PCI: Move pci_iomap.c to drivers/pci/

The entirety of pci_iomap.c is guarded by an #ifdef CONFIG_PCI. It,
consequently, does not belong to lib/ because it is not generic
infrastructure.

Move pci_iomap.c to drivers/pci/ and implement the necessary changes to
Makefiles and Kconfigs.

Update MAINTAINERS file.

Update Documentation.

Link: https://lore.kernel.org/r/20240131090023.12331-3-pstanner@redhat.com
[bhelgaas: squash in https://lore.kernel.org/r/20240212150934.24559-1-pstanner@redhat.com]
Suggested-by: Danilo Krummrich <dakr@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

string: Convert helpers selftest to KUnit

Convert test-string_helpers.c to KUnit so it can be easily run with
everything else.

Failure reporting doesn't need to be open-coded in most places, for
example, forcing a failure in the expected output for upper/lower
testing looks like this:

[12:18:43] # test_upper_lower: EXPECTATION FAILED at lib/string_helpers_kunit.c:579
[12:18:43] Expected dst == strings_upper[i].out, but
[12:18:43] dst == "ABCDEFGH1234567890TEST"
[12:18:43] strings_upper[i].out == "ABCDEFGH1234567890TeST"
[12:18:43] [FAILED] test_upper_lower

Currently passes without problems:

$ ./tools/testing/kunit/kunit.py run string_helpers
...
[12:23:55] Starting KUnit Kernel (1/1)...
[12:23:55] ============================================================
[12:23:55] =============== string_helpers (3 subtests) ================
[12:23:55] [PASSED] test_get_size
[12:23:55] [PASSED] test_upper_lower
[12:23:55] [PASSED] test_unescape
[12:23:55] ================= [PASSED] string_helpers ==================
[12:23:55] ============================================================
[12:23:55] Testing complete. Ran 3 tests: passed: 3
[12:23:55] Elapsed time: 6.709s total, 0.001s configuring, 6.591s building, 0.066s running

Link: https://lore.kernel.org/r/20240301202732.2688342-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>

string: Convert selftest to KUnit

Convert test_string.c to KUnit so it can be easily run with everything
else.

Additional text context is retained for failure reporting. For example,
when forcing a bad match, we can see the loop counters reported for the
memset() tests:

[09:21:52] # test_memset64: ASSERTION FAILED at lib/string_kunit.c:93
[09:21:52] Expected v == 0xa2a1a1a1a1a1a1a1ULL, but
[09:21:52] v == -6799976246779207263 (0xa1a1a1a1a1a1a1a1)
[09:21:52] 0xa2a1a1a1a1a1a1a1ULL == -6727918652741279327 (0xa2a1a1a1a1a1a1a1)
[09:21:52] i:0 j:0 k:0
[09:21:52] [FAILED] test_memset64

Currently passes without problems:

$ ./tools/testing/kunit/kunit.py run string
...
[09:37:40] Starting KUnit Kernel (1/1)...
[09:37:40] ============================================================
[09:37:40] =================== string (6 subtests) ====================
[09:37:40] [PASSED] test_memset16
[09:37:40] [PASSED] test_memset32
[09:37:40] [PASSED] test_memset64
[09:37:40] [PASSED] test_strchr
[09:37:40] [PASSED] test_strnchr
[09:37:40] [PASSED] test_strspn
[09:37:40] ===================== [PASSED] string ======================
[09:37:40] ============================================================
[09:37:40] Testing complete. Ran 6 tests: passed: 6
[09:37:40] Elapsed time: 6.730s total, 0.001s configuring, 6.562s building, 0.131s running

Link: https://lore.kernel.org/r/20240301202732.2688342-1-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>

fortify: Add KUnit tests for runtime overflows

With fortify overflows able to be redirected, we can use KUnit to
exercise the overflow conditions. Add tests for every API covered by
CONFIG_FORTIFY_SOURCE, except for memset() and memcpy(), which are
special-cased for now.

Disable warnings in the Makefile since we're explicitly testing
known-bad string handling code patterns.

Note that this makes the LKDTM FORTIFY_STR* tests obsolete, but those
can be removed separately.

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

ubsan: Silence W=1 warnings in self-test

Silence a handful of W=1 warnings in the UBSan selftest, which set
variables without using them. For example:

lib/test_ubsan.c:101:6: warning: variable 'val1' set but not used [-Wunused-but-set-variable]
101 | int val1 = 10;
| ^

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202401310423.XpCIk6KO-lkp@intel.com/
Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

livepatch: Move tests from lib/livepatch to selftests/livepatch

The modules are being moved from lib/livepatch to
tools/testing/selftests/livepatch/test_modules.

This code moving will allow writing more complex tests, like for example an
userspace C code that will call a livepatched kernel function.

The modules are now built as out-of-tree
modules, but being part of the kernel source means they will be maintained.

Another advantage of the code moving is to be able to easily change,
debug and rebuild the tests by running make on the selftests/livepatch
directory, which is not currently possible since the modules on
lib/livepatch are build and installed using the "modules" target.

The current approach also keeps the ability to execute the tests manually
by executing the scripts inside selftests/livepatch directory, as it's
currently supported. If the modules are modified, they needed to be
rebuilt before running the scripts though.

The modules are built before running the selftests when using the
kselftest invocations:

make kselftest TARGETS=livepatch
or
make -C tools/testing/selftests/livepatch run_tests

Having the modules being built as out-of-modules requires changing the
currently used 'modprobe' by 'insmod' and adapt the test scripts that
check for the kernel message buffer.

Now it is possible to only compile the modules by running:

make -C tools/testing/selftests/livepatch/

This way the test modules and other test program can be built in order
to be packaged if so desired.

As there aren't any modules being built on lib/livepatch, remove the
TEST_LIVEPATCH Kconfig and it's references.

Note: "make gen_tar" packages the pre-built binaries into the tarball.
It means that it will store the test modules pre-built for
the kernel running on the build host.

Note that these modules need not binary compatible with
the kernel built from the same sources. But the same
is true for other packaged selftest binaries.

The entire kernel sources are needed for rebuilding
the selftests on another system.

Reviewed-by: Joe Lawrence <joe.lawrence@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

acpi: Move common tables helper functions to common lib

Some of the routines in ACPI driver/acpi/tables.c can be shared with
parsing CDAT. CDAT is a device-provided data structure that is formatted
similar to a platform provided ACPI table. CDAT is used by CXL and can
exist on platforms that do not use ACPI. Split out the common routine
from ACPI to accommodate platforms that do not support ACPI and move that
to /lib. The common routines can be built outside of ACPI if
FIRMWARE_TABLES is selected.

Link: https://lore.kernel.org/linux-cxl/CAJZ5v0jipbtTNnsA0-o5ozOk8ZgWnOg34m34a9pPenTyRLj=6A@mail.gmail.com/
Suggested-by: "Rafael J. Wysocki" <rafael@kernel.org>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/169713683430.2205276.17899451119920103445.stgit@djiang5-mobl3
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

lib/bitmap: split-out string-related operations to a separate files

lib/bitmap.c and corresponding include/linux/bitmap.h are intended to
hold functions related to operations on bitmaps, like bitmap_shift or
bitmap_set. Historically, some string-related operations like
bitmap_parse are also reside in lib/bitmap.c.

Now that the subsystem evolves, string-related bitmap operations became a
significant part of the file. Because they are quite different from the
other bitmap functions by nature, it's worth to split them to a separate
source/header files.

CC: Andrew Morton <akpm@linux-foundation.org>
CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

lib: objpool test module added

The test_objpool module (test_objpool) will run several testcases
for objpool stress and performance evaluation. Each testcase will
have all available cpu cores involved to create a situation of high
parallel and high contention.

As of now there are 5 groups and 5 * 2 testcases in total:

1) group 1: synchronous mode
objpool is managed synchronously, that is, all objects are to be
reclaimed before objpool finalization and the objpool owner makes
sure of it. All threads on different cores run in the same pace
2) group 2: synchronous mode + hrtimer
this case have 2 customers: normal threads and hrtimer softirqs
3) group 3: synchronous + overrun mode
This test group is mainly for performance evaluation of missing
cases when pre-allocated objects are less than the requested
4) group 4: asynchronous mode
This case is just an emulation of kretprobe, with refcount used
to control the objpool lifecycle
5) group 5: asynchronous mode with hrtimer
hrtimer softirq is introduced to stress async objpool operations

Link: https://lore.kernel.org/all/20231017135654.82270-3-wuqiang.matt@bytedance.com/

Signed-off-by: wuqiang.matt <wuqiang.matt@bytedance.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

lib: objpool added: ring-array based lockless MPMC

objpool is a scalable implementation of high performance queue for
object allocation and reclamation, such as kretprobe instances.

With leveraging percpu ring-array to mitigate hot spots of memory
contention, it delivers near-linear scalability for high parallel
scenarios. The objpool is best suited for the following cases:
1) Memory allocation or reclamation are prohibited or too expensive
2) Consumers are of different priorities, such as irqs and threads

Limitations:
1) Maximum objects (capacity) is fixed after objpool creation
2) All pre-allocated objects are managed in percpu ring array,
which consumes more memory than linked lists

Link: https://lore.kernel.org/all/20231017135654.82270-2-wuqiang.matt@bytedance.com/

Signed-off-by: wuqiang.matt <wuqiang.matt@bytedance.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

bcache: move closures to lib/

Prep work for bcachefs - being a fork of bcache it also uses closures

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Acked-by: Coly Li <colyli@suse.de>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>

lib: add light-weight queuing mechanism.

lwq is a FIFO single-linked queue that only requires a spinlock
for dequeueing, which happens in process context. Enqueueing is atomic
with no spinlock and can happen in any context.

This is particularly useful when work items are queued from BH or IRQ
context, and when they are handled one at a time by dedicated threads.

Avoiding any locking when enqueueing means there is no need to disable
BH or interrupts, which is generally best avoided (particularly when
there are any RT tasks on the machine).

This solution is superior to using "list_head" links because we need
half as many pointers in the data structures, and because list_head
lists would need locking to add items to the queue.

This solution is superior to a bespoke solution as all locking and
container_of casting is integrated, so the interface is simple.

Despite the similar name, this solution meets a distinctly different
need to kfifo. kfifo provides a fixed sized circular buffer to which
data can be added at one end and removed at the other, and does not
provide any locking. lwq does not have any size limit and works with
data structures (objects?) rather than data (bytes).

A unit test for basic functionality, which runs at boot time, is included.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: David Gow <davidgow@google.com>
Cc: linux-kernel@vger.kernel.org
Message-Id: <20230911111333.4d1a872330e924a00acb905b@linux-foundation.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

iov_iter: Kunit tests for copying to/from an iterator

Add some kunit tests for page extraction for ITER_BVEC, ITER_KVEC and
ITER_XARRAY type iterators. ITER_UBUF and ITER_IOVEC aren't dealt with
as they require userspace VM interaction. ITER_DISCARD isn't dealt with
either as that does nothing.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

crypto: lib - Move mpi into lib/crypto

As lib/mpi is mostly used by crypto code, move it under lib/crypto
so that patches touching it get directed to the right mailing list.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

list: Introduce CONFIG_LIST_HARDENED

Numerous production kernel configs (see [1, 2]) are choosing to enable
CONFIG_DEBUG_LIST, which is also being recommended by KSPP for hardened
configs [3]. The motivation behind this is that the option can be used
as a security hardening feature (e.g. CVE-2019-2215 and CVE-2019-2025
are mitigated by the option [4]).

The feature has never been designed with performance in mind, yet common
list manipulation is happening across hot paths all over the kernel.

Introduce CONFIG_LIST_HARDENED, which performs list pointer checking
inline, and only upon list corruption calls the reporting slow path.

To generate optimal machine code with CONFIG_LIST_HARDENED:

1. Elide checking for pointer values which upon dereference would
result in an immediate access fault (i.e. minimal hardening
checks). The trade-off is lower-quality error reports.

2. Use the __preserve_most function attribute (available with Clang,
but not yet with GCC) to minimize the code footprint for calling
the reporting slow path. As a result, function size of callers is
reduced by avoiding saving registers before calling the rarely
called reporting slow path.

Note that all TUs in lib/Makefile already disable function tracing,
including list_debug.c, and __preserve_most's implied notrace has
no effect in this case.

3. Because the inline checks are a subset of the full set of checks in
__list_*_valid_or_report(), always return false if the inline
checks failed. This avoids redundant compare and conditional
branch right after return from the slow path.

As a side-effect of the checks being inline, if the compiler can prove
some condition to always be true, it can completely elide some checks.

Since DEBUG_LIST is functionally a superset of LIST_HARDENED, the
Kconfig variables are changed to reflect that: DEBUG_LIST selects
LIST_HARDENED, whereas LIST_HARDENED itself has no dependency on
DEBUG_LIST.

Running netperf with CONFIG_LIST_HARDENED (using a Clang compiler with
"preserve_most") shows throughput improvements, in my case of ~7% on
average (up to 20-30% on some test cases).

Link: https://r.android.com/1266735 [1]
Link: https://gitlab.archlinux.org/archlinux/packaging/packages/linux/-/blob/main/config [2]
Link: https://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project/Recommended_Settings [3]
Link: https://googleprojectzero.blogspot.com/2019/11/bad-binder-android-in-wild-exploit.html [4]
Signed-off-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20230811151847.1594958-3-elver@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>

lib/bitmap: workaround const_eval test build failure

When building with Clang, and when KASAN and GCOV_PROFILE_ALL are both
enabled, the test fails to build [1]:

>> lib/test_bitmap.c:920:2: error: call to '__compiletime_assert_239' declared with 'error' attribute: BUILD_BUG_ON failed: !__builtin_constant_p(res)
BUILD_BUG_ON(!__builtin_constant_p(res));
^
include/linux/build_bug.h:50:2: note: expanded from macro 'BUILD_BUG_ON'
BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
^
include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^
include/linux/compiler_types.h:352:2: note: expanded from macro 'compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^
include/linux/compiler_types.h:340:2: note: expanded from macro '_compiletime_assert'
__compiletime_assert(condition, msg, prefix, suffix)
^
include/linux/compiler_types.h:333:4: note: expanded from macro '__compiletime_assert'
prefix ## suffix(); \
^
<scratch space>:185:1: note: expanded from here
__compiletime_assert_239

Originally it was attributed to s390, which now looks seemingly wrong. The
issue is not related to bitmap code itself, but it breaks build for a given
configuration.

Disabling the const_eval test under that config may potentially hide other
bugs. Instead, workaround it by disabling GCOV for the test_bitmap unless
the compiler will get fixed.

[1] https://github.com/ClangBuiltLinux/linux/issues/1874

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307171254.yFcH97ej-lkp@intel.com/
Fixes: dc34d5036692 ("lib: test_bitmap: add compile-time optimization/evaluations assertions")
Co-developed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>

mm: page_alloc: collect mem statistic into show_mem.c

Let's move show_mem.c from lib to mm, as it belongs memory subsystem, also
split some memory statistic related functions from page_alloc.c to
show_mem.c, and we cleanup some unneeded include.

There is no functional change.

Link: https://lkml.kernel.org/r/20230516063821.121844-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

x86/csum: Improve performance of `csum_partial`

1) Add special case for len == 40 as that is the hottest value. The
nets a ~8-9% latency improvement and a ~30% throughput improvement
in the len == 40 case.

2) Use multiple accumulators in the 64-byte loop. This dramatically
improves ILP and results in up to a 40% latency/throughput
improvement (better for more iterations).

Results from benchmarking on Icelake. Times measured with rdtsc()
len lat_new lat_old r tput_new tput_old r
8 3.58 3.47 1.032 3.58 3.51 1.021
16 4.14 4.02 1.028 3.96 3.78 1.046
24 4.99 5.03 0.992 4.23 4.03 1.050
32 5.09 5.08 1.001 4.68 4.47 1.048
40 5.57 6.08 0.916 3.05 4.43 0.690
48 6.65 6.63 1.003 4.97 4.69 1.059
56 7.74 7.72 1.003 5.22 4.95 1.055
64 6.65 7.22 0.921 6.38 6.42 0.994
96 9.43 9.96 0.946 7.46 7.54 0.990
128 9.39 12.15 0.773 8.90 8.79 1.012
200 12.65 18.08 0.699 11.63 11.60 1.002
272 15.82 23.37 0.677 14.43 14.35 1.005
440 24.12 36.43 0.662 21.57 22.69 0.951
952 46.20 74.01 0.624 42.98 53.12 0.809
1024 47.12 78.24 0.602 46.36 58.83 0.788
1552 72.01 117.30 0.614 71.92 96.78 0.743
2048 93.07 153.25 0.607 93.28 137.20 0.680
2600 114.73 194.30 0.590 114.28 179.32 0.637
3608 156.34 268.41 0.582 154.97 254.02 0.610
4096 175.01 304.03 0.576 175.89 292.08 0.602

There is no such thing as a free lunch, however, and the special case
for len == 40 does add overhead to the len != 40 cases. This seems to
amount to be ~5% throughput and slightly less in terms of latency.

Testing:
Part of this change is a new kunit test. The tests check all
alignment X length pairs in [0, 64) X [0, 512).
There are three cases.
1) Precomputed random inputs/seed. The expected results where
generated use the generic implementation (which is assumed to be
non-buggy).
2) An input of all 1s. The goal of this test is to catch any case
a carry is missing.
3) An input that never carries. The goal of this test si to catch
any case of incorrectly carrying.

More exhaustive tests that test all alignment X length pairs in
[0, 8192) X [0, 8192] on random data are also available here:
https://github.com/goldsteinn/csum-reproduction

The reposity also has the code for reproducing the above benchmark
numbers.

Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20230511011002.935690-1-goldstein.w.n%40gmail.com

string: Add Kunit tests for strcat() family

Add tests to make sure the strcat() family of functions behave
correctly.

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

dyndbg: cleanup dynamic usage in ib_srp.c

Currently, in dynamic_debug.h we only provide
DEFINE_DYNAMIC_DEBUG_METADATA() and DYNAMIC_DEBUG_BRANCH()
definitions if CONFIG_DYNAMIC_CORE is enabled. Thus, drivers
such as infiniband srp (see: drivers/infiniband/ulp/srp/ib_srp.c)
must provide their own definitions for !CONFIG_DYNAMIC_CORE.

Thus, let's move this !CONFIG_DYNAMIC_CORE case into dynamic_debug.h.
However, the dynamic debug interfaces should really only be defined
if CONFIG_DYNAMIC_DEBUG is set or CONFIG_DYNAMIC_CORE is set along
with DYNAMIC_DEBUG_MODULE, (see:
Documentation/admin-guide/dynamic-debug-howto.rst). Thus, the
undefined case becomes: !((CONFIG_DYNAMIC_DEBUG ||
(CONFIG_DYNAMIC_CORE && DYNAMIC_DEBUG_MODULE)).
With those changes in place, we can remove the !CONFIG_DYNAMIC_CORE
case from ib_srp.c

This change was prompted by a build breakeage in ib_srp.c stemming
from the inclusion of dynamic_debug.h unconditionally in module.h, due
to commit 7deabd674988 ("dyndbg: use the module notifier callbacks").
In that case, if we have CONFIG_DYNAMIC_CORE=y and
CONFIG_DYNAMIC_DEBUG=n then the definitions for
DEFINE_DYNAMIC_DEBUG_METADATA() and DYNAMIC_DEBUG_BRANCH() are defined
once in ib_srp.c and then again in the dynamic_debug.h. This had been
working prior to the above referenced commit because dynamic_debug.h
was only pulled into ib_srp.c conditinally via printk.h if
CONFIG_DYNAMIC_DEBUG was set.

Also, the exported functions in lib/dynamic_debug.c itself may
not have a prototype if CONFIG_DYNAMIC_DEBUG=n and
CONFIG_DYNAMIC_CORE=y. This would trigger the -Wmissing-prototypes
warning.

The exported functions are behind (include/linux/dynamic_debug.h):

if defined(CONFIG_DYNAMIC_DEBUG) || \
(defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))

Thus, by adding -DDYNAMIC_CONFIG_MODULE to the lib/Makefile we
can ensure that the exported functions have a prototype in all cases,
since lib/dynamic_debug.c is built whenever
CONFIG_DYNAMIC_DEBUG_CORE=y.

Fixes: 7deabd674988 ("dyndbg: use the module notifier callbacks")
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202303071444.sIbZTDCy-lkp@intel.com/
Signed-off-by: Jason Baron <jbaron@akamai.com>
[mcgrof: adjust commit log, and remove urldefense from URL]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

atomics: Provide rcuref - scalable reference counting

atomic_t based reference counting, including refcount_t, uses
atomic_inc_not_zero() for acquiring a reference. atomic_inc_not_zero() is
implemented with a atomic_try_cmpxchg() loop. High contention of the
reference count leads to retry loops and scales badly. There is nothing to
improve on this implementation as the semantics have to be preserved.

Provide rcuref as a scalable alternative solution which is suitable for RCU
managed objects. Similar to refcount_t it comes with overflow and underflow
detection and mitigation.

rcuref treats the underlying atomic_t as an unsigned integer and partitions
this space into zones:

0x00000000 - 0x7FFFFFFF valid zone (1 .. (INT_MAX + 1) references)
0x80000000 - 0xBFFFFFFF saturation zone
0xC0000000 - 0xFFFFFFFE dead zone
0xFFFFFFFF no reference

rcuref_get() unconditionally increments the reference count with
atomic_add_negative_relaxed(). rcuref_put() unconditionally decrements the
reference count with atomic_add_negative_release().

This unconditional increment avoids the inc_not_zero() problem, but
requires a more complex implementation on the put() side when the count
drops from 0 to -1.

When this transition is detected then it is attempted to mark the reference
count dead, by setting it to the midpoint of the dead zone with a single
atomic_cmpxchg_release() operation. This operation can fail due to a
concurrent rcuref_get() elevating the reference count from -1 to 0 again.

If the unconditional increment in rcuref_get() hits a reference count which
is marked dead (or saturated) it will detect it after the fact and bring
back the reference count to the midpoint of the respective zone. The zones
provide enough tolerance which makes it practically impossible to escape
from a zone.

The racy implementation of rcuref_put() requires to protect rcuref_put()
against a grace period ending in order to prevent a subtle use after
free. As RCU is the only mechanism which allows to protect against that, it
is not possible to fully replace the atomic_inc_not_zero() based
implementation of refcount_t with this scheme.

The final drop is slightly more expensive than the atomic_dec_return()
counterpart, but that's not the case which this is optimized for. The
optimization is on the high frequeunt get()/put() pairs and their
scalability.

