History log of /linux-master/include/linux/sem.h
Revision Date Author Comments
# e034d49e 11-Dec-2023 Kent Overstreet <kent.overstreet@linux.dev>

sem: Split out sem_types.h

More sched.h dependency pruning.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>


# 1a5c1349 22-Mar-2018 Eric W. Biederman <ebiederm@xmission.com>

sem: Move struct sem and struct sem_array into ipc/sem.c

All of the users are now in ipc/sem.c so make the definitions
local to that file to make code maintenance easier. AKA
to prevent rebuilding the entire kernel when one of these
files is changed.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>


# b2441318 01-Nov-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>


# e54d02b2 02-Aug-2017 Deepa Dinamani <deepa.kernel@gmail.com>

ipc: sem: Make sem_array timestamps y2038 safe

time_t is not y2038 safe. Replace all uses of
time_t by y2038 safe time64_t.

Similarly, replace the calls to get_seconds() with
y2038 safe ktime_get_real_seconds().
Note that this preserves fast access on 64 bit systems,
but 32 bit systems need sequence counters.

The syscall interface themselves are not changed as part of
the patch. They will be part of a different series.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>


# 2cd648c1 12-Jul-2017 Manfred Spraul <manfred@colorfullife.com>

include/linux/sem.h: correctly document sem_ctime

sem_ctime is initialized to the semget() time and then updated at every
semctl() that changes the array.

Thus it does not represent the time of the last change.

Especially, semop() calls are only stored in sem_otime, not in
sem_ctime.

This is already described in ipc/sem.c, I just overlooked that there is
a comment in include/linux/sem.h and man semctl(2) as well.

So: Correct wrong comments.

Link: http://lkml.kernel.org/r/20170515171912.6298-4-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: <1vier1@web.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 1a233956 12-Jul-2017 Manfred Spraul <manfred@colorfullife.com>

ipc/sem.c: remove sem_base, embed struct sem

sma->sem_base is initialized with

sma->sem_base = (struct sem *) &sma[1];

The current code has four problems:
- There is an unnecessary pointer dereference - sem_base is not needed.
- Alignment for struct sem only works by chance.
- The current code causes false positive for static code analysis.
- This is a cast between different non-void types, which the future
randstruct GCC plugin warns on.

And, as bonus, the code size gets smaller:

Before:
0 .text 00003770
After:
0 .text 0000374e

[manfred@colorfullife.com: s/[0]/[]/, per hch]
Link: http://lkml.kernel.org/r/20170525185107.12869-2-manfred@colorfullife.com
Link: http://lkml.kernel.org/r/20170515171912.6298-2-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: <1vier1@web.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 3859a271 28-Oct-2016 Kees Cook <keescook@chromium.org>

randstruct: Mark various structs for randomization

This marks many critical kernel structures for randomization. These are
structures that have been targeted in the past in security exploits, or
contain functions pointers, pointers to function pointer tables, lists,
workqueues, ref-counters, credentials, permissions, or are otherwise
sensitive. This initial list was extracted from Brad Spengler/PaX Team's
code in the last public patch of grsecurity/PaX based on my understanding
of the code. Changes or omissions from the original code are mine and
don't reflect the original grsecurity/PaX code.

Left out of this list is task_struct, which requires special handling
and will be covered in a subsequent patch.

Signed-off-by: Kees Cook <keescook@chromium.org>


# 60f3e00d 08-May-2017 Davidlohr Bueso <dave@stgolabs.net>

sysv,ipc: cacheline align kern_ipc_perm

Assign 'struct kern_ipc_perm' its own cacheline to avoid false sharing
with sysv ipc calls.

While the structure itself is rather read-mostly throughout the lifespan
of ipc, the spinlock causes most of the invalidations. One example is
commit 31a7c4746e9 ("ipc/sem.c: cacheline align the ipc spinlock for
semaphores"). Therefore, extend this to all ipc.

The effect of cacheline alignment on sems can be seen in sembench, which
deals mostly with semtimedop wait/wakes is seen to improve raw
throughput (worker loops) between 8 to 12% on a 24-core x86 with over 4
threads.

Link: http://lkml.kernel.org/r/1486673582-6979-4-git-send-email-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 9de5ab8a 27-Feb-2017 Manfred Spraul <manfred@colorfullife.com>

ipc/sem: add hysteresis

sysv sem has two lock modes: One with per-semaphore locks, one lock mode
with a single global lock for the whole array. When switching from the
per-semaphore locks to the global lock, all per-semaphore locks must be
scanned for ongoing operations.

