of classes:

(0) stx_dev_*, stx_blksize.

These are local system information and are always available.

(1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
stx_size, stx_blocks.

These will be returned whether the caller asks for them or not. The
corresponding bits in stx_mask will be set to indicate whether they
actually have valid values.

If the caller didn't ask for them, then they may be approximated. For
example, NFS won't waste any time updating them from the server,
unless as a byproduct of updating something requested.

If the values don't actually exist for the underlying object (such as
UID or GID on a DOS file), then the bit won't be set in the stx_mask,
even if the caller asked for the value. In such a case, the returned
value will be a fabrication.

Note that there are instances where the type might not be valid, for
instance Windows reparse points.

(2) stx_rdev_*.

This will be set only if stx_mode indicates we're looking at a
blockdev or a chardev, otherwise will be 0.

(3) stx_btime.

Similar to (1), except this will be set to 0 if it doesn't exist.

=======
TESTING
=======

The following test program can be used to test the statx system call:

samples/statx/test-statx.c

Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.

Here's some example output. Firstly, an NFS directory that crosses to
another FSID. Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.

[root@andromeda ~]# /tmp/test-statx -A /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:26 Inode: 1703937 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)

Secondly, the result of automounting on that directory.

[root@andromeda ~]# /tmp/test-statx /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:27 Inode: 2 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff e7d4cb6b Mon Aug 18 03:38:44 MDT 2008 Tao Ma <tao.ma@oracle.com> ocfs2: Abstract ocfs2_extent_tree in b-tree operations.

In the old extent tree operation, we take the hypothesis that we
are using the ocfs2_extent_list in ocfs2_dinode as the tree root.
As xattr will also use ocfs2_extent_list to store large value
for a xattr entry, we refactor the tree operation so that xattr
can use it directly.

The refactoring includes 4 steps:
1. Abstract set/get of last_eb_blk and update_clusters since they may
be stored in different location for dinode and xattr.
2. Add a new structure named ocfs2_extent_tree to indicate the
extent tree the operation will work on.
3. Remove all the use of fe_bh and di, use root_bh and root_el in
extent tree instead. So now all the fe_bh is replaced with
et->root_bh, el with root_el accordingly.
4. Make ocfs2_lock_allocators generic. Now it is limited to be only used
in file extend allocation. But the whole function is useful when we want
to store large EAs.

Note: This patch doesn't touch ocfs2_commit_truncate() since it is not used
for anything other than truncate inode data btrees.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
diff e7d4cb6b Mon Aug 18 03:38:44 MDT 2008 Tao Ma <tao.ma@oracle.com> ocfs2: Abstract ocfs2_extent_tree in b-tree operations.

In the old extent tree operation, we take the hypothesis that we
are using the ocfs2_extent_list in ocfs2_dinode as the tree root.
As xattr will also use ocfs2_extent_list to store large value
for a xattr entry, we refactor the tree operation so that xattr
can use it directly.

The refactoring includes 4 steps:
1. Abstract set/get of last_eb_blk and update_clusters since they may
be stored in different location for dinode and xattr.
2. Add a new structure named ocfs2_extent_tree to indicate the
extent tree the operation will work on.
3. Remove all the use of fe_bh and di, use root_bh and root_el in
extent tree instead. So now all the fe_bh is replaced with
et->root_bh, el with root_el accordingly.
4. Make ocfs2_lock_allocators generic. Now it is limited to be only used
in file extend allocation. But the whole function is useful when we want
to store large EAs.

Note: This patch doesn't touch ocfs2_commit_truncate() since it is not used
for anything other than truncate inode data btrees.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
/linux-master/fs/openpromfs/
H A Dinode.cdiff 4ba9b9d0 Wed Oct 17 00:25:51 MDT 2007 Christoph Lameter <clameter@sgi.com> Slab API: remove useless ctor parameter and reorder parameters

Slab constructors currently have a flags parameter that is never used. And
the order of the arguments is opposite to other slab functions. The object
pointer is placed before the kmem_cache pointer.

Convert

ctor(void *object, struct kmem_cache *s, unsigned long flags)

to

ctor(struct kmem_cache *s, void *object)

throughout the kernel

[akpm@linux-foundation.org: coupla fixes]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
/linux-master/fs/
H A Dpipe.cdiff 68279f9c Wed Oct 11 10:55:00 MDT 2023 Alexey Dobriyan <adobriyan@gmail.com> treewide: mark stuff as __ro_after_init

__read_mostly predates __ro_after_init. Many variables which are marked
__read_mostly should have been __ro_after_init from day 1.

Also, mark some stuff as "const" and "__init" while I'm at it.

[akpm@linux-foundation.org: revert sysctl_nr_open_min, sysctl_nr_open_max changes due to arm warning]
[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/4f6bb9c0-abba-4ee4-a7aa-89265e886817@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 68279f9c Wed Oct 11 10:55:00 MDT 2023 Alexey Dobriyan <adobriyan@gmail.com> treewide: mark stuff as __ro_after_init

__read_mostly predates __ro_after_init. Many variables which are marked
__read_mostly should have been __ro_after_init from day 1.

Also, mark some stuff as "const" and "__init" while I'm at it.

[akpm@linux-foundation.org: revert sysctl_nr_open_min, sysctl_nr_open_max changes due to arm warning]
[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/4f6bb9c0-abba-4ee4-a7aa-89265e886817@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 478dbf12 Thu Sep 21 01:57:55 MDT 2023 Max Kellermann <max.kellermann@ionos.com> fs/pipe: use spinlock in pipe_read() only if there is a watch_queue

If there is no watch_queue, holding the pipe mutex is enough to
prevent concurrent writes, and we can avoid the spinlock.

O_NOTIFICATION_QUEUE is an exotic and rarely used feature, and of all
the pipes that exist at any given time, only very few actually have a
watch_queue, therefore it appears worthwile to optimize the common
case.

This patch does not optimize pipe_resize_ring() where the spinlocks
could be avoided as well; that does not seem like a worthwile
optimization because this function is not called often.

Related commits:

- commit 8df441294dd3 ("pipe: Check for ring full inside of the
spinlock in pipe_write()")
- commit b667b8673443 ("pipe: Advance tail pointer inside of wait
spinlock in pipe_read()")
- commit 189b0ddc2451 ("pipe: Fix missing lock in pipe_resize_ring()")

Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Message-Id: <20230921075755.1378787-4-max.kellermann@ionos.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
diff 515c5046 Wed Feb 01 09:18:53 MST 2023 Luca Vizzarro <Luca.Vizzarro@arm.com> pipe: Pass argument of pipe_fcntl as int

The interface for fcntl expects the argument passed for the command
F_SETPIPE_SZ to be of type int. The current code wrongly treats it as
a long. In order to avoid access to undefined bits, we should explicitly
cast the argument to int.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Kevin Brodsky <Kevin.Brodsky@arm.com>
Cc: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: David Laight <David.Laight@ACULAB.com>
Cc: Mark Rutland <Mark.Rutland@arm.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-morello@op-lists.linaro.org
Signed-off-by: Luca Vizzarro <Luca.Vizzarro@arm.com>
Message-Id: <20230414152459.816046-4-Luca.Vizzarro@arm.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
diff c04fe8e3 Tue May 09 09:12:24 MDT 2023 Jens Axboe <axboe@kernel.dk> pipe: check for IOCB_NOWAIT alongside O_NONBLOCK

Pipe reads or writes need to enable nonblocking attempts, if either
O_NONBLOCK is set on the file, or IOCB_NOWAIT is set in the iocb being
passed in. The latter isn't currently true, ensure we check for both
before waiting on data or space.

Fixes: afed6271f5b0 ("pipe: set FMODE_NOWAIT on pipes")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <e5946d67-4e5e-b056-ba80-656bab12d9f6@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
diff 189b0ddc Thu May 26 00:34:52 MDT 2022 David Howells <dhowells@redhat.com> pipe: Fix missing lock in pipe_resize_ring()

pipe_resize_ring() needs to take the pipe->rd_wait.lock spinlock to
prevent post_one_notification() from trying to insert into the ring
whilst the ring is being replaced.

The occupancy check must be done after the lock is taken, and the lock
must be taken after the new ring is allocated.

The bug can lead to an oops looking something like:

BUG: KASAN: use-after-free in post_one_notification.isra.0+0x62e/0x840
Read of size 4 at addr ffff88801cc72a70 by task poc/27196
...
Call Trace:
post_one_notification.isra.0+0x62e/0x840
__post_watch_notification+0x3b7/0x650
key_create_or_update+0xb8b/0xd20
__do_sys_add_key+0x175/0x340
__x64_sys_add_key+0xbe/0x140
do_syscall_64+0x5c/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Selim Enes Karaduman @Enesdex working with Trend Micro Zero
Day Initiative.

Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-17291
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff f485922d Fri Apr 29 15:38:01 MDT 2022 Kuniyuki Iwashima <kuniyu@amazon.co.jp> pipe: make poll_usage boolean and annotate its access

Patch series "Fix data-races around epoll reported by KCSAN."

This series suppresses a false positive KCSAN's message and fixes a real
data-race.


This patch (of 2):

pipe_poll() runs locklessly and assigns 1 to poll_usage. Once poll_usage
is set to 1, it never changes in other places. However, concurrent writes
of a value trigger KCSAN, so let's make KCSAN happy.

BUG: KCSAN: data-race in pipe_poll / pipe_poll

write to 0xffff8880042f6678 of 4 bytes by task 174 on cpu 3:
pipe_poll (fs/pipe.c:656)
ep_item_poll.isra.0 (./include/linux/poll.h:88 fs/eventpoll.c:853)
do_epoll_wait (fs/eventpoll.c:1692 fs/eventpoll.c:1806 fs/eventpoll.c:2234)
__x64_sys_epoll_wait (fs/eventpoll.c:2246 fs/eventpoll.c:2241 fs/eventpoll.c:2241)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113)

write to 0xffff8880042f6678 of 4 bytes by task 177 on cpu 1:
pipe_poll (fs/pipe.c:656)
ep_item_poll.isra.0 (./include/linux/poll.h:88 fs/eventpoll.c:853)
do_epoll_wait (fs/eventpoll.c:1692 fs/eventpoll.c:1806 fs/eventpoll.c:2234)
__x64_sys_epoll_wait (fs/eventpoll.c:2246 fs/eventpoll.c:2241 fs/eventpoll.c:2241)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113)

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 177 Comm: epoll_race Not tainted 5.17.0-58927-gf443e374ae13 #6
Hardware name: Red Hat KVM, BIOS 1.11.0-2.amzn2 04/01/2014

Link: https://lkml.kernel.org/r/20220322002653.33865-1-kuniyu@amazon.co.jp
Link: https://lkml.kernel.org/r/20220322002653.33865-2-kuniyu@amazon.co.jp
Fixes: 3b844826b6c6 ("pipe: avoid unnecessary EPOLLET wakeups under normal loads")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kuniyuki Iwashima <kuni1840@gmail.com>
Cc: "Soheil Hassas Yeganeh" <soheil@google.com>
Cc: "Sridhar Samudrala" <sridhar.samudrala@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff f485922d Fri Apr 29 15:38:01 MDT 2022 Kuniyuki Iwashima <kuniyu@amazon.co.jp> pipe: make poll_usage boolean and annotate its access

Patch series "Fix data-races around epoll reported by KCSAN."

This series suppresses a false positive KCSAN's message and fixes a real
data-race.


This patch (of 2):

pipe_poll() runs locklessly and assigns 1 to poll_usage. Once poll_usage
is set to 1, it never changes in other places. However, concurrent writes
of a value trigger KCSAN, so let's make KCSAN happy.

BUG: KCSAN: data-race in pipe_poll / pipe_poll

write to 0xffff8880042f6678 of 4 bytes by task 174 on cpu 3:
pipe_poll (fs/pipe.c:656)
ep_item_poll.isra.0 (./include/linux/poll.h:88 fs/eventpoll.c:853)
do_epoll_wait (fs/eventpoll.c:1692 fs/eventpoll.c:1806 fs/eventpoll.c:2234)
__x64_sys_epoll_wait (fs/eventpoll.c:2246 fs/eventpoll.c:2241 fs/eventpoll.c:2241)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113)

write to 0xffff8880042f6678 of 4 bytes by task 177 on cpu 1:
pipe_poll (fs/pipe.c:656)
ep_item_poll.isra.0 (./include/linux/poll.h:88 fs/eventpoll.c:853)
do_epoll_wait (fs/eventpoll.c:1692 fs/eventpoll.c:1806 fs/eventpoll.c:2234)
__x64_sys_epoll_wait (fs/eventpoll.c:2246 fs/eventpoll.c:2241 fs/eventpoll.c:2241)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:113)

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 177 Comm: epoll_race Not tainted 5.17.0-58927-gf443e374ae13 #6
Hardware name: Red Hat KVM, BIOS 1.11.0-2.amzn2 04/01/2014

Link: https://lkml.kernel.org/r/20220322002653.33865-1-kuniyu@amazon.co.jp
Link: https://lkml.kernel.org/r/20220322002653.33865-2-kuniyu@amazon.co.jp
Fixes: 3b844826b6c6 ("pipe: avoid unnecessary EPOLLET wakeups under normal loads")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kuniyuki Iwashima <kuni1840@gmail.com>
Cc: "Soheil Hassas Yeganeh" <soheil@google.com>
Cc: "Sridhar Samudrala" <sridhar.samudrala@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 9857a17f Thu Sep 02 15:53:54 MDT 2021 John Hubbard <jhubbard@nvidia.com> mm/gup: remove try_get_page(), call try_get_compound_head() directly

try_get_page() is very similar to try_get_compound_head(), and in fact
try_get_page() has fallen a little behind in terms of maintenance:
try_get_compound_head() handles speculative page references more
thoroughly.

There are only two try_get_page() callsites, so just call
try_get_compound_head() directly from those, and remove try_get_page()
entirely.

Also, seeing as how this changes try_get_compound_head() into a non-static
function, provide some kerneldoc documentation for it.

Link: https://lkml.kernel.org/r/20210813044133.1536842-4-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 3a34b13a Fri Jul 30 16:42:34 MDT 2021 Linus Torvalds <torvalds@linux-foundation.org> pipe: make pipe writes always wake up readers

Since commit 1b6b26ae7053 ("pipe: fix and clarify pipe write wakeup
logic") we have sanitized the pipe write logic, and would only try to
wake up readers if they needed it.

In particular, if the pipe already had data in it before the write,
there was no point in trying to wake up a reader, since any existing
readers must have been aware of the pre-existing data already. Doing
extraneous wakeups will only cause potential thundering herd problems.

However, it turns out that some Android libraries have misused the EPOLL
interface, and expected "edge triggered" be to "any new write will
trigger it". Even if there was no edge in sight.

