BOOT_CF9_SAFE_STR is an internal value used only by the x86 code and it's
not possible to set it from userspace.
Remove it, and rename 'cf9_force' to 'pci', so to make it coherent with
the kernel command line reboot= option.
Tested with this script:
cd /sys/kernel/reboot/
for i in cold warm hard soft gpio; do
echo $i >mode
read j <mode
[ $i = $j ] || echo "mode $i != $j"
done
for i in bios acpi kbd triple efi pci; do
echo $i >type
read j <type
[ $i = $j ] || echo "type $i != $j"
done
for i in $(seq 0 $(nproc --ignore=1)); do
echo $i >cpu
read j <cpu
[ $i = $j ] || echo "cpu $i != $j"
done
for i in 0 1; do
echo $i >force
read j <force
[ $i = $j ] || echo "force $i != $j"
done
Link: https://lkml.kernel.org/r/20201113015900.543923-1-mcroce@linux.microsoft.com
Fixes: eab8da48579d ("reboot: allow to specify reboot mode via sysfs")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel cmdline reboot= option offers some sort of control on how the
reboot is issued.
We don't always know in advance what type of reboot to perform.
Sometimes a warm reboot is preferred to persist certain memory regions
across the reboot. Others a cold one is needed to apply a future system
update that makes a memory memory model change, like changing the base
page size or resizing a persistent memory region.
Or simply we want to enable reboot_force because we noticed that
something bad happened.
Add handles in sysfs to allow setting these reboot options, so they can
be changed when the system is booted, other than at boot time.
The handlers are under <sysfs>/kernel/reboot, can be read to get the
current configuration and written to alter it.
# cd /sys/kernel/reboot/
# grep . *
cpu:0
force:0
mode:cold
type:acpi
# echo 2 >cpu
# echo yes >force
# echo soft >mode
# echo bios >type
# grep . *
cpu:2
force:1
mode:soft
type:bios
Before setting anything, check for CAP_SYS_BOOT capability, so it's
possible to allow an unpriviledged process to change these settings simply
by relaxing the handles permissions, without opening them to the world.
[natechancellor@gmail.com: fix variable assignments in type_store]
Link: https://lkml.kernel.org/r/20201112035023.974748-1-natechancellor@gmail.com
Link: https://github.com/ClangBuiltLinux/linux/issues/1197
Link: https://lkml.kernel.org/r/20201110202746.9690-1-mcroce@linux.microsoft.com
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Small improvements to the code, without changing the way it works:
- use a local variable, to avoid a small time lapse where reboot_cpu
can have an invalid value
- comment the code which is not easy to understand at a glance
- merge two identical code blocks into one
- replace pointer arithmetics with equivalent array syntax
Link: https://lkml.kernel.org/r/20201103214025.116799-4-mcroce@linux.microsoft.com
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Robin Holt <robinmholt@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following sparse warning:
lib/ubsan.c:20:12: warning: symbol 'type_check_kinds' was not declared. Should it be static?
[akpm@linux-foundation.org: make it `static const char * const' while we're in there]
Link: https://lkml.kernel.org/r/1607602638-79584-1-git-send-email-zou_wei@huawei.com
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Both KCOV and UBSAN use compiler instrumentation. If UBSAN detects a bug
in KCOV, it may cause infinite recursion via printk and other common
functions. We already don't instrument KCOV with KASAN/KCSAN for this
reason, don't instrument it with UBSAN as well.
As a side effect this also resolves the following gcc warning:
conflicting types for built-in function '__sanitizer_cov_trace_switch';
expected 'void(long unsigned int, void *)'
[-Wbuiltin-declaration-mismatch]
It's only reported when kcov.c is compiled with any of the sanitizers
enabled. Size of the arguments is correct, it's just that gcc uses 'long'
on 64-bit arches and 'long long' on 32-bit arches, while kernel type is
always 'long long'.
Link: https://lkml.kernel.org/r/20201209100152.2492072-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: Marco Elver <elver@google.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Expand the UBSAN tests to include some additional UB cases. Notably the
out-of-bounds enum loading appears not to work. Also include per-test
reporting, including the relevant CONFIG_UBSAN... Kconfigs.