The patch adds a hysteresis for switching from the global lock to the
per semaphore locks. This reduces how often the per-semaphore locks
must be scanned.

Compared to the initial patch, this is a simplified solution: Setting
USE_GLOBAL_LOCK_HYSTERESIS to 1 restores the current behavior.

In theory, a workload with exactly 10 simple sops and then one complex
op now scales a bit worse, but this is pure theory: If there is
concurrency, the it won't be exactly 10:1:10:1:10:1:... If there is no
concurrency, then there is no need for scalability.

Link: http://lkml.kernel.org/r/1476851896-3590-3-git-send-email-manfred@colorfullife.com
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: <1vier1@web.de>
Cc: kernel test robot <xiaolong.ye@intel.com>
Cc: <felixh@informatik.uni-bremen.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 5864a2fd 11-Oct-2016 Manfred Spraul <manfred@colorfullife.com>

ipc/sem.c: fix complex_count vs. simple op race

Commit 6d07b68ce16a ("ipc/sem.c: optimize sem_lock()") introduced a
race:

sem_lock has a fast path that allows parallel simple operations.
There are two reasons why a simple operation cannot run in parallel:
- a non-simple operations is ongoing (sma->sem_perm.lock held)
- a complex operation is sleeping (sma->complex_count != 0)

As both facts are stored independently, a thread can bypass the current
checks by sleeping in the right positions. See below for more details
(or kernel bugzilla 105651).

The patch fixes that by creating one variable (complex_mode)
that tracks both reasons why parallel operations are not possible.

The patch also updates stale documentation regarding the locking.

With regards to stable kernels:
The patch is required for all kernels that include the
commit 6d07b68ce16a ("ipc/sem.c: optimize sem_lock()") (3.10?)

The alternative is to revert the patch that introduced the race.

The patch is safe for backporting, i.e. it makes no assumptions
about memory barriers in spin_unlock_wait().

Background:
Here is the race of the current implementation:

Thread A: (simple op)
- does the first "sma->complex_count == 0" test

Thread B: (complex op)
- does sem_lock(): This includes an array scan. But the scan can't
find Thread A, because Thread A does not own sem->lock yet.
- the thread does the operation, increases complex_count,
drops sem_lock, sleeps

Thread A:
- spin_lock(&sem->lock), spin_is_locked(sma->sem_perm.lock)
- sleeps before the complex_count test

Thread C: (complex op)
- does sem_lock (no array scan, complex_count==1)
- wakes up Thread B.
- decrements complex_count

Thread A:
- does the complex_count test

Bug:
Now both thread A and thread C operate on the same array, without
any synchronization.

Fixes: 6d07b68ce16a ("ipc/sem.c: optimize sem_lock()")
Link: http://lkml.kernel.org/r/1469123695-5661-1-git-send-email-manfred@colorfullife.com
Reported-by: <felixh@informatik.uni-bremen.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: <1vier1@web.de>
Cc: <stable@vger.kernel.org> [3.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# d12e1e50 08-Jul-2013 Manfred Spraul <manfred@colorfullife.com>

ipc/sem.c: replace shared sem_otime with per-semaphore value

sem_otime contains the time of the last semaphore operation that
completed successfully. Every operation updates this value, thus access
from multiple cpus can cause thrashing.

Therefore the patch replaces the variable with a per-semaphore variable.
The per-array sem_otime is only calculated when required.

No performance improvement on a single-socket i3 - only important for
larger systems.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 1a82e9e1 08-Jul-2013 Manfred Spraul <manfred@colorfullife.com>

ipc/sem: separate wait-for-zero and alter tasks into seperate queues

Introduce separate queues for operations that do not modify the
semaphore values. Advantages:

- Simpler logic in check_restart().
- Faster update_queue(): Right now, all wait-for-zero operations are
always tested, even if the semaphore value is not 0.
- wait-for-zero gets again priority, as in linux <=3.0.9

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 607ca46e 13-Oct-2012 David Howells <dhowells@redhat.com>

UAPI: (Scripted) Disintegrate include/linux

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>


# f567a185 02-Nov-2011 Manfred Spraul <manfred@colorfullife.com>

include/linux/sem.h: make sysv_sem empty if SYSVIPC is disabled

For the sysvsem undo, each task struct contains a sysv_sem structure with
a pointer to the undo information.