The performance of an uncontended rcuref_get()/put() pair where the put()
is not dropping the last reference is still on par with the plain atomic
operations, while at the same time providing overflow and underflow
detection and mitigation.

The performance of rcuref compared to plain atomic_inc_not_zero() and
atomic_dec_return() based reference counting under contention:

- Micro benchmark: All CPUs running a increment/decrement loop on an
elevated reference count, which means the 0 to -1 transition never
happens.

The performance gain depends on microarchitecture and the number of
CPUs and has been observed in the range of 1.3X to 4.7X

- Conversion of dst_entry::__refcnt to rcuref and testing with the
localhost memtier/memcached benchmark. That benchmark shows the
reference count contention prominently.

The performance gain depends on microarchitecture and the number of
CPUs and has been observed in the range of 1.1X to 2.6X over the
previous fix for the false sharing issue vs. struct
dst_entry::__refcnt.

When memtier is run over a real 1Gb network connection, there is a
small gain on top of the false sharing fix. The two changes combined
result in a 2%-5% total gain for that networked test.

Reported-by: Wangyang Guo <wangyang.guo@intel.com>
Reported-by: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230323102800.158429195@linutronix.de

kunit: Fix 'hooks.o' build by recursing into kunit

KUnit's 'hooks.o' file need to be built-in whenever KUnit is enabled
(even if CONFIG_KUNIT=m). We'd previously attemtped to do this by
adding 'kunit/hooks.o' to obj-y in lib/Makefile, but this caused hooks.c
to be rebuilt even when it was unchanged.

Instead, always recurse into lib/kunit using obj-y when KUnit is
enabled, and add the hooks there.

Fixes: 7170b7ed6acb ("kunit: Add "hooks" to call into KUnit when it's built as a module").
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/linux-kselftest/CAHk-=wiEf7irTKwPJ0jTMOF3CS-13UXmF6Fns3wuWpOZ_wGyZQ@mail.gmail.com/
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/hashtable_test.c: add test for the hashtable structure

Add a KUnit test for the kernel hashtable implementation in
include/linux/hashtable.h.

Note that this version does not yet test each of the rcu
alternative versions of functions.

Signed-off-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Add "hooks" to call into KUnit when it's built as a module

KUnit has several macros and functions intended for use from non-test
code. These hooks, currently the kunit_get_current_test() and
kunit_fail_current_test() macros, didn't work when CONFIG_KUNIT=m.

In order to support this case, the required functions and static data
need to be available unconditionally, even when KUnit itself is not
built-in. The new 'hooks.c' file is therefore always included, and has
both the static key required for kunit_get_current_test(), and a table
of function pointers in struct kunit_hooks_table. This is filled in with
the real implementations by kunit_install_hooks(), which is kept in
hooks-impl.h and called when the kunit module is loaded.

This can be extended for future features which require similar
"hook" behaviour, such as static stubs, by simply adding new entries to
the struct, and the appropriate code to set them.

Fixed white-space errors during commit:
Shuah Khan <skhan@linuxfoundation.org>

Resolved merge conflicts with:
db105c37a4d6 ("kunit: Export kunit_running()")
This patch supersedes the above.
Shuah Khan <skhan@linuxfoundation.org>

Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lib: add Dhrystone benchmark test

When working on SoC bring-up, (a full) userspace may not be available,
making it hard to benchmark the CPU performance of the system under
development. Still, one may want to have a rough idea of the (relative)
performance of one or more CPU cores, especially when working on e.g. the
clock driver that controls the CPU core clock(s).

Hence make the classical Dhrystone 2.1 benchmark available as a Linux
kernel test module, based on[1].

When built-in, this benchmark can be run without any userspace present.

Parallel runs (run on multiple CPU cores) are supported, just kick the
"run" file multiple times.

Note that the actual figures depend on the configuration options that
control compiler optimization (e.g. CONFIG_CC_OPTIMIZE_FOR_SIZE vs.
CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE), and on the compiler options used when
building the kernel in general. Hence numbers may differ from those
obtained by running similar benchmarks in userspace.

[1] https://github.com/qris/dhrystone-deb.git

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lkml.kernel.org/r/4d07ad990740a5f1e426ce4566fb514f60ec9bdd.1670509558.git.geert+renesas@glider.be
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
[geert+renesas@glider.be: fix uninitialized use of ret]
Link: https://lkml.kernel.org/r/alpine.DEB.2.22.394.2212190857310.137329@ramsan.of.borg
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arm64: Support Clang UBSAN trap codes for better reporting

When building with CONFIG_UBSAN_TRAP=y on arm64, Clang encodes the UBSAN
check (handler) type in the esr. Extract this and actually report these
traps as coming from the specific UBSAN check that tripped.

Before:

Internal error: BRK handler: 00000000f20003e8 [#1] PREEMPT SMP

After:

Internal error: UBSAN: shift out of bounds: 00000000f2005514 [#1] PREEMPT SMP

Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: John Stultz <jstultz@google.com>
Cc: Yongqin Liu <yongqin.liu@linaro.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: llvm@lists.linux.dev
Signed-off-by: Kees Cook <keescook@chromium.org>

genirq/affinity: Move group_cpus_evenly() into lib/

group_cpus_evenly() has become a generic function which can be used for
other subsystems than the interrupt subsystem, so move it into lib/.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20221227022905.352674-6-ming.lei@redhat.com

lib: fortify_kunit: build without structleak plugin

Building allmodconfig with aarch64-linux-gnu-gcc (Debian 11.3.0-6),
fortify_kunit with strucleak plugin enabled makes the stack frame size
to grow too large:

lib/fortify_kunit.c:140:1: error: the frame size of 2368 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]

Turn off the structleak plugin checks for fortify_kunit.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

kunit/fortify: Validate __alloc_size attribute results

Validate the effect of the __alloc_size attribute on allocators. If the
compiler doesn't support __builtin_dynamic_object_size(), skip the
associated tests.

(For GCC, just remove the "--make_options" line below...)

$ ./tools/testing/kunit/kunit.py run --arch x86_64 \
--kconfig_add CONFIG_FORTIFY_SOURCE=y \
--make_options LLVM=1
fortify
...
[15:16:30] ================== fortify (10 subtests) ===================
[15:16:30] [PASSED] known_sizes_test
[15:16:30] [PASSED] control_flow_split_test
[15:16:30] [PASSED] alloc_size_kmalloc_const_test
[15:16:30] [PASSED] alloc_size_kmalloc_dynamic_test
[15:16:30] [PASSED] alloc_size_vmalloc_const_test
[15:16:30] [PASSED] alloc_size_vmalloc_dynamic_test
[15:16:30] [PASSED] alloc_size_kvmalloc_const_test
[15:16:30] [PASSED] alloc_size_kvmalloc_dynamic_test
[15:16:30] [PASSED] alloc_size_devm_kmalloc_const_test
[15:16:30] [PASSED] alloc_size_devm_kmalloc_dynamic_test
[15:16:30] ===================== [PASSED] fortify =====================
[15:16:30] ============================================================
[15:16:30] Testing complete. Ran 10 tests: passed: 10
[15:16:31] Elapsed time: 8.348s total, 0.002s configuring, 6.923s building, 1.075s running

For earlier GCC prior to version 12, the dynamic tests will be skipped:

[15:18:59] ================== fortify (10 subtests) ===================
[15:18:59] [PASSED] known_sizes_test
[15:18:59] [PASSED] control_flow_split_test
[15:18:59] [PASSED] alloc_size_kmalloc_const_test
[15:18:59] [SKIPPED] alloc_size_kmalloc_dynamic_test
[15:18:59] [PASSED] alloc_size_vmalloc_const_test
[15:18:59] [SKIPPED] alloc_size_vmalloc_dynamic_test
[15:18:59] [PASSED] alloc_size_kvmalloc_const_test
[15:18:59] [SKIPPED] alloc_size_kvmalloc_dynamic_test
[15:18:59] [PASSED] alloc_size_devm_kmalloc_const_test
[15:18:59] [SKIPPED] alloc_size_devm_kmalloc_dynamic_test
[15:18:59] ===================== [PASSED] fortify =====================
[15:18:59] ============================================================
[15:18:59] Testing complete. Ran 10 tests: passed: 6, skipped: 4
[15:18:59] Elapsed time: 11.965s total, 0.002s configuring, 10.540s building, 1.068s running

Cc: David Gow <davidgow@google.com>
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

overflow: Introduce overflows_type() and castable_to_type()

Implement a robust overflows_type() macro to test if a variable or
constant value would overflow another variable or type. This can be
used as a constant expression for static_assert() (which requires a
constant expression[1][2]) when used on constant values. This must be
constructed manually, since __builtin_add_overflow() does not produce
a constant expression[3].

Additionally adds castable_to_type(), similar to __same_type(), but for
checking if a constant value would overflow if cast to a given type.

Add unit tests for overflows_type(), __same_type(), and castable_to_type()
to the existing KUnit "overflow" test:

[16:03:33] ================== overflow (21 subtests) ==================
...
[16:03:33] [PASSED] overflows_type_test
[16:03:33] [PASSED] same_type_test
[16:03:33] [PASSED] castable_to_type_test
[16:03:33] ==================== [PASSED] overflow =====================
[16:03:33] ============================================================
[16:03:33] Testing complete. Ran 21 tests: passed: 21
[16:03:33] Elapsed time: 24.022s total, 0.002s configuring, 22.598s building, 0.767s running

[1] https://en.cppreference.com/w/c/language/_Static_assert
[2] C11 standard (ISO/IEC 9899:2011): 6.7.10 Static assertions
[3] https://gcc.gnu.org/onlinedocs/gcc/Integer-Overflow-Builtins.html
6.56 Built-in Functions to Perform Arithmetic with Overflow Checking
Built-in Function: bool __builtin_add_overflow (type1 a, type2 b,

Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Tom Rix <trix@redhat.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Vitor Massaru Iha <vitor@massaru.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-hardening@vger.kernel.org
Cc: llvm@lists.linux.dev
Co-developed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221024201125.1416422-1-gwan-gyeong.mun@intel.com

siphash: Convert selftest to KUnit

Convert the siphash self-test to KUnit so it will be included in "all
KUnit tests" coverage, and can be run individually still:

$ ./tools/testing/kunit/kunit.py run siphash
...
[02:58:45] Starting KUnit Kernel (1/1)...
[02:58:45] ============================================================
[02:58:45] =================== siphash (1 subtest) ====================
[02:58:45] [PASSED] siphash_test
[02:58:45] ===================== [PASSED] siphash =====================
[02:58:45] ============================================================
[02:58:45] Testing complete. Ran 1 tests: passed: 1
[02:58:45] Elapsed time: 21.421s total, 4.306s configuring, 16.947s building, 0.148s running

Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Steven Rostedt (Google)" <rostedt@goodmis.org>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Sander Vanheule <sander@svanheule.net>
Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com>
Link: https://lore.kernel.org/lkml/CAHmME9r+9MPH6zk3Vn=buEMSbQiWMFryqqzerKarmjYk+tHLJA@mail.gmail.com
Tested-by: David Gow <davidgow@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

string: Convert strscpy() self-test to KUnit

Convert the strscpy() self-test to a KUnit test.

Cc: David Gow <davidgow@google.com>
Cc: Tobin C. Harding <tobin@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/lkml/Y072ZMk/hNkfwqMv@dev-arch.thelio-3990X
Signed-off-by: Kees Cook <keescook@chromium.org>

maple_tree: reorganize testing to restore module testing

Along the development cycle, the testing code support for module/in-kernel
compiles was removed. Restore this functionality by moving any internal
API tests to the userspace side, as well as threading tests. Fix the
lockdep issues and add a way to reduce memory usage so the tests can
complete with KASAN + memleak detection. Make the tests work on 32 bit
hosts where possible and detect 32 bit hosts in the radix test suite.

[akpm@linux-foundation.org: fix module export]
[akpm@linux-foundation.org: fix it some more]
[liam.howlett@oracle.com: fix compile warnings on 32bit build in check_find()]
Link: https://lkml.kernel.org/r/20221107203816.1260327-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20221028180415.3074673-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kmsan: disable instrumentation of unsupported common kernel code

EFI stub cannot be linked with KMSAN runtime, so we disable
instrumentation for it.

Instrumenting kcov, stackdepot or lockdep leads to infinite recursion
caused by instrumentation hooks calling instrumented code again.

Link: https://lkml.kernel.org/r/20220915150417.722975-13-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kasan: move tests to mm/kasan/

Move KASAN tests to mm/kasan/ to keep the test code alongside the
implementation.

Link: https://lkml.kernel.org/r/676398f0aeecd47d2f8e3369ea0e95563f641a36.1662416260.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Maple Tree: add new data structure

Patch series "Introducing the Maple Tree"

The maple tree is an RCU-safe range based B-tree designed to use modern
processor cache efficiently. There are a number of places in the kernel
that a non-overlapping range-based tree would be beneficial, especially
one with a simple interface. If you use an rbtree with other data
structures to improve performance or an interval tree to track
non-overlapping ranges, then this is for you.

The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf
nodes. With the increased branching factor, it is significantly shorter
than the rbtree so it has fewer cache misses. The removal of the linked
list between subsequent entries also reduces the cache misses and the need
to pull in the previous and next VMA during many tree alterations.

The first user that is covered in this patch set is the vm_area_struct,
where three data structures are replaced by the maple tree: the augmented
rbtree, the vma cache, and the linked list of VMAs in the mm_struct. The
long term goal is to reduce or remove the mmap_lock contention.

The plan is to get to the point where we use the maple tree in RCU mode.
Readers will not block for writers. A single write operation will be
allowed at a time. A reader re-walks if stale data is encountered. VMAs
would be RCU enabled and this mode would be entered once multiple tasks
are using the mm_struct.

Davidlor said

: Yes I like the maple tree, and at this stage I don't think we can ask for
: more from this series wrt the MM - albeit there seems to still be some
: folks reporting breakage. Fundamentally I see Liam's work to (re)move
: complexity out of the MM (not to say that the actual maple tree is not
: complex) by consolidating the three complimentary data structures very
: much worth it considering performance does not take a hit. This was very
: much a turn off with the range locking approach, which worst case scenario
: incurred in prohibitive overhead. Also as Liam and Matthew have
: mentioned, RCU opens up a lot of nice performance opportunities, and in
: addition academia[1] has shown outstanding scalability of address spaces
: with the foundation of replacing the locked rbtree with RCU aware trees.

A similar work has been discovered in the academic press

https://pdos.csail.mit.edu/papers/rcuvm:asplos12.pdf

Sheer coincidence. We designed our tree with the intention of solving the
hardest problem first. Upon settling on a b-tree variant and a rough
outline, we researched ranged based b-trees and RCU b-trees and did find
that article. So it was nice to find reassurances that we were on the
right path, but our design choice of using ranges made that paper unusable
for us.

This patch (of 70):

The maple tree is an RCU-safe range based B-tree designed to use modern
processor cache efficiently. There are a number of places in the kernel
that a non-overlapping range-based tree would be beneficial, especially
one with a simple interface. If you use an rbtree with other data
structures to improve performance or an interval tree to track
non-overlapping ranges, then this is for you.

The tree has a branching factor of 10 for non-leaf nodes and 16 for leaf
nodes. With the increased branching factor, it is significantly shorter
than the rbtree so it has fewer cache misses. The removal of the linked
list between subsequent entries also reduces the cache misses and the need
to pull in the previous and next VMA during many tree alterations.

The first user that is covered in this patch set is the vm_area_struct,
where three data structures are replaced by the maple tree: the augmented
rbtree, the vma cache, and the linked list of VMAs in the mm_struct. The
long term goal is to reduce or remove the mmap_lock contention.

The plan is to get to the point where we use the maple tree in RCU mode.
Readers will not block for writers. A single write operation will be
allowed at a time. A reader re-walks if stale data is encountered. VMAs
would be RCU enabled and this mode would be entered once multiple tasks
are using the mm_struct.

There is additional BUG_ON() calls added within the tree, most of which
are in debug code. These will be replaced with a WARN_ON() call in the
future. There is also additional BUG_ON() calls within the code which
will also be reduced in number at a later date. These exist to catch
things such as out-of-range accesses which would crash anyways.

Link: https://lkml.kernel.org/r/20220906194824.2110408-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20220906194824.2110408-2-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

crypto: lib - create utils module and move __crypto_memneq into it

As requested at
https://lore.kernel.org/r/YtEgzHuuMts0YBCz@gondor.apana.org.au, move
__crypto_memneq into lib/crypto/ and put it under a new tristate. The
tristate is CRYPTO_LIB_UTILS, and it builds a module libcryptoutils. As
more crypto library utilities are being added, this creates a single
place for them to go without cluttering up the main lib directory.

The module's main file will be lib/crypto/utils.c. However, leave
memneq.c as its own file because of its nonstandard license.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

dyndbg: add test_dynamic_debug module

Provide a simple module to allow testing DYNAMIC_DEBUG behavior. It
calls do_prints() from module-init, and with a sysfs-node.

dmesg -C
dmesg -w &
modprobe test_dynamic_debug dyndbg=+p
echo 1 > /sys/module/dynamic_debug/parameters/verbose

cat /sys/module/test_dynamic_debug/parameters/do_prints
echo module test_dynamic_debug +mftl > /proc/dynamic_debug/control
echo junk > /sys/module/test_dynamic_debug/parameters/do_prints

Acked-by: Jason Baron <jbaron@akamai.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20220904214134.408619-9-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fortify: Add KUnit test for FORTIFY_SOURCE internals

Add lib/fortify_kunit.c KUnit test for checking the expected behavioral
characteristics of FORTIFY_SOURCE internals.

Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Tom Rix <trix@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Steven Rostedt (Google)" <rostedt@goodmis.org>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Sander Vanheule <sander@svanheule.net>
Cc: linux-hardening@vger.kernel.org
Cc: llvm@lists.linux.dev
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>

testing/selftests: Add tests for the is_signed_type() macro

Although not documented, is_signed_type() must support the 'bool' and
pointer types next to scalar and enumeration types. Add a selftest that
verifies that this macro handles all supported types correctly.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Isabella Basso <isabbasso@riseup.net>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sander Vanheule <sander@svanheule.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Isabella Basso <isabbasso@riseup.net>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220826162116.1050972-2-bvanassche@acm.org

lib/test_cpumask: follow KUnit style guidelines

The cpumask test suite doesn't follow the KUnit style guidelines, as
laid out in Documentation/dev-tools/kunit/style.rst. The file is
renamed to lib/cpumask_kunit.c to clearly distinguish it from other,
non-KUnit, tests.

Link: https://lore.kernel.org/lkml/346cb279-8e75-24b0-7d12-9803f2b41c73@riseup.net/
Suggested-by: Maíra Canal <mairacanal@riseup.net>
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Reviewed-by: Maíra Canal <mairacanal@riseup.net>
Reviewed-by: David Gow <davidgow@google.com>
Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

lib/cpumask: add inline cpumask_next_wrap() for UP

In the uniprocessor case, cpumask_next_wrap() can be simplified, as the
number of valid argument combinations is limited:
- 'start' can only be 0
- 'n' can only be -1 or 0

The only valid CPU that can then be returned, if any, will be the first
one set in the provided 'mask'.

For NR_CPUS == 1, include/linux/cpumask.h now provides an inline
definition of cpumask_next_wrap(), which will conflict with the one
provided by lib/cpumask.c. Make building of lib/cpumask.o again depend
on CONFIG_SMP=y (i.e. NR_CPUS > 1) to avoid the re-definition.

Suggested-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

lib/nodemask: inline next_node_in() and node_random()

The functions are pretty thin wrappers around find_bit engine, and
keeping them in c-file prevents compiler from small_const_nbits()
optimization, which must take place for all systems with MAX_NUMNODES
less than BITS_PER_LONG (default is 16 for me).

Moving them to header file doesn't blow up the kernel size:
add/remove: 1/2 grow/shrink: 9/5 up/down: 968/-88 (880)

CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Michael Ellerman <mpe@ellerman.id.au>
CC: Paul Mackerras <paulus@samba.org>
CC: Rasmus Villemoes <linux@rasmusvillemoes.dk>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
CC: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Yury Norov <yury.norov@gmail.com>

lib/test: introduce cpumask KUnit test suite

Add a basic suite of tests for cpumask, providing some tests for empty and
completely filled cpumasks.

Link: https://lkml.kernel.org/r/c96980ec35c3bd23f17c3374bf42c22971545e85.1656777646.git.sander@svanheule.net
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Yury Norov <yury.norov@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

cpumask: Fix invalid uniprocessor mask assumption

On uniprocessor builds, any CPU mask is assumed to contain exactly one CPU
(cpu0). This assumption ignores the existence of empty masks, resulting
in incorrect behaviour.

cpumask_first_zero(), cpumask_next_zero(), and for_each_cpu_not() don't
provide behaviour matching the assumption that a UP mask is always "1",
and instead provide behaviour matching the empty mask.

Drop the incorrectly optimised code and use the generic implementations in
all cases.

Link: https://lkml.kernel.org/r/86bf3f005abba2d92120ddd0809235cab4f759a6.1656777646.git.sander@svanheule.net
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Suggested-by: Yury Norov <yury.norov@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib: Add register read/write tracing support

Generic MMIO read/write i.e., __raw_{read,write}{b,l,w,q} accessors
are typically used to read/write from/to memory mapped registers
and can cause hangs or some undefined behaviour in following few
cases,

* If the access to the register space is unclocked, for example: if
there is an access to multimedia(MM) block registers without MM
clocks.

* If the register space is protected and not set to be accessible from
non-secure world, for example: only EL3 (EL: Exception level) access
is allowed and any EL2/EL1 access is forbidden.

* If xPU(memory/register protection units) is controlling access to
certain memory/register space for specific clients.

and more...

Such cases usually results in instant reboot/SErrors/NOC or interconnect
hangs and tracing these register accesses can be very helpful to debug
such issues during initial development stages and also in later stages.

So use ftrace trace events to log such MMIO register accesses which
provides rich feature set such as early enablement of trace events,
filtering capability, dumping ftrace logs on console and many more.