Quoting Sandeep Patil:
"The commit 1b6b26ae7053 ('pipe: fix and clarify pipe write wakeup
logic') changed pipe write logic to wakeup readers only if the pipe
was empty at the time of write. However, there are libraries that
relied upon the older behavior for notification scheme similar to
what's described in [1]

One such library 'realm-core'[2] is used by numerous Android
applications. The library uses a similar notification mechanism as GNU
Make but it never drains the pipe until it is full. When Android moved
to v5.10 kernel, all applications using this library stopped working.

The library has since been fixed[3] but it will be a while before all
applications incorporate the updated library"

Our regression rule for the kernel is that if applications break from
new behavior, it's a regression, even if it was because the application
did something patently wrong. Also note the original report [4] by
Michal Kerrisk about a test for this epoll behavior - but at that point
we didn't know of any actual broken use case.

So add the extraneous wakeup, to approximate the old behavior.

[ I say "approximate", because the exact old behavior was to do a wakeup
not for each write(), but for each pipe buffer chunk that was filled
in. The behavior introduced by this change is not that - this is just
"every write will cause a wakeup, whether necessary or not", which
seems to be sufficient for the broken library use. ]

It's worth noting that this adds the extraneous wakeup only for the
write side, while the read side still considers the "edge" to be purely
about reading enough from the pipe to allow further writes.

See commit f467a6a66419 ("pipe: fix and clarify pipe read wakeup logic")
for the pipe read case, which remains that "only wake up if the pipe was
full, and we read something from it".

Link: https://lore.kernel.org/lkml/CAHk-=wjeG0q1vgzu4iJhW5juPkTsjTYmiqiMUYAebWW+0bam6w@mail.gmail.com/ [1]
Link: https://github.com/realm/realm-core [2]
Link: https://github.com/realm/realm-core/issues/4666 [3]
Link: https://lore.kernel.org/lkml/CAKgNAkjMBGeAwF=2MKK758BhxvW58wYTgYKB2V-gY1PwXxrH+Q@mail.gmail.com/ [4]
Link: https://lore.kernel.org/lkml/20210729222635.2937453-1-sspatil@android.com/
Reported-by: Sandeep Patil <sspatil@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 3a34b13a Fri Jul 30 16:42:34 MDT 2021 Linus Torvalds <torvalds@linux-foundation.org> pipe: make pipe writes always wake up readers

Since commit 1b6b26ae7053 ("pipe: fix and clarify pipe write wakeup
logic") we have sanitized the pipe write logic, and would only try to
wake up readers if they needed it.

In particular, if the pipe already had data in it before the write,
there was no point in trying to wake up a reader, since any existing
readers must have been aware of the pre-existing data already. Doing
extraneous wakeups will only cause potential thundering herd problems.

However, it turns out that some Android libraries have misused the EPOLL
interface, and expected "edge triggered" be to "any new write will
trigger it". Even if there was no edge in sight.

Quoting Sandeep Patil:
"The commit 1b6b26ae7053 ('pipe: fix and clarify pipe write wakeup
logic') changed pipe write logic to wakeup readers only if the pipe
was empty at the time of write. However, there are libraries that
relied upon the older behavior for notification scheme similar to
what's described in [1]

One such library 'realm-core'[2] is used by numerous Android
applications. The library uses a similar notification mechanism as GNU
Make but it never drains the pipe until it is full. When Android moved
to v5.10 kernel, all applications using this library stopped working.

The library has since been fixed[3] but it will be a while before all
applications incorporate the updated library"

Our regression rule for the kernel is that if applications break from
new behavior, it's a regression, even if it was because the application
did something patently wrong. Also note the original report [4] by
Michal Kerrisk about a test for this epoll behavior - but at that point
we didn't know of any actual broken use case.

So add the extraneous wakeup, to approximate the old behavior.

[ I say "approximate", because the exact old behavior was to do a wakeup
not for each write(), but for each pipe buffer chunk that was filled
in. The behavior introduced by this change is not that - this is just
"every write will cause a wakeup, whether necessary or not", which
seems to be sufficient for the broken library use. ]

It's worth noting that this adds the extraneous wakeup only for the
write side, while the read side still considers the "edge" to be purely
about reading enough from the pipe to allow further writes.

See commit f467a6a66419 ("pipe: fix and clarify pipe read wakeup logic")
for the pipe read case, which remains that "only wake up if the pipe was
full, and we read something from it".

Link: https://lore.kernel.org/lkml/CAHk-=wjeG0q1vgzu4iJhW5juPkTsjTYmiqiMUYAebWW+0bam6w@mail.gmail.com/ [1]
Link: https://github.com/realm/realm-core [2]
Link: https://github.com/realm/realm-core/issues/4666 [3]
Link: https://lore.kernel.org/lkml/CAKgNAkjMBGeAwF=2MKK758BhxvW58wYTgYKB2V-gY1PwXxrH+Q@mail.gmail.com/ [4]
Link: https://lore.kernel.org/lkml/20210729222635.2937453-1-sspatil@android.com/
Reported-by: Sandeep Patil <sspatil@android.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
H A Dread_write.cdiff 73065126 Thu Nov 30 07:16:24 MST 2023 Amir Goldstein <amir73il@gmail.com> fs: use do_splice_direct() for nfsd/ksmbd server-side-copy

nfsd/ksmbd call vfs_copy_file_range() with flag COPY_FILE_SPLICE to
perform kernel copy between two files on any two filesystems.

Splicing input file, while holding file_start_write() on the output file
which is on a different sb, posses a risk for fanotify related deadlocks.

We only need to call splice_file_range() from within the context of
->copy_file_range() filesystem methods with file_start_write() held.

To avoid the possible deadlocks, always use do_splice_direct() instead of
splice_file_range() for the kernel copy fallback in vfs_copy_file_range()
without holding file_start_write().

Reported-and-tested-by: Bert Karwatzki <spasswolf@web.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231130141624.3338942-4-amir73il@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
diff 4e3299ea Wed Jun 29 07:06:59 MDT 2022 Jason A. Donenfeld <Jason@zx2c4.com> fs: do not compare against ->llseek

Now vfs_llseek() can simply check for FMODE_LSEEK; if it's set,
we know that ->llseek() won't be NULL and if it's not we should
just fail with -ESPIPE.

A couple of other places where we used to check for special
values of ->llseek() (somewhat inconsistently) switched to
checking FMODE_LSEEK.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff 868f9f2f Thu Jun 30 13:58:49 MDT 2022 Amir Goldstein <amir73il@gmail.com> vfs: fix copy_file_range() regression in cross-fs copies

A regression has been reported by Nicolas Boichat, found while using the
copy_file_range syscall to copy a tracefs file.

Before commit 5dae222a5ff0 ("vfs: allow copy_file_range to copy across
devices") the kernel would return -EXDEV to userspace when trying to
copy a file across different filesystems. After this commit, the
syscall doesn't fail anymore and instead returns zero (zero bytes
copied), as this file's content is generated on-the-fly and thus reports
a size of zero.

Another regression has been reported by He Zhe - the assertion of
WARN_ON_ONCE(ret == -EOPNOTSUPP) can be triggered from userspace when
copying from a sysfs file whose read operation may return -EOPNOTSUPP.

Since we do not have test coverage for copy_file_range() between any two
types of filesystems, the best way to avoid these sort of issues in the
future is for the kernel to be more picky about filesystems that are
allowed to do copy_file_range().

This patch restores some cross-filesystem copy restrictions that existed
prior to commit 5dae222a5ff0 ("vfs: allow copy_file_range to copy across
devices"), namely, cross-sb copy is not allowed for filesystems that do
not implement ->copy_file_range().

Filesystems that do implement ->copy_file_range() have full control of
the result - if this method returns an error, the error is returned to
the user. Before this change this was only true for fs that did not
implement the ->remap_file_range() operation (i.e. nfsv3).

Filesystems that do not implement ->copy_file_range() still fall-back to
the generic_copy_file_range() implementation when the copy is within the
same sb. This helps the kernel can maintain a more consistent story
about which filesystems support copy_file_range().

nfsd and ksmbd servers are modified to fall-back to the
generic_copy_file_range() implementation in case vfs_copy_file_range()
fails with -EOPNOTSUPP or -EXDEV, which preserves behavior of
server-side-copy.

fall-back to generic_copy_file_range() is not implemented for the smb
operation FSCTL_DUPLICATE_EXTENTS_TO_FILE, which is arguably a correct
change of behavior.

Fixes: 5dae222a5ff0 ("vfs: allow copy_file_range to copy across devices")
Link: https://lore.kernel.org/linux-fsdevel/20210212044405.4120619-1-drinkcat@chromium.org/
Link: https://lore.kernel.org/linux-fsdevel/CANMq1KDZuxir2LM5jOTm0xx+BnvW=ZmpsG47CyHFJwnw7zSX6Q@mail.gmail.com/
Link: https://lore.kernel.org/linux-fsdevel/20210126135012.1.If45b7cdc3ff707bc1efa17f5366057d60603c45f@changeid/
Link: https://lore.kernel.org/linux-fsdevel/20210630161320.29006-1-lhenriques@suse.de/
Reported-by: Nicolas Boichat <drinkcat@chromium.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Luis Henriques <lhenriques@suse.de>
Fixes: 64bf5ff58dff ("vfs: no fallback for ->copy_file_range")
Link: https://lore.kernel.org/linux-fsdevel/20f17f64-88cb-4e80-07c1-85cb96c83619@windriver.com/
Reported-by: He Zhe <zhe.he@windriver.com>
Tested-by: Namjae Jeon <linkinjeon@kernel.org>
Tested-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff c51acdb7 Fri Dec 31 00:57:50 MST 2021 Tal Zussman <tz2294@columbia.edu> fs: Remove FIXME comment in generic_write_checks()

This patch removes an unnecessary comment that had to do with block special
files from `generic_write_checks()`.

The comment, originally added in Linux v2.4.14.9, was to clarify that we only
set `pos` to the file size when the file was opened with `O_APPEND` if the file
wasn't a block special file. Prior to Linux v2.4, block special files had a
different `write()` function which was unified into a generic `write()` function
in Linux v2.4. This generic `write()` function called `generic_write_checks()`.
For more details, see this earlier conversation:
https://lore.kernel.org/linux-fsdevel/Yc4Czk5A+p5p2Y4W@mit.edu/

Currently, block special devices have their own `write_iter()` function and no
longer share the same `generic_write_checks()`, therefore rendering the comment
irrelevant.

Signed-off-by: Tal Zussman <tz2294@columbia.edu>
Co-authored-by: Xijiao Li <xl2950@columbia.edu>
Co-authored-by: Hans Montero <hjm2133@columbia.edu>
Suggested-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff c51acdb7 Fri Dec 31 00:57:50 MST 2021 Tal Zussman <tz2294@columbia.edu> fs: Remove FIXME comment in generic_write_checks()

This patch removes an unnecessary comment that had to do with block special
files from `generic_write_checks()`.

The comment, originally added in Linux v2.4.14.9, was to clarify that we only
set `pos` to the file size when the file was opened with `O_APPEND` if the file
wasn't a block special file. Prior to Linux v2.4, block special files had a
different `write()` function which was unified into a generic `write()` function
in Linux v2.4. This generic `write()` function called `generic_write_checks()`.
For more details, see this earlier conversation:
https://lore.kernel.org/linux-fsdevel/Yc4Czk5A+p5p2Y4W@mit.edu/

Currently, block special devices have their own `write_iter()` function and no
longer share the same `generic_write_checks()`, therefore rendering the comment
irrelevant.

Signed-off-by: Tal Zussman <tz2294@columbia.edu>
Co-authored-by: Xijiao Li <xl2950@columbia.edu>
Co-authored-by: Hans Montero <hjm2133@columbia.edu>
Suggested-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff 4c207ef4 Fri Oct 02 20:55:22 MDT 2020 Matthew Wilcox (Oracle) <willy@infradead.org> fs: Allow a NULL pos pointer to __kernel_write

Linus prefers that callers be allowed to pass in a NULL pointer for ppos
like new_sync_write().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff 4d03e3cc Thu Sep 03 08:22:33 MDT 2020 Christoph Hellwig <hch@lst.de> fs: don't allow kernel reads and writes without iter ops

Don't allow calling ->read or ->write with set_fs as a preparation for
killing off set_fs. All the instances that we use kernel_read/write on
are using the iter ops already.

If a file has both the regular ->read/->write methods and the iter
variants those could have different semantics for messed up enough
drivers. Also fails the kernel access to them in that case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff 10dce8af Tue Mar 26 16:20:43 MDT 2019 Kirill Smelkov <kirr@nexedi.com> fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock

Commit 9c225f2655e3 ("vfs: atomic f_pos accesses as per POSIX") added
locking for file.f_pos access and in particular made concurrent read and
write not possible - now both those functions take f_pos lock for the
whole run, and so if e.g. a read is blocked waiting for data, write will
deadlock waiting for that read to complete.

This caused regression for stream-like files where previously read and
write could run simultaneously, but after that patch could not do so
anymore. See e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes
to /proc/xen/xenbus") which fixes such regression for particular case of
/proc/xen/xenbus.

The patch that added f_pos lock in 2014 did so to guarantee POSIX thread
safety for read/write/lseek and added the locking to file descriptors of
all regular files. In 2014 that thread-safety problem was not new as it
was already discussed earlier in 2006.

However even though 2006'th version of Linus's patch was adding f_pos
locking "only for files that are marked seekable with FMODE_LSEEK (thus
avoiding the stream-like objects like pipes and sockets)", the 2014
version - the one that actually made it into the tree as 9c225f2655e3 -
is doing so irregardless of whether a file is seekable or not.

See

https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/
https://lwn.net/Articles/180387
https://lwn.net/Articles/180396

for historic context.

The reason that it did so is, probably, that there are many files that
are marked non-seekable, but e.g. their read implementation actually
depends on knowing current position to correctly handle the read. Some
examples:

kernel/power/user.c snapshot_read
fs/debugfs/file.c u32_array_read
fs/fuse/control.c fuse_conn_waiting_read + ...
drivers/hwmon/asus_atk0110.c atk_debugfs_ggrp_read
arch/s390/hypfs/inode.c hypfs_read_iter
...

Despite that, many nonseekable_open users implement read and write with
pure stream semantics - they don't depend on passed ppos at all. And for
those cases where read could wait for something inside, it creates a
situation similar to xenbus - the write could be never made to go until
read is done, and read is waiting for some, potentially external, event,
for potentially unbounded time -> deadlock.