This pointer is only necessary if sysvipc is enabled - thus the pointer
can be made conditional on CONFIG_SYSVIPC.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# e57940d7 02-Nov-2011 Manfred Spraul <manfred@colorfullife.com>

ipc/sem.c: remove private structures from public header file

include/linux/sem.h contains several structures that are only used within
ipc/sem.c.

The patch moves them into ipc/sem.c - there is no need to expose the
structures to the whole kernel.

No functional changes, only whitespace cleanups and 80-char per line
fixes.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 60063497 26-Jul-2011 Arun Sharma <asharma@fb.com>

atomic: use <linux/atomic.h>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 31a7c474 26-May-2010 Manfred Spraul <manfred@colorfullife.com>

ipc/sem.c: cacheline align the ipc spinlock for semaphores

Cacheline align the spinlock for sysv semaphores. Without the patch, the
spinlock and sem_otime [written by every semop that modified the array]
and sem_base [read in the hot path of try_atomic_semop()] can be in the
same cacheline.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# b97e820f 15-Dec-2009 Manfred Spraul <manfred@colorfullife.com>

ipc/sem.c: add a per-semaphore pending list

Based on Nick's findings:

sysv sem has the concept of semaphore arrays that consist out of multiple
semaphores. Atomic operations that affect multiple semaphores are
supported.

The patch is the first step for optimizing simple, single semaphore
operations: In addition to the global list of all pending operations, a
2nd, per-semaphore list with the simple operations is added.

Note: this patch does not make sense by itself, the new list is used
nowhere.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 380af1b3 25-Jul-2008 Manfred Spraul <manfred@colorfullife.com>

ipc/sem.c: rewrite undo list locking

The attached patch:
- reverses the locking order of ulp->lock and sem_lock:
Previously, it was first ulp->lock, then inside sem_lock.
Now it's the other way around.
- converts the undo structure to rcu.

Benefits:
- With the old locking order, IPC_RMID could not kfree the undo structures.
The stale entries remained in the linked lists and were released later.
- The patch fixes a a race in semtimedop(): if both IPC_RMID and a semget() that
recreates exactly the same id happen between find_alloc_undo() and sem_lock,
then semtimedop() would access already kfree'd memory.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# a1193f8e 25-Jul-2008 Manfred Spraul <manfred@colorfullife.com>

ipc/sem.c: convert sem_array.sem_pending to struct list_head

sem_array.sem_pending is a double linked list, the attached patch converts
it to struct list_head.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 2c0c29d4 25-Jul-2008 Manfred Spraul <manfred@colorfullife.com>

ipc/sem.c: remove unused entries from struct sem_queue

sem_queue.sma and sem_queue.id were never used, the attached patch removes
them.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 4daa28f6 25-Jul-2008 Manfred Spraul <manfred@colorfullife.com>

ipc/sem.c: convert undo structures to struct list_head

The undo structures contain two linked lists, the attached patch replaces
them with generic struct list_head lists.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 7ca7e564 19-Oct-2007 Nadia Derbey <Nadia.Derbey@bull.net>

ipc: store ipcs into IDRs

This patch introduces ipcs storage into IDRs. The main changes are:
. This ipc_ids structure is changed: the entries array is changed into a
root idr structure.
. The grow_ary() routine is removed: it is not needed anymore when adding
an ipc structure, since we are now using the IDR facility.
. The ipc_rmid() routine interface is changed:
. there is no need for this routine to return the pointer passed in as
argument: it is now declared as a void
. since the id is now part of the kern_ipc_perm structure, no need to
have it as an argument to the routine

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>


# 8ffbc759 25-Apr-2006 David Woodhouse <dwmw2@infradead.org>

Don't include <asm/atomic.h> from user-visible part of linux/sem.h

Signed-off-by: David Woodhouse <dwmw2@infradead.org>


# 8c65b4a6 07-Nov-2005 Tim Schmielau <tim@physik3.uni-rostock.de>

[PATCH] fix remaining missing includes

Fix more include file problems that surfaced since I submitted the previous
fix-missing-includes.patch. This should now allow not to include sched.h
from module.h, which is done by a followup patch.

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>


# 19b4946c 06-Sep-2005 Mike Waychison <mikew@google.com>

[PATCH] ipc: convert /proc/sysvipc/* to generic seq_file interface

Change the /proc/sysvipc/shm|sem|msg files to use the generic seq_file
implementation for struct ipc_ids.

Signed-off-by: Mike Waychison <mikew@google.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>


# 1da177e4 16-Apr-2005 Linus Torvalds <torvalds@ppc970.osdl.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!