Sample output:

rwmmio_write: __qcom_geni_serial_console_write+0x160/0x1e0 width=32 val=0xa0d5d addr=0xfffffbfffdbff700
rwmmio_post_write: __qcom_geni_serial_console_write+0x160/0x1e0 width=32 val=0xa0d5d addr=0xfffffbfffdbff700
rwmmio_read: qcom_geni_serial_poll_bit+0x94/0x138 width=32 addr=0xfffffbfffdbff610
rwmmio_post_read: qcom_geni_serial_poll_bit+0x94/0x138 width=32 val=0x0 addr=0xfffffbfffdbff610

Co-developed-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

lib/base64: RFC4648-compliant base64 encoding

Add RFC4648-compliant base64 encoding and decoding routines, based on
the base64url encoding in fs/crypto/fname.c.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Cc: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

crypto: lib - move lib/sha1.c into lib/crypto/

SHA-1 is a crypto algorithm (or at least was intended to be -- it's not
considered secure anymore), so move it out of the top-level library
directory and into lib/crypto/.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: memneq - move into lib/

This is used by code that doesn't need CONFIG_CRYPTO, so move this into
lib/ with a Kconfig option so that it can be selected by whatever needs
it.

This fixes a linker error Zheng pointed out when
CRYPTO_MANAGER_DISABLE_TESTS!=y and CRYPTO=m:

lib/crypto/curve25519-selftest.o: In function `curve25519_selftest':
curve25519-selftest.c:(.init.text+0x60): undefined reference to `__crypto_memneq'
curve25519-selftest.c:(.init.text+0xec): undefined reference to `__crypto_memneq'
curve25519-selftest.c:(.init.text+0x114): undefined reference to `__crypto_memneq'
curve25519-selftest.c:(.init.text+0x154): undefined reference to `__crypto_memneq'

Reported-by: Zheng Bin <zhengbin13@huawei.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: stable@vger.kernel.org
Fixes: aa127963f1ca ("crypto: lib/curve25519 - re-add selftests")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: memneq - move into lib/

This is used by code that doesn't need CONFIG_CRYPTO, so move this into
lib/ with a Kconfig option so that it can be selected by whatever needs
it.

This fixes a linker error Zheng pointed out when
CRYPTO_MANAGER_DISABLE_TESTS!=y and CRYPTO=m:

lib/crypto/curve25519-selftest.o: In function `curve25519_selftest':
curve25519-selftest.c:(.init.text+0x60): undefined reference to `__crypto_memneq'
curve25519-selftest.c:(.init.text+0xec): undefined reference to `__crypto_memneq'
curve25519-selftest.c:(.init.text+0x114): undefined reference to `__crypto_memneq'
curve25519-selftest.c:(.init.text+0x154): undefined reference to `__crypto_memneq'

Reported-by: Zheng Bin <zhengbin13@huawei.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: stable@vger.kernel.org
Fixes: aa127963f1ca ("crypto: lib/curve25519 - re-add selftests")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

bootconfig: Support embedding a bootconfig file in kernel

This allows kernel developer to embed a default bootconfig file in
the kernel instead of embedding it in the initrd. This will be good
for who are using the kernel without initrd, or who needs a default
bootconfigs.
This needs to set two kconfigs: CONFIG_BOOT_CONFIG_EMBED=y and set
the file path to CONFIG_BOOT_CONFIG_EMBED_FILE.

Note that you still need 'bootconfig' command line option to load the
embedded bootconfig. Also if you boot using an initrd with a different
bootconfig, the kernel will use the bootconfig in the initrd, instead
of the default bootconfig.

Link: https://lkml.kernel.org/r/164921227943.1090670.14035119557571329218.stgit@devnote2

Cc: Padmanabha Srinivasaiah <treasure4paddy@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

bootconfig: Make the bootconfig.o as a normal object file

Since the APIs defined in the bootconfig.o are not individually used,
it is meaningless to build it as library by lib-y. Use obj-y for that.

Link: https://lkml.kernel.org/r/164921225875.1090670.15565363126983098971.stgit@devnote2

Cc: Padmanabha Srinivasaiah <treasure4paddy@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>
Reported-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

lib: add generic polynomial calculation

Some temperature and voltage sensors use a polynomial to convert between
raw data points and actual temperature or voltage. The polynomial is
usually the result of a curve fitting of the diode characteristic.

The BT1 PVT hwmon driver already uses such a polynonmial calculation
which is rather generic. Move it to lib/ so other drivers can reuse it.

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220401214032.3738095-2-michael@walle.cc
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

crypto: add rocksoft 64b crc guard tag framework

Hardware specific features may be able to calculate a crc64, so provide
a framework for drivers to register their implementation. If nothing is
registered, fallback to the generic table lookup implementation. The
implementation is modeled after the crct10dif equivalent.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20220303201312.3255347-7-kbusch@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fortify: Detect struct member overflows in memcpy() at compile-time

memcpy() is dead; long live memcpy()

tl;dr: In order to eliminate a large class of common buffer overflow
flaws that continue to persist in the kernel, have memcpy() (under
CONFIG_FORTIFY_SOURCE) perform bounds checking of the destination struct
member when they have a known size. This would have caught all of the
memcpy()-related buffer write overflow flaws identified in at least the
last three years.

Background and analysis:

While stack-based buffer overflow flaws are largely mitigated by stack
canaries (and similar) features, heap-based buffer overflow flaws continue
to regularly appear in the kernel. Many classes of heap buffer overflows
are mitigated by FORTIFY_SOURCE when using the strcpy() family of
functions, but a significant number remain exposed through the memcpy()
family of functions.

At its core, FORTIFY_SOURCE uses the compiler's __builtin_object_size()
internal[0] to determine the available size at a target address based on
the compile-time known structure layout details. It operates in two
modes: outer bounds (0) and inner bounds (1). In mode 0, the size of the
enclosing structure is used. In mode 1, the size of the specific field
is used. For example:

struct object {
u16 scalar1; /* 2 bytes */
char array[6]; /* 6 bytes */
u64 scalar2; /* 8 bytes */
u32 scalar3; /* 4 bytes */
u32 scalar4; /* 4 bytes */
} instance;

__builtin_object_size(instance.array, 0) == 22, since the remaining size
of the enclosing structure starting from "array" is 22 bytes (6 + 8 +
4 + 4).

__builtin_object_size(instance.array, 1) == 6, since the remaining size
of the specific field "array" is 6 bytes.

The initial implementation of FORTIFY_SOURCE used mode 0 because there
were many cases of both strcpy() and memcpy() functions being used to
write (or read) across multiple fields in a structure. For example,
it would catch this, which is writing 2 bytes beyond the end of
"instance":

memcpy(&instance.array, data, 25);

While this didn't protect against overwriting adjacent fields in a given
structure, it would at least stop overflows from reaching beyond the
end of the structure into neighboring memory, and provided a meaningful
mitigation of a subset of buffer overflow flaws. However, many desirable
targets remain within the enclosing structure (for example function
pointers).

As it happened, there were very few cases of strcpy() family functions
intentionally writing beyond the end of a string buffer. Once all known
cases were removed from the kernel, the strcpy() family was tightened[1]
to use mode 1, providing greater mitigation coverage.

What remains is switching memcpy() to mode 1 as well, but making the
switch is much more difficult because of how frustrating it can be to
find existing "normal" uses of memcpy() that expect to write (or read)
across multiple fields. The root cause of the problem is that the C
language lacks a common pattern to indicate the intent of an author's
use of memcpy(), and is further complicated by the available compile-time
and run-time mitigation behaviors.

The FORTIFY_SOURCE mitigation comes in two halves: the compile-time half,
when both the buffer size _and_ the length of the copy is known, and the
run-time half, when only the buffer size is known. If neither size is
known, there is no bounds checking possible. At compile-time when the
compiler sees that a length will always exceed a known buffer size,
a warning can be deterministically emitted. For the run-time half,
the length is tested against the known size of the buffer, and the
overflowing operation is detected. (The performance overhead for these
tests is virtually zero.)

It is relatively easy to find compile-time false-positives since a warning
is always generated. Fixing the false positives, however, can be very
time-consuming as there are hundreds of instances. While it's possible
some over-read conditions could lead to kernel memory exposures, the bulk
of the risk comes from the run-time flaws where the length of a write
may end up being attacker-controlled and lead to an overflow.

Many of the compile-time false-positives take a form similar to this:

memcpy(&instance.scalar2, data, sizeof(instance.scalar2) +
sizeof(instance.scalar3));

and the run-time ones are similar, but lack a constant expression for the
size of the copy:

memcpy(instance.array, data, length);

The former is meant to cover multiple fields (though its style has been
frowned upon more recently), but has been technically legal. Both lack
any expressivity in the C language about the author's _intent_ in a way
that a compiler can check when the length isn't known at compile time.
A comment doesn't work well because what's needed is something a compiler
can directly reason about. Is a given memcpy() call expected to overflow
into neighbors? Is it not? By using the new struct_group() macro, this
intent can be much more easily encoded.

It is not as easy to find the run-time false-positives since the code path
to exercise a seemingly out-of-bounds condition that is actually expected
may not be trivially reachable. Tightening the restrictions to block an
operation for a false positive will either potentially create a greater
flaw (if a copy is truncated by the mitigation), or destabilize the kernel
(e.g. with a BUG()), making things completely useless for the end user.

As a result, tightening the memcpy() restriction (when there is a
reasonable level of uncertainty of the number of false positives), needs
to first WARN() with no truncation. (Though any sufficiently paranoid
end-user can always opt to set the panic_on_warn=1 sysctl.) Once enough
development time has passed, the mitigation can be further intensified.
(Note that this patch is only the compile-time checking step, which is
a prerequisite to doing run-time checking, which will come in future
patches.)

Given the potential frustrations of weeding out all the false positives
when tightening the run-time checks, it is reasonable to wonder if these
changes would actually add meaningful protection. Looking at just the
last three years, there are 23 identified flaws with a CVE that mention
"buffer overflow", and 11 are memcpy()-related buffer overflows.

(For the remaining 12: 7 are array index overflows that would be
mitigated by systems built with CONFIG_UBSAN_BOUNDS=y: CVE-2019-0145,
CVE-2019-14835, CVE-2019-14896, CVE-2019-14897, CVE-2019-14901,
CVE-2019-17666, CVE-2021-28952. 2 are miscalculated allocation
sizes which could be mitigated with memory tagging: CVE-2019-16746,
CVE-2019-2181. 1 is an iovec buffer bug maybe mitigated by memory tagging:
CVE-2020-10742. 1 is a type confusion bug mitigated by stack canaries:
CVE-2020-10942. 1 is a string handling logic bug with no mitigation I'm
aware of: CVE-2021-28972.)

At my last count on an x86_64 allmodconfig build, there are 35,294
calls to memcpy(). With callers instrumented to report all places
where the buffer size is known but the length remains unknown (i.e. a
run-time bounds check is added), we can count how many new run-time
bounds checks are added when the destination and source arguments of
memcpy() are changed to use "mode 1" bounds checking: 1,276. This means
for the future run-time checking, there is a worst-case upper bounds
of 3.6% false positives to fix. In addition, there were around 150 new
compile-time warnings to evaluate and fix (which have now been fixed).

With this instrumentation it's also possible to compare the places where
the known 11 memcpy() flaw overflows manifested against the resulting
list of potential new run-time bounds checks, as a measure of potential
efficacy of the tightened mitigation. Much to my surprise, horror, and
delight, all 11 flaws would have been detected by the newly added run-time
bounds checks, making this a distinctly clear mitigation improvement: 100%
coverage for known memcpy() flaws, with a possible 2 orders of magnitude
gain in coverage over existing but undiscovered run-time dynamic length
flaws (i.e. 1265 newly covered sites in addition to the 11 known), against
only <4% of all memcpy() callers maybe gaining a false positive run-time
check, with only about 150 new compile-time instances needing evaluation.

Specifically these would have been mitigated:
CVE-2020-24490 https://git.kernel.org/linus/a2ec905d1e160a33b2e210e45ad30445ef26ce0e
CVE-2020-12654 https://git.kernel.org/linus/3a9b153c5591548612c3955c9600a98150c81875
CVE-2020-12653 https://git.kernel.org/linus/b70261a288ea4d2f4ac7cd04be08a9f0f2de4f4d
CVE-2019-14895 https://git.kernel.org/linus/3d94a4a8373bf5f45cf5f939e88b8354dbf2311b
CVE-2019-14816 https://git.kernel.org/linus/7caac62ed598a196d6ddf8d9c121e12e082cac3a
CVE-2019-14815 https://git.kernel.org/linus/7caac62ed598a196d6ddf8d9c121e12e082cac3a
CVE-2019-14814 https://git.kernel.org/linus/7caac62ed598a196d6ddf8d9c121e12e082cac3a
CVE-2019-10126 https://git.kernel.org/linus/69ae4f6aac1578575126319d3f55550e7e440449
CVE-2019-9500 https://git.kernel.org/linus/1b5e2423164b3670e8bc9174e4762d297990deff
no-CVE-yet https://git.kernel.org/linus/130f634da1af649205f4a3dd86cbe5c126b57914
no-CVE-yet https://git.kernel.org/linus/d10a87a3535cce2b890897914f5d0d83df669c63

To accelerate the review of potential run-time false positives, it's
also worth noting that it is possible to partially automate checking
by examining the memcpy() buffer argument to check for the destination
struct member having a neighboring array member. It is reasonable to
expect that the vast majority of run-time false positives would look like
the already evaluated and fixed compile-time false positives, where the
most common pattern is neighboring arrays. (And, FWIW, many of the
compile-time fixes were actual bugs, so it is reasonable to assume we'll
have similar cases of actual bugs getting fixed for run-time checks.)

Implementation:

Tighten the memcpy() destination buffer size checking to use the actual
("mode 1") target buffer size as the bounds check instead of their
enclosing structure's ("mode 0") size. Use a common inline for memcpy()
(and memmove() in a following patch), since all the tests are the
same. All new cross-field memcpy() uses must use the struct_group() macro
or similar to target a specific range of fields, so that FORTIFY_SOURCE
can reason about the size and safety of the copy.

For now, cross-member "mode 1" _read_ detection at compile-time will be
limited to W=1 builds, since it is, unfortunately, very common. As the
priority is solving write overflows, read overflows will be part of a
future phase (and can be fixed in parallel, for anyone wanting to look
at W=1 build output).

For run-time, the "mode 0" size checking and mitigation is left unchanged,
with "mode 1" to be added in stages. In this patch, no new run-time
checks are added. Future patches will first bounds-check writes,
and only perform a WARN() for now. This way any missed run-time false
positives can be flushed out over the coming several development cycles,
but system builders who have tested their workloads to be WARN()-free
can enable the panic_on_warn=1 sysctl to immediately gain a mitigation
against this class of buffer overflows. Once that is under way, run-time
bounds-checking of reads can be similarly enabled.

Related classes of flaws that will remain unmitigated:

- memcpy() with flexible array structures, as the compiler does not
currently have visibility into the size of the trailing flexible
array. These can be fixed in the future by refactoring such cases
to use a new set of flexible array structure helpers to perform the
common serialization/deserialization code patterns doing allocation
and/or copying.

- memcpy() with raw pointers (e.g. void *, char *, etc), or otherwise
having their buffer size unknown at compile time, have no good
mitigation beyond memory tagging (and even that would only protect
against inter-object overflow, not intra-object neighboring field
overflows), or refactoring. Some kind of "fat pointer" solution is
likely needed to gain proper size-of-buffer awareness. (e.g. see
struct membuf)

- type confusion where a higher level type's allocation size does
not match the resulting cast type eventually passed to a deeper
memcpy() call where the compiler cannot see the true type. In
theory, greater static analysis could catch these, and the use
of -Warray-bounds will help find some of these.

[0] https://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
[1] https://git.kernel.org/linus/6a39e62abbafd1d58d1722f40c7d26ef379c6a2f

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

fprobe: Add a selftest for fprobe

Add a KUnit based selftest for fprobe interface.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/164735295554.1084943.18347620679928750960.stgit@devnote2

lib: stackinit: Convert to KUnit

Convert stackinit unit tests to KUnit, for better integration
into the kernel self test framework. Includes a rename of
test_stackinit.c to stackinit_kunit.c, and CONFIG_TEST_STACKINIT to
CONFIG_STACKINIT_KUNIT_TEST.

Adjust expected test results based on which stack initialization method
was chosen:

$ CMD="./tools/testing/kunit/kunit.py run stackinit --raw_output \
--arch=x86_64 --kconfig_add"

$ $CMD | grep stackinit:
# stackinit: pass:36 fail:0 skip:29 total:65

$ $CMD CONFIG_GCC_PLUGIN_STRUCTLEAK_USER=y | grep stackinit:
# stackinit: pass:37 fail:0 skip:28 total:65

$ $CMD CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF=y | grep stackinit:
# stackinit: pass:55 fail:0 skip:10 total:65

$ $CMD CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y | grep stackinit:
# stackinit: pass:62 fail:0 skip:3 total:65

$ $CMD CONFIG_INIT_STACK_ALL_PATTERN=y --make_option LLVM=1 | grep stackinit:
# stackinit: pass:60 fail:0 skip:5 total:65

$ $CMD CONFIG_INIT_STACK_ALL_ZERO=y --make_option LLVM=1 | grep stackinit:
# stackinit: pass:60 fail:0 skip:5 total:65

Temporarily remove the userspace-build mode, which will be restored in a
later patch.

Expand the size of the pre-case switch variable so it doesn't get
accidentally cleared.

Cc: David Gow <davidgow@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
v1: https://lore.kernel.org/lkml/20220224055145.1853657-1-keescook@chromium.org
v2:
- split "userspace KUnit stub" into separate header and patch (Daniel)
- Improve commit log and comments (David)
- Provide mapping of expected XFAIL tests to CONFIGs (David)

lib: overflow: Convert to Kunit

Convert overflow unit tests to KUnit, for better integration into the
kernel self test framework. Includes a rename of test_overflow.c to
overflow_kunit.c, and CONFIG_TEST_OVERFLOW to CONFIG_OVERFLOW_KUNIT_TEST.

$ ./tools/testing/kunit/kunit.py run overflow
...
[14:33:51] Starting KUnit Kernel (1/1)...
[14:33:51] ============================================================
[14:33:51] ================== overflow (11 subtests) ==================
[14:33:51] [PASSED] u8_overflow_test
[14:33:51] [PASSED] s8_overflow_test
[14:33:51] [PASSED] u16_overflow_test
[14:33:51] [PASSED] s16_overflow_test
[14:33:51] [PASSED] u32_overflow_test
[14:33:51] [PASSED] s32_overflow_test
[14:33:51] [PASSED] u64_overflow_test
[14:33:51] [PASSED] s64_overflow_test
[14:33:51] [PASSED] overflow_shift_test
[14:33:51] [PASSED] overflow_allocation_test
[14:33:51] [PASSED] overflow_size_helpers_test
[14:33:51] ==================== [PASSED] overflow =====================
[14:33:51] ============================================================
[14:33:51] Testing complete. Passed: 11, Failed: 0, Crashed: 0, Skipped: 0, Errors: 0
[14:33:51] Elapsed time: 12.525s total, 0.001s configuring, 12.402s building, 0.101s running

Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Co-developed-by: Vitor Massaru Iha <vitor@massaru.org>
Signed-off-by: Vitor Massaru Iha <vitor@massaru.org>
Link: https://lore.kernel.org/lkml/20200720224418.200495-1-vitor@massaru.org/
Co-developed-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Link: https://lore.kernel.org/linux-kselftest/20210503211536.1384578-1-dlatypov@google.com/
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/lkml/CAKwvOdm62iA1dNiC6Q11UJ-MnTqtc4kXkm-ubPaFMK824_k0nw@mail.gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/lkml/CABVgOS=TWVh649_Vjo3wnMu9gZnq66gkV-LtGgsksAWMqc+MSA@mail.gmail.com

test_hash.c: refactor into kunit

Use KUnit framework to make tests more easily integrable with CIs. Even
though these tests are not yet properly written as unit tests this
change should help in debugging.

Also remove kernel messages (i.e. through pr_info) as KUnit handles all
debugging output and let it handle module init and exit details.

Link: https://lkml.kernel.org/r/20211208183711.390454-6-isabbasso@riseup.net
Reviewed-by: David Gow <davidgow@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Tested-by: David Gow <davidgow@google.com>
Co-developed-by: Augusto Durães Camargo <augusto.duraes33@gmail.com>
Signed-off-by: Augusto Durães Camargo <augusto.duraes33@gmail.com>
Co-developed-by: Enzo Ferreira <ferreiraenzoa@gmail.com>
Signed-off-by: Enzo Ferreira <ferreiraenzoa@gmail.com>
Signed-off-by: Isabella Basso <isabbasso@riseup.net>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/Kconfig.debug: properly split hash test kernel entries

Split TEST_HASH so that each entry only has one file.

Note that there's no stringhash test file, but actually
<linux/stringhash.h> tests are performed in lib/test_hash.c.

Link: https://lkml.kernel.org/r/20211208183711.390454-5-isabbasso@riseup.net
Reviewed-by: David Gow <davidgow@google.com>
Tested-by: David Gow <davidgow@google.com>
Signed-off-by: Isabella Basso <isabbasso@riseup.net>
Cc: Augusto Durães Camargo <augusto.duraes33@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Daniel Latypov <dlatypov@google.com>
Cc: Enzo Ferreira <ferreiraenzoa@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: kernel test robot <lkp@intel.com>
Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: add tests for reference tracker

This module uses reference tracker, forcing two issues.

1) Double free of a tracker

2) leak of two trackers, one being allocated from softirq context.