Besides xenbus, there are 14 such places in the kernel that I've found
with semantic patch (see below):

drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write()
drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write()
drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write()
drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write()
net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write()
drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write()
drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write()
drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write()
net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write()
drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write()
drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write()
drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write()
drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write()
drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write()

In addition to the cases above another regression caused by f_pos
locking is that now FUSE filesystems that implement open with
FOPEN_NONSEEKABLE flag, can no longer implement bidirectional
stream-like files - for the same reason as above e.g. read can deadlock
write locking on file.f_pos in the kernel.

FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990f715 ("fuse:
implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp
in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and
write routines not depending on current position at all, and with both
read and write being potentially blocking operations:

See

https://github.com/libfuse/osspd
https://lwn.net/Articles/308445

https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406
https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477
https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510

Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as
"somewhat pipe-like files ..." with read handler not using offset.
However that test implements only read without write and cannot exercise
the deadlock scenario:

https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131
https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163
https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216

I've actually hit the read vs write deadlock for real while implementing
my FUSE filesystem where there is /head/watch file, for which open
creates separate bidirectional socket-like stream in between filesystem
and its user with both read and write being later performed
simultaneously. And there it is semantically not easy to split the
stream into two separate read-only and write-only channels:

https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169

Let's fix this regression. The plan is:

1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS -
doing so would break many in-kernel nonseekable_open users which
actually use ppos in read/write handlers.

2. Add stream_open() to kernel to open stream-like non-seekable file
descriptors. Read and write on such file descriptors would never use
nor change ppos. And with that property on stream-like files read and
write will be running without taking f_pos lock - i.e. read and write
could be running simultaneously.

3. With semantic patch search and convert to stream_open all in-kernel
nonseekable_open users for which read and write actually do not
depend on ppos and where there is no other methods in file_operations
which assume @offset access.

4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via
steam_open if that bit is present in filesystem open reply.

It was tempting to change fs/fuse/ open handler to use stream_open
instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but
grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE,
and in particular GVFS which actually uses offset in its read and
write handlers

https://codesearch.debian.net/search?q=-%3Enonseekable+%3D
https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080
https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346
https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481

so if we would do such a change it will break a real user.

5. Add stream_open and FOPEN_STREAM handling to stable kernels starting
from v3.14+ (the kernel where 9c225f2655 first appeared).

This will allow to patch OSSPD and other FUSE filesystems that
provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE
in their open handler and this way avoid the deadlock on all kernel
versions. This should work because fs/fuse/ ignores unknown open
flags returned from a filesystem and so passing FOPEN_STREAM to a
kernel that is not aware of this flag cannot hurt. In turn the kernel
that is not aware of FOPEN_STREAM will be < v3.14 where just
FOPEN_NONSEEKABLE is sufficient to implement streams without read vs
write deadlock.

This patch adds stream_open, converts /proc/xen/xenbus to it and adds
semantic patch to automatically locate in-kernel places that are either
required to be converted due to read vs write deadlock, or that are just
safe to be converted because read and write do not use ppos and there
are no other funky methods in file_operations.

Regarding semantic patch I've verified each generated change manually -
that it is correct to convert - and each other nonseekable_open instance
left - that it is either not correct to convert there, or that it is not
converted due to current stream_open.cocci limitations.

The script also does not convert files that should be valid to convert,
but that currently have .llseek = noop_llseek or generic_file_llseek for
unknown reason despite file being opened with nonseekable_open (e.g.
drivers/input/mousedev.c)

Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yongzhi Pan <panyongzhi@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Tejun Heo <tj@kernel.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Nikolaus Rath <Nikolaus@rath.org>
Cc: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 6da2ec56 Tue Jun 12 14:55:00 MDT 2018 Kees Cook <keescook@chromium.org> treewide: kmalloc() -> kmalloc_array()

The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

kmalloc(a * b, gfp)

with:
kmalloc_array(a * b, gfp)

as well as handling cases of:

kmalloc(a * b * c, gfp)

with:

kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kmalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kmalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kmalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kmalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kmalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kmalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kmalloc(sizeof(THING) * C2, ...)
|
kmalloc(sizeof(TYPE) * C2, ...)
|
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * E2
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
/linux-master/fs/proc/
H A Dkcore.cdiff 17457784 Mon Jul 31 15:50:21 MDT 2023 Lorenzo Stoakes <lstoakes@gmail.com> fs/proc/kcore: reinstate bounce buffer for KCORE_TEXT regions

Some architectures do not populate the entire range categorised by
KCORE_TEXT, so we must ensure that the kernel address we read from is
valid.

Unfortunately there is no solution currently available to do so with a
purely iterator solution so reinstate the bounce buffer in this instance
so we can use copy_from_kernel_nofault() in order to avoid page faults
when regions are unmapped.

This change partly reverts commit 2e1c0170771e ("fs/proc/kcore: avoid
bounce buffer for ktext data"), reinstating the bounce buffer, but adapts
the code to continue to use an iterator.

[lstoakes@gmail.com: correct comment to be strictly correct about reasoning]
Link: https://lkml.kernel.org/r/525a3f14-74fa-4c22-9fca-9dab4de8a0c3@lucifer.local
Link: https://lkml.kernel.org/r/20230731215021.70911-1-lstoakes@gmail.com
Fixes: 2e1c0170771e ("fs/proc/kcore: avoid bounce buffer for ktext data")
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reported-by: Jiri Olsa <olsajiri@gmail.com>
Closes: https://lore.kernel.org/all/ZHc2fm+9daF6cgCE@krava
Tested-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Will Deacon <will@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 4c91c07c Wed Mar 22 12:57:04 MDT 2023 Lorenzo Stoakes <lstoakes@gmail.com> mm: vmalloc: convert vread() to vread_iter()

Having previously laid the foundation for converting vread() to an
iterator function, pull the trigger and do so.

This patch attempts to provide minimal refactoring and to reflect the
existing logic as best we can, for example we continue to zero portions of
memory not read, as before.

Overall, there should be no functional difference other than a performance
improvement in /proc/kcore access to vmalloc regions.

Now we have eliminated the need for a bounce buffer in read_kcore_iter(),
we dispense with it, and try to write to user memory optimistically but
with faults disabled via copy_page_to_iter_nofault(). We already have
preemption disabled by holding a spin lock. We continue faulting in until
the operation is complete.

Additionally, we must account for the fact that at any point a copy may
fail (most likely due to a fault not being able to occur), we exit
indicating fewer bytes retrieved than expected.

[sfr@canb.auug.org.au: fix sparc64 warning]
Link: https://lkml.kernel.org/r/20230320144721.663280c3@canb.auug.org.au
[lstoakes@gmail.com: redo Stephen's sparc build fix]
Link: https://lkml.kernel.org/r/8506cbc667c39205e65a323f750ff9c11a463798.1679566220.git.lstoakes@gmail.com
[akpm@linux-foundation.org: unbreak uio.h includes]
Link: https://lkml.kernel.org/r/941f88bc5ab928e6656e1e2593b91bf0f8c81e1b.1679511146.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 2e1c0170 Wed Mar 22 12:57:01 MDT 2023 Lorenzo Stoakes <lstoakes@gmail.com> fs/proc/kcore: avoid bounce buffer for ktext data

Patch series "convert read_kcore(), vread() to use iterators", v8.

While reviewing Baoquan's recent changes to permit vread() access to
vm_map_ram regions of vmalloc allocations, Willy pointed out [1] that it
would be nice to refactor vread() as a whole, since its only user is
read_kcore() and the existing form of vread() necessitates the use of a
bounce buffer.

This patch series does exactly that, as well as adjusting how we read the
kernel text section to avoid the use of a bounce buffer in this case as
well.

This has been tested against the test case which motivated Baoquan's
changes in the first place [2] which continues to function correctly, as
do the vmalloc self tests.


This patch (of 4):

Commit df04abfd181a ("fs/proc/kcore.c: Add bounce buffer for ktext data")
introduced the use of a bounce buffer to retrieve kernel text data for
/proc/kcore in order to avoid failures arising from hardened user copies
enabled by CONFIG_HARDENED_USERCOPY in check_kernel_text_object().

We can avoid doing this if instead of copy_to_user() we use
_copy_to_user() which bypasses the hardening check. This is more
efficient than using a bounce buffer and simplifies the code.

We do so as part an overall effort to eliminate bounce buffer usage in the
function with an eye to converting it an iterator read.

Link: https://lkml.kernel.org/r/cover.1679566220.git.lstoakes@gmail.com
Link: https://lore.kernel.org/all/Y8WfDSRkc%2FOHP3oD@casper.infradead.org/ [1]
Link: https://lore.kernel.org/all/87ilk6gos2.fsf@oracle.com/T/#u [2]
Link: https://lkml.kernel.org/r/fd39b0bfa7edc76d360def7d034baaee71d90158.1679511146.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 0daa322b Wed Jun 30 19:50:10 MDT 2021 David Hildenbrand <david@redhat.com> fs/proc/kcore: don't read offline sections, logically offline pages and hwpoisoned pages

Let's avoid reading:

1) Offline memory sections: the content of offline memory sections is
stale as the memory is effectively unused by the kernel. On s390x with
standby memory, offline memory sections (belonging to offline storage
increments) are not accessible. With virtio-mem and the hyper-v
balloon, we can have unavailable memory chunks that should not be
accessed inside offline memory sections. Last but not least, offline
memory sections might contain hwpoisoned pages which we can no longer
identify because the memmap is stale.

2) PG_offline pages: logically offline pages that are documented as
"The content of these pages is effectively stale. Such pages should
not be touched (read/write/dump/save) except by their owner.".
Examples include pages inflated in a balloon or unavailble memory
ranges inside hotplugged memory sections with virtio-mem or the hyper-v
balloon.

3) PG_hwpoison pages: Reading pages marked as hwpoisoned can be fatal.
As documented: "Accessing is not safe since it may cause another
machine check. Don't touch!"

Introduce is_page_hwpoison(), adding a comment that it is inherently racy
but best we can really do.

Reading /proc/kcore now performs similar checks as when reading
/proc/vmcore for kdump via makedumpfile: problematic pages are exclude.
It's also similar to hibernation code, however, we don't skip hwpoisoned
pages when processing pages in kernel/power/snapshot.c:saveable_page()
yet.

Note 1: we can race against memory offlining code, especially memory going
offline and getting unplugged: however, we will properly tear down the
identity mapping and handle faults gracefully when accessing this memory
from kcore code.

Note 2: we can race against drivers setting PageOffline() and turning
memory inaccessible in the hypervisor. We'll handle this in a follow-up
patch.

Link: https://lkml.kernel.org/r/20210526093041.8800-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Aili Yao <yaoaili@kingsoft.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff a8dd9c4d Tue Aug 21 22:54:51 MDT 2018 Omar Sandoval <osandov@fb.com> proc/kcore: don't grab lock for kclist_add()

Patch series "/proc/kcore improvements", v4.

This series makes a few improvements to /proc/kcore. It fixes a couple of
small issues in v3 but is otherwise the same. Patches 1, 2, and 3 are
prep patches. Patch 4 is a fix/cleanup. Patch 5 is another prep patch.
Patches 6 and 7 are optimizations to ->read(). Patch 8 makes it possible
to enable CRASH_CORE on any architecture, which is needed for patch 9.
Patch 9 adds vmcoreinfo to /proc/kcore.

This patch (of 9):

kclist_add() is only called at init time, so there's no point in grabbing
any locks. We're also going to replace the rwlock with a rwsem, which we
don't want to try grabbing during early boot.

While we're here, mark kclist_add() with __init so that we'll get a
warning if it's called from non-init code.

Link: http://lkml.kernel.org/r/98208db1faf167aa8b08eebfa968d95c70527739.1531953780.git.osandov@fb.com
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com>
Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Bhupesh Sharma <bhsharma@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 6855dc41 Wed Jun 06 06:54:11 MDT 2018 Adrian Hunter <adrian.hunter@intel.com> x86: Add entry trampolines to kcore

Without program headers for PTI entry trampoline pages, the trampoline
virtual addresses do not map to anything.

Example before:

sudo gdb --quiet vmlinux /proc/kcore
Reading symbols from vmlinux...done.
[New process 1]
Core was generated by `BOOT_IMAGE=/boot/vmlinuz-4.16.0 root=UUID=a6096b83-b763-4101-807e-f33daff63233'.
#0 0x0000000000000000 in irq_stack_union ()
(gdb) x /21ib 0xfffffe0000006000
0xfffffe0000006000: Cannot access memory at address 0xfffffe0000006000
(gdb) quit

After:

sudo gdb --quiet vmlinux /proc/kcore
[sudo] password for ahunter:
Reading symbols from vmlinux...done.
[New process 1]
Core was generated by `BOOT_IMAGE=/boot/vmlinuz-4.16.0-fix-4-00005-gd6e65a8b4072 root=UUID=a6096b83-b7'.
#0 0x0000000000000000 in irq_stack_union ()
(gdb) x /21ib 0xfffffe0000006000
0xfffffe0000006000: swapgs
0xfffffe0000006003: mov %rsp,-0x3e12(%rip) # 0xfffffe00000021f8
0xfffffe000000600a: xchg %ax,%ax
0xfffffe000000600c: mov %cr3,%rsp
0xfffffe000000600f: bts $0x3f,%rsp
0xfffffe0000006014: and $0xffffffffffffe7ff,%rsp
0xfffffe000000601b: mov %rsp,%cr3
0xfffffe000000601e: mov -0x3019(%rip),%rsp # 0xfffffe000000300c
0xfffffe0000006025: pushq $0x2b
0xfffffe0000006027: pushq -0x3e35(%rip) # 0xfffffe00000021f8
0xfffffe000000602d: push %r11
0xfffffe000000602f: pushq $0x33
0xfffffe0000006031: push %rcx
0xfffffe0000006032: push %rdi
0xfffffe0000006033: mov $0xffffffff91a00010,%rdi
0xfffffe000000603a: callq 0xfffffe0000006046
0xfffffe000000603f: pause
0xfffffe0000006041: lfence
0xfffffe0000006044: jmp 0xfffffe000000603f
0xfffffe0000006046: mov %rdi,(%rsp)
0xfffffe000000604a: retq
(gdb) quit

In addition, entry trampolines all map to the same page. Represent that
by giving the corresponding program headers in kcore the same offset.

This has the benefit that, when perf tools uses /proc/kcore as a source
for kernel object code, samples from different CPU trampolines are
aggregated together. Note, such aggregation is normal for profiling
i.e. people want to profile the object code, not every different virtual
address the object code might be mapped to (across different processes
for example).

Notes by PeterZ:

This also adds the KCORE_REMAP functionality.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1528289651-4113-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff 6855dc41 Wed Jun 06 06:54:11 MDT 2018 Adrian Hunter <adrian.hunter@intel.com> x86: Add entry trampolines to kcore

Without program headers for PTI entry trampoline pages, the trampoline
virtual addresses do not map to anything.

Example before:

sudo gdb --quiet vmlinux /proc/kcore
Reading symbols from vmlinux...done.
[New process 1]
Core was generated by `BOOT_IMAGE=/boot/vmlinuz-4.16.0 root=UUID=a6096b83-b763-4101-807e-f33daff63233'.
#0 0x0000000000000000 in irq_stack_union ()
(gdb) x /21ib 0xfffffe0000006000
0xfffffe0000006000: Cannot access memory at address 0xfffffe0000006000
(gdb) quit

After:

sudo gdb --quiet vmlinux /proc/kcore
[sudo] password for ahunter:
Reading symbols from vmlinux...done.
[New process 1]
Core was generated by `BOOT_IMAGE=/boot/vmlinuz-4.16.0-fix-4-00005-gd6e65a8b4072 root=UUID=a6096b83-b7'.
#0 0x0000000000000000 in irq_stack_union ()
(gdb) x /21ib 0xfffffe0000006000
0xfffffe0000006000: swapgs
0xfffffe0000006003: mov %rsp,-0x3e12(%rip) # 0xfffffe00000021f8
0xfffffe000000600a: xchg %ax,%ax
0xfffffe000000600c: mov %cr3,%rsp
0xfffffe000000600f: bts $0x3f,%rsp
0xfffffe0000006014: and $0xffffffffffffe7ff,%rsp
0xfffffe000000601b: mov %rsp,%cr3
0xfffffe000000601e: mov -0x3019(%rip),%rsp # 0xfffffe000000300c
0xfffffe0000006025: pushq $0x2b
0xfffffe0000006027: pushq -0x3e35(%rip) # 0xfffffe00000021f8
0xfffffe000000602d: push %r11
0xfffffe000000602f: pushq $0x33
0xfffffe0000006031: push %rcx
0xfffffe0000006032: push %rdi
0xfffffe0000006033: mov $0xffffffff91a00010,%rdi
0xfffffe000000603a: callq 0xfffffe0000006046
0xfffffe000000603f: pause
0xfffffe0000006041: lfence
0xfffffe0000006044: jmp 0xfffffe000000603f
0xfffffe0000006046: mov %rdi,(%rsp)
0xfffffe000000604a: retq
(gdb) quit

In addition, entry trampolines all map to the same page. Represent that
by giving the corresponding program headers in kcore the same offset.

This has the benefit that, when perf tools uses /proc/kcore as a source
for kernel object code, samples from different CPU trampolines are
aggregated together. Note, such aggregation is normal for profiling
i.e. people want to profile the object code, not every different virtual
address the object code might be mapped to (across different processes
for example).

Notes by PeterZ:

This also adds the KCORE_REMAP functionality.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1528289651-4113-4-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 4ff1b2c2 Wed Dec 12 14:51:25 MST 2012 Lai Jiangshan <laijs@cn.fujitsu.com> procfs: use N_MEMORY instead N_HIGH_MEMORY

N_HIGH_MEMORY stands for the nodes that has normal or high memory.
N_MEMORY stands for the nodes that has any memory.

The code here need to handle with the nodes which have memory, we should
use N_MEMORY instead.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Lin Feng <linfeng@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 5a0e3ad6 Wed Mar 24 02:04:11 MDT 2010 Tejun Heo <tj@kernel.org> include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
H A Dkmsg.cdiff d919b33d Mon Apr 06 21:09:01 MDT 2020 Alexey Dobriyan <adobriyan@gmail.com> proc: faster open/read/close with "permanent" files

Now that "struct proc_ops" exist we can start putting there stuff which
could not fly with VFS "struct file_operations"...

Most of fs/proc/inode.c file is dedicated to make open/read/.../close
reliable in the event of disappearing /proc entries which usually happens
if module is getting removed. Files like /proc/cpuinfo which never
disappear simply do not need such protection.

Save 2 atomic ops, 1 allocation, 1 free per open/read/close sequence for such
"permanent" files.

Enable "permanent" flag for

/proc/cpuinfo
/proc/kmsg
/proc/modules
/proc/slabinfo
/proc/stat
/proc/sysvipc/*
/proc/swaps

More will come once I figure out foolproof way to prevent out module
authors from marking their stuff "permanent" for performance reasons
when it is not.

This should help with scalability: benchmark is "read /proc/cpuinfo R times
by N threads scattered over the system".

N R t, s (before) t, s (after)
-----------------------------------------------------
64 4096 1.582458 1.530502 -3.2%
256 4096 6.371926 6.125168 -3.9%
1024 4096 25.64888 24.47528 -4.6%

Benchmark source:

#include <chrono>
#include <iostream>
#include <thread>
#include <vector>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

const int NR_CPUS = sysconf(_SC_NPROCESSORS_ONLN);
int N;
const char *filename;
int R;

int xxx = 0;

int glue(int n)
{
cpu_set_t m;
CPU_ZERO(&m);
CPU_SET(n, &m);
return sched_setaffinity(0, sizeof(cpu_set_t), &m);
}

void f(int n)
{
glue(n % NR_CPUS);

while (*(volatile int *)&xxx == 0) {
}

for (int i = 0; i < R; i++) {
int fd = open(filename, O_RDONLY);
char buf[4096];
ssize_t rv = read(fd, buf, sizeof(buf));
asm volatile ("" :: "g" (rv));
close(fd);
}
}

int main(int argc, char *argv[])
{
if (argc < 4) {
std::cerr << "usage: " << argv[0] << ' ' << "N /proc/filename R
";
return 1;
}

N = atoi(argv[1]);
filename = argv[2];
R = atoi(argv[3]);

for (int i = 0; i < NR_CPUS; i++) {
if (glue(i) == 0)
break;
}

std::vector<std::thread> T;
T.reserve(N);
for (int i = 0; i < N; i++) {
T.emplace_back(f, i);
}

auto t0 = std::chrono::system_clock::now();
{
*(volatile int *)&xxx = 1;
for (auto& t: T) {
t.join();
}
}
auto t1 = std::chrono::system_clock::now();
std::chrono::duration<double> dt = t1 - t0;
std::cout << dt.count() << '
';

return 0;
}

P.S.:
Explicit randomization marker is added because adding non-function pointer
will silently disable structure layout randomization.

[akpm@linux-foundation.org: coding style fixes]
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Joe Perches <joe@perches.com>
Link: http://lkml.kernel.org/r/20200222201539.GA22576@avx2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
H A Dvmcore.cdiff 641db40f Tue Jul 25 11:03:16 MDT 2023 Dan Carpenter <dan.carpenter@linaro.org> proc/vmcore: fix signedness bug in read_from_oldmem()

The bug is the error handling:

if (tmp < nr_bytes) {

"tmp" can hold negative error codes but because "nr_bytes" is type size_t
the negative error codes are treated as very high positive values
(success). Fix this by changing "nr_bytes" to type ssize_t. The
"nr_bytes" variable is used to store values between 1 and PAGE_SIZE and
they can fit in ssize_t without any issue.

Link: https://lkml.kernel.org/r/b55f7eed-1c65-4adc-95d1-6c7c65a54a6e@moroto.mountain
Fixes: 5d8de293c224 ("vmcore: convert copy_oldmem_page() to take an iov_iter")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 60592fb6 Thu May 11 20:25:28 MDT 2023 Fangrui Song <maskray@google.com> coredump, vmcore: Set p_align to 4 for PT_NOTE

Tools like readelf/llvm-readelf use p_align to parse a PT_NOTE program
header as an array of 4-byte entries or 8-byte entries. Currently, there
are workarounds[1] in place for Linux to treat p_align==0 as 4. However,
it would be more appropriate to set the correct alignment so that tools
do not have to rely on guesswork. FreeBSD coredumps set p_align to 4 as
well.

[1]: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=82ed9683ec099d8205dc499ac84febc975235af6
[2]: https://reviews.llvm.org/D150022

Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230512022528.3430327-1-maskray@google.com
diff 60592fb6 Thu May 11 20:25:28 MDT 2023 Fangrui Song <maskray@google.com> coredump, vmcore: Set p_align to 4 for PT_NOTE

Tools like readelf/llvm-readelf use p_align to parse a PT_NOTE program
header as an array of 4-byte entries or 8-byte entries. Currently, there
are workarounds[1] in place for Linux to treat p_align==0 as 4. However,
it would be more appropriate to set the correct alignment so that tools
do not have to rely on guesswork. FreeBSD coredumps set p_align to 4 as
well.

[1]: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=82ed9683ec099d8205dc499ac84febc975235af6
[2]: https://reviews.llvm.org/D150022

Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230512022528.3430327-1-maskray@google.com
diff 60592fb6 Thu May 11 20:25:28 MDT 2023 Fangrui Song <maskray@google.com> coredump, vmcore: Set p_align to 4 for PT_NOTE

Tools like readelf/llvm-readelf use p_align to parse a PT_NOTE program
header as an array of 4-byte entries or 8-byte entries. Currently, there
are workarounds[1] in place for Linux to treat p_align==0 as 4. However,
it would be more appropriate to set the correct alignment so that tools
do not have to rely on guesswork. FreeBSD coredumps set p_align to 4 as
well.

[1]: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=82ed9683ec099d8205dc499ac84febc975235af6
[2]: https://reviews.llvm.org/D150022

Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230512022528.3430327-1-maskray@google.com
diff 60592fb6 Thu May 11 20:25:28 MDT 2023 Fangrui Song <maskray@google.com> coredump, vmcore: Set p_align to 4 for PT_NOTE

Tools like readelf/llvm-readelf use p_align to parse a PT_NOTE program
header as an array of 4-byte entries or 8-byte entries. Currently, there
are workarounds[1] in place for Linux to treat p_align==0 as 4. However,
it would be more appropriate to set the correct alignment so that tools
do not have to rely on guesswork. FreeBSD coredumps set p_align to 4 as
well.

[1]: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=82ed9683ec099d8205dc499ac84febc975235af6
[2]: https://reviews.llvm.org/D150022

Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230512022528.3430327-1-maskray@google.com
diff 12b9d301 Wed Sep 28 10:29:33 MDT 2022 Jianglei Nie <niejianglei2021@163.com> proc/vmcore: fix potential memory leak in vmcore_init()

Patch series "Some minor cleanup patches resent".

The first three patches trivial clean up patches.

And for the patch "kexec: replace crash_mem_range with range", I got a
ibm-p9wr ppc64le system to test, it works well.


This patch (of 4):

elfcorehdr_alloc() allocates a memory chunk for elfcorehdr_addr with
kzalloc(). If is_vmcore_usable() returns false, elfcorehdr_addr is a
predefined value. If parse_crash_elf_headers() gets some error and
returns a negetive value, the elfcorehdr_addr should be released with
elfcorehdr_free().

Fix it by calling elfcorehdr_free() when parse_crash_elf_headers() fails.

Link: https://lkml.kernel.org/r/20220929042936.22012-1-bhe@redhat.com
Link: https://lkml.kernel.org/r/20220929042936.22012-2-bhe@redhat.com
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chen Lifu <chenlifu@huawei.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Li Chen <lchen@ambarella.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: ye xingchen <ye.xingchen@zte.com.cn>
Cc: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff e0690479 Fri Apr 29 15:37:59 MDT 2022 Matthew Wilcox (Oracle) <willy@infradead.org> vmcore: convert read_from_oldmem() to take an iov_iter

Remove the read_from_oldmem() wrapper introduced earlier and convert all
the remaining callers to pass an iov_iter.

Link: https://lkml.kernel.org/r/20220408090636.560886-4-bhe@redhat.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 4a22fd20 Fri Apr 29 15:37:59 MDT 2022 Matthew Wilcox (Oracle) <willy@infradead.org> vmcore: convert __read_vmcore to use an iov_iter

This gets rid of copy_to() and let us use proc_read_iter() instead of
proc_read().

Link: https://lkml.kernel.org/r/20220408090636.560886-3-bhe@redhat.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff c1e63117 Fri Nov 19 17:43:58 MST 2021 David Hildenbrand <david@redhat.com> proc/vmcore: fix clearing user buffer by properly using clear_user()

To clear a user buffer we cannot simply use memset, we have to use
clear_user(). With a virtio-mem device that registers a vmcore_cb and
has some logically unplugged memory inside an added Linux memory block,
I can easily trigger a BUG by copying the vmcore via "cp":

systemd[1]: Starting Kdump Vmcore Save Service...
kdump[420]: Kdump is using the default log level(3).
kdump[453]: saving to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
kdump[458]: saving vmcore-dmesg.txt to /sysroot/var/crash/127.0.0.1-2021-11-11-14:59:22/
kdump[465]: saving vmcore-dmesg.txt complete
kdump[467]: saving vmcore
BUG: unable to handle page fault for address: 00007f2374e01000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0003) - permissions violation
PGD 7a523067 P4D 7a523067 PUD 7a528067 PMD 7a525067 PTE 800000007048f867
Oops: 0003 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 468 Comm: cp Not tainted 5.15.0+ #6
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-27-g64f37cc530f1-prebuilt.qemu.org 04/01/2014
RIP: 0010:read_from_oldmem.part.0.cold+0x1d/0x86
Code: ff ff ff e8 05 ff fe ff e9 b9 e9 7f ff 48 89 de 48 c7 c7 38 3b 60 82 e8 f1 fe fe ff 83 fd 08 72 3c 49 8d 7d 08 4c 89 e9 89 e8 <49> c7 45 00 00 00 00 00 49 c7 44 05 f8 00 00 00 00 48 83 e7 f81
RSP: 0018:ffffc9000073be08 EFLAGS: 00010212
RAX: 0000000000001000 RBX: 00000000002fd000 RCX: 00007f2374e01000
RDX: 0000000000000001 RSI: 00000000ffffdfff RDI: 00007f2374e01008
RBP: 0000000000001000 R08: 0000000000000000 R09: ffffc9000073bc50
R10: ffffc9000073bc48 R11: ffffffff829461a8 R12: 000000000000f000
R13: 00007f2374e01000 R14: 0000000000000000 R15: ffff88807bd421e8
FS: 00007f2374e12140(0000) GS:ffff88807f000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2374e01000 CR3: 000000007a4aa000 CR4: 0000000000350eb0
Call Trace:
read_vmcore+0x236/0x2c0
proc_reg_read+0x55/0xa0
vfs_read+0x95/0x190
ksys_read+0x4f/0xc0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae

Some x86-64 CPUs have a CPU feature called "Supervisor Mode Access
Prevention (SMAP)", which is used to detect wrong access from the kernel
to user buffers like this: SMAP triggers a permissions violation on
wrong access. In the x86-64 variant of clear_user(), SMAP is properly
handled via clac()+stac().

To fix, properly use clear_user() when we're dealing with a user buffer.