"modprobe test_ref_tracker" would emit the following traces.
(Use scripts/decode_stacktrace.sh if necessary)

[ 171.648681] reference already released.
[ 171.653213] allocated in:
[ 171.656523] alloctest_ref_tracker_alloc2+0x1c/0x20 [test_ref_tracker]
[ 171.656526] init_module+0x86/0x1000 [test_ref_tracker]
[ 171.656528] do_one_initcall+0x9c/0x220
[ 171.656532] do_init_module+0x60/0x240
[ 171.656536] load_module+0x32b5/0x3610
[ 171.656538] __do_sys_init_module+0x148/0x1a0
[ 171.656540] __x64_sys_init_module+0x1d/0x20
[ 171.656542] do_syscall_64+0x4a/0xb0
[ 171.656546] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 171.656549] freed in:
[ 171.659520] alloctest_ref_tracker_free+0x13/0x20 [test_ref_tracker]
[ 171.659522] init_module+0xec/0x1000 [test_ref_tracker]
[ 171.659523] do_one_initcall+0x9c/0x220
[ 171.659525] do_init_module+0x60/0x240
[ 171.659527] load_module+0x32b5/0x3610
[ 171.659529] __do_sys_init_module+0x148/0x1a0
[ 171.659532] __x64_sys_init_module+0x1d/0x20
[ 171.659534] do_syscall_64+0x4a/0xb0
[ 171.659536] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 171.659575] ------------[ cut here ]------------
[ 171.659576] WARNING: CPU: 5 PID: 13016 at lib/ref_tracker.c:112 ref_tracker_free+0x224/0x270
[ 171.659581] Modules linked in: test_ref_tracker(+)
[ 171.659591] CPU: 5 PID: 13016 Comm: modprobe Tainted: G S 5.16.0-smp-DEV #290
[ 171.659595] RIP: 0010:ref_tracker_free+0x224/0x270
[ 171.659599] Code: 5e 41 5f 5d c3 48 c7 c7 04 9c 74 a6 31 c0 e8 62 ee 67 00 83 7b 14 00 75 1a 83 7b 18 00 75 30 4c 89 ff 4c 89 f6 e8 9c 00 69 00 <0f> 0b bb ea ff ff ff eb ae 48 c7 c7 3a 0a 77 a6 31 c0 e8 34 ee 67
[ 171.659601] RSP: 0018:ffff89058ba0bbd0 EFLAGS: 00010286
[ 171.659603] RAX: 0000000000000029 RBX: ffff890586b19780 RCX: 08895bff57c7d100
[ 171.659604] RDX: c0000000ffff7fff RSI: 0000000000000282 RDI: ffffffffc0407000
[ 171.659606] RBP: ffff89058ba0bc88 R08: 0000000000000000 R09: ffffffffa6f342e0
[ 171.659607] R10: 00000000ffff7fff R11: 0000000000000000 R12: 000000008f000000
[ 171.659608] R13: 0000000000000014 R14: 0000000000000282 R15: ffffffffc0407000
[ 171.659609] FS: 00007f97ea29d740(0000) GS:ffff8923ff940000(0000) knlGS:0000000000000000
[ 171.659611] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 171.659613] CR2: 00007f97ea299000 CR3: 0000000186b4a004 CR4: 00000000001706e0
[ 171.659614] Call Trace:
[ 171.659615] <TASK>
[ 171.659631] ? alloctest_ref_tracker_free+0x13/0x20 [test_ref_tracker]
[ 171.659633] ? init_module+0x105/0x1000 [test_ref_tracker]
[ 171.659636] ? do_one_initcall+0x9c/0x220
[ 171.659638] ? do_init_module+0x60/0x240
[ 171.659641] ? load_module+0x32b5/0x3610
[ 171.659644] ? __do_sys_init_module+0x148/0x1a0
[ 171.659646] ? __x64_sys_init_module+0x1d/0x20
[ 171.659649] ? do_syscall_64+0x4a/0xb0
[ 171.659652] ? entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 171.659656] ? 0xffffffffc040a000
[ 171.659658] alloctest_ref_tracker_free+0x13/0x20 [test_ref_tracker]
[ 171.659660] init_module+0x105/0x1000 [test_ref_tracker]
[ 171.659663] do_one_initcall+0x9c/0x220
[ 171.659666] do_init_module+0x60/0x240
[ 171.659669] load_module+0x32b5/0x3610
[ 171.659672] __do_sys_init_module+0x148/0x1a0
[ 171.659676] __x64_sys_init_module+0x1d/0x20
[ 171.659678] do_syscall_64+0x4a/0xb0
[ 171.659694] ? exc_page_fault+0x6e/0x140
[ 171.659696] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 171.659698] RIP: 0033:0x7f97ea3dbe7a
[ 171.659700] Code: 48 8b 0d 61 8d 06 00 f7 d8 64 89 01 48 83 c8 ff c3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 ca b8 af 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 2e 8d 06 00 f7 d8 64 89 01 48
[ 171.659701] RSP: 002b:00007ffea67ce608 EFLAGS: 00000246 ORIG_RAX: 00000000000000af
[ 171.659703] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f97ea3dbe7a
[ 171.659704] RDX: 00000000013a0ba0 RSI: 0000000000002808 RDI: 00007f97ea299000
[ 171.659705] RBP: 00007ffea67ce670 R08: 0000000000000003 R09: 0000000000000000
[ 171.659706] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000013a1048
[ 171.659707] R13: 00000000013a0ba0 R14: 0000000001399930 R15: 00000000013a1030
[ 171.659709] </TASK>
[ 171.659710] ---[ end trace f5dbd6afa41e60a9 ]---
[ 171.659712] leaked reference.
[ 171.663393] alloctest_ref_tracker_alloc0+0x1c/0x20 [test_ref_tracker]
[ 171.663395] test_ref_tracker_timer_func+0x9/0x20 [test_ref_tracker]
[ 171.663397] call_timer_fn+0x31/0x140
[ 171.663401] expire_timers+0x46/0x110
[ 171.663403] __run_timers+0x16f/0x1b0
[ 171.663404] run_timer_softirq+0x1d/0x40
[ 171.663406] __do_softirq+0x148/0x2d3
[ 171.663408] leaked reference.
[ 171.667101] alloctest_ref_tracker_alloc1+0x1c/0x20 [test_ref_tracker]
[ 171.667103] init_module+0x81/0x1000 [test_ref_tracker]
[ 171.667104] do_one_initcall+0x9c/0x220
[ 171.667106] do_init_module+0x60/0x240
[ 171.667108] load_module+0x32b5/0x3610
[ 171.667111] __do_sys_init_module+0x148/0x1a0
[ 171.667113] __x64_sys_init_module+0x1d/0x20
[ 171.667115] do_syscall_64+0x4a/0xb0
[ 171.667117] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 171.667131] ------------[ cut here ]------------
[ 171.667132] WARNING: CPU: 5 PID: 13016 at lib/ref_tracker.c:30 ref_tracker_dir_exit+0x104/0x130
[ 171.667136] Modules linked in: test_ref_tracker(+)
[ 171.667144] CPU: 5 PID: 13016 Comm: modprobe Tainted: G S W 5.16.0-smp-DEV #290
[ 171.667147] RIP: 0010:ref_tracker_dir_exit+0x104/0x130
[ 171.667150] Code: 01 00 00 00 00 ad de 48 89 03 4c 89 63 08 48 89 df e8 20 a0 d5 ff 4c 89 f3 4d 39 ee 75 a8 4c 89 ff 48 8b 75 d0 e8 7c 05 69 00 <0f> 0b eb 0c 4c 89 ff 48 8b 75 d0 e8 6c 05 69 00 41 8b 47 08 83 f8
[ 171.667151] RSP: 0018:ffff89058ba0bc68 EFLAGS: 00010286
[ 171.667154] RAX: 08895bff57c7d100 RBX: ffffffffc0407010 RCX: 000000000000003b
[ 171.667156] RDX: 000000000000003c RSI: 0000000000000282 RDI: ffffffffc0407000
[ 171.667157] RBP: ffff89058ba0bc98 R08: 0000000000000000 R09: ffffffffa6f342e0
[ 171.667159] R10: 00000000ffff7fff R11: 0000000000000000 R12: dead000000000122
[ 171.667160] R13: ffffffffc0407010 R14: ffffffffc0407010 R15: ffffffffc0407000
[ 171.667162] FS: 00007f97ea29d740(0000) GS:ffff8923ff940000(0000) knlGS:0000000000000000
[ 171.667164] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 171.667166] CR2: 00007f97ea299000 CR3: 0000000186b4a004 CR4: 00000000001706e0
[ 171.667169] Call Trace:
[ 171.667170] <TASK>
[ 171.667171] ? 0xffffffffc040a000
[ 171.667173] init_module+0x126/0x1000 [test_ref_tracker]
[ 171.667175] do_one_initcall+0x9c/0x220
[ 171.667179] do_init_module+0x60/0x240
[ 171.667182] load_module+0x32b5/0x3610
[ 171.667186] __do_sys_init_module+0x148/0x1a0
[ 171.667189] __x64_sys_init_module+0x1d/0x20
[ 171.667192] do_syscall_64+0x4a/0xb0
[ 171.667194] ? exc_page_fault+0x6e/0x140
[ 171.667196] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 171.667199] RIP: 0033:0x7f97ea3dbe7a
[ 171.667200] Code: 48 8b 0d 61 8d 06 00 f7 d8 64 89 01 48 83 c8 ff c3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 ca b8 af 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 2e 8d 06 00 f7 d8 64 89 01 48
[ 171.667201] RSP: 002b:00007ffea67ce608 EFLAGS: 00000246 ORIG_RAX: 00000000000000af
[ 171.667203] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f97ea3dbe7a
[ 171.667204] RDX: 00000000013a0ba0 RSI: 0000000000002808 RDI: 00007f97ea299000
[ 171.667205] RBP: 00007ffea67ce670 R08: 0000000000000003 R09: 0000000000000000
[ 171.667206] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000013a1048
[ 171.667207] R13: 00000000013a0ba0 R14: 0000000001399930 R15: 00000000013a1030
[ 171.667209] </TASK>
[ 171.667210] ---[ end trace f5dbd6afa41e60aa ]---

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

lib: add reference counting tracking infrastructure

It can be hard to track where references are taken and released.

In networking, we have annoying issues at device or netns dismantles,
and we had various proposals to ease root causing them.

This patch adds new infrastructure pairing refcount increases
and decreases. This will self document code, because programmers
will have to associate increments/decrements.

This is controled by CONFIG_REF_TRACKER which can be selected
by users of this feature.

This adds both cpu and memory costs, and thus should probably be
used with care.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

test_kprobes: Move it from kernel/ to lib/

Since config KPROBES_SANITY_TEST is in lib/Kconfig.debug, it is better to
let test_kprobes.c in lib/, just like other similar tests found in lib/.

Link: https://lkml.kernel.org/r/1635213091-24387-4-git-send-email-yangtiezhu@loongson.cn

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

lib: Introduce CONFIG_MEMCPY_KUNIT_TEST

Before changing anything about memcpy(), memmove(), and memset(), add
run-time tests to check basic behaviors for any regressions.

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

fortify: Add compile-time FORTIFY_SOURCE tests

While the run-time testing of FORTIFY_SOURCE is already present in
LKDTM, there is no testing of the expected compile-time detections. In
preparation for correctly supporting FORTIFY_SOURCE under Clang, adding
additional FORTIFY_SOURCE defenses, and making sure FORTIFY_SOURCE
doesn't silently regress with GCC, introduce a build-time test suite that
checks each expected compile-time failure condition.

As this is relatively backwards from standard build rules in the
sense that a successful test is actually a compile _failure_, create
a wrapper script to check for the correct errors, and wire it up as
a dummy dependency to lib/string.o, collecting the results into a log
file artifact.

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

bitfield: build kunit tests without structleak plugin

The structleak plugin causes the stack frame size to grow immensely:

lib/bitfield_kunit.c: In function 'test_bitfields_constants':
lib/bitfield_kunit.c:93:1: error: the frame size of 7440 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]

Turn it off in this file.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lib: add iomem emulation (logic_iomem)

Add IO memory emulation that uses callbacks for read/write to
the allocated regions. The callbacks can be registered by the
users using logic_iomem_alloc().

To use, an architecture must 'select LOGIC_IOMEM' in Kconfig
and then include <asm-generic/logic_io.h> into asm/io.h to get
the __raw_read*/__raw_write* functions.

Optionally, an architecture may 'select LOGIC_IOMEM_FALLBACK'
in which case non-emulated regions will 'fall back' to the
various real_* functions that must then be provided.

Cc: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

mm/slub, kunit: add a KUnit test for SLUB debugging functionality

SLUB has resiliency_test() function which is hidden behind #ifdef
SLUB_RESILIENCY_TEST that is not part of Kconfig, so nobody runs it.
KUnit should be a proper replacement for it.

Try changing byte in redzone after allocation and changing pointer to next
free node, first byte, 50th byte and redzone byte. Check if validation
finds errors.

There are several differences from the original resiliency test: Tests
create own caches with known state instead of corrupting shared kmalloc
caches.

The corruption of freepointer uses correct offset, the original resiliency
test got broken with freepointer changes.

Scratch changing random byte test, because it does not have meaning in
this form where we need deterministic results.

Add new option CONFIG_SLUB_KUNIT_TEST in Kconfig. Tests next_pointer,
first_word and clobber_50th_byte do not run with KASAN option on. Because
the test deliberately modifies non-allocated objects.

Use kunit_resource to count errors in cache and silence bug reports.
Count error whenever slab_bug() or slab_fix() is called or when the count
of pages is wrong.

[glittao@gmail.com: remove unused function test_exit(), from SLUB KUnit test]
Link: https://lkml.kernel.org/r/20210512140656.12083-1-glittao@gmail.com
[akpm@linux-foundation.org: export kasan_enable/disable_current to modules]

Link: https://lkml.kernel.org/r/20210511150734.3492-2-glittao@gmail.com
Signed-off-by: Oliver Glitta <glittao@gmail.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Daniel Latypov <dlatypov@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: test_scanf: Add tests for sscanf number conversion

Adds test_sscanf to test various number conversion cases, as
number conversion was previously broken.

This also tests the simple_strtoxxx() functions exported from
vsprintf.c.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210514161206.30821-3-rf@opensource.cirrus.com

lib: kunit: suppress a compilation warning of frame size

lib/bitfield_kunit.c: In function `test_bitfields_constants':
lib/bitfield_kunit.c:93:1: warning: the frame size of 7456 bytes is larger than 2048 bytes [-Wframe-larger-than=]
}
^

As the description of BITFIELD_KUNIT in lib/Kconfig.debug, it "Only useful
for kernel devs running the KUnit test harness, and not intended for
inclusion into a production build". Therefore, it is not worth modifying
variable 'test_bitfields_constants' to clear this warning. Just suppress
it.

Link: https://lkml.kernel.org/r/20210518094533.7652-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Vitor Massaru Iha <vitor@massaru.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: Add ASN.1 encoder

We have a need in the TPM2 trusted keys to return the ASN.1 form of the TPM
key blob so it can be operated on by tools outside of the kernel. The
specific tools are the openssl_tpm2_engine, openconnect and the Intel
tpm2-tss-engine. To do that, we have to be able to read and write the same
binary key format the tools use. The current ASN.1 decoder does fine for
reading, but we need pieces of an ASN.1 encoder to write the key blob in
binary compatible form.

For backwards compatibility, the trusted key reader code will still accept
the two TPM2B quantities that it uses today, but the writer will only
output the ASN.1 form.

The current implementation only encodes the ASN.1 bits we actually need.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

kasan: rename CONFIG_TEST_KASAN_MODULE

Rename CONFIG_TEST_KASAN_MODULE to CONFIG_KASAN_MODULE_TEST.

This naming is more consistent with the existing CONFIG_KASAN_KUNIT_TEST.

Link: https://linux-review.googlesource.com/id/Id347dfa5fe8788b7a1a189863e039f409da0ae5f
Link: https://lkml.kernel.org/r/f08250246683981bcf8a094fbba7c361995624d2.1610733117.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

random32: Re-enable KCSAN instrumentation

Re-enable KCSAN instrumentation, now that KCSAN no longer relies on code
in lib/random32.c.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

bpf: Move stack_map_get_build_id into lib

Moving stack_map_get_build_id into lib with
declaration in linux/buildid.h header:

int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id);

This function returns build id for given struct vm_area_struct.
There is no functional change to stack_map_get_build_id function.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210114134044.1418404-2-jolsa@kernel.org

lib/cmdline_kunit: add a new test suite for cmdline API

Test get_option() for a starter which is provided by cmdline.c.

[akpm@linux-foundation.org: fix warning by constifying cmdline_test_values]
[andriy.shevchenko@linux.intel.com: type of expected returned values should be int]
Link: https://lkml.kernel.org/r/20201116104244.15472-1-andriy.shevchenko@linux.intel.com
[andriy.shevchenko@linux.intel.com: provide meaningful MODULE_LICENSE()]
Link: https://lkml.kernel.org/r/20201116104257.15527-1-andriy.shevchenko@linux.intel.com

Link: https://lkml.kernel.org/r/20201112180732.75589-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Vitor Massaru Iha <vitor@massaru.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Gow <davidgow@google.com>
Cc: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

selftest/fpu: avoid clang warning

With extra warnings enabled, clang complains about the redundant
-mhard-float argument:

clang: error: argument unused during compilation: '-mhard-float' [-Werror,-Wunused-command-line-argument]

Move this into the gcc-only part of the Makefile.

Link: https://lkml.kernel.org/r/20201203223652.1320700-1-arnd@kernel.org
Fixes: 4185b3b92792 ("selftests/fpu: Add an FPU selftest")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Petteri Aimonen <jpa@git.mail.kapsi.fi>
Cc: Borislav Petkov <bp@suse.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: Add a generic version of devmem_is_allowed()

As part of adding support for STRICT_DEVMEM to the RISC-V port, Zong
provided a devmem_is_allowed() implementation that's exactly the same as
all the others I checked. Instead I'm adding a generic version, which
will soon be used.

Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

lib, include/linux: add usercopy failure capability

Patch series "add fault injection to user memory access", v3.

The goal of this series is to improve testing of fault-tolerance in usages
of user memory access functions, by adding support for fault injection.

syzkaller/syzbot are using the existing fault injection modes and will use
this particular feature also.

The first patch adds failure injection capability for usercopy functions.
The second changes usercopy functions to use this new failure capability
(copy_from_user, ...). The third patch adds get/put/clear_user failures
to x86.

This patch (of 3):

Add a failure injection capability to improve testing of fault-tolerance
in usages of user memory access functions.

Add CONFIG_FAULT_INJECTION_USERCOPY to enable faults in usercopy
functions. The should_fail_usercopy function is to be called by these
functions (copy_from_user, get_user, ...) in order to fail or not.

Signed-off-by: Albert van der Linde <alinde@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20200831171733.955393-1-alinde@google.com
Link: http://lkml.kernel.org/r/20200831171733.955393-2-alinde@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c: fix freeing non-compound pages

Here is a very rare race which leaks memory:

Page P0 is allocated to the page cache. Page P1 is free.

Thread A Thread B Thread C
find_get_entry():
xas_load() returns P0
Removes P0 from page cache
P0 finds its buddy P1
alloc_pages(GFP_KERNEL, 1) returns P0
P0 has refcount 1
page_cache_get_speculative(P0)
P0 has refcount 2
__free_pages(P0)
P0 has refcount 1
put_page(P0)
P1 is not freed

Fix this by freeing all the pages in __free_pages() that won't be freed
by the call to put_page(). It's usually not a good idea to split a page,
but this is a very unlikely scenario.

Fixes: e286781d5f2e ("mm: speculative page references")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200926213919.26642-1-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

KASAN: port KASAN Tests to KUnit

Transfer all previous tests for KASAN to KUnit so they can be run more
easily. Using kunit_tool, developers can run these tests with their other
KUnit tests and see "pass" or "fail" with the appropriate KASAN report
instead of needing to parse each KASAN report to test KASAN
functionalities. All KASAN reports are still printed to dmesg.

Stack tests do not work properly when KASAN_STACK is enabled so those
tests use a check for "if IS_ENABLED(CONFIG_KASAN_STACK)" so they only run
if stack instrumentation is enabled. If KASAN_STACK is not enabled, KUnit
will print a statement to let the user know this test was not run with
KASAN_STACK enabled.

copy_user_test and kasan_rcu_uaf cannot be run in KUnit so there is a
separate test file for those tests, which can be run as before as a
module.

[trishalfonso@google.com: v14]
Link: https://lkml.kernel.org/r/20200915035828.570483-4-davidgow@google.com

Signed-off-by: Patricia Alfonso <trishalfonso@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20200910070331.3358048-4-davidgow@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: kunit: add bitfield test conversion to KUnit

This adds the conversion of the runtime tests of test_bitfield,
from `lib/test_bitfield.c` to KUnit tests.

Code Style Documentation: [0]

Signed-off-by: Vitor Massaru Iha <vitor@massaru.org>
Link: [0] https://lore.kernel.org/linux-kselftest/20200620054944.167330-1-davidgow@google.com/T/#u
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lib/string.c: Use freestanding environment

gcc can transform the loop in a naive implementation of memset/memcpy
etc into a call to the function itself. This optimization is enabled by
-ftree-loop-distribute-patterns.

This has been the case for a while, but gcc-10.x enables this option at
-O2 rather than -O3 as in previous versions.

Add -ffreestanding, which implicitly disables this optimization with
gcc. It is unclear whether clang performs such optimizations, but
hopefully it will also not do so in a freestanding environment.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56888
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/test_bits.c: add tests of GENMASK

Add tests of GENMASK and GENMASK_ULL.

A few test cases that should fail compilation are provided under #ifdef
TEST_GENMASK_FAILURES

[rd.dunlap@gmail.com: add MODULE_LICENSE()]
Link: http://lkml.kernel.org/r/dfc74524-0789-2827-4eff-476ddab65699@gmail.com
[weiyongjun1@huawei.com: make some functions static]
Link: http://lkml.kernel.org/r/20200702150336.4756-1-weiyongjun1@huawei.com

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Randy Dunlap <rd.dunlap@gmail.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Cc: Syed Nayyar Waris <syednwaris@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Link: http://lkml.kernel.org/r/20200621054210.14804-2-rikard.falkeborn@gmail.com
Link: http://lkml.kernel.org/r/20200608221823.35799-2-rikard.falkeborn@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kbuild: introduce ccflags-remove-y and asflags-remove-y

CFLAGS_REMOVE_<file>.o filters out flags when compiling a particular
object, but there is no convenient way to do that for every object in
a directory.

Add ccflags-remove-y and asflags-remove-y to make it easily.

Use ccflags-remove-y to clean up some Makefiles.

The add/remove order works as follows:

[1] KBUILD_CFLAGS specifies compiler flags used globally

[2] ccflags-y adds compiler flags for all objects in the
current Makefile

[3] ccflags-remove-y removes compiler flags for all objects in the
current Makefile (New feature)

[4] CFLAGS_<file> adds compiler flags per file.

[5] CFLAGS_REMOVE_<file> removes compiler flags per file.

Having [3] before [4] allows us to remove flags from most (but not all)
objects in the current Makefile.

For example, kernel/trace/Makefile removes $(CC_FLAGS_FTRACE)
from all objects in the directory, then adds it back to
trace_selftest_dynamic.o and CFLAGS_trace_kprobe_selftest.o

The same applies to lib/livepatch/Makefile.

Please note ccflags-remove-y has no effect to the sub-directories.
In contrast, the previous notation got rid of compiler flags also from
all the sub-directories.

The following are not affected because they have no sub-directories:

arch/arm/boot/compressed/
arch/powerpc/xmon/
arch/sh/
kernel/trace/

However, lib/ has several sub-directories.

To keep the behavior, I added ccflags-remove-y to all Makefiles
in subdirectories of lib/, except the following:

lib/vdso/Makefile - Kbuild does not descend into this Makefile
lib/raid/test/Makefile - This is not used for the kernel build

I think commit 2464a609ded0 ("ftrace: do not trace library functions")
excluded too much. In the next commit, I will remove ccflags-remove-y
from the sub-directories of lib/.