Link: https://lkml.kernel.org/r/20211112092750.6921-1-david@redhat.com
Fixes: 997c136f518c ("fs/proc/vmcore.c: add hook to read_from_oldmem() to check for non-ram pages")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 4eb5fec3 Tue Apr 30 01:44:21 MDT 2019 Lianbo Jiang <lijiang@redhat.com> fs/proc/vmcore: Enable dumping of encrypted memory when SEV was active

In the kdump kernel, the memory of the first kernel gets to be dumped
into a vmcore file.

Similarly to SME kdump, if SEV was enabled in the first kernel, the old
memory has to be remapped encrypted in order to access it properly.

Commit

992b649a3f01 ("kdump, proc/vmcore: Enable kdumping encrypted memory with SME enabled")

took care of the SME case but it uses sme_active() which checks for SME
only. Use mem_encrypt_active() instead, which returns true when either
SME or SEV is active.

Unlike SME, the second kernel images (kernel and initrd) are loaded into
encrypted memory when SEV is active, hence the kernel elf header must be
remapped as encrypted in order to access it properly.

[ bp: Massage commit message. ]

Co-developed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: bhe@redhat.com
Cc: dyoung@redhat.com
Cc: Ganesh Goudar <ganeshgr@chelsio.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: kexec@lists.infradead.org
Cc: linux-fsdevel@vger.kernel.org
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: mingo@redhat.com
Cc: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190430074421.7852-4-lijiang@redhat.com
diff 4eb5fec3 Tue Apr 30 01:44:21 MDT 2019 Lianbo Jiang <lijiang@redhat.com> fs/proc/vmcore: Enable dumping of encrypted memory when SEV was active

In the kdump kernel, the memory of the first kernel gets to be dumped
into a vmcore file.

Similarly to SME kdump, if SEV was enabled in the first kernel, the old
memory has to be remapped encrypted in order to access it properly.

Commit

992b649a3f01 ("kdump, proc/vmcore: Enable kdumping encrypted memory with SME enabled")

took care of the SME case but it uses sme_active() which checks for SME
only. Use mem_encrypt_active() instead, which returns true when either
SME or SEV is active.

Unlike SME, the second kernel images (kernel and initrd) are loaded into
encrypted memory when SEV is active, hence the kernel elf header must be
remapped as encrypted in order to access it properly.

[ bp: Massage commit message. ]

Co-developed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: bhe@redhat.com
Cc: dyoung@redhat.com
Cc: Ganesh Goudar <ganeshgr@chelsio.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: kexec@lists.infradead.org
Cc: linux-fsdevel@vger.kernel.org
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: mingo@redhat.com
Cc: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190430074421.7852-4-lijiang@redhat.com
/linux-master/fs/qnx4/
H A Ddir.cdiff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
/linux-master/fs/ramfs/
H A Dfile-mmu.cdiff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
H A Dfile-nommu.cdiff 5a0e3ad6 Wed Mar 24 02:04:11 MDT 2010 Tejun Heo <tj@kernel.org> include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
diff 4f98a2fe Sat Oct 18 21:26:32 MDT 2008 Rik van Riel <riel@redhat.com> vmscan: split LRU lists into anon & file sets

Split the LRU lists in two, one set for pages that are backed by real file
systems ("file") and one for pages that are backed by memory and swap
("anon"). The latter includes tmpfs.

The advantage of doing this is that the VM will not have to scan over lots
of anonymous pages (which we generally do not want to swap out), just to
find the page cache pages that it should evict.

This patch has the infrastructure and a basic policy to balance how much
we scan the anon lists and how much we scan the file lists. The big
policy changes are in separate patches.

[lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset]
[kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru]
[kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page]
[hugh@veritas.com: memcg swapbacked pages active]
[hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED]
[akpm@linux-foundation.org: fix /proc/vmstat units]
[nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration]
[kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo]
[kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()]
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 4b19de6d Thu Oct 02 15:50:16 MDT 2008 Nick Piggin <npiggin@suse.de> mm: tiny-shmem nommu fix

The previous patch db203d53d474aa068984e409d807628f5841da1b ("mm:
tiny-shmem fix lock ordering: mmap_sem vs i_mutex") to fix the lock
ordering in tiny-shmem breaks shared anonymous and IPC memory on NOMMU
architectures because it was using the expanding truncate to signal ramfs
to allocate a physically contiguous RAM backing the inode (otherwise it is
unusable for "memory mapping" it to userspace).

However do_truncate is what caused the lock ordering error, due to it
taking i_mutex. In this case, we can actually just call ramfs directly to
allocate memory for the mapping, rather than go via truncate.

Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
/linux-master/fs/reiserfs/
H A Ddir.cdiff 4cf5f7ad Wed Apr 23 08:00:35 MDT 2014 Jeff Mahoney <jeffm@suse.com> reiserfs: cleanup, rename key and item accessors to more friendly names

This patch does a quick search and replace:
B_N_PITEM_HEAD() -> item_head()
B_N_PDELIM_KEY() -> internal_key()
B_N_PKEY() -> leaf_key()
B_N_PITEM() -> item_body()

And the item_head version:
B_I_PITEM() -> ih_item_body()
I_ENTRY_COUNT() -> ih_entry_count()

And the treepath variants:
get_ih() -> tp_item_head()
PATH_PITEM_HEAD() -> tp_item_head()
get_item() -> tp_item_body()

... which makes the code much easier on the eyes.

I've also removed a few unused macros.

Checkpatch will complain about the 80 character limit for do_balan.c.
I've addressed that in a later patchset to split up balance_leaf().

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff 4acf381e Fri May 17 20:42:17 MDT 2013 Al Viro <viro@zeniv.linux.org.uk> [readdir] convert reiserfs

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff 5a0e3ad6 Wed Mar 24 02:04:11 MDT 2010 Tejun Heo <tj@kernel.org> include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
H A Dfile.cdiff 4e34e719 Sat Jul 23 09:37:31 MDT 2011 Christoph Hellwig <hch@lst.de> fs: take the ACL checks to common code

Replace the ->check_acl method with a ->get_acl method that simply reads an
ACL from disk after having a cache miss. This means we can replace the ACL
checking boilerplate code with a single implementation in namei.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff 17973f5a Mon Jul 16 00:40:08 MDT 2007 Micah Cowan <micah@cowan.name> Only send SIGXFSZ when exceeding rlimits.

Some users have been having problems with utilities like cp or dd dumping
core when they try to copy a file that's too large for the destination
filesystem (typically, > 4gb). Apparently, some defunct standards required
SIGXFSZ to be sent in such circumstances, but SUS only requires/allows it
for when a written file exceeds the process's resource limits. I'd like to
limit SIGXFSZs to the bare minimum required by SUS.

Patch sent per http://lkml.org/lkml/2007/4/10/302

Signed-off-by: Micah Cowan <micahcowan@ubuntu.com>
Acked-by: Alan Cox <alan@redhat.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 17973f5a Mon Jul 16 00:40:08 MDT 2007 Micah Cowan <micah@cowan.name> Only send SIGXFSZ when exceeding rlimits.

Some users have been having problems with utilities like cp or dd dumping
core when they try to copy a file that's too large for the destination
filesystem (typically, > 4gb). Apparently, some defunct standards required
SIGXFSZ to be sent in such circumstances, but SUS only requires/allows it
for when a written file exceeds the process's resource limits. I'd like to
limit SIGXFSZs to the bare minimum required by SUS.

Patch sent per http://lkml.org/lkml/2007/4/10/302

Signed-off-by: Micah Cowan <micahcowan@ubuntu.com>
Acked-by: Alan Cox <alan@redhat.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
H A Dprocfs.cdiff 5a622f2d Wed Dec 05 00:45:28 MST 2007 Alexey Dobriyan <adobriyan@sw.ru> proc: fix proc_dir_entry refcounting

Creating PDEs with refcount 0 and "deleted" flag has problems (see below).
Switch to usual scheme:
* PDE is created with refcount 1
* every de_get does +1
* every de_put() and remove_proc_entry() do -1
* once refcount reaches 0, PDE is freed.

This elegantly fixes at least two following races (both observed) without
introducing new locks, without abusing old locks, without spreading
lock_kernel():

1) PDE leak

remove_proc_entry de_put
----------------- ------
[refcnt = 1]
if (atomic_read(&de->count) == 0)
if (atomic_dec_and_test(&de->count))
if (de->deleted)
/* also not taken! */
free_proc_entry(de);
else
de->deleted = 1;
[refcount=0, deleted=1]

2) use after free

remove_proc_entry de_put
----------------- ------
[refcnt = 1]

if (atomic_dec_and_test(&de->count))
if (atomic_read(&de->count) == 0)
free_proc_entry(de);
/* boom! */
if (de->deleted)
free_proc_entry(de);

BUG: unable to handle kernel paging request at virtual address 6b6b6b6b
printing eip: c10acdda *pdpt = 00000000338f8001 *pde = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom
Pid: 23161, comm: cat Not tainted (2.6.24-rc2-8c0863403f109a43d7000b4646da4818220d501f #4)
EIP: 0060:[<c10acdda>] EFLAGS: 00210097 CPU: 1
EIP is at strnlen+0x6/0x18
EAX: 6b6b6b6b EBX: 6b6b6b6b ECX: 6b6b6b6b EDX: fffffffe
ESI: c128fa3b EDI: f380bf34 EBP: ffffffff ESP: f380be44
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 23161, ti=f380b000 task=f38f2570 task.ti=f380b000)
Stack: c10ac4f0 00000278 c12ce000 f43cd2a8 00000163 00000000 7da86067 00000400
c128fa20 00896b18 f38325a8 c128fe20 ffffffff 00000000 c11f291e 00000400
f75be300 c128fa20 f769c9a0 c10ac779 f380bf34 f7bfee70 c1018e6b f380bf34
Call Trace:
[<c10ac4f0>] vsnprintf+0x2ad/0x49b
[<c10ac779>] vscnprintf+0x14/0x1f
[<c1018e6b>] vprintk+0xc5/0x2f9
[<c10379f1>] handle_fasteoi_irq+0x0/0xab
[<c1004f44>] do_IRQ+0x9f/0xb7
[<c117db3b>] preempt_schedule_irq+0x3f/0x5b
[<c100264e>] need_resched+0x1f/0x21
[<c10190ba>] printk+0x1b/0x1f
[<c107c8ad>] de_put+0x3d/0x50
[<c107c8f8>] proc_delete_inode+0x38/0x41
[<c107c8c0>] proc_delete_inode+0x0/0x41
[<c1066298>] generic_delete_inode+0x5e/0xc6
[<c1065aa9>] iput+0x60/0x62
[<c1063c8e>] d_kill+0x2d/0x46
[<c1063fa9>] dput+0xdc/0xe4
[<c10571a1>] __fput+0xb0/0xcd
[<c1054e49>] filp_close+0x48/0x4f
[<c1055ee9>] sys_close+0x67/0xa5
[<c10026b6>] sysenter_past_esp+0x5f/0x85
=======================
Code: c9 74 0c f2 ae 74 05 bf 01 00 00 00 4f 89 fa 5f 89 d0 c3 85 c9 57 89 c7 89 d0 74 05 f2 ae 75 01 4f 89 f8 5f c3 89 c1 89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 c3 90 90 90 57 83 c9
EIP: [<c10acdda>] strnlen+0x6/0x18 SS:ESP 0068:f380be44

Also, remove broken usage of ->deleted from reiserfs: if sget() succeeds,
module is already pinned and remove_proc_entry() can't happen => nobody
can mark PDE deleted.

Dummy proc root in netns code is not marked with refcount 1. AFAICS, we
never get it, it's just for proper /proc/net removal. I double checked
CLONE_NETNS continues to work.

Patch survives many hours of modprobe/rmmod/cat loops without new bugs
which can be attributed to refcounting.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 5a622f2d Wed Dec 05 00:45:28 MST 2007 Alexey Dobriyan <adobriyan@sw.ru> proc: fix proc_dir_entry refcounting

Creating PDEs with refcount 0 and "deleted" flag has problems (see below).
Switch to usual scheme:
* PDE is created with refcount 1
* every de_get does +1
* every de_put() and remove_proc_entry() do -1
* once refcount reaches 0, PDE is freed.

This elegantly fixes at least two following races (both observed) without
introducing new locks, without abusing old locks, without spreading
lock_kernel():

1) PDE leak

remove_proc_entry de_put
----------------- ------
[refcnt = 1]
if (atomic_read(&de->count) == 0)
if (atomic_dec_and_test(&de->count))
if (de->deleted)
/* also not taken! */
free_proc_entry(de);
else
de->deleted = 1;
[refcount=0, deleted=1]

2) use after free

remove_proc_entry de_put
----------------- ------
[refcnt = 1]

if (atomic_dec_and_test(&de->count))
if (atomic_read(&de->count) == 0)
free_proc_entry(de);
/* boom! */
if (de->deleted)
free_proc_entry(de);

BUG: unable to handle kernel paging request at virtual address 6b6b6b6b
printing eip: c10acdda *pdpt = 00000000338f8001 *pde = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom
Pid: 23161, comm: cat Not tainted (2.6.24-rc2-8c0863403f109a43d7000b4646da4818220d501f #4)
EIP: 0060:[<c10acdda>] EFLAGS: 00210097 CPU: 1
EIP is at strnlen+0x6/0x18
EAX: 6b6b6b6b EBX: 6b6b6b6b ECX: 6b6b6b6b EDX: fffffffe
ESI: c128fa3b EDI: f380bf34 EBP: ffffffff ESP: f380be44
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 23161, ti=f380b000 task=f38f2570 task.ti=f380b000)
Stack: c10ac4f0 00000278 c12ce000 f43cd2a8 00000163 00000000 7da86067 00000400
c128fa20 00896b18 f38325a8 c128fe20 ffffffff 00000000 c11f291e 00000400
f75be300 c128fa20 f769c9a0 c10ac779 f380bf34 f7bfee70 c1018e6b f380bf34
Call Trace:
[<c10ac4f0>] vsnprintf+0x2ad/0x49b
[<c10ac779>] vscnprintf+0x14/0x1f
[<c1018e6b>] vprintk+0xc5/0x2f9
[<c10379f1>] handle_fasteoi_irq+0x0/0xab
[<c1004f44>] do_IRQ+0x9f/0xb7
[<c117db3b>] preempt_schedule_irq+0x3f/0x5b
[<c100264e>] need_resched+0x1f/0x21
[<c10190ba>] printk+0x1b/0x1f
[<c107c8ad>] de_put+0x3d/0x50
[<c107c8f8>] proc_delete_inode+0x38/0x41
[<c107c8c0>] proc_delete_inode+0x0/0x41
[<c1066298>] generic_delete_inode+0x5e/0xc6
[<c1065aa9>] iput+0x60/0x62
[<c1063c8e>] d_kill+0x2d/0x46
[<c1063fa9>] dput+0xdc/0xe4
[<c10571a1>] __fput+0xb0/0xcd
[<c1054e49>] filp_close+0x48/0x4f
[<c1055ee9>] sys_close+0x67/0xa5
[<c10026b6>] sysenter_past_esp+0x5f/0x85
=======================
Code: c9 74 0c f2 ae 74 05 bf 01 00 00 00 4f 89 fa 5f 89 d0 c3 85 c9 57 89 c7 89 d0 74 05 f2 ae 75 01 4f 89 f8 5f c3 89 c1 89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 c3 90 90 90 57 83 c9
EIP: [<c10acdda>] strnlen+0x6/0x18 SS:ESP 0068:f380be44

Also, remove broken usage of ->deleted from reiserfs: if sget() succeeds,
module is already pinned and remove_proc_entry() can't happen => nobody
can mark PDE deleted.