Suggested-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Brendan Higgins <brendanhiggins@google.com> (KUnit)
Tested-by: Anders Roxell <anders.roxell@linaro.org>

mm: move lib/ioremap.c to mm/

The functionality in lib/ioremap.c deals with pagetables, vmalloc and
caches, so it naturally belongs to mm/ Moving it there will also allow
declaring p?d_alloc_track functions in an header file inside mm/ rather
than having those declarations in include/linux/mm.h

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Matthew Wilcox <willy@infradead.org>
Link: http://lkml.kernel.org/r/20200627143453.31835-8-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: Add zstd support to decompress

- Add unzstd() and the zstd decompress interface.

- Add zstd support to decompress_method().

The decompress_method() and unzstd() functions are used to decompress
the initramfs and the initrd. The __decompress() function is used in
the preboot environment to decompress a zstd compressed kernel.

The zstd decompression function allows the input and output buffers to
overlap because that is used by x86 kernel decompression.

Signed-off-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200730190841.2071656-3-nickrterrell@gmail.com

Add pldmfw library for PLDM firmware update

The pldmfw library is used to implement common logic needed to flash
devices based on firmware files using the format described by the PLDM
for Firmware Update standard.

This library consists of logic to parse the PLDM file format from
a firmware file object, as well as common logic for sending the relevant
PLDM header data to the device firmware.

A simple ops table is provided so that device drivers can implement
device specific hardware interactions while keeping the common logic to
the pldmfw library.

This library will be used by the Intel ice networking driver as part of
implementing device flash update via devlink. The library aims to be
vendor and device agnostic. For this reason, it has been placed in
lib/pldmfw, in the hopes that other devices which use the PLDM firmware
file format may benefit from it in the future. However, do note that not
all features defined in the PLDM standard have been implemented.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

kbuild: remove cc-option test of -fno-stack-protector

Some Makefiles already pass -fno-stack-protector unconditionally.
For example, arch/arm64/kernel/vdso/Makefile, arch/x86/xen/Makefile.

No problem report so far about hard-coding this option. So, we can
assume all supported compilers know -fno-stack-protector.

GCC 4.8 and Clang support this option (https://godbolt.org/z/_HDGzN)

Get rid of cc-option from -fno-stack-protector.

Remove CONFIG_CC_HAS_STACKPROTECTOR_NONE, which is always 'y'.

Note:
arch/mips/vdso/Makefile adds -fno-stack-protector twice, first
unconditionally, and second conditionally. I removed the second one.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

selftests/fpu: Add an FPU selftest

Add a selftest for the usage of FPU code in kernel mode.

Currently only implemented for x86. In the future, kernel FPU testing
could be unified between the different architectures supporting it.

[ bp:

- Split out from a conglomerate patch, put comments over statements.
- run the test only on debugfs write.
- Add bare-minimum run_test_fpu.sh, run 1000 iterations on all CPUs
by default.
- Add conditionally -msse2 so that clang doesn't generate library
calls.
- Use cc-option to detect gcc 7.1 not supporting -mpreferred-stack-boundary=3 (amluto).
- Document stuff so that we don't forget.
- Fix:
ld: lib/test_fpu.o: in function `test_fpu_get':
>> test_fpu.c:(.text+0x16e): undefined reference to `__sanitizer_cov_trace_cmpd'
>> ld: test_fpu.c:(.text+0x1a7): undefined reference to `__sanitizer_cov_trace_cmpd'
ld: test_fpu.c:(.text+0x1e0): undefined reference to `__sanitizer_cov_trace_cmpd'
]

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Petteri Aimonen <jpa@git.mail.kapsi.fi>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lkml.kernel.org/r/20200624114646.28953-3-bp@alien8.de

dynamic_debug: add an option to enable dynamic debug for modules only

Instead of enabling dynamic debug globally with CONFIG_DYNAMIC_DEBUG,
CONFIG_DYNAMIC_DEBUG_CORE will only enable core function of dynamic
debug. With the DYNAMIC_DEBUG_MODULE defined for any modules, dynamic
debug will be tied to them.

This is useful for people who only want to enable dynamic debug for
kernel modules without worrying about kernel image size and memory
consumption is increasing too much.

[orson.zhai@unisoc.com: v2]
Link: http://lkml.kernel.org/r/1587408228-10861-1-git-send-email-orson.unisoc@gmail.com

Signed-off-by: Orson Zhai <orson.zhai@unisoc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: http://lkml.kernel.org/r/1586521984-5890-1-git-send-email-orson.unisoc@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: make a test module with set/clear bit

Test some bit clears/sets to make sure assembly doesn't change, and that
the set_bit and clear_bit functions work and don't cause sparse warnings.

Instruct Kbuild to build this file with extra warning level -Wextra, to
catch new issues, and also doesn't hurt to build with C=1.

This was used to test changes to arch/x86/include/asm/bitops.h.

In particular, sparse (C=1) was very concerned when the last bit before a
natural boundary, like 7, or 31, was being tested, as this causes sign
extension (0xffffff7f) for instance when clearing bit 7.

Recommended usage:

make defconfig
scripts/config -m CONFIG_TEST_BITOPS
make modules_prepare
make C=1 W=1 lib/test_bitops.ko
objdump -S -d lib/test_bitops.ko
insmod lib/test_bitops.ko
rmmod lib/test_bitops.ko

<check dmesg>, there should be no compiler/sparse warnings and no
error messages in log.

Link: http://lkml.kernel.org/r/20200310221747.2848474-2-jesse.brandeburg@intel.com
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
CcL Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/hmm/test: add selftest driver for HMM

This driver is for testing device private memory migration and devices
which use hmm_range_fault() to access system memory via device page tables.

Link: https://lore.kernel.org/r/20200422195028.3684-2-rcampbell@nvidia.com
Link: https://lore.kernel.org/r/20200516010424.2013-1-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Link: https://lore.kernel.org/r/20200509030225.14592-1-weiyongjun1@huawei.com
Link: https://lore.kernel.org/r/20200509030234.14747-1-weiyongjun1@huawei.com
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20200511183704.GA225608@mwanda
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

lib/test_linear_ranges: add a test for the 'linear_ranges'

Add a KUnit test for the linear_ranges helper.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Link: https://lore.kernel.org/r/311fea741bafdcd33804d3187c1642e24275e3e5.1588944082.git.matti.vaittinen@fi.rohmeurope.com
Signed-off-by: Mark Brown <broonie@kernel.org>

lib: add linear ranges helpers

Many devices have control registers which control some measurable
property. Often a register contains control field so that change in
this field causes linear change in the controlled property. It is not
a rare case that user wants to give 'meaningful' control values and
driver needs to convert them to register field values. Even more
often user wants to 'see' the currently set value - again in
meaningful units - and driver needs to convert the values it reads
from register to these meaningful units. Examples of this include:

- regulators, voltage/current configurations
- power, voltage/current configurations
- clk(?) NCOs

and maybe others I can't think of right now.

Provide a linear_range helper which can do conversion from user value
to register value 'selector'.

The idea here is stolen from regulator framework and patches refactoring
the regulator helpers to use this are following.

Current implementation does not support inversely proportional ranges
but it might be useful if we could support also inversely proportional
ranges?

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/59259bc475e0c800eb4bb163f02528c7c01f7b3a.1588944082.git.matti.vaittinen@fi.rohmeurope.com
Signed-off-by: Mark Brown <broonie@kernel.org>

ubsan: add trap instrumentation option

Patch series "ubsan: Split out bounds checker", v5.

This splits out the bounds checker so it can be individually used. This
is enabled in Android and hopefully for syzbot. Includes LKDTM tests for
behavioral corner-cases (beyond just the bounds checker), and adjusts
ubsan and kasan slightly for correct panic handling.

This patch (of 6):

The Undefined Behavior Sanitizer can operate in two modes: warning
reporting mode via lib/ubsan.c handler calls, or trap mode, which uses
__builtin_trap() as the handler. Using lib/ubsan.c means the kernel image
is about 5% larger (due to all the debugging text and reporting structures
to capture details about the warning conditions). Using the trap mode,
the image size changes are much smaller, though at the loss of the
"warning only" mode.

In order to give greater flexibility to system builders that want minimal
changes to image size and are prepared to deal with kernel code being
aborted and potentially destabilizing the system, this introduces
CONFIG_UBSAN_TRAP. The resulting image sizes comparison:

text data bss dec hex filename
19533663 6183037 18554956 44271656 2a38828 vmlinux.stock
19991849 7618513 18874448 46484810 2c54d4a vmlinux.ubsan
19712181 6284181 18366540 44362902 2a4ec96 vmlinux.ubsan-trap

CONFIG_UBSAN=y: image +4.8% (text +2.3%, data +18.9%)
CONFIG_UBSAN_TRAP=y: image +0.2% (text +0.9%, data +1.6%)

Additionally adjusts the CONFIG_UBSAN Kconfig help for clarity and removes
the mention of non-existing boot param "ubsan_handle".

Suggested-by: Elena Petrova <lenaptr@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Link: http://lkml.kernel.org/r/20200227193516.32566-2-keescook@chromium.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/stackdepot.c: build with -fno-builtin

Clang may replace stackdepot_memcmp() with a call to instrumented bcmp(),
which is exactly what we wanted to avoid creating stackdepot_memcmp().
Building the file with -fno-builtin prevents such optimizations.

This patch has been previously mailed as part of KMSAN RFC patch series.

Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Link: http://lkml.kernel.org/r/20200220141916.55455-2-glider@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: test_stackinit.c: XFAIL switch variable init tests

The tests for initializing a variable defined between a switch statement's
test and its first "case" statement are currently not initialized in
Clang[1] nor the proposed auto-initialization feature in GCC.

We should retain the test (so that we can evaluate compiler fixes), but
mark it as an "expected fail". The rest of the kernel source will be
adjusted to avoid this corner case.

Also disable -Wswitch-unreachable for the test so that the intentionally
broken code won't trigger warnings for GCC (nor future Clang) when
initialization happens this unhandled place.

[1] https://bugs.llvm.org/show_bug.cgi?id=44916

Suggested-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Jann Horn <jannh@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Link: http://lkml.kernel.org/r/202002191358.2897A07C6@keescook
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/test_lockup: test module to generate lockups

CONFIG_TEST_LOCKUP=m adds module "test_lockup" that helps to make sure
that watchdogs and lockup detectors are working properly.

Depending on module parameters test_lockup could emulate soft or hard
lockup, "hung task", hold arbitrary lock, allocate bunch of pages.

Also it could generate series of lockups with cooling-down periods, in
this way it could be used as "ping" for locks or page allocator. Loop
checks signals between iteration thus could be stopped by ^C.

# modinfo test_lockup
...
parm: time_secs:lockup time in seconds, default 0 (uint)
parm: time_nsecs:nanoseconds part of lockup time, default 0 (uint)
parm: cooldown_secs:cooldown time between iterations in seconds, default 0 (uint)
parm: cooldown_nsecs:nanoseconds part of cooldown, default 0 (uint)
parm: iterations:lockup iterations, default 1 (uint)
parm: all_cpus:trigger lockup at all cpus at once (bool)
parm: state:wait in 'R' running (default), 'D' uninterruptible, 'K' killable, 'S' interruptible state (charp)
parm: use_hrtimer:use high-resolution timer for sleeping (bool)
parm: iowait:account sleep time as iowait (bool)
parm: lock_read:lock read-write locks for read (bool)
parm: lock_single:acquire locks only at one cpu (bool)
parm: reacquire_locks:release and reacquire locks/irq/preempt between iterations (bool)
parm: touch_softlockup:touch soft-lockup watchdog between iterations (bool)
parm: touch_hardlockup:touch hard-lockup watchdog between iterations (bool)
parm: call_cond_resched:call cond_resched() between iterations (bool)
parm: measure_lock_wait:measure lock wait time (bool)
parm: lock_wait_threshold:print lock wait time longer than this in nanoseconds, default off (ulong)
parm: disable_irq:disable interrupts: generate hard-lockups (bool)
parm: disable_softirq:disable bottom-half irq handlers (bool)
parm: disable_preempt:disable preemption: generate soft-lockups (bool)
parm: lock_rcu:grab rcu_read_lock: generate rcu stalls (bool)
parm: lock_mmap_sem:lock mm->mmap_sem: block procfs interfaces (bool)
parm: lock_rwsem_ptr:lock rw_semaphore at address (ulong)
parm: lock_mutex_ptr:lock mutex at address (ulong)
parm: lock_spinlock_ptr:lock spinlock at address (ulong)
parm: lock_rwlock_ptr:lock rwlock at address (ulong)
parm: alloc_pages_nr:allocate and free pages under locks (uint)
parm: alloc_pages_order:page order to allocate (uint)
parm: alloc_pages_gfp:allocate pages with this gfp_mask, default GFP_KERNEL (uint)
parm: alloc_pages_atomic:allocate pages with GFP_ATOMIC (bool)
parm: reallocate_pages:free and allocate pages between iterations (bool)

Parameters for locking by address are unsafe and taints kernel. With
CONFIG_DEBUG_SPINLOCK=y they at least check magics for embedded spinlocks.

Examples:

task hang in D-state:
modprobe test_lockup time_secs=1 iterations=60 state=D

task hang in io-wait D-state:
modprobe test_lockup time_secs=1 iterations=60 state=D iowait

softlockup:
modprobe test_lockup time_secs=1 iterations=60 state=R

hardlockup:
modprobe test_lockup time_secs=1 iterations=60 state=R disable_irq

system-wide hardlockup:
modprobe test_lockup time_secs=1 iterations=60 state=R \
disable_irq all_cpus

rcu stall:
modprobe test_lockup time_secs=1 iterations=60 state=R \
lock_rcu touch_softlockup

lock mmap_sem / block procfs interfaces:
modprobe test_lockup time_secs=1 iterations=60 state=S lock_mmap_sem

lock tasklist_lock for read / block forks:
TASKLIST_LOCK=$(awk '$3 == "tasklist_lock" {print "0x"$1}' /proc/kallsyms)
modprobe test_lockup time_secs=1 iterations=60 state=R \
disable_irq lock_read lock_rwlock_ptr=$TASKLIST_LOCK

lock namespace_sem / block vfs mount operations:
NAMESPACE_SEM=$(awk '$3 == "namespace_sem" {print "0x"$1}' /proc/kallsyms)
modprobe test_lockup time_secs=1 iterations=60 state=S \
lock_rwsem_ptr=$NAMESPACE_SEM

lock cgroup mutex / block cgroup operations:
CGROUP_MUTEX=$(awk '$3 == "cgroup_mutex" {print "0x"$1}' /proc/kallsyms)
modprobe test_lockup time_secs=1 iterations=60 state=S \
lock_mutex_ptr=$CGROUP_MUTEX

ping cgroup_mutex every second and measure maximum lock wait time:
modprobe test_lockup cooldown_secs=1 iterations=60 state=S \
lock_mutex_ptr=$CGROUP_MUTEX reacquire_locks measure_lock_wait

[linux@roeck-us.net: rename disable_irq to fix build error]
Link: http://lkml.kernel.org/r/20200317133614.23152-1-linux@roeck-us.net
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Link: http://lkml.kernel.org/r/158132859146.2797.525923171323227836.stgit@buzz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: Introduce generic min-heap

Supports push, pop and converting an array into a heap. If the sense of
the compare function is inverted then it can provide a max-heap.

Based-on-work-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200214075133.181299-3-irogers@google.com

bootconfig: Remove unneeded CONFIG_LIBXBC

Since there is no user except CONFIG_BOOT_CONFIG and no plan
to use it from other functions, CONFIG_LIBXBC can be removed
and we can use CONFIG_BOOT_CONFIG directly.

Link: http://lkml.kernel.org/r/158098769281.939.16293492056419481105.stgit@devnote2

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kbuild: rename hostprogs-y/always to hostprogs/always-y

In old days, the "host-progs" syntax was used for specifying host
programs. It was renamed to the current "hostprogs-y" in 2004.

It is typically useful in scripts/Makefile because it allows Kbuild to
selectively compile host programs based on the kernel configuration.

This commit renames like follows:

always -> always-y
hostprogs-y -> hostprogs

So, scripts/Makefile will look like this:

always-$(CONFIG_BUILD_BIN2C) += ...
always-$(CONFIG_KALLSYMS) += ...
...
hostprogs := $(always-y) $(always-m)

I think this makes more sense because a host program is always a host
program, irrespective of the kernel configuration. We want to specify
which ones to compile by CONFIG options, so always-y will be handier.

The "always", "hostprogs-y", "hostprogs-m" will be kept for backward
compatibility for a while.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

kcov: ignore fault-inject and stacktrace

Don't instrument 3 more files that contain debugging facilities and
produce large amounts of uninteresting coverage for every syscall.

The following snippets are sprinkled all over the place in kcov traces
in a debugging kernel. We already try to disable instrumentation of
stack unwinding code and of most debug facilities. I guess we did not
use fault-inject.c at the time, and stacktrace.c was somehow missed (or
something has changed in kernel/configs). This change both speeds up
kcov (kernel doesn't need to store these PCs, user-space doesn't need to
process them) and frees trace buffer capacity for more useful coverage.

should_fail
lib/fault-inject.c:149
fail_dump
lib/fault-inject.c:45

stack_trace_save
kernel/stacktrace.c:124
stack_trace_consume_entry
kernel/stacktrace.c:86
stack_trace_consume_entry
kernel/stacktrace.c:89
... a hundred frames skipped ...
stack_trace_consume_entry
kernel/stacktrace.c:93
stack_trace_consume_entry
kernel/stacktrace.c:86

Link: http://lkml.kernel.org/r/20200116111449.217744-1-dvyukov@gmail.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/zlib: add s390 hardware support for kernel zlib_deflate

Patch series "S390 hardware support for kernel zlib", v3.

With IBM z15 mainframe the new DFLTCC instruction is available. It
implements deflate algorithm in hardware (Nest Acceleration Unit - NXU)
with estimated compression and decompression performance orders of
magnitude faster than the current zlib.

This patchset adds s390 hardware compression support to kernel zlib.
The code is based on the userspace zlib implementation:

https://github.com/madler/zlib/pull/410

The coding style is also preserved for future maintainability. There is
only limited set of userspace zlib functions represented in kernel.
Apart from that, all the memory allocation should be performed in
advance. Thus, the workarea structures are extended with the parameter
lists required for the DEFLATE CONVENTION CALL instruction.

Since kernel zlib itself does not support gzip headers, only Adler-32
checksum is processed (also can be produced by DFLTCC facility). Like
it was implemented for userspace, kernel zlib will compress in hardware
on level 1, and in software on all other levels. Decompression will
always happen in hardware (when enabled).

Two DFLTCC compression calls produce the same results only when they
both are made on machines of the same generation, and when the
respective buffers have the same offset relative to the start of the
page. Therefore care should be taken when using hardware compression
when reproducible results are desired. However it does always produce
the standard conform output which can be inflated anyway.

The new kernel command line parameter 'dfltcc' is introduced to
configure s390 zlib hardware support:

Format: { on | off | def_only | inf_only | always }
on: s390 zlib hardware support for compression on
level 1 and decompression (default)
off: No s390 zlib hardware support
def_only: s390 zlib hardware support for deflate
only (compression on level 1)
inf_only: s390 zlib hardware support for inflate
only (decompression)
always: Same as 'on' but ignores the selected compression
level always using hardware support (used for debugging)

The main purpose of the integration of the NXU support into the kernel
zlib is the use of hardware deflate in btrfs filesystem with on-the-fly
compression enabled. Apart from that, hardware support can also be used
during boot for decompressing the kernel or the ramdisk image

With the patch for btrfs expanding zlib buffer from 1 to 4 pages (patch
6) the following performance results have been achieved using the
ramdisk with btrfs. These are relative numbers based on throughput rate
and compression ratio for zlib level 1:

Input data Deflate rate Inflate rate Compression ratio
NXU/Software NXU/Software NXU/Software
stream of zeroes 1.46 1.02 1.00
random ASCII data 10.44 3.00 0.96
ASCII text (dickens) 6,21 3.33 0.94
binary data (vmlinux) 8,37 3.90 1.02

This means that s390 hardware deflate can provide up to 10 times faster
compression (on level 1) and up to 4 times faster decompression (refers
to all compression levels) for btrfs zlib.

Disclaimer: Performance results are based on IBM internal tests using DD
command-line utility on btrfs on a Fedora 30 based internal driver in
native LPAR on a z15 system. Results may vary based on individual
workload, configuration and software levels.

This patch (of 9):

Create zlib_dfltcc library with the s390 DEFLATE CONVERSION CALL
implementation and related compression functions. Update zlib_deflate
functions with the hooks for s390 hardware support and adjust workspace
structures with extra parameter lists required for hardware deflate.

Link: http://lkml.kernel.org/r/20200103223334.20669-2-zaslonko@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Co-developed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Chris Mason <clm@fb.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
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>

bootconfig: Add Extra Boot Config support

Extra Boot Config (XBC) allows admin to pass a tree-structured
boot configuration file when boot up the kernel. This extends
the kernel command line in an efficient way.

Boot config will contain some key-value commands, e.g.

key.word = value1
another.key.word = value2

It can fold same keys with braces, also you can write array
data. For example,

key {
word1 {
setting1 = data
setting2
}
word2.array = "val1", "val2"
}

User can access these key-value pair and tree structure via
SKC APIs.

Link: http://lkml.kernel.org/r/157867221257.17873.1775090991929862549.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

libfdt: include fdt_addresses.c

In the implementation of kexec_file_loaded-based kdump for arm64,
fdt_appendprop_addrrange() will be needed.

So include fdt_addresses.c in making libfdt.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Will Deacon <will@kernel.org>

kcsan, ubsan: Make KCSAN+UBSAN work together

Context:
http://lkml.kernel.org/r/fb7e25d8-aba4-3dcf-7761-cb7ecb3ebb71@infradead.org

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

crypto: chacha - move existing library code into lib/crypto

Currently, our generic ChaCha implementation consists of a permute
function in lib/chacha.c that operates on the 64-byte ChaCha state
directly [and which is always included into the core kernel since it
is used by the /dev/random driver], and the crypto API plumbing to
expose it as a skcipher.

In order to support in-kernel users that need the ChaCha streamcipher
but have no need [or tolerance] for going through the abstractions of
the crypto API, let's expose the streamcipher bits via a library API
as well, in a way that permits the implementation to be superseded by
an architecture specific one if provided.

So move the streamcipher code into a separate module in lib/crypto,
and expose the init() and crypt() routines to users of the library.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

kcsan: Add Kernel Concurrency Sanitizer infrastructure

Kernel Concurrency Sanitizer (KCSAN) is a dynamic data-race detector for
kernel space. KCSAN is a sampling watchpoint-based data-race detector.
See the included Documentation/dev-tools/kcsan.rst for more details.

This patch adds basic infrastructure, but does not yet enable KCSAN for
any architecture.

Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

lib: Uplevel the pmem "region" ida to a global allocator

In preparation for handling platform differentiated memory types beyond
persistent memory, uplevel the "region" identifier to a global number
space. This enables a device-dax instance to be registered to any memory
type with guaranteed unique names.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

logic_pio: Build into a library

Object file logic_pio.o is always built.

Ideally the object file should only be built when required. This is
tricky, as that would be for archs which define PCI_IOBASE, but no common
config option exists for that.

For now, continue to always build but at least ensure the symbols are not
included in the vmlinux when not referenced.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>

lib/list-test: add a test for the 'list' doubly linked list

Add a KUnit test for the kernel doubly linked list implementation in
include/linux/list.h

Each test case (list_test_x) is focused on testing the behaviour of the
list function/macro 'x'. None of the tests pass invalid lists to these
macros, and so should behave identically with DEBUG_LIST enabled and
disabled.

Note that, at present, it only tests the list_ types (not the
singly-linked hlist_), and does not yet test all of the
list_for_each_entry* macros (and some related things like
list_prepare_entry).

Ignoring checkpatch.pl spurious errors related to its handling of for_each
and other list macros. checkpatch.pl expects anything with for_each in its
name to be a loop and expects that the open brace is placed on the same
line as for a for loop. In this case, test case naming scheme includes
name of the macro it is testing, which results in the spurious errors.
Commit message updated by Shuah Khan <skhan@linuxfoundation.org>

Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

printf: add support for printing symbolic error names

It has been suggested several times to extend vsnprintf() to be able
to convert the numeric value of ENOSPC to print "ENOSPC". This
implements that as a %p extension: With %pe, one can do

if (IS_ERR(foo)) {
pr_err("Sorry, can't do that: %pe\n", foo);
return PTR_ERR(foo);
}

instead of what is seen in quite a few places in the kernel:

if (IS_ERR(foo)) {
pr_err("Sorry, can't do that: %ld\n", PTR_ERR(foo));
return PTR_ERR(foo);
}

If the value passed to %pe is an ERR_PTR, but the library function
errname() added here doesn't know about the value, the value is simply
printed in decimal. If the value passed to %pe is not an ERR_PTR, we
treat it as an ordinary %p and thus print the hashed value (passing
non-ERR_PTR values to %pe indicates a bug in the caller, but we can't
do much about that).

With my embedded hat on, and because it's not very invasive to do,
I've made it possible to remove this. The errname() function and
associated lookup tables take up about 3K. For most, that's probably
quite acceptable and a price worth paying for more readable
dmesg (once this starts getting used), while for those that disable
printk() it's of very little use - I don't see a
procfs/sysfs/seq_printf() file reasonably making use of this - and
they clearly want to squeeze vmlinux as much as possible. Hence the
default y if PRINTK.

The symbols to include have been found by massaging the output of

find arch include -iname 'errno*.h' | xargs grep -E 'define\s*E'

In the cases where some common aliasing exists
(e.g. EAGAIN=EWOULDBLOCK on all platforms, EDEADLOCK=EDEADLK on most),
I've moved the more popular one (in terms of 'git grep -w Efoo | wc)
to the bottom so that one takes precedence.

Link: http://lkml.kernel.org/r/20191015190706.15989-1-linux@rasmusvillemoes.dk
To: "Jonathan Corbet" <corbet@lwn.net>
To: linux-kernel@vger.kernel.org
Cc: "Andy Shevchenko" <andy.shevchenko@gmail.com>
Cc: "Andrew Morton" <akpm@linux-foundation.org>
Cc: "Joe Perches" <joe@perches.com>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
[andy.shevchenko@gmail.com: use abs()]
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

lib: enable building KUnit in lib/

KUnit is a new unit testing framework for the kernel and when used is
built into the kernel as a part of it. Add KUnit to the lib Kconfig and
Makefile to allow it to be actually built.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lib: Remove redundant ftrace flag removal

Since architectures can implement ftrace using a variety of mechanisms,
generic code should always use CC_FLAGS_FTRACE rather than assuming that
ftrace is built using -pg.

Since commit:

2464a609ded09420 ("ftrace: do not trace library functions")

... lib/Makefile has removed CC_FLAGS_FTRACE from KBUILD_CFLAGS, so ftrace is
disabled for all files under lib/.

Given that, we shouldn't explicitly remove -pg when building
lib/string.o, as this is redundant and bad form.

Clean things up accordingly.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Coly Li <colyli@suse.de>
Cc: Gary R Hook <gary.hook@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthew Wilcox <willy@infradead.org>
Link: https://lkml.kernel.org/r/20190806162539.51918-1-mark.rutland@arm.com

ubsan: build ubsan.c more conservatively

objtool points out several conditions that it does not like, depending
on the combination with other configuration options and compiler
variants:

stack protector:
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0xbf: call to __stack_chk_fail() with UACCESS enabled
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0xbe: call to __stack_chk_fail() with UACCESS enabled

stackleak plugin:
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0x4a: call to stackleak_track_stack() with UACCESS enabled
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0x4a: call to stackleak_track_stack() with UACCESS enabled

kasan:
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0x25: call to memcpy() with UACCESS enabled
lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0x25: call to memcpy() with UACCESS enabled

The stackleak and kasan options just need to be disabled for this file
as we do for other files already. For the stack protector, we already
attempt to disable it, but this fails on clang because the check is
mixed with the gcc specific -fno-conserve-stack option. According to
Andrey Ryabinin, that option is not even needed, dropping it here fixes
the stackprotector issue.

Link: http://lkml.kernel.org/r/20190722125139.1335385-1-arnd@arndb.de
Link: https://lore.kernel.org/lkml/20190617123109.667090-1-arnd@arndb.de/t/
Link: https://lore.kernel.org/lkml/20190722091050.2188664-1-arnd@arndb.de/t/
Fixes: d08965a27e84 ("x86/uaccess, ubsan: Fix UBSAN vs. SMAP")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: introduce test_meminit module

Add tests for heap and pagealloc initialization. These can be used to
check init_on_alloc and init_on_free implementations as well as other
approaches to initialization.

Expected test output in the case the kernel provides heap initialization
(e.g. when running with either init_on_alloc=1 or init_on_free=1):

test_meminit: all 10 tests in test_pages passed
test_meminit: all 40 tests in test_kvmalloc passed
test_meminit: all 60 tests in test_kmemcache passed
test_meminit: all 10 tests in test_rcu_persistent passed
test_meminit: all 120 tests passed!

Link: http://lkml.kernel.org/r/20190529123812.43089-4-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Sandeep Patil <sspatil@android.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

blackhole_dev: add a selftest

Since this is not really a device with all capabilities, this test
ensures that it has *enough* to make it through the data path
without causing unwanted side-effects (read crash!).

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

linux/dim: Move implementation to .c files

Moved all logic from dim.h and net_dim.h to dim.c and net_dim.c.
This is both more structurally appealing and would allow to only
expose externally used functions.

Signed-off-by: Tal Gilboa <talgi@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

crypto: arc4 - refactor arc4 core code into separate library

Refactor the core rc4 handling so we can move most users to a library
interface, permitting us to drop the cipher interface entirely in a
future patch. This is part of an effort to simplify the crypto API
and improve its robustness against incorrect use.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

memory: move jedec_ddr_data.c from lib/ to drivers/memory/

jedec_ddr_data.c exports 3 symbols, and all of them are only
referenced from drivers/memory/{emif.c,of_memory.c}

drivers/memory/ is a better location than lib/.

I removed the Kconfig prompt "JEDEC DDR data" because it is only
select'ed by TI_EMIF, and there is no other user. There is no good
reason in making it a user-configurable CONFIG option.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

lib: Move mathematic helpers to separate folder

For better maintenance and expansion move the mathematic helpers to the
separate folder.

No functional change intended.

Note, the int_sqrt() is not used as a part of lib, so, moved to regular
obj.

Link: http://lkml.kernel.org/r/20190323172531.80025-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Ray Jui <rjui@broadcom.com>
[mchehab+samsung@kernel.org: fix broken doc references for div64.c and gcd.c]
Link: http://lkml.kernel.org/r/734f49bae5d4052b3c25691dfefad59bea2e5843.1555580999.git.mchehab+samsung@kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: Add support for generic packing operations

This provides an unified API for accessing register bit fields
regardless of memory layout. The basic unit of data for these API
functions is the u64. The process of transforming an u64 from native CPU
encoding into the peripheral's encoding is called 'pack', and
transforming it from peripheral to native CPU encoding is 'unpack'.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

x86/mm/mem_encrypt: Disable all instrumentation for early SME setup

Enablement of AMD's Secure Memory Encryption feature is determined very
early after start_kernel() is entered. Part of this procedure involves
scanning the command line for the parameter 'mem_encrypt'.

To determine intended state, the function sme_enable() uses library
functions cmdline_find_option() and strncmp(). Their use occurs early
enough such that it cannot be assumed that any instrumentation subsystem
is initialized.

For example, making calls to a KASAN-instrumented function before KASAN
is set up will result in the use of uninitialized memory and a boot
failure.

When AMD's SME support is enabled, conditionally disable instrumentation
of these dependent functions in lib/string.c and arch/x86/lib/cmdline.c.

[ bp: Get rid of intermediary nostackp var and cleanup whitespace. ]

Fixes: aca20d546214 ("x86/mm: Add support to make use of Secure Memory Encryption")
Reported-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: Coly Li <colyli@suse.de>
Cc: "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: "luto@kernel.org" <luto@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "mingo@redhat.com" <mingo@redhat.com>
Cc: "peterz@infradead.org" <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/155657657552.7116.18363762932464011367.stgit@sosrh3.amd.com

lib: Add test module for strscpy_pad

Add a test module for the new strscpy_pad() function. Tie it into the
kselftest infrastructure for lib/ tests.

Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Shuah Khan <shuah@kernel.org>

x86/uaccess, ubsan: Fix UBSAN vs. SMAP

UBSAN can insert extra code in random locations; including AC=1
sections. Typically this code is not safe and needs wrapping.

So far, only __ubsan_handle_type_mismatch* have been observed in AC=1
sections and therefore only those are annotated.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

libfdt: prefix header search paths with $(srctree)/

Currently, the Kbuild core manipulates header search paths in a crazy
way [1].

To fix this mess, I want all Makefiles to add explicit $(srctree)/ to
the search paths in the srctree. Some Makefiles are already written in
that way, but not all. The goal of this work is to make the notation
consistent, and finally get rid of the gross hacks.

Having whitespaces after -I does not matter since commit 48f6e3cf5bc6
("kbuild: do not drop -I without parameter").

[1]: https://patchwork.kernel.org/patch/9632347/

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Drop flex_arrays

All existing users have been converted to generic radix trees

Link: http://lkml.kernel.org/r/20181217131929.11727-8-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

generic radix trees

Very simple radix tree implementation that supports storing arbitrary
size entries, up to PAGE_SIZE - upcoming patches will convert existing
flex_array users to genradixes. The new genradix code has a much
simpler API and implementation, and doesn't have a hard limit on the
number of elements like flex_array does.

Link: http://lkml.kernel.org/r/20181217131929.11727-5-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vmalloc: add test driver to analyse vmalloc allocator

This adds a new kernel module for analysis of vmalloc allocator. It is
only enabled as a module. There are two main reasons this module should
be used for: performance evaluation and stressing of vmalloc subsystem.

It consists of several test cases. As of now there are 8. The module
has five parameters we can specify to change its the behaviour.

1) run_test_mask - set of tests to be run

id: 1, name: fix_size_alloc_test
id: 2, name: full_fit_alloc_test
id: 4, name: long_busy_list_alloc_test
id: 8, name: random_size_alloc_test
id: 16, name: fix_align_alloc_test
id: 32, name: random_size_align_alloc_test
id: 64, name: align_shift_alloc_test
id: 128, name: pcpu_alloc_test

By default all tests are in run test mask. If you want to select some
specific tests it is possible to pass the mask. For example for first,
second and fourth tests we go 11 value.

2) test_repeat_count - how many times each test should be repeated
By default it is one time per test. It is possible to pass any number.
As high the value is the test duration gets increased.

3) test_loop_count - internal test loop counter. By default it is set
to 1000000.

4) single_cpu_test - use one CPU to run the tests
By default this parameter is set to false. It means that all online
CPUs execute tests. By setting it to 1, the tests are executed by
first online CPU only.

5) sequential_test_order - run tests in sequential order
By default this parameter is set to false. It means that before running
tests the order is shuffled. It is possible to make it sequential, just
set it to 1.

Performance analysis:
In order to evaluate performance of vmalloc allocations, usually it
makes sense to use only one CPU that runs tests, use sequential order,
number of repeat tests can be different as well as set of test mask.

For example if we want to run all tests, to use one CPU and repeat each
test 3 times. Insert the module passing following parameters:

single_cpu_test=1 sequential_test_order=1 test_repeat_count=3

with following output:

<snip>
Summary: fix_size_alloc_test passed: 3 failed: 0 repeat: 3 loops: 1000000 avg: 901177 usec
Summary: full_fit_alloc_test passed: 3 failed: 0 repeat: 3 loops: 1000000 avg: 1039341 usec
Summary: long_busy_list_alloc_test passed: 3 failed: 0 repeat: 3 loops: 1000000 avg: 11775763 usec
Summary: random_size_alloc_test passed 3: failed: 0 repeat: 3 loops: 1000000 avg: 6081992 usec
Summary: fix_align_alloc_test passed: 3 failed: 0 repeat: 3, loops: 1000000 avg: 2003712 usec
Summary: random_size_align_alloc_test passed: 3 failed: 0 repeat: 3 loops: 1000000 avg: 2895689 usec
Summary: align_shift_alloc_test passed: 0 failed: 3 repeat: 3 loops: 1000000 avg: 573 usec
Summary: pcpu_alloc_test passed: 3 failed: 0 repeat: 3 loops: 1000000 avg: 95802 usec
All test took CPU0=192945605995 cycles
<snip>

The align_shift_alloc_test is expected to be failed.

Stressing:
In order to stress the vmalloc subsystem we run all available test cases
on all available CPUs simultaneously. In order to prevent constant behaviour
pattern, the test cases array is shuffled by default to randomize the order
of test execution.

For example if we want to run all tests(default), use all online CPUs(default)
with shuffled order(default) and to repeat each test 30 times. The command
would be like:

modprobe vmalloc_test test_repeat_count=30

Expected results are the system is alive, there are no any BUG_ONs or Kernel
Panics the tests are completed, no memory leaks.

[urezki@gmail.com: fix 32-bit builds]
Link: http://lkml.kernel.org/r/20190106214839.ffvjvmrn52uqog7k@pc636
[urezki@gmail.com: make CONFIG_TEST_VMALLOC depend on CONFIG_MMU]
Link: http://lkml.kernel.org/r/20190219085441.s6bg2gpy4esny5vw@pc636
Link: http://lkml.kernel.org/r/20190103142108.20744-3-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: Introduce test_stackinit module

Adds test for stack initialization coverage. We have several build options
that control the level of stack variable initialization. This test lets us
visualize which options cover which cases, and provide tests for some of
the pathological padding conditions the compiler will sometimes fail to
initialize.

All options pass the explicit initialization cases and the partial
initializers (even with padding):

test_stackinit: u8_zero ok
test_stackinit: u16_zero ok
test_stackinit: u32_zero ok
test_stackinit: u64_zero ok
test_stackinit: char_array_zero ok
test_stackinit: small_hole_zero ok
test_stackinit: big_hole_zero ok
test_stackinit: trailing_hole_zero ok
test_stackinit: packed_zero ok
test_stackinit: small_hole_dynamic_partial ok
test_stackinit: big_hole_dynamic_partial ok
test_stackinit: trailing_hole_dynamic_partial ok
test_stackinit: packed_dynamic_partial ok
test_stackinit: small_hole_static_partial ok
test_stackinit: big_hole_static_partial ok
test_stackinit: trailing_hole_static_partial ok
test_stackinit: packed_static_partial ok
test_stackinit: packed_static_all ok
test_stackinit: packed_dynamic_all ok
test_stackinit: packed_runtime_all ok

The results of the other tests (which contain no explicit initialization),
change based on the build's configured compiler instrumentation.

No options:

test_stackinit: small_hole_static_all FAIL (uninit bytes: 3)
test_stackinit: big_hole_static_all FAIL (uninit bytes: 61)
test_stackinit: trailing_hole_static_all FAIL (uninit bytes: 7)
test_stackinit: small_hole_dynamic_all FAIL (uninit bytes: 3)
test_stackinit: big_hole_dynamic_all FAIL (uninit bytes: 61)
test_stackinit: trailing_hole_dynamic_all FAIL (uninit bytes: 7)
test_stackinit: small_hole_runtime_partial FAIL (uninit bytes: 23)
test_stackinit: big_hole_runtime_partial FAIL (uninit bytes: 127)
test_stackinit: trailing_hole_runtime_partial FAIL (uninit bytes: 24)
test_stackinit: packed_runtime_partial FAIL (uninit bytes: 24)
test_stackinit: small_hole_runtime_all FAIL (uninit bytes: 3)
test_stackinit: big_hole_runtime_all FAIL (uninit bytes: 61)
test_stackinit: trailing_hole_runtime_all FAIL (uninit bytes: 7)
test_stackinit: u8_none FAIL (uninit bytes: 1)
test_stackinit: u16_none FAIL (uninit bytes: 2)
test_stackinit: u32_none FAIL (uninit bytes: 4)
test_stackinit: u64_none FAIL (uninit bytes: 8)
test_stackinit: char_array_none FAIL (uninit bytes: 16)
test_stackinit: switch_1_none FAIL (uninit bytes: 8)
test_stackinit: switch_2_none FAIL (uninit bytes: 8)
test_stackinit: small_hole_none FAIL (uninit bytes: 24)
test_stackinit: big_hole_none FAIL (uninit bytes: 128)
test_stackinit: trailing_hole_none FAIL (uninit bytes: 32)
test_stackinit: packed_none FAIL (uninit bytes: 32)
test_stackinit: user FAIL (uninit bytes: 32)
test_stackinit: failures: 25

CONFIG_GCC_PLUGIN_STRUCTLEAK_USER=y
This only tries to initialize structs with __user markings, so
only the difference from above is now the "user" test passes:

test_stackinit: small_hole_static_all FAIL (uninit bytes: 3)
test_stackinit: big_hole_static_all FAIL (uninit bytes: 61)
test_stackinit: trailing_hole_static_all FAIL (uninit bytes: 7)
test_stackinit: small_hole_dynamic_all FAIL (uninit bytes: 3)
test_stackinit: big_hole_dynamic_all FAIL (uninit bytes: 61)
test_stackinit: trailing_hole_dynamic_all FAIL (uninit bytes: 7)
test_stackinit: small_hole_runtime_partial FAIL (uninit bytes: 23)
test_stackinit: big_hole_runtime_partial FAIL (uninit bytes: 127)
test_stackinit: trailing_hole_runtime_partial FAIL (uninit bytes: 24)
test_stackinit: packed_runtime_partial FAIL (uninit bytes: 24)
test_stackinit: small_hole_runtime_all FAIL (uninit bytes: 3)
test_stackinit: big_hole_runtime_all FAIL (uninit bytes: 61)
test_stackinit: trailing_hole_runtime_all FAIL (uninit bytes: 7)
test_stackinit: u8_none FAIL (uninit bytes: 1)
test_stackinit: u16_none FAIL (uninit bytes: 2)
test_stackinit: u32_none FAIL (uninit bytes: 4)
test_stackinit: u64_none FAIL (uninit bytes: 8)
test_stackinit: char_array_none FAIL (uninit bytes: 16)
test_stackinit: switch_1_none FAIL (uninit bytes: 8)
test_stackinit: switch_2_none FAIL (uninit bytes: 8)
test_stackinit: small_hole_none FAIL (uninit bytes: 24)
test_stackinit: big_hole_none FAIL (uninit bytes: 128)
test_stackinit: trailing_hole_none FAIL (uninit bytes: 32)
test_stackinit: packed_none FAIL (uninit bytes: 32)
test_stackinit: user ok
test_stackinit: failures: 24

CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF=y
This initializes all structures passed by reference (scalars and strings
remain uninitialized):

test_stackinit: small_hole_static_all ok
test_stackinit: big_hole_static_all ok
test_stackinit: trailing_hole_static_all ok
test_stackinit: small_hole_dynamic_all ok
test_stackinit: big_hole_dynamic_all ok
test_stackinit: trailing_hole_dynamic_all ok
test_stackinit: small_hole_runtime_partial ok
test_stackinit: big_hole_runtime_partial ok
test_stackinit: trailing_hole_runtime_partial ok
test_stackinit: packed_runtime_partial ok
test_stackinit: small_hole_runtime_all ok
test_stackinit: big_hole_runtime_all ok
test_stackinit: trailing_hole_runtime_all ok
test_stackinit: u8_none FAIL (uninit bytes: 1)
test_stackinit: u16_none FAIL (uninit bytes: 2)
test_stackinit: u32_none FAIL (uninit bytes: 4)
test_stackinit: u64_none FAIL (uninit bytes: 8)
test_stackinit: char_array_none FAIL (uninit bytes: 16)
test_stackinit: switch_1_none FAIL (uninit bytes: 8)
test_stackinit: switch_2_none FAIL (uninit bytes: 8)
test_stackinit: small_hole_none ok
test_stackinit: big_hole_none ok
test_stackinit: trailing_hole_none ok
test_stackinit: packed_none ok
test_stackinit: user ok
test_stackinit: failures: 7

CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL=y
This initializes all variables, so it matches above with the scalars
and arrays included:

test_stackinit: small_hole_static_all ok
test_stackinit: big_hole_static_all ok
test_stackinit: trailing_hole_static_all ok
test_stackinit: small_hole_dynamic_all ok
test_stackinit: big_hole_dynamic_all ok
test_stackinit: trailing_hole_dynamic_all ok
test_stackinit: small_hole_runtime_partial ok
test_stackinit: big_hole_runtime_partial ok
test_stackinit: trailing_hole_runtime_partial ok
test_stackinit: packed_runtime_partial ok
test_stackinit: small_hole_runtime_all ok
test_stackinit: big_hole_runtime_all ok
test_stackinit: trailing_hole_runtime_all ok
test_stackinit: u8_none ok
test_stackinit: u16_none ok
test_stackinit: u32_none ok
test_stackinit: u64_none ok
test_stackinit: char_array_none ok
test_stackinit: switch_1_none ok
test_stackinit: switch_2_none ok
test_stackinit: small_hole_none ok
test_stackinit: big_hole_none ok
test_stackinit: trailing_hole_none ok
test_stackinit: packed_none ok
test_stackinit: user ok
test_stackinit: all tests passed!