Dummy proc root in netns code is not marked with refcount 1. AFAICS, we
never get it, it's just for proper /proc/net removal. I double checked
CLONE_NETNS continues to work.

Patch survives many hours of modprobe/rmmod/cat loops without new bugs
which can be attributed to refcounting.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 5a622f2d Wed Dec 05 00:45:28 MST 2007 Alexey Dobriyan <adobriyan@sw.ru> proc: fix proc_dir_entry refcounting

Creating PDEs with refcount 0 and "deleted" flag has problems (see below).
Switch to usual scheme:
* PDE is created with refcount 1
* every de_get does +1
* every de_put() and remove_proc_entry() do -1
* once refcount reaches 0, PDE is freed.

This elegantly fixes at least two following races (both observed) without
introducing new locks, without abusing old locks, without spreading
lock_kernel():

1) PDE leak

remove_proc_entry de_put
----------------- ------
[refcnt = 1]
if (atomic_read(&de->count) == 0)
if (atomic_dec_and_test(&de->count))
if (de->deleted)
/* also not taken! */
free_proc_entry(de);
else
de->deleted = 1;
[refcount=0, deleted=1]

2) use after free

remove_proc_entry de_put
----------------- ------
[refcnt = 1]

if (atomic_dec_and_test(&de->count))
if (atomic_read(&de->count) == 0)
free_proc_entry(de);
/* boom! */
if (de->deleted)
free_proc_entry(de);

BUG: unable to handle kernel paging request at virtual address 6b6b6b6b
printing eip: c10acdda *pdpt = 00000000338f8001 *pde = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom
Pid: 23161, comm: cat Not tainted (2.6.24-rc2-8c0863403f109a43d7000b4646da4818220d501f #4)
EIP: 0060:[<c10acdda>] EFLAGS: 00210097 CPU: 1
EIP is at strnlen+0x6/0x18
EAX: 6b6b6b6b EBX: 6b6b6b6b ECX: 6b6b6b6b EDX: fffffffe
ESI: c128fa3b EDI: f380bf34 EBP: ffffffff ESP: f380be44
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 23161, ti=f380b000 task=f38f2570 task.ti=f380b000)
Stack: c10ac4f0 00000278 c12ce000 f43cd2a8 00000163 00000000 7da86067 00000400
c128fa20 00896b18 f38325a8 c128fe20 ffffffff 00000000 c11f291e 00000400
f75be300 c128fa20 f769c9a0 c10ac779 f380bf34 f7bfee70 c1018e6b f380bf34
Call Trace:
[<c10ac4f0>] vsnprintf+0x2ad/0x49b
[<c10ac779>] vscnprintf+0x14/0x1f
[<c1018e6b>] vprintk+0xc5/0x2f9
[<c10379f1>] handle_fasteoi_irq+0x0/0xab
[<c1004f44>] do_IRQ+0x9f/0xb7
[<c117db3b>] preempt_schedule_irq+0x3f/0x5b
[<c100264e>] need_resched+0x1f/0x21
[<c10190ba>] printk+0x1b/0x1f
[<c107c8ad>] de_put+0x3d/0x50
[<c107c8f8>] proc_delete_inode+0x38/0x41
[<c107c8c0>] proc_delete_inode+0x0/0x41
[<c1066298>] generic_delete_inode+0x5e/0xc6
[<c1065aa9>] iput+0x60/0x62
[<c1063c8e>] d_kill+0x2d/0x46
[<c1063fa9>] dput+0xdc/0xe4
[<c10571a1>] __fput+0xb0/0xcd
[<c1054e49>] filp_close+0x48/0x4f
[<c1055ee9>] sys_close+0x67/0xa5
[<c10026b6>] sysenter_past_esp+0x5f/0x85
=======================
Code: c9 74 0c f2 ae 74 05 bf 01 00 00 00 4f 89 fa 5f 89 d0 c3 85 c9 57 89 c7 89 d0 74 05 f2 ae 75 01 4f 89 f8 5f c3 89 c1 89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 c3 90 90 90 57 83 c9
EIP: [<c10acdda>] strnlen+0x6/0x18 SS:ESP 0068:f380be44

Also, remove broken usage of ->deleted from reiserfs: if sget() succeeds,
module is already pinned and remove_proc_entry() can't happen => nobody
can mark PDE deleted.

Dummy proc root in netns code is not marked with refcount 1. AFAICS, we
never get it, it's just for proper /proc/net removal. I double checked
CLONE_NETNS continues to work.

Patch survives many hours of modprobe/rmmod/cat loops without new bugs
which can be attributed to refcounting.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 5a622f2d Wed Dec 05 00:45:28 MST 2007 Alexey Dobriyan <adobriyan@sw.ru> proc: fix proc_dir_entry refcounting

Creating PDEs with refcount 0 and "deleted" flag has problems (see below).
Switch to usual scheme:
* PDE is created with refcount 1
* every de_get does +1
* every de_put() and remove_proc_entry() do -1
* once refcount reaches 0, PDE is freed.

This elegantly fixes at least two following races (both observed) without
introducing new locks, without abusing old locks, without spreading
lock_kernel():

1) PDE leak

remove_proc_entry de_put
----------------- ------
[refcnt = 1]
if (atomic_read(&de->count) == 0)
if (atomic_dec_and_test(&de->count))
if (de->deleted)
/* also not taken! */
free_proc_entry(de);
else
de->deleted = 1;
[refcount=0, deleted=1]

2) use after free

remove_proc_entry de_put
----------------- ------
[refcnt = 1]

if (atomic_dec_and_test(&de->count))
if (atomic_read(&de->count) == 0)
free_proc_entry(de);
/* boom! */
if (de->deleted)
free_proc_entry(de);

BUG: unable to handle kernel paging request at virtual address 6b6b6b6b
printing eip: c10acdda *pdpt = 00000000338f8001 *pde = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: af_packet ipv6 cpufreq_ondemand loop serio_raw psmouse k8temp hwmon sr_mod cdrom
Pid: 23161, comm: cat Not tainted (2.6.24-rc2-8c0863403f109a43d7000b4646da4818220d501f #4)
EIP: 0060:[<c10acdda>] EFLAGS: 00210097 CPU: 1
EIP is at strnlen+0x6/0x18
EAX: 6b6b6b6b EBX: 6b6b6b6b ECX: 6b6b6b6b EDX: fffffffe
ESI: c128fa3b EDI: f380bf34 EBP: ffffffff ESP: f380be44
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process cat (pid: 23161, ti=f380b000 task=f38f2570 task.ti=f380b000)
Stack: c10ac4f0 00000278 c12ce000 f43cd2a8 00000163 00000000 7da86067 00000400
c128fa20 00896b18 f38325a8 c128fe20 ffffffff 00000000 c11f291e 00000400
f75be300 c128fa20 f769c9a0 c10ac779 f380bf34 f7bfee70 c1018e6b f380bf34
Call Trace:
[<c10ac4f0>] vsnprintf+0x2ad/0x49b
[<c10ac779>] vscnprintf+0x14/0x1f
[<c1018e6b>] vprintk+0xc5/0x2f9
[<c10379f1>] handle_fasteoi_irq+0x0/0xab
[<c1004f44>] do_IRQ+0x9f/0xb7
[<c117db3b>] preempt_schedule_irq+0x3f/0x5b
[<c100264e>] need_resched+0x1f/0x21
[<c10190ba>] printk+0x1b/0x1f
[<c107c8ad>] de_put+0x3d/0x50
[<c107c8f8>] proc_delete_inode+0x38/0x41
[<c107c8c0>] proc_delete_inode+0x0/0x41
[<c1066298>] generic_delete_inode+0x5e/0xc6
[<c1065aa9>] iput+0x60/0x62
[<c1063c8e>] d_kill+0x2d/0x46
[<c1063fa9>] dput+0xdc/0xe4
[<c10571a1>] __fput+0xb0/0xcd
[<c1054e49>] filp_close+0x48/0x4f
[<c1055ee9>] sys_close+0x67/0xa5
[<c10026b6>] sysenter_past_esp+0x5f/0x85
=======================
Code: c9 74 0c f2 ae 74 05 bf 01 00 00 00 4f 89 fa 5f 89 d0 c3 85 c9 57 89 c7 89 d0 74 05 f2 ae 75 01 4f 89 f8 5f c3 89 c1 89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 c3 90 90 90 57 83 c9
EIP: [<c10acdda>] strnlen+0x6/0x18 SS:ESP 0068:f380be44

Also, remove broken usage of ->deleted from reiserfs: if sget() succeeds,
module is already pinned and remove_proc_entry() can't happen => nobody
can mark PDE deleted.

Dummy proc root in netns code is not marked with refcount 1. AFAICS, we
never get it, it's just for proper /proc/net removal. I double checked
CLONE_NETNS continues to work.

Patch survives many hours of modprobe/rmmod/cat loops without new bugs
which can be attributed to refcounting.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
/linux-master/fs/sysfs/
H A Ddir.cdiff 4e4d6d86 Sun Dec 18 21:05:43 MST 2011 Eric W. Biederman <ebiederm@xmission.com> sysfs: Add s_hash to sysfs_dirent and order directory entries by hash

Compute a 31 bit hash of directory entries (that can fit in a signed
32bit off_t) and index the sysfs directory entries by that hash,
replacing the per directory indexes by name and by inode. Because we
now only use a single rbtree this reduces the size of sysfs_dirent by 2
pointers. Because we have fewer cases to deal with the code is now
simpler.

For now I use the simple hash that the dcache uses as that is easy to
use and seems simple enough.

In addition to makeing the code simpler using a hash for the file
position in readdir brings sysfs in line with other filesystems that
have non-trivial directory structures.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff c4253cb0 Thu Sep 22 11:34:33 MDT 2011 Heiko Carstens <hca@linux.ibm.com> sysfs: add unsigned long cast to prevent compile warning

"sysfs: use rb-tree for inode number lookup" added a new printk which
causes a new compile warning on s390 (and few other architectures):

fs/sysfs/dir.c: In function 'sysfs_link_sibling':
fs/sysfs/dir.c:63:4: warning: format '%lx' expects argument of type
'long unsigned int', but argument 2 has type 'ino_t' [-Wform

Add an explicit unsigned long cast since ino_t is an unsigned long on
most architectures.

Cc: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff 4f72c0ca Mon Jul 25 15:55:57 MDT 2011 Mikulas Patocka <mpatocka@redhat.com> sysfs: use rb-tree for name lookups

sysfs: use rb-tree for name lookups

Use red-black tree for name lookups.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff 4c3da220 Wed Nov 04 03:50:06 MST 2009 Eric W. Biederman <ebiederm@xmission.com> sysfs: Don't leak secdata when a sysfs_dirent is freed.

While refreshing my sysfs patches I noticed a leak in the secdata
implementation. We don't free the secdata when we free the
sysfs dirent.

This is a bug in 2.6.32-rc5 that we really should close.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
H A Dfile.cdiff a90bca22 Wed Mar 13 15:43:41 MDT 2024 Alan Stern <stern@rowland.harvard.edu> fs: sysfs: Fix reference leak in sysfs_break_active_protection()

The sysfs_break_active_protection() routine has an obvious reference
leak in its error path. If the call to kernfs_find_and_get() fails then
kn will be NULL, so the companion sysfs_unbreak_active_protection()
routine won't get called (and would only cause an access violation by
trying to dereference kn->parent if it was called). As a result, the
reference to kobj acquired at the start of the function will never be
released.

Fix the leak by adding an explicit kobject_put() call when kn is NULL.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: 2afc9166f79b ("scsi: sysfs: Introduce sysfs_{un,}break_active_protection()")
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: stable@vger.kernel.org
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/8a4d3f0f-c5e3-4b70-a188-0ca433f9e6f9@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 4bd4e92c Thu Dec 20 14:50:28 MST 2018 Stephen Martin <lockwood@opperline.com> sysfs: fix blank line coding style warning

Fixed a coding style issue.

Signed-off-by: Stephen Martin <lockwood@opperline.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff c8a139d0 Sun Apr 02 19:30:34 MDT 2017 NeilBrown <neilb@suse.com> sysfs: be careful of error returns from ops->show()

ops->show() can return a negative error code.
Commit 65da3484d9be ("sysfs: correctly handle short reads on PREALLOC attrs.")
(in v4.4) caused this to be stored in an unsigned 'size_t' variable, so errors
would look like large numbers.
As a result, if an error is returned, sysfs_kf_read() will return the
value of 'count', typically 4096.

Commit 17d0774f8068 ("sysfs: correctly handle read offset on PREALLOC attrs")
(in v4.8) extended this error to use the unsigned large 'len' as a size for
memmove().
Consequently, if ->show returns an error, then the first read() on the
sysfs file will return 4096 and could return uninitialized memory to
user-space.
If the application performs a subsequent read, this will trigger a memmove()
with extremely large count, and is likely to crash the machine is bizarre ways.

This bug can currently only be triggered by reading from an md
sysfs attribute declared with __ATTR_PREALLOC() during the
brief period between when mddev_put() deletes an mddev from
the ->all_mddevs list, and when mddev_delayed_delete() - which is
scheduled on a workqueue - completes.
Before this, an error won't be returned by the ->show()
After this, the ->show() won't be called.

I can reproduce it reliably only by putting delay like
usleep_range(500000,700000);
early in mddev_delayed_delete(). Then after creating an
md device md0 run
echo clear > /sys/block/md0/md/array_state; cat /sys/block/md0/md/array_state

The bug can be triggered without the usleep.

Fixes: 65da3484d9be ("sysfs: correctly handle short reads on PREALLOC attrs.")
Fixes: 17d0774f8068 ("sysfs: correctly handle read offset on PREALLOC attrs")
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 17d0774f Wed Jun 22 12:42:16 MDT 2016 Konstantin Khlebnikov <koct9i@gmail.com> sysfs: correctly handle read offset on PREALLOC attrs

Attributes declared with __ATTR_PREALLOC use sysfs_kf_read() which returns
zero bytes for non-zero offset. This breaks script checkarray in mdadm tool
in debian where /bin/sh is 'dash' because its builtin 'read' reads only one
byte at a time. Script gets 'i' instead of 'idle' when reads current action
from /sys/block/$dev/md/sync_action and as a result does nothing.