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

selftests/livepatch: introduce tests

Add a few livepatch modules and simple target modules that the included
regression suite can run tests against:

- basic livepatching (multiple patches, atomic replace)
- pre/post (un)patch callbacks
- shadow variable API

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Tested-by: Miroslav Benes <mbenes@suse.cz>
Tested-by: Alice Ferrazzi <alice.ferrazzi@gmail.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

crypto: chacha20-generic - refactor to allow varying number of rounds

In preparation for adding XChaCha12 support, rename/refactor
chacha20-generic to support different numbers of rounds. The
justification for needing XChaCha12 support is explained in more detail
in the patch "crypto: chacha - add XChaCha12 support".

The only difference between ChaCha{8,12,20} are the number of rounds
itself; all other parts of the algorithm are the same. Therefore,
remove the "20" from all definitions, structures, functions, files, etc.
that will be shared by all ChaCha versions.

Also make ->setkey() store the round count in the chacha_ctx (previously
chacha20_ctx). The generic code then passes the round count through to
chacha_block(). There will be a ->setkey() function for each explicitly
allowed round count; the encrypt/decrypt functions will be the same. I
decided not to do it the opposite way (same ->setkey() function for all
round counts, with different encrypt/decrypt functions) because that
would have required more boilerplate code in architecture-specific
implementations of ChaCha and XChaCha.

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

lib: introduce initial implementation of object aggregation manager

This lib tracks objects which could be of two types:
1) root object
2) nested object - with a "delta" which differentiates it from
the associated root object
The objects are tracked by a hashtable and reference-counted. User is
responsible of implementing callbacks to create/destroy root entity
related to each root object and callback to create/destroy nested object
delta.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Revert "lib: Add umoddi3 and udivmoddi4 of GCC library routines"

We don't want 64-bit divide in the kernel.

This reverts commit 6315730e9eab7de5fa9864bb13a352713f48aef1.

Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

lib: Add umoddi3 and udivmoddi4 of GCC library routines

Add umoddi3 and udivmoddi4 support for 32-bit.

The RV32 need the umoddi3 to do modulo when the operands are long long
type, like other libraries implementation such as ucmpdi2, lshrdi3 and
so on.

I encounter the undefined reference 'umoddi3' when I use the in
house dma driver, although it is in house driver, but I think that
umoddi3 is a common function for RV32.

The udivmoddi4 and umoddi3 are copies from libgcc in gcc. There are other
functions use the udivmoddi4 in libgcc, so I separate the umoddi3 and
udivmoddi4 for flexible extension in the future.

Signed-off-by: Zong Li <zong@andestech.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

xarray: Add XArray load operation

The xa_load function brings with it a lot of infrastructure; xa_empty(),
xa_is_err(), and large chunks of the XArray advanced API that are used
to implement xa_load.

As the test-suite demonstrates, it is possible to use the XArray functions
on a radix tree. The radix tree functions depend on the GFP flags being
stored in the root of the tree, so it's not possible to use the radix
tree functions on an XArray.

Signed-off-by: Matthew Wilcox <willy@infradead.org>

xarray: Add definition of struct xarray

This is a direct replacement for struct radix_tree_root. Some of the
struct members have changed name; convert those, and use a #define so
that radix_tree users continue to work without change.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>

lib: Fix ia64 bootloader linkage

kbuild robot reports that since commit ce76d938dd98 ("lib: Add memcat_p():
paste 2 pointer arrays together") the ia64/hp/sim/boot fails to link:

> LD arch/ia64/hp/sim/boot/bootloader
> lib/string.o: In function `__memcat_p':
> string.c:(.text+0x1f22): undefined reference to `__kmalloc'
> string.c:(.text+0x1ff2): undefined reference to `__kmalloc'
> make[1]: *** [arch/ia64/hp/sim/boot/Makefile:37: arch/ia64/hp/sim/boot/bootloader] Error 1

The reason is, the above commit, via __memcat_p(), adds a call to
__kmalloc to string.o, which happens to be used in the bootloader, but
there's no kmalloc or slab or anything.

Since the linker would only pull in objects that contain referenced
symbols, moving __memcat_p() to a different compilation unit solves the
problem.

Fixes: ce76d938dd98 ("lib: Add memcat_p(): paste 2 pointer arrays together")
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reported-by: kbuild test robot <lkp@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

lib/bch: fix possible stack overrun

The previous patch introduced very large kernel stack usage and a Makefile
change to hide the warning about it.

From what I can tell, a number of things went wrong here:

- The BCH_MAX_T constant was set to the maximum value for 'n',
not the maximum for 't', which is much smaller.

- The stack usage is actually larger than the entire kernel stack
on some architectures that can use 4KB stacks (m68k, sh, c6x), which
leads to an immediate overrun.

- The justification in the patch description claimed that nothing
changed, however that is not the case even without the two points above:
the configuration is machine specific, and most boards never use the
maximum BCH_ECC_WORDS() length but instead have something much smaller.
That maximum would only apply to machines that use both the maximum
block size and the maximum ECC strength.

The largest value for 't' that I could find is '32', which in turn leads
to a 60 byte array instead of 2048 bytes. Making it '64' for future
extension seems also worthwhile, with 120 bytes for the array. Anything
larger won't fit into the OOB area on NAND flash.

With that changed, the warning can be enabled again.

Only linux-4.19+ contains the breakage, so this is only needed
as a stable backport if it does not make it into the release.

Fixes: 02361bc77888 ("lib/bch: Remove VLA usage")
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

Makefile: Globally enable VLA warning

Now that Variable Length Arrays (VLAs) have been entirely removed[1]
from the kernel, enable the VLA warning globally. The only exceptions
to this are the KASan an UBSan tests which are explicitly checking that
VLAs trigger their respective tests.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Airlie <airlied@linux.ie>
Cc: linux-kbuild@vger.kernel.org
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Kees Cook <keescook@chromium.org>

lib: Add memcat_p(): paste 2 pointer arrays together

This adds a helper to paste 2 pointer arrays together, useful for merging
various types of attribute arrays. There are a few places in the kernel
tree where this is open coded, and I just added one more in the STM class.

The naming is inspired by memset_p() and memcat(), and partial credit for
it goes to Andy Shevchenko.

This patch adds the function wrapped in a type-enforcing macro and a test
module.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

lib: add crc64 calculation routines

Patch series "add crc64 calculation as kernel library", v5.

This patchset adds basic implementation of crc64 calculation as a Linux
kernel library. Since bcache already does crc64 by itself, this patchset
also modifies bcache code to use the new crc64 library routine.

Currently bcache is the only user of crc64 calculation, another potential
user is bcachefs which is on the way to be in mainline kernel. Therefore
it makes sense to make crc64 calculation to be a public library.

bcache uses crc64 as storage checksum, if a change of crc lib routines
results an inconsistent result, the unmatched checksum may make bcache
'think' the on-disk is corrupted, such a change should be avoided or
detected as early as possible. Therefore a patch is being prepared which
adds a crc test framework, to check consistency of different calculations.

This patch (of 2):

Add the re-write crc64 calculation routines for Linux kernel. The CRC64
polynomical arithmetic follows ECMA-182 specification, inspired by CRC
paper of Dr. Ross N. Williams (see
http://www.ross.net/crc/download/crc_v3.txt) and other public domain
implementations.

All the changes work in this way,
- When Linux kernel is built, host program lib/gen_crc64table.c will be
compiled to lib/gen_crc64table and executed.
- The output of gen_crc64table execution is an array called as lookup
table (a.k.a POLY 0x42f0e1eba9ea369) which contain 256 64-bit long
numbers, this table is dumped into header file lib/crc64table.h.
- Then the header file is included by lib/crc64.c for normal 64bit crc
calculation.
- Function declaration of the crc64 calculation routines is placed in
include/linux/crc64.h

Currently bcache is the only user of crc64_be(), another potential user is
bcachefs which is on the way to be in mainline kernel. Therefore it makes
sense to move crc64 calculation into lib/crc64.c as public code.

[colyli@suse.de: fix review comments from v4]
Link: http://lkml.kernel.org/r/20180726053352.2781-2-colyli@suse.de
Link: http://lkml.kernel.org/r/20180718165545.1622-2-colyli@suse.de
Signed-off-by: Coly Li <colyli@suse.de>
Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Michael Lyle <mlyle@lyle.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Noah Massey <noah.massey@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ida: Start new test_ida module

Start transitioning the IDA tests into kernel space. Framework heavily
cribbed from test_xarray.c.

Signed-off-by: Matthew Wilcox <willy@infradead.org>

bitfield: add tests

Add tests for the bitfield helpers. The constant ones will all
be folded to nothing by the compiler (if everything is correct
in the header file), and the variable ones do some tests against
open-coding the necessary shifts.

A few test cases that should fail/warn compilation are provided
under ifdef.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

lib/bch: Remove VLA usage

In the quest to remove all stack VLA usage from the kernel[1], this
allocates a fixed size stack array to cover the range needed for
bch. This was done instead of a preallocation on the SLAB due to
performance reasons, shown by Ivan Djelic:

little-endian, type sizes: int=4 long=8 longlong=8
cpu: Intel(R) Core(TM) i5 CPU         650  @ 3.20GHz
calibration: iter=4.9143µs niter=2034 nsamples=200 m=13 t=4

  Buffer allocation |  Encoding throughput (Mbit/s)
---------------------------------------------------
 on-stack, VLA      |   3988
 on-stack, fixed    |   4494
 kmalloc            |   1967

So this change actually improves performance too, it seems.

The resulting stack allocation can get rather large; without
CONFIG_BCH_CONST_PARAMS, it will allocate 4096 bytes, which
trips the stack size checking:

lib/bch.c: In function ‘encode_bch’:
lib/bch.c:261:1: warning: the frame size of 4432 bytes is larger than 2048 bytes [-Wframe-larger-than=]

Even the default case for "allmodconfig" (with CONFIG_BCH_CONST_M=14 and
CONFIG_BCH_CONST_T=4) would have started throwing a warning:

lib/bch.c: In function ‘encode_bch’:
lib/bch.c:261:1: warning: the frame size of 2288 bytes is larger than 2048 bytes [-Wframe-larger-than=]

But this is how large it's always been; it was just hidden from
the checker because it was a VLA. So the Makefile has been adjusted to
silence this warning for anything smaller than 4500 bytes, which should
provide room for normal cases, but still low enough to catch any future
pathological situations.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ivan Djelic <ivan.djelic@parrot.com>
Tested-by: Ivan Djelic <ivan.djelic@parrot.com>
Acked-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

scsi: Remove percpu_ida

With its one user gone, remove the library code.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

dma-mapping: move all DMA mapping code to kernel/dma

Currently the code is split over various files with dma- prefixes in the
lib/ and drives/base directories, and the number of files keeps growing.
Move them into a single directory to keep the code together and remove
the file name prefixes. To match the irq infrastructure this directory
is placed under the kernel/ directory.

Signed-off-by: Christoph Hellwig <hch@lst.de>

dma-mapping: use obj-y instead of lib-y for generic dma ops

We already have exact config symbols to select the direct, non-coherent,
or virt dma ops. So use the normal obj- scheme to select them.

Signed-off-by: Christoph Hellwig <hch@lst.de>

alpha: Remove custom dec_and_lock() implementation

Alpha provides a custom implementation of dec_and_lock(). The functions
is split into two parts:
- atomic_add_unless() + return 0 (fast path in assembly)
- remaining part including locking (slow path in C)

Comparing the result of the alpha implementation with the generic
implementation compiled by gcc it looks like the fast path is optimized
by avoiding a stack frame (and reloading the GP), register store and all
this. This is only done in the slowpath.
After marking the slowpath (atomic_dec_and_lock_1()) as "noinline" and
doing the slowpath in C (the atomic_add_unless(atomic, -1, 1) part) I
noticed differences in the resulting assembly:
- the GP is still reloaded
- atomic_add_unless() adds more memory barriers compared to the custom
assembly
- the custom assembly here does "load, sub, beq" while
atomic_add_unless() does "load, cmpeq, add, bne". This is okay because
it compares against zero after subtraction while the generic code
compares against 1 before.

I'm not sure if avoiding the stack frame (and GP reloading) brings a lot
in terms of performance. Regarding the different barriers, Peter
Zijlstra says:

|refcount decrement needs to be a RELEASE operation, such that all the
|load/stores to the object happen before we decrement the refcount.
|
|Otherwise things like:
|
| obj->foo = 5;
| refcnt_dec(&obj->ref);
|
|can be re-ordered, which then allows fun scenarios like:
|
| CPU0 CPU1
|
| refcnt_dec(&obj->ref);
| if (dec_and_test(&obj->ref))
| free(obj);
| obj->foo = 5; // oops UaF
|
|
|This means (for alpha) that there should be a memory barrier _before_
|the decrement, however the dec_and_lock asm thing only has one _after_,
|which, per the above, is too late.
|
|The generic version using add_unless will result in memory barrier
|before and after (because that is the rule for atomic ops with a return
|value) which is strictly too many barriers for the refcount story, but
|who knows what other ordering requirements code has.

Remove the custom alpha implementation of dec_and_lock() and if it is an
issue (performance wise) then the fast path could still be inlined.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: linux-alpha@vger.kernel.org
Link: https://lkml.kernel.org/r/20180606115918.GG12198@hirez.programming.kicks-ass.net
Link: https://lkml.kernel.org/r20180612161621.22645-2-bigeasy@linutronix.de

lib: add runtime test of check_*_overflow functions

This adds a small module for testing that the check_*_overflow
functions work as expected, whether implemented in C or using gcc
builtins.

Example output:

test_overflow: u8 : 18 tests
test_overflow: s8 : 19 tests
test_overflow: u16: 17 tests
test_overflow: s16: 17 tests
test_overflow: u32: 17 tests
test_overflow: s32: 17 tests
test_overflow: u64: 17 tests
test_overflow: s64: 21 tests

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
[kees: add output to commit log, drop u64 tests on 32-bit]
Signed-off-by: Kees Cook <keescook@chromium.org>

dma-mapping: provide a generic dma-noncoherent implementation

Add a new dma_map_ops implementation that uses dma-direct for the
address mapping of streaming mappings, and which requires arch-specific
implemenations of coherent allocate/free.

Architectures have to provide flushing helpers to ownership trasnfers
to the device and/or CPU, and can provide optional implementations of
the coherent mmap functionality, and the cache_flush routines for
non-coherent long term allocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Alexey Brodkin <abrodkin@synopsys.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>

iommu-common: move to arch/sparc

This code is only used by sparc, and all new iommu drivers should use the
drivers/iommu/ framework. Also remove the unused exports.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>

lib: Rename compiler intrinsic selects to GENERIC_LIB_*

When these are included into arch Kconfig files, maintaining
alphabetical ordering of the selects means these get split up. To allow
for keeping things tidier and alphabetical, rename the selects to
GENERIC_LIB_*

Signed-off-by: Matt Redfearn <matt.redfearn@mips.com>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-riscv@lists.infradead.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/19049/
Signed-off-by: James Hogan <jhogan@kernel.org>

lib: add testing module for UBSAN

This is a test module for UBSAN. It triggers all undefined behaviors
that linux supports now, and detect them.

All test-cases have passed by compiling with gcc-5.5.0.

If use gcc-4.9.x, misaligned, out-of-bounds, object-size-mismatch will not
be detected. Because gcc-4.9.x doesn't support them.

Link: http://lkml.kernel.org/r/20180309102247.GA2944@pjb1027-Latitude-E5410
Signed-off-by: Jinbum Park <jinb.park7@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kasan: prevent compiler from optimizing away memset in tests

A compiler can optimize away memset calls by replacing them with mov
instructions. There are KASAN tests that specifically test that KASAN
correctly handles memset calls so we don't want this optimization to
happen.

The solution is to add -fno-builtin flag to test_kasan.ko

Link: http://lkml.kernel.org/r/105ec9a308b2abedb1a0d1fdced0c22d765e4732.1519924383.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Chris Mason <clm@fb.com>
Cc: Yury Norov <ynorov@caviumnetworks.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Cc: Kostya Serebryany <kcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: Add generic PIO mapping method

41f8bba7f555 ("of/pci: Add pci_register_io_range() and
pci_pio_to_address()") added support for PCI I/O space mapped into CPU
physical memory space. With that support, the I/O ranges configured for
PCI/PCIe hosts on some architectures can be mapped to logical PIO and
converted easily between CPU address and the corresponding logical PIO.
Based on this, PCI I/O port space can be accessed via in/out accessors that
use memory read/write.

But on some platforms, there are bus hosts that access I/O port space with
host-local I/O port addresses rather than memory addresses.

Add a more generic I/O mapping method to support those devices. With this
patch, both the CPU addresses and the host-local port can be mapped into
the logical PIO space with different logical/fake PIOs. After this, all
the I/O accesses to either PCI MMIO devices or host-local I/O peripherals
can be unified into the existing I/O accessors defined in asm-generic/io.h
and be redirected to the right device-specific hooks based on the input
logical PIO.

Tested-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Zhichang Yuan <yuanzhichang@hisilicon.com>
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
[bhelgaas: remove -EFAULT return from logic_pio_register_range() per
https://lkml.kernel.org/r/20180403143909.GA21171@ulmo, fix NULL pointer
checking per https://lkml.kernel.org/r/20180403211505.GA29612@embeddedor.com]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

printk: move dump stack related code to lib/dump_stack.c

dump_stack related stuff should belong to lib/dump_stack.c thus move them
there. Also conditionally compile lib/dump_stack.c since dump_stack code
does not make sense if printk is disabled.

Link: http://lkml.kernel.org/r/20180213072834.GA24784@dhcp-128-65.nay.redhat.com
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Cc: akpm@linux-foundation.org
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Dave Young <dyoung@redhat.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

lib/test_find_bit.c: rename to find_bit_benchmark.c

As suggested in review comments, rename test_find_bit.c to
find_bit_benchmark.c.

Link: http://lkml.kernel.org/r/20171124143040.a44jvhmnaiyedg2i@yury-thinkpad
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Clement Courbet <courbet@google.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

dma-direct: rename dma_noop to dma_direct

The trivial direct mapping implementation already does a virtual to
physical translation which isn't strictly a noop, and will soon learn
to do non-direct but linear physical to dma translations through the
device offset and a few small tricks. Rename it to a better fitting
name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>

error-injection: Separate error-injection from kprobe

Since error-injection framework is not limited to be used
by kprobes, nor bpf. Other kernel subsystems can use it
freely for checking safeness of error-injection, e.g.
livepatch, ftrace etc.
So this separate error-injection framework from kprobes.

Some differences has been made:

- "kprobe" word is removed from any APIs/structures.
- BPF_ALLOW_ERROR_INJECTION() is renamed to
ALLOW_ERROR_INJECTION() since it is not limited for BPF too.
- CONFIG_FUNCTION_ERROR_INJECTION is the config item of this
feature. It is automatically enabled if the arch supports
error injection feature for kprobe or ftrace etc.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

spinlock: Add library function to allocate spinlock buckets array

Add two new library functions: alloc_bucket_spinlocks and
free_bucket_spinlocks. These are used to allocate and free an array
of spinlocks that are useful as locks for hash buckets. The interface
specifies the maximum number of spinlocks in the array as well
as a CPU multiplier to derive the number of spinlocks to allocate.
The number allocated is rounded up to a power of two to make the
array amenable to hash lookup.

Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

lib: test module for find_*_bit() functions

find_bit functions are widely used in the kernel, including hot paths.
This module tests performance of those functions in 2 typical scenarios:
randomly filled bitmap with relatively equal distribution of set and
cleared bits, and sparse bitmap which has 1 set bit for 500 cleared
bits.

On ThunderX machine:

Start testing find_bit() with random-filled bitmap
find_next_bit: 240043 cycles, 164062 iterations
find_next_zero_bit: 312848 cycles, 163619 iterations
find_last_bit: 193748 cycles, 164062 iterations
find_first_bit: 177720874 cycles, 164062 iterations

Start testing find_bit() with sparse bitmap
find_next_bit: 3633 cycles, 656 iterations
find_next_zero_bit: 620399 cycles, 327025 iterations
find_last_bit: 3038 cycles, 656 iterations
find_first_bit: 691407 cycles, 656 iterations

[arnd@arndb.de: use correct format string for find-bit tests]
Link: http://lkml.kernel.org/r/20171113135605.3166307-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20171109140714.13168-1-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Clement Courbet <courbet@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: add module support to string tests

Extract the string test code into its own source file, to allow
compiling it either to a loadable module, or built into the kernel.

Fixes: 03270c13c5ffaa6a ("lib/string.c: add testcases for memset16/32/64")
Link: http://lkml.kernel.org/r/1505397744-3387-1-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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>

lib: Add shared copies of some GCC library routines

Many ports (m32r, microblaze, mips, parisc, score, and sparc) use
functionally identical copies of various GCC library routine files,
which came up as we were submitting the RISC-V port (which also uses
some of these).

This patch adds a new copy of these library routine files, which are
functionally identical to the various other copies. These are
availiable via Kconfig as CONFIG_GENERIC_$ROUTINE, which currently isn't
used anywhere.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>

lib: add test module for CONFIG_DEBUG_VIRTUAL

Add a test module that allows testing that CONFIG_DEBUG_VIRTUAL works
correctly, at least that it can catch invalid calls to virt_to_phys()
against the non-linear kernel virtual address map.

Link: http://lkml.kernel.org/r/20170808164035.26725-1-f.fainelli@gmail.com
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: Add zstd modules

Add zstd compression and decompression kernel modules.
zstd offers a wide varity of compression speed and quality trade-offs.
It can compress at speeds approaching lz4, and quality approaching lzma.
zstd decompressions at speeds more than twice as fast as zlib, and
decompression speed remains roughly the same across all compression levels.

The code was ported from the upstream zstd source repository. The
`linux/zstd.h` header was modified to match linux kernel style.
The cross-platform and allocation code was stripped out. Instead zstd
requires the caller to pass a preallocated workspace. The source files
were clang-formatted [1] to match the Linux Kernel style as much as
possible. Otherwise, the code was unmodified. We would like to avoid
as much further manual modification to the source code as possible, so it
will be easier to keep the kernel zstd up to date.

I benchmarked zstd compression as a special character device. I ran zstd
and zlib compression at several levels, as well as performing no
compression, which measure the time spent copying the data to kernel space.
Data is passed to the compresser 4096 B at a time. The benchmark file is
located in the upstream zstd source repository under
`contrib/linux-kernel/zstd_compress_test.c` [2].

I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM.
The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor,
16 GB of RAM, and a SSD. I benchmarked using `silesia.tar` [3], which is
211,988,480 B large. Run the following commands for the benchmark:

sudo modprobe zstd_compress_test
sudo mknod zstd_compress_test c 245 0
sudo cp silesia.tar zstd_compress_test

The time is reported by the time of the userland `cp`.
The MB/s is computed with

1,536,217,008 B / time(buffer size, hash)

which includes the time to copy from userland.
The Adjusted MB/s is computed with

1,536,217,088 B / (time(buffer size, hash) - time(buffer size, none)).

The memory reported is the amount of memory the compressor requests.

| Method | Size (B) | Time (s) | Ratio | MB/s | Adj MB/s | Mem (MB) |
|----------|----------|----------|-------|---------|----------|----------|
| none | 11988480 | 0.100 | 1 | 2119.88 | - | - |
| zstd -1 | 73645762 | 1.044 | 2.878 | 203.05 | 224.56 | 1.23 |
| zstd -3 | 66988878 | 1.761 | 3.165 | 120.38 | 127.63 | 2.47 |
| zstd -5 | 65001259 | 2.563 | 3.261 | 82.71 | 86.07 | 2.86 |
| zstd -10 | 60165346 | 13.242 | 3.523 | 16.01 | 16.13 | 13.22 |
| zstd -15 | 58009756 | 47.601 | 3.654 | 4.45 | 4.46 | 21.61 |
| zstd -19 | 54014593 | 102.835 | 3.925 | 2.06 | 2.06 | 60.15 |
| zlib -1 | 77260026 | 2.895 | 2.744 | 73.23 | 75.85 | 0.27 |
| zlib -3 | 72972206 | 4.116 | 2.905 | 51.50 | 52.79 | 0.27 |
| zlib -6 | 68190360 | 9.633 | 3.109 | 22.01 | 22.24 | 0.27 |
| zlib -9 | 67613382 | 22.554 | 3.135 | 9.40 | 9.44 | 0.27 |

I benchmarked zstd decompression using the same method on the same machine.
The benchmark file is located in the upstream zstd repo under
`contrib/linux-kernel/zstd_decompress_test.c` [4]. The memory reported is
the amount of memory required to decompress data compressed with the given
compression level. If you know the maximum size of your input, you can
reduce the memory usage of decompression irrespective of the compression
level.

| Method | Time (s) | MB/s | Adjusted MB/s | Memory (MB) |
|----------|----------|---------|---------------|-------------|
| none | 0.025 | 8479.54 | - | - |
| zstd -1 | 0.358 | 592.15 | 636.60 | 0.84 |
| zstd -3 | 0.396 | 535.32 | 571.40 | 1.46 |
| zstd -5 | 0.396 | 535.32 | 571.40 | 1.46 |
| zstd -10 | 0.374 | 566.81 | 607.42 | 2.51 |
| zstd -15 | 0.379 | 559.34 | 598.84 | 4.61 |
| zstd -19 | 0.412 | 514.54 | 547.77 | 8.80 |
| zlib -1 | 0.940 | 225.52 | 231.68 | 0.04 |
| zlib -3 | 0.883 | 240.08 | 247.07 | 0.04 |
| zlib -6 | 0.844 | 251.17 | 258.84 | 0.04 |
| zlib -9 | 0.837 | 253.27 | 287.64 | 0.04 |

Tested in userland using the test-suite in the zstd repo under
`contrib/linux-kernel/test/UserlandTest.cpp` [5] by mocking the kernel
functions. Fuzz tested using libfuzzer [6] with the fuzz harnesses under
`contrib/linux-kernel/test/{RoundTripCrash.c,DecompressCrash.c}` [7] [8]
with ASAN, UBSAN, and MSAN. Additionaly, it was tested while testing the
BtrFS and SquashFS patches coming next.

[1] https://clang.llvm.org/docs/ClangFormat.html
[2] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/zstd_compress_test.c
[3] http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia
[4] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/zstd_decompress_test.c
[5] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/test/UserlandTest.cpp
[6] http://llvm.org/docs/LibFuzzer.html
[7] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/test/RoundTripCrash.c
[8] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/test/DecompressCrash.c

zstd source repository: https://github.com/facebook/zstd

Signed-off-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>

lib: Add xxhash module

Adds xxhash kernel module with xxh32 and xxh64 hashes. xxhash is an
extremely fast non-cryptographic hash algorithm for checksumming.
The zstd compression and decompression modules added in the next patch
require xxhash. I extracted it out from zstd since it is useful on its
own. I copied the code from the upstream XXHash source repository and
translated it into kernel style. I ran benchmarks and tests in the kernel
and tests in userland.

I benchmarked xxhash as a special character device. I ran in four modes,
no-op, xxh32, xxh64, and crc32. The no-op mode simply copies the data to
kernel space and ignores it. The xxh32, xxh64, and crc32 modes compute
hashes on the copied data. I also ran it with four different buffer sizes.
The benchmark file is located in the upstream zstd source repository under
`contrib/linux-kernel/xxhash_test.c` [1].

I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM.
The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor,
16 GB of RAM, and a SSD. I benchmarked using the file `filesystem.squashfs`
from `ubuntu-16.10-desktop-amd64.iso`, which is 1,536,217,088 B large.
Run the following commands for the benchmark:

modprobe xxhash_test
mknod xxhash_test c 245 0
time cp filesystem.squashfs xxhash_test

The time is reported by the time of the userland `cp`.
The GB/s is computed with

1,536,217,008 B / time(buffer size, hash)

which includes the time to copy from userland.
The Normalized GB/s is computed with

1,536,217,088 B / (time(buffer size, hash) - time(buffer size, none)).

| Buffer Size (B) | Hash | Time (s) | GB/s | Adjusted GB/s |
|-----------------|-------|----------|------|---------------|
| 1024 | none | 0.408 | 3.77 | - |
| 1024 | xxh32 | 0.649 | 2.37 | 6.37 |
| 1024 | xxh64 | 0.542 | 2.83 | 11.46 |
| 1024 | crc32 | 1.290 | 1.19 | 1.74 |
| 4096 | none | 0.380 | 4.04 | - |
| 4096 | xxh32 | 0.645 | 2.38 | 5.79 |
| 4096 | xxh64 | 0.500 | 3.07 | 12.80 |
| 4096 | crc32 | 1.168 | 1.32 | 1.95 |
| 8192 | none | 0.351 | 4.38 | - |
| 8192 | xxh32 | 0.614 | 2.50 | 5.84 |
| 8192 | xxh64 | 0.464 | 3.31 | 13.60 |
| 8192 | crc32 | 1.163 | 1.32 | 1.89 |
| 16384 | none | 0.346 | 4.43 | - |
| 16384 | xxh32 | 0.590 | 2.60 | 6.30 |
| 16384 | xxh64 | 0.466 | 3.30 | 12.80 |
| 16384 | crc32 | 1.183 | 1.30 | 1.84 |

Tested in userland using the test-suite in the zstd repo under
`contrib/linux-kernel/test/XXHashUserlandTest.cpp` [2] by mocking the
kernel functions. A line in each branch of every function in `xxhash.c`
was commented out to ensure that the test-suite fails. Additionally
tested while testing zstd and with SMHasher [3].

[1] https://phabricator.intern.facebook.com/P57526246
[2] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/test/XXHashUserlandTest.cpp
[3] https://github.com/aappleby/smhasher

zstd source repository: https://github.com/facebook/zstd
XXHash source repository: https://github.com/cyan4973/xxhash

Signed-off-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>

kmod: add test driver to stress test the module loader

This adds a new stress test driver for kmod: the kernel module loader.
The new stress test driver, test_kmod, is only enabled as a module right
now. It should be possible to load this as built-in and load tests
early (refer to the force_init_test module parameter), however since a
lot of test can get a system out of memory fast we leave this disabled
for now.

Using a system with 1024 MiB of RAM can *easily* get your kernel OOM
fast with this test driver.

The test_kmod driver exposes API knobs for us to fine tune simple
request_module() and get_fs_type() calls. Since these API calls only
allow each one parameter a test driver for these is rather simple.
Other factors that can help out test driver though are the number of
calls we issue and knowing current limitations of each. This exposes
configuration as much as possible through userspace to be able to build
tests directly from userspace.

Since it allows multiple misc devices its will eventually (once we add a
knob to let us create new devices at will) also be possible to perform
more tests in parallel, provided you have enough memory.

We only enable tests we know work as of right now.

Demo screenshots:

# tools/testing/selftests/kmod/kmod.sh
kmod_test_0001_driver: OK! - loading kmod test
kmod_test_0001_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND
kmod_test_0001_fs: OK! - loading kmod test
kmod_test_0001_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL
kmod_test_0002_driver: OK! - loading kmod test
kmod_test_0002_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND
kmod_test_0002_fs: OK! - loading kmod test
kmod_test_0002_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL
kmod_test_0003: OK! - loading kmod test
kmod_test_0003: OK! - Return value: 0 (SUCCESS), expected SUCCESS
kmod_test_0004: OK! - loading kmod test
kmod_test_0004: OK! - Return value: 0 (SUCCESS), expected SUCCESS
kmod_test_0005: OK! - loading kmod test
kmod_test_0005: OK! - Return value: 0 (SUCCESS), expected SUCCESS
kmod_test_0006: OK! - loading kmod test
kmod_test_0006: OK! - Return value: 0 (SUCCESS), expected SUCCESS
kmod_test_0005: OK! - loading kmod test
kmod_test_0005: OK! - Return value: 0 (SUCCESS), expected SUCCESS
kmod_test_0006: OK! - loading kmod test
kmod_test_0006: OK! - Return value: 0 (SUCCESS), expected SUCCESS
XXX: add test restult for 0007
Test completed

You can also request for specific tests:

# tools/testing/selftests/kmod/kmod.sh -t 0001
kmod_test_0001_driver: OK! - loading kmod test
kmod_test_0001_driver: OK! - Return value: 256 (MODULE_NOT_FOUND), expected MODULE_NOT_FOUND
kmod_test_0001_fs: OK! - loading kmod test
kmod_test_0001_fs: OK! - Return value: -22 (-EINVAL), expected -EINVAL
Test completed

Lastly, the current available number of tests:

# tools/testing/selftests/kmod/kmod.sh --help
Usage: tools/testing/selftests/kmod/kmod.sh [ -t <4-number-digit> ]
Valid tests: 0001-0009

0001 - Simple test - 1 thread for empty string
0002 - Simple test - 1 thread for modules/filesystems that do not exist
0003 - Simple test - 1 thread for get_fs_type() only
0004 - Simple test - 2 threads for get_fs_type() only
0005 - multithreaded tests with default setup - request_module() only
0006 - multithreaded tests with default setup - get_fs_type() only
0007 - multithreaded tests with default setup test request_module() and get_fs_type()
0008 - multithreaded - push kmod_concurrent over max_modprobes for request_module()
0009 - multithreaded - push kmod_concurrent over max_modprobes for get_fs_type()

The following test cases currently fail, as such they are not currently
enabled by default:

# tools/testing/selftests/kmod/kmod.sh -t 0008
# tools/testing/selftests/kmod/kmod.sh -t 0009

To be sure to run them as intended please unload both of the modules:

o test_module
o xfs

And ensure they are not loaded on your system prior to testing them. If
you use these paritions for your rootfs you can change the default test
driver used for get_fs_type() by exporting it into your environment. For
example of other test defaults you can override refer to kmod.sh
allow_user_defaults().

Behind the scenes this is how we fine tune at a test case prior to
hitting a trigger to run it:

cat /sys/devices/virtual/misc/test_kmod0/config
echo -n "2" > /sys/devices/virtual/misc/test_kmod0/config_test_case
echo -n "ext4" > /sys/devices/virtual/misc/test_kmod0/config_test_fs
echo -n "80" > /sys/devices/virtual/misc/test_kmod0/config_num_threads
cat /sys/devices/virtual/misc/test_kmod0/config
echo -n "1" > /sys/devices/virtual/misc/test_kmod0/config_num_threads

Finally to trigger:

echo -n "1" > /sys/devices/virtual/misc/test_kmod0/trigger_config

The kmod.sh script uses the above constructs to build different test cases.

A bit of interpretation of the current failures follows, first two
premises:

a) When request_module() is used userspace figures out an optimized
version of module order for us. Once it finds the modules it needs, as
per depmod symbol dep map, it will finit_module() the respective
modules which are needed for the original request_module() request.

b) We have an optimization in place whereby if a kernel uses
request_module() on a module already loaded we never bother userspace
as the module already is loaded. This is all handled by kernel/kmod.c.

A few things to consider to help identify root causes of issues:

0) kmod 19 has a broken heuristic for modules being assumed to be
built-in to your kernel and will return 0 even though request_module()
failed. Upgrade to a newer version of kmod.

1) A get_fs_type() call for "xfs" will request_module() for "fs-xfs",
not for "xfs". The optimization in kernel described in b) fails to
catch if we have a lot of consecutive get_fs_type() calls. The reason
is the optimization in place does not look for aliases. This means two
consecutive get_fs_type() calls will bump kmod_concurrent, whereas
request_module() will not.

This one explanation why test case 0009 fails at least once for
get_fs_type().

2) If a module fails to load --- for whatever reason (kmod_concurrent
limit reached, file not yet present due to rootfs switch, out of
memory) we have a period of time during which module request for the
same name either with request_module() or get_fs_type() will *also*
fail to load even if the file for the module is ready.

This explains why *multiple* NULLs are possible on test 0009.

3) finit_module() consumes quite a bit of memory.

4) Filesystems typically also have more dependent modules than other
modules, its important to note though that even though a get_fs_type()
call does not incur additional kmod_concurrent bumps, since userspace
loads dependencies it finds it needs via finit_module_fd(), it *will*
take much more memory to load a module with a lot of dependencies.

Because of 3) and 4) we will easily run into out of memory failures with
certain tests. For instance test 0006 fails on qemu with 1024 MiB of RAM.
It panics a box after reaping all userspace processes and still not
having enough memory to reap.

[arnd@arndb.de: add dependencies for test module]
Link: http://lkml.kernel.org/r/20170630154834.3689272-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20170628223155.26472-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

test_sysctl: add dedicated proc sysctl test driver

The existing tools/testing/selftests/sysctl/ tests include two test
cases, but these use existing production kernel sysctl interfaces. We
want to expand test coverage but we can't just be looking for random
safe production values to poke at, that's just insane!

Instead just dedicate a test driver for debugging purposes and port the
existing scripts to use it. This will make it easier for further tests
to be added.

Subsequent patches will extend our test coverage for sysctl.

The stress test driver uses a new license (GPL on Linux, copyleft-next
outside of Linux). Linus was fine with this [0] and later due to Ted's
and Alans's request ironed out an "or" language clause to use [1] which
is already present upstream.

[0] https://lkml.kernel.org/r/CA+55aFyhxcvD+q7tp+-yrSFDKfR0mOHgyEAe=f_94aKLsOu0Og@mail.gmail.com
[1] https://lkml.kernel.org/r/1495234558.7848.122.camel@linux.intel.com

Link: http://lkml.kernel.org/r/20170630224431.17374-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: add errseq_t type and infrastructure for handling it

An errseq_t is a way of recording errors in one place, and allowing any
number of "subscribers" to tell whether an error has been set again
since a previous time.

It's implemented as an unsigned 32-bit value that is managed with atomic
operations. The low order bits are designated to hold an error code
(max size of MAX_ERRNO). The upper bits are used as a counter.

The API works with consumers sampling an errseq_t value at a particular
point in time. Later, that value can be used to tell whether new errors
have been set since that time.

Note that there is a 1 in 512k risk of collisions here if new errors
are being recorded frequently, since we have so few bits to use as a
counter. To mitigate this, one bit is used as a flag to tell whether the
value has been sampled since a new value was recorded. That allows
us to avoid bumping the counter if no one has sampled it since it
was last bumped.

Later patches will build on this infrastructure to change how writeback
errors are tracked in the kernel.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Reviewed-by: Jan Kara <jack@suse.cz>

lib: Add crc4 module

Add a little helper for crc4 calculations. This works 4-bits-at-a-time,
using a simple table approach.

We will need this in the FSI core code, as well as any master
implementations that need to calculate CRCs in software.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Chris Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

rcu: Remove SPARSE_RCU_POINTER Kconfig option

The sparse-based checking for non-RCU accesses to RCU-protected pointers
has been around for a very long time, and it is now the only type of
sparse-based checking that is optional. This commit therefore makes
it unconditional.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>

lib: add module support to linked list sorting tests

Extract the linked list sorting test code into its own source file, to
allow to compile it either to a loadable module, or builtin into the
kernel.

Link: http://lkml.kernel.org/r/1488287219-15832-4-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

CONFIG_ARCH_HAS_RAW_COPY_USER is unconditional now

all architectures converted

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

generic ...copy_..._user primitives

provide raw_copy_..._user() and select ARCH_HAS_RAW_COPY_USER to use those.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

md5: remove from lib and only live in crypto

The md5_transform function is no longer used any where in the tree,
except for the crypto api's actual implementation of md5, so we can drop
the function from lib and put it as a static function of the crypto
file, where it belongs. There should be no new users of md5_transform,
anyway, since there are more modern ways of doing what it once achieved.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

lib: add CONFIG_TEST_SORT to enable self-test of sort()

Along with the addition made to Kconfig.debug, the prior existing but
permanently disabled test function has been slightly refactored.

Patch has been tested using QEMU 2.1.2 with a .config obtained through
'make defconfig' (x86_64) and manually enabling the option.

[arnd@arndb.de: move sort self-test into a separate file]
Link: http://lkml.kernel.org/r/20170112110657.3123790-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/HE1PR09MB0394B0418D504DCD27167D4FD49B0@HE1PR09MB0394.eurprd09.prod.outlook.com
Signed-off-by: Kostenzer Felix <fkostenzer@live.at>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: add module support to glob tests

Extract the glob test code into its own source file, to allow to compile
it either to a loadable module, or builtin into the kernel.

Link: http://lkml.kernel.org/r/1483470276-10517-2-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib: add module support to crc32 tests

Extract the crc32 test code into its own source file, to allow to
compile it either to a loadable module, or builtin into the kernel.

Link: http://lkml.kernel.org/r/1483470276-10517-1-git-send-email-geert@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

locking/refcounts: Out-of-line everything

Linus asked to please make this real C code.

And since size then isn't an issue what so ever anymore, remove the
debug knob and make all WARN()s unconditional.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dwindsor@gmail.com
Cc: elena.reshetova@intel.com
Cc: gregkh@linuxfoundation.org
Cc: ishkamiel@gmail.com
Cc: keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

idr: Add missing __rcu annotations

Where we use the radix tree iteration macros, we need to annotate 'slot'
with __rcu. Make sure we don't forget any new places in the future with
the same CFLAGS check used for radix-tree.c.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

radix-tree: Fix __rcu annotations

Many places were missing __rcu annotations. A few places needed a few
lines of explanation about why it was safe to not use RCU accessors.
Add a custom CFLAGS setting to the Makefile to ensure that new patches
don't miss RCU annotations.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

lib: Introduce priority array area manager

This introduces a infrastructure for management of linear priority
areas. Priority order in an array matters, however order of items inside
a priority group does not matter.

As an initial implementation, L-sort algorithm is used. It is quite
trivial. More advanced algorithm called P-sort will be introduced as a
follow-up. The infrastructure is prepared for other algos.

Alongside this, a testing module is introduced as well.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ext4: move halfmd4 into hash.c directly

The "half md4" transform should not be used by any new code. And
fortunately, it's only used now by ext4. Since ext4 supports several
hashing methods, at some point it might be desirable to move to
something like SipHash. As an intermediate step, remove half md4 from
cryptohash.h and lib, and make it just a local function in ext4's
hash.c. There's precedent for doing this; the other function ext can use
for its hashes -- TEA -- is also implemented in the same place. Also, by
being a local function, this might allow gcc to perform some additional
optimizations.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

lib/dma-virt: Add dma_virt_ops

Several RDMA drivers (hfi1, qib and rxe) expect that ib_sge.addr
is a virtual address. Provide DMA mapping operations that are
suitable for these drivers.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

lib/dma-noop: Only build dma_noop_ops for s390 and m32r

Reduce the kernel size by only building dma_noop_ops for those
architectures that actually use it. This was suggested by
Christoph Hellwig.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Doug Ledford <dledford@redhat.com>

siphash: add cryptographically secure PRF

SipHash is a 64-bit keyed hash function that is actually a
cryptographically secure PRF, like HMAC. Except SipHash is super fast,
and is meant to be used as a hashtable keyed lookup function, or as a
general PRF for short input use cases, such as sequence numbers or RNG
chaining.

For the first usage:

There are a variety of attacks known as "hashtable poisoning" in which an
attacker forms some data such that the hash of that data will be the
same, and then preceeds to fill up all entries of a hashbucket. This is
a realistic and well-known denial-of-service vector. Currently
hashtables use jhash, which is fast but not secure, and some kind of
rotating key scheme (or none at all, which isn't good). SipHash is meant
as a replacement for jhash in these cases.

There are a modicum of places in the kernel that are vulnerable to
hashtable poisoning attacks, either via userspace vectors or network
vectors, and there's not a reliable mechanism inside the kernel at the
moment to fix it. The first step toward fixing these issues is actually
getting a secure primitive into the kernel for developers to use. Then
we can, bit by bit, port things over to it as deemed appropriate.

While SipHash is extremely fast for a cryptographically secure function,
it is likely a bit slower than the insecure jhash, and so replacements
will be evaluated on a case-by-case basis based on whether or not the
difference in speed is negligible and whether or not the current jhash usage
poses a real security risk.

For the second usage:

A few places in the kernel are using MD5 or SHA1 for creating secure
sequence numbers, syn cookies, port numbers, or fast random numbers.
SipHash is a faster and more fitting, and more secure replacement for MD5
in those situations. Replacing MD5 and SHA1 with SipHash for these uses is
obvious and straight-forward, and so is submitted along with this patch
series. There shouldn't be much of a debate over its efficacy.

Dozens of languages are already using this internally for their hash
tables and PRFs. Some of the BSDs already use this in their kernels.
SipHash is a widely known high-speed solution to a widely known set of
problems, and it's time we catch-up.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>