This patch adds trivial implementation of partial read: generate whole
string and move required part into buffer head.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: 4ef67a8c95f3 ("sysfs/kernfs: make read requests on pre-alloc files use the buffer.")
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=787950
Cc: Stable <stable@vger.kernel.org> # v3.19+
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 4ef67a8c Mon Oct 13 23:57:26 MDT 2014 NeilBrown <neilb@suse.de> sysfs/kernfs: make read requests on pre-alloc files use the buffer.

To match the previous patch which used the pre-alloc buffer for
writes, this patch causes reads to use the same buffer.
This is not strictly necessary as the current seq_read() will allocate
on first read, so user-space can trigger the required pre-alloc. But
consistency is valuable.

The read function is somewhat simpler than seq_read() and, for example,
does not support reading from an offset into the file: reads must be
at the start of the file.

As seq_read() does not use the prealloc buffer, ->seq_show is
incompatible with ->prealloc and caused an EINVAL return from open().
sysfs code which calls into kernfs always chooses the correct function.

As the buffer is shared with writes and other reads, the mutex is
extended to cover the copy_to_user.

Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 09368960 Wed Sep 24 09:21:04 MDT 2014 Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> fs: sysfs: return EGBIG on write if offset is larger than file size

According to the user expectations common utilities like dd or sh
redirection operator > should work correctly over binary files from
sysfs. At the moment doing excessive write can not be completed:

write(1, "\0\0\0\0\0\0\0\0", 8) = 4
write(1, "\0\0\0\0", 4) = 0
write(1, "\0\0\0\0", 4) = 0
write(1, "\0\0\0\0", 4) = 0
...

Fix the problem by returning EFBIG described in man 2 write.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 09368960 Wed Sep 24 09:21:04 MDT 2014 Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> fs: sysfs: return EGBIG on write if offset is larger than file size

According to the user expectations common utilities like dd or sh
redirection operator > should work correctly over binary files from
sysfs. At the moment doing excessive write can not be completed:

write(1, "\0\0\0\0\0\0\0\0", 8) = 4
write(1, "\0\0\0\0", 4) = 0
write(1, "\0\0\0\0", 4) = 0
write(1, "\0\0\0\0", 4) = 0
...

Fix the problem by returning EFBIG described in man 2 write.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 09368960 Wed Sep 24 09:21:04 MDT 2014 Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> fs: sysfs: return EGBIG on write if offset is larger than file size

According to the user expectations common utilities like dd or sh
redirection operator > should work correctly over binary files from
sysfs. At the moment doing excessive write can not be completed:

write(1, "\0\0\0\0\0\0\0\0", 8) = 4
write(1, "\0\0\0\0", 4) = 0
write(1, "\0\0\0\0", 4) = 0
write(1, "\0\0\0\0", 4) = 0
...

Fix the problem by returning EFBIG described in man 2 write.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 09368960 Wed Sep 24 09:21:04 MDT 2014 Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> fs: sysfs: return EGBIG on write if offset is larger than file size

According to the user expectations common utilities like dd or sh
redirection operator > should work correctly over binary files from
sysfs. At the moment doing excessive write can not be completed:

write(1, "\0\0\0\0\0\0\0\0", 8) = 4
write(1, "\0\0\0\0", 4) = 0
write(1, "\0\0\0\0", 4) = 0
write(1, "\0\0\0\0", 4) = 0
...

Fix the problem by returning EFBIG described in man 2 write.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 4c6974f5 Sun Nov 08 00:27:02 MST 2009 Eric W. Biederman <ebiederm@xmission.com> sysfs: Simplify sysfs_chmod_file semantics

Currently every caller of sysfs_chmod_file happens at either
file creation time to set a non-default mode or in response
to a specific user requested space change in policy. Making
timestamps of when the chmod happens and notification of
a file changing mode uninteresting.

Remove the unnecessary time stamp and filesystem change
notification, and removes the last of the explicit inotify
and donitfy support from sysfs.

Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
H A Dsysfs.hdiff 2b25a629 Thu Nov 28 12:54:28 MST 2013 Tejun Heo <tj@kernel.org> sysfs, kernfs: reorganize SYSFS_* constants

We want to add one more SYSFS_FLAG_* but we can't use the next higher
bit, 0x10000, as the flag field is 16bits wide. The flags are
currently arranged weirdly - 8 bits are set aside for the type flags
when there are only three three used, the first flag starts at 0x1000
instead of 0x0100 and flag literals have 5 digits (20 bits) when only
4 digits can be used.

Rearrange them so that type bits are only the lowest four, flags start
at 0x0010 and similar flags are grouped.

This patch doesn't cause any behavior difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 4e4d6d86 Sun Dec 18 21:05:43 MST 2011 Eric W. Biederman <ebiederm@xmission.com> sysfs: Add s_hash to sysfs_dirent and order directory entries by hash

Compute a 31 bit hash of directory entries (that can fit in a signed
32bit off_t) and index the sysfs directory entries by that hash,
replacing the per directory indexes by name and by inode. Because we
now only use a single rbtree this reduces the size of sysfs_dirent by 2
pointers. Because we have fewer cases to deal with the code is now
simpler.

For now I use the simple hash that the dcache uses as that is easy to
use and seems simple enough.

In addition to makeing the code simpler using a hash for the file
position in readdir brings sysfs in line with other filesystems that
have non-trivial directory structures.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff 4f72c0ca Mon Jul 25 15:55:57 MDT 2011 Mikulas Patocka <mpatocka@redhat.com> sysfs: use rb-tree for name lookups

sysfs: use rb-tree for name lookups

Use red-black tree for name lookups.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
/linux-master/fs/sysv/
H A Ddir.cdiff 4bb1a137 Thu Jan 19 08:32:29 MST 2023 Fabio M. De Francesco <fmdefrancesco@gmail.com> fs/sysv: Use the offset_in_page() helper

Use the offset_in_page() helper because it is more suitable than doing
explicit subtractions between pointers to directory entries and kernel
virtual addresses of mapped pages.

Cc: Ira Weiny <ira.weiny@intel.com>
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 54b21a79 Sun Jan 08 02:03:05 MST 2006 Andrew Morton <akpm@osdl.org> [PATCH] fix possible PAGE_CACHE_SHIFT overflows

We've had two instances recently of overflows when doing

64_bit_value = (32_bit_value << PAGE_CACHE_SHIFT)

I did a tree-wide grep of `<<.*PAGE_CACHE_SHIFT' and this is the result.

- afs_rxfs_fetch_descriptor.offset is of type off_t, which seems broken.

- jfs and jffs are limited to 4GB anyway.

- reiserfs map_block_for_writepage() takes an unsigned long for the block -
it should take sector_t. (It'll fail for huge filesystems with
blocksize<PAGE_CACHE_SIZE)

- cramfs_read() needs to use sector_t (I think cramsfs is busted on large
filesystems anyway)

- affs is limited in file size anyway.

- I generally didn't fix 32-bit overflows in directory operations.

- arm's __flush_dcache_page() is peculiar. What if the page lies beyond 4G?

- gss_wrap_req_priv() needs checking (snd_buf->page_base)

Cc: Oleg Drokin <green@linuxhacker.ru>
Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: <reiserfs-dev@namesys.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 54b21a79 Sun Jan 08 02:03:05 MST 2006 Andrew Morton <akpm@osdl.org> [PATCH] fix possible PAGE_CACHE_SHIFT overflows

We've had two instances recently of overflows when doing

64_bit_value = (32_bit_value << PAGE_CACHE_SHIFT)

I did a tree-wide grep of `<<.*PAGE_CACHE_SHIFT' and this is the result.

- afs_rxfs_fetch_descriptor.offset is of type off_t, which seems broken.

- jfs and jffs are limited to 4GB anyway.

- reiserfs map_block_for_writepage() takes an unsigned long for the block -
it should take sector_t. (It'll fail for huge filesystems with
blocksize<PAGE_CACHE_SIZE)

- cramfs_read() needs to use sector_t (I think cramsfs is busted on large
filesystems anyway)

- affs is limited in file size anyway.

- I generally didn't fix 32-bit overflows in directory operations.

- arm's __flush_dcache_page() is peculiar. What if the page lies beyond 4G?

- gss_wrap_req_priv() needs checking (snd_buf->page_base)

Cc: Oleg Drokin <green@linuxhacker.ru>
Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: <reiserfs-dev@namesys.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
H A Dfile.cdiff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
H A Dsysv.hdiff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff a528d35e Tue Jan 31 09:46:22 MST 2017 David Howells <dhowells@redhat.com> statx: Add a system call to make enhanced file info available

Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.

The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode. This change is propagated to the vfs_getattr*()
function.

Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.

========
OVERVIEW
========

The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.

A number of requests were gathered for features to be included. The
following have been included:

(1) Make the fields a consistent size on all arches and make them large.

(2) Spare space, request flags and information flags are provided for
future expansion.

(3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
__s64).

(4) Creation time: The SMB protocol carries the creation time, which could
be exported by Samba, which will in turn help CIFS make use of
FS-Cache as that can be used for coherency data (stx_btime).

This is also specified in NFSv4 as a recommended attribute and could
be exported by NFSD [Steve French].

(5) Lightweight stat: Ask for just those details of interest, and allow a
netfs (such as NFS) to approximate anything not of interest, possibly
without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
Dilger] (AT_STATX_DONT_SYNC).

(6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
its cached attributes are up to date [Trond Myklebust]
(AT_STATX_FORCE_SYNC).

And the following have been left out for future extension:

(7) Data version number: Could be used by userspace NFS servers [Aneesh
Kumar].

Can also be used to modify fill_post_wcc() in NFSD which retrieves
i_version directly, but has just called vfs_getattr(). It could get
it from the kstat struct if it used vfs_xgetattr() instead.

(There's disagreement on the exact semantics of a single field, since
not all filesystems do this the same way).

(8) BSD stat compatibility: Including more fields from the BSD stat such
as creation time (st_btime) and inode generation number (st_gen)
[Jeremy Allison, Bernd Schubert].

(9) Inode generation number: Useful for FUSE and userspace NFS servers
[Bernd Schubert].

(This was asked for but later deemed unnecessary with the
open-by-handle capability available and caused disagreement as to
whether it's a security hole or not).

(10) Extra coherency data may be useful in making backups [Andreas Dilger].

(No particular data were offered, but things like last backup
timestamp, the data version number and the DOS archive bit would come
into this category).

(11) Allow the filesystem to indicate what it can/cannot provide: A
filesystem can now say it doesn't support a standard stat feature if
that isn't available, so if, for instance, inode numbers or UIDs don't
exist or are fabricated locally...

(This requires a separate system call - I have an fsinfo() call idea
for this).

(12) Store a 16-byte volume ID in the superblock that can be returned in
struct xstat [Steve French].

(Deferred to fsinfo).

(13) Include granularity fields in the time data to indicate the
granularity of each of the times (NFSv4 time_delta) [Steve French].

(Deferred to fsinfo).

(14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
Note that the Linux IOC flags are a mess and filesystems such as Ext4
define flags that aren't in linux/fs.h, so translation in the kernel
may be a necessity (or, possibly, we provide the filesystem type too).

(Some attributes are made available in stx_attributes, but the general
feeling was that the IOC flags were to ext[234]-specific and shouldn't
be exposed through statx this way).

(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
Michael Kerrisk].

(Deferred, probably to fsinfo. Finding out if there's an ACL or
seclabal might require extra filesystem operations).

(16) Femtosecond-resolution timestamps [Dave Chinner].

(A __reserved field has been left in the statx_timestamp struct for
this - if there proves to be a need).

(17) A set multiple attributes syscall to go with this.

===============
NEW SYSTEM CALL
===============

The new system call is:

int ret = statx(int dfd,
const char *filename,
unsigned int flags,
unsigned int mask,
struct statx *buffer);

The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat(). There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.

Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):

(1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
respect.

(2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
its attributes with the server - which might require data writeback to
occur to get the timestamps correct.

(3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
network filesystem. The resulting values should be considered
approximate.

mask is a bitmask indicating the fields in struct statx that are of
interest to the caller. The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat(). It should be noted that asking for
more information may entail extra I/O operations.

buffer points to the destination for the data. This must be 256 bytes in
size.

======================
MAIN ATTRIBUTES RECORD
======================

The following structures are defined in which to return the main attribute
set:

struct statx_timestamp {
__s64 tv_sec;
__s32 tv_nsec;
__s32 __reserved;
};

struct statx {
__u32 stx_mask;
__u32 stx_blksize;
__u64 stx_attributes;
__u32 stx_nlink;
__u32 stx_uid;
__u32 stx_gid;
__u16 stx_mode;
__u16 __spare0[1];
__u64 stx_ino;
__u64 stx_size;
__u64 stx_blocks;
__u64 __spare1[1];
struct statx_timestamp stx_atime;
struct statx_timestamp stx_btime;
struct statx_timestamp stx_ctime;
struct statx_timestamp stx_mtime;
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major;
__u32 stx_dev_minor;
__u64 __spare2[14];
};

The defined bits in request_mask and stx_mask are:

STATX_TYPE Want/got stx_mode & S_IFMT
STATX_MODE Want/got stx_mode & ~S_IFMT
STATX_NLINK Want/got stx_nlink
STATX_UID Want/got stx_uid
STATX_GID Want/got stx_gid
STATX_ATIME Want/got stx_atime{,_ns}
STATX_MTIME Want/got stx_mtime{,_ns}
STATX_CTIME Want/got stx_ctime{,_ns}
STATX_INO Want/got stx_ino
STATX_SIZE Want/got stx_size
STATX_BLOCKS Want/got stx_blocks
STATX_BASIC_STATS [The stuff in the normal stat struct]
STATX_BTIME Want/got stx_btime{,_ns}
STATX_ALL [All currently available stuff]

stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.

Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution. Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.

The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does. The following
attributes map to FS_*_FL flags and are the same numerical value:

STATX_ATTR_COMPRESSED File is compressed by the fs
STATX_ATTR_IMMUTABLE File is marked immutable
STATX_ATTR_APPEND File is append-only
STATX_ATTR_NODUMP File is not to be dumped
STATX_ATTR_ENCRYPTED File requires key to decrypt in fs

Within the kernel, the supported flags are listed by:

KSTAT_ATTR_FS_IOC_FLAGS

[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]

New flags include:

STATX_ATTR_AUTOMOUNT Object is an automount trigger

These are for the use of GUI tools that might want to mark files specially,
depending on what they are.

Fields in struct statx come in a number of classes:

(0) stx_dev_*, stx_blksize.

These are local system information and are always available.

(1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
stx_size, stx_blocks.

These will be returned whether the caller asks for them or not. The
corresponding bits in stx_mask will be set to indicate whether they
actually have valid values.

If the caller didn't ask for them, then they may be approximated. For
example, NFS won't waste any time updating them from the server,
unless as a byproduct of updating something requested.

If the values don't actually exist for the underlying object (such as
UID or GID on a DOS file), then the bit won't be set in the stx_mask,
even if the caller asked for the value. In such a case, the returned
value will be a fabrication.

Note that there are instances where the type might not be valid, for
instance Windows reparse points.

(2) stx_rdev_*.

This will be set only if stx_mode indicates we're looking at a
blockdev or a chardev, otherwise will be 0.

(3) stx_btime.

Similar to (1), except this will be set to 0 if it doesn't exist.

=======
TESTING
=======

The following test program can be used to test the statx system call:

samples/statx/test-statx.c

Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.

Here's some example output. Firstly, an NFS directory that crosses to
another FSID. Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.

[root@andromeda ~]# /tmp/test-statx -A /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:26 Inode: 1703937 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)

Secondly, the result of automounting on that directory.

[root@andromeda ~]# /tmp/test-statx /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:27 Inode: 2 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
/linux-master/fs/udf/
H A Ddir.cdiff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4d399cae Tue Jan 03 05:19:13 MST 2006 Adrian Bunk <bunk@stusta.de> remove pointers to the defunct UDF mailing list

This patch removes pointers to the defunct UDF mailing list.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
H A Dfile.cdiff 0af57378 Mon Jun 28 20:36:12 MDT 2021 Christoph Hellwig <hch@lst.de> mm: require ->set_page_dirty to be explicitly wired up

Remove the CONFIG_BLOCK default to __set_page_dirty_buffers and just wire
that method up for the missing instances.

[hch@lst.de: ecryptfs: add a ->set_page_dirty cludge]
Link: https://lkml.kernel.org/r/20210624125250.536369-1-hch@lst.de

Link: https://lkml.kernel.org/r/20210614061512.3966143-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Tyler Hicks <code@tyhicks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 02f92b38 Thu Jan 21 06:19:22 MST 2021 Christian Brauner <christian.brauner@ubuntu.com> fs: add file and path permissions helpers

Add two simple helpers to check permissions on a file and path
respectively and convert over some callers. It simplifies quite a few
codepaths and also reduces the churn in later patches quite a bit.
Christoph also correctly points out that this makes codepaths (e.g.
ioctls) way easier to follow that would otherwise have to do more
complex argument passing than necessary.

Link: https://lore.kernel.org/r/20210121131959.646623-4-christian.brauner@ubuntu.com
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
diff 41fc56d5 Sat Feb 08 22:58:52 MST 2014 Al Viro <viro@zeniv.linux.org.uk> kill the 4th argument of __generic_file_aio_write()

It's always equal to &iocb->ki_pos, where iocb is the value of the 1st
argument.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff 4d0fb621 Tue Nov 16 10:40:47 MST 2010 Alessio Igor Bogani <abogani@texware.it> udf: Replace bkl with the UDF_I(inode)->i_data_sem for protect udf_inode_info struct

Replace bkl with the UDF_I(inode)->i_data_sem rw semaphore in
udf_release_file(), udf_symlink(), udf_symlink_filler(), udf_get_block(),
udf_block_map(), and udf_setattr(). The rule now is that any operation
on regular file's or symlink's extents (or generally allocation information
including goal block) needs to hold i_data_sem.

This work was supported by a hardware donation from the CE Linux Forum.

Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
Signed-off-by: Jan Kara <jack@suse.cz>
diff 4b11111a Fri Feb 08 05:20:36 MST 2008 Marcin Slusarz <marcin.slusarz@gmail.com> udf: fix coding style

fix coding style errors found by checkpatch:
- assignments in if conditions
- braces {} around single statement blocks
- no spaces after commas
- printks without KERN_*
- lines longer than 80 characters
- spaces between "type *" and variable name

before: 192 errors, 561 warnings, 8987 lines checked
after: 1 errors, 38 warnings, 9468 lines checked

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4d399cae Tue Jan 03 05:19:13 MST 2006 Adrian Bunk <bunk@stusta.de> remove pointers to the defunct UDF mailing list

This patch removes pointers to the defunct UDF mailing list.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
H A Dudfdecl.hdiff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 1ed16171 Fri Feb 08 05:20:48 MST 2008 Marcin Slusarz <marcin.slusarz@gmail.com> udf: fix 3 signedness & 1 unitialized variable warnings

sparse generated:
fs/udf/inode.c:324:41: warning: incorrect type in argument 4 (different signedness)
fs/udf/inode.c:324:41: expected long *<noident>
fs/udf/inode.c:324:41: got unsigned long *<noident>

inode_getblk always set 4th argument to uint32_t value
3rd parameter of map_bh is sector_t (which is unsigned long or u64)
so convert phys value to sector_t

fs/udf/inode.c:1818:47: warning: incorrect type in argument 3 (different signedness)
fs/udf/inode.c:1818:47: expected int *<noident>
fs/udf/inode.c:1818:47: got unsigned int *<noident>
fs/udf/inode.c:1826:46: warning: incorrect type in argument 3 (different signedness)
fs/udf/inode.c:1826:46: expected int *<noident>
fs/udf/inode.c:1826:46: got unsigned int *<noident>

udf_get_filelongad and udf_get_shortad are called always for uint32_t
values (struct extent_position->offset), so it's safe to convert offset
parameter to uint32_t

gcc warned:
fs/udf/inode.c: In function 'udf_get_block':
fs/udf/inode.c:299: warning: 'phys' may be used uninitialized in this function
initialize it to 0 (if someday someone will break inode_getblk we will catch it immediately)

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Ben Fennema <bfennema@falcon.csc.calpoly.edu>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 1ed16171 Fri Feb 08 05:20:48 MST 2008 Marcin Slusarz <marcin.slusarz@gmail.com> udf: fix 3 signedness & 1 unitialized variable warnings

sparse generated:
fs/udf/inode.c:324:41: warning: incorrect type in argument 4 (different signedness)
fs/udf/inode.c:324:41: expected long *<noident>
fs/udf/inode.c:324:41: got unsigned long *<noident>

inode_getblk always set 4th argument to uint32_t value
3rd parameter of map_bh is sector_t (which is unsigned long or u64)
so convert phys value to sector_t

fs/udf/inode.c:1818:47: warning: incorrect type in argument 3 (different signedness)
fs/udf/inode.c:1818:47: expected int *<noident>
fs/udf/inode.c:1818:47: got unsigned int *<noident>
fs/udf/inode.c:1826:46: warning: incorrect type in argument 3 (different signedness)
fs/udf/inode.c:1826:46: expected int *<noident>
fs/udf/inode.c:1826:46: got unsigned int *<noident>

udf_get_filelongad and udf_get_shortad are called always for uint32_t
values (struct extent_position->offset), so it's safe to convert offset
parameter to uint32_t

gcc warned:
fs/udf/inode.c: In function 'udf_get_block':
fs/udf/inode.c:299: warning: 'phys' may be used uninitialized in this function
initialize it to 0 (if someday someone will break inode_getblk we will catch it immediately)

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Ben Fennema <bfennema@falcon.csc.calpoly.edu>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
/linux-master/fs/ufs/
H A Ddir.cdiff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff abf5d15f Sun Jun 25 06:47:24 MDT 2006 Evgeniy Dushistov <dushistov@mail.ru> [PATCH] ufs: easy debug

Currently to turn on debug mode "user" has to edit ~10 files, to turn off he
has to do it again.

This patch introduce such changes:
1)turn on(off) debug messages via ".config"
2)remove unnecessary duplication of code
3)make "UFSD" macros more similar to function
4)fix some compiler warnings

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
H A Dfile.cdiff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
/linux-master/include/linux/
H A Dcrash_dump.hdiff e0690479 Fri Apr 29 15:37:59 MDT 2022 Matthew Wilcox (Oracle) <willy@infradead.org> vmcore: convert read_from_oldmem() to take an iov_iter

Remove the read_from_oldmem() wrapper introduced earlier and convert all
the remaining callers to pass an iov_iter.

Link: https://lkml.kernel.org/r/20220408090636.560886-4-bhe@redhat.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff 65fddcfc Mon Jun 08 22:32:42 MDT 2020 Mike Rapoport <rppt@kernel.org> mm: reorder includes after introduction of linux/pgtable.h

The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include
of the latter in the middle of asm includes. Fix this up with the aid of
the below script and manual adjustments here and there.

import sys
import re

if len(sys.argv) is not 3:
print "USAGE: %s <file> <header>" % (sys.argv[0])
sys.exit(1)

hdr_to_move="#include <linux/%s>" % sys.argv[2]
moved = False
in_hdrs = False

with open(sys.argv[1], "r") as f:
lines = f.readlines()
for _line in lines:
line = _line.rstrip('
')
if line == hdr_to_move:
continue
if line.startswith("#include <linux/"):
in_hdrs = True
elif not moved and in_hdrs:
moved = True
print hdr_to_move
print line

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 4c5b566c Mon Mar 30 12:15:44 MDT 2020 Kairui Song <kasong@redhat.com> crash_dump: Remove no longer used saved_max_pfn

saved_max_pfn was originally introduced in commit

92aa63a5a1bf ("[PATCH] kdump: Retrieve saved max pfn")

It used to make sure that the user does not try to read the physical memory
beyond saved_max_pfn. But since commit

921d58c0e699 ("vmcore: remove saved_max_pfn check")

it's no longer used for the check. This variable doesn't have any users
anymore so just remove it.

[ bp: Drop the Calgary IOMMU reference from the commit message. ]

Signed-off-by: Kairui Song <kasong@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lkml.kernel.org/r/20200330181544.1595733-1-kasong@redhat.com
diff b2441318 Wed Nov 01 08:07:57 MDT 2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org> License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff be8a8d06 Wed Sep 11 15:24:49 MDT 2013 Michael Holzheu <holzheu@linux.vnet.ibm.com> vmcore: introduce ELF header in new memory feature

For s390 we want to use /proc/vmcore for our SCSI stand-alone dump
(zfcpdump). We have support where the first HSA_SIZE bytes are saved into
a hypervisor owned memory area (HSA) before the kdump kernel is booted.
When the kdump kernel starts, it is restricted to use only HSA_SIZE bytes.

The advantages of this mechanism are:

* No crashkernel memory has to be defined in the old kernel.
* Early boot problems (before kexec_load has been done) can be dumped
* Non-Linux systems can be dumped.

We modify the s390 copy_oldmem_page() function to read from the HSA memory
if memory below HSA_SIZE bytes is requested.

Since we cannot use the kexec tool to load the kernel in this scenario,
we have to build the ELF header in the 2nd (kdump/new) kernel.

So with the following patch set we would like to introduce the new
function that the ELF header for /proc/vmcore can be created in the 2nd
kernel memory.

The following steps are done during zfcpdump execution:

1. Production system crashes
2. User boots a SCSI disk that has been prepared with the zfcpdump tool
3. Hypervisor saves CPU state of boot CPU and HSA_SIZE bytes of memory into HSA
4. Boot loader loads kernel into low memory area
5. Kernel boots and uses only HSA_SIZE bytes of memory
6. Kernel saves registers of non-boot CPUs
7. Kernel does memory detection for dump memory map
8. Kernel creates ELF header for /proc/vmcore
9. /proc/vmcore uses this header for initialization
10. The zfcpdump user space reads /proc/vmcore to write dump to SCSI disk
- copy_oldmem_page() copies from HSA for memory below HSA_SIZE
- copy_oldmem_page() copies from real memory for memory above HSA_SIZE

Currently for s390 we create the ELF core header in the 2nd kernel with a
small trick. We relocate the addresses in the ELF header in a way that
for the /proc/vmcore code it seems to be in the 1st kernel (old) memory
and the read_from_oldmem() returns the correct data. This allows the
/proc/vmcore code to use the ELF header in the 2nd kernel.

This patch:

Exchange the old mechanism with the new and much cleaner function call
override feature that now offcially allows to create the ELF core header
in the 2nd kernel.

To use the new feature the following function have to be defined
by the architecture backend code to read from new memory:

* elfcorehdr_alloc: Allocate ELF header
* elfcorehdr_free: Free the memory of the ELF header
* elfcorehdr_read: Read from ELF header
* elfcorehdr_read_notes: Read from ELF notes

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Jan Willeke <willeke@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff 313162d0 Mon Jan 30 09:46:54 MST 2012 Paul Gortmaker <paul.gortmaker@windriver.com> device.h: audit and cleanup users in main include dir

The <linux/device.h> header includes a lot of stuff, and
it in turn gets a lot of use just for the basic "struct device"
which appears so often.

Clean up the users as follows:

1) For those headers only needing "struct device" as a pointer
in fcn args, replace the include with exactly that.

2) For headers not really using anything from device.h, simply
delete the include altogether.

3) For headers relying on getting device.h implicitly before
being included themselves, now explicitly include device.h

4) For files in which doing #1 or #2 uncovers an implicit
dependency on some other header, fix by explicitly adding
the required header(s).

Any C files that were implicitly relying on device.h to be
present have already been dealt with in advance.

Total removals from #1 and #2: 51. Total additions coming
from #3: 9. Total other implicit dependencies from #4: 7.

As of 3.3-rc1, there were 110, so a net removal of 42 gives
about a 38% reduction in device.h presence in include/*

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff 313162d0 Mon Jan 30 09:46:54 MST 2012 Paul Gortmaker <paul.gortmaker@windriver.com> device.h: audit and cleanup users in main include dir

The <linux/device.h> header includes a lot of stuff, and
it in turn gets a lot of use just for the basic "struct device"
which appears so often.

Clean up the users as follows:

1) For those headers only needing "struct device" as a pointer
in fcn args, replace the include with exactly that.

2) For headers not really using anything from device.h, simply
delete the include altogether.

3) For headers relying on getting device.h implicitly before
being included themselves, now explicitly include device.h

4) For files in which doing #1 or #2 uncovers an implicit
dependency on some other header, fix by explicitly adding
the required header(s).

Any C files that were implicitly relying on device.h to be
present have already been dealt with in advance.

Total removals from #1 and #2: 51. Total additions coming
from #3: 9. Total other implicit dependencies from #4: 7.

As of 3.3-rc1, there were 110, so a net removal of 42 gives
about a 38% reduction in device.h presence in include/*

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff 4b6f5d20 Tue Mar 28 02:56:42 MST 2006 Arjan van de Ven <arjan@infradead.org> [PATCH] Make most file operations structs in fs/ const

This is a conversion to make the various file_operations structs in fs/
const. Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Completed in 689 milliseconds

12345