Link: https://lkml.kernel.org/r/20201203004437.389959-8-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make each UBSAN option individually selectable and remove UBSAN_MISC which
no longer has any purpose. Add help text for each Kconfig, and include a
reference to the Clang sanitizer documentation. Disable unsigned overflow
by default (not available with GCC and makes x86 unbootable with Clang).
Disable unreachable when objtool is in use (redundant and confuses things:
instrumentation appears at unreachable locations).
Link: https://lkml.kernel.org/r/20201203004437.389959-7-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With UBSAN_OBJECT_SIZE disabled for GCC, only UBSAN_ALIGNMENT remained a
noisy UBSAN option. Disable it for COMPILE_TEST so the rest of UBSAN can
be used for full all*config builds or other large combinations.
[sfr@canb.auug.org.au: add .data..Lubsan_data*/.data..Lubsan_type* sections explicitly]
Link: https://lkml.kernel.org/r/20201208230157.42c42789@canb.auug.org.au
Link: https://lore.kernel.org/lkml/CAHk-=wgXW=YLxGN0QVpp-1w5GDd2pf1W-FqY15poKzoVfik2qA@mail.gmail.com/
Link: https://lkml.kernel.org/r/20201203004437.389959-6-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Doing all*config builds attempts to build as much as possible. UBSAN_TRAP
effectively short-circuits lib/usban.c, so it should be disabled for
COMPILE_TEST so that the lib/ubsan.c code gets built.
Link: https://lkml.kernel.org/r/20201203004437.389959-5-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of doing if/endif blocks with cc-option calls in the UBSAN
Makefile, move all the tests into Kconfig and use the Makefile to collect
the results.
Link: https://lkml.kernel.org/r/20201203004437.389959-3-keescook@chromium.org
Link: https://lore.kernel.org/lkml/CAHk-=wjPasyJrDuwDnpHJS2TuQfExwe=px-SzLeN8GFMAQJPmQ@mail.gmail.com/
Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Clean up UBSAN Makefile", v2.
This series attempts to address the issues seen with UBSAN's object-size
sanitizer causing problems under GCC. In the process, the Kconfig and
Makefile are refactored to do all the cc-option calls in the Kconfig.
Additionally start to detangle -Wno-maybe-uninitialized, disable
UBSAN_TRAP under COMPILE_TEST for wider build coverage, and expand the
libusan tests.
This patch (of 7):
In commit 78a5255ffb ("Stop the ad-hoc games with
-Wno-maybe-initialized") -Wmaybe-uninitialized was disabled globally, so
keeping the disabling logic here too doesn't make sense.
Link: https://lkml.kernel.org/r/20201203004437.389959-1-keescook@chromium.org
Link: https://lkml.kernel.org/r/20201203004437.389959-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: George Popescu <georgepope@android.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kernel-doc markups should use this format:
identifier - description
While here, fix a kernel-doc tag that was using, instead,
a normal comment block.
[akpm@linux-foundation.org: coding style fixes]
Link: https://lkml.kernel.org/r/c5e38e1070f8dbe2f9607a10b44afe2875bd966c.1605521731.git.mchehab+huawei@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: "Jonathan Corbet" <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that relay_open() accepts const callbacks, make relay callbacks
const.
Link: https://lkml.kernel.org/r/7ff5ce0b735901eb4f10e13da2704f1d8c4a2507.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that relay_open() accepts const callbacks, make relay callbacks
const.
Link: https://lkml.kernel.org/r/7db0286c428f3a478dd7544afef04a3b131f1aa0.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that relay_open() accepts const callbacks, make relay callbacks
const.
Link: https://lkml.kernel.org/r/44e3d65b71025c462948d0c554061dc7b40ab488.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that relay_open() accepts const callbacks, make relay callbacks const.
Link: https://lkml.kernel.org/r/85cabc6d4b0d0ca43d4e0fb94897ccd16e3b7930.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that relay_open() accepts const callbacks, make relay callbacks const.
Link: https://lkml.kernel.org/r/534d089f413db98aa0b94773fa49d5275d0d3c25.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
None of the relay users require the use of mutable structs for callbacks,
however the relay code does. Instead of assigning the default callback
for subbuf_start, add a wrapper to conditionally call the client callback
if available, and fall back to default behaviour otherwise.
This lets all relay users make their struct rchan_callbacks const data.
[jani.nikula@intel.com: cleanups, per Christoph]
Link: https://lkml.kernel.org/r/20201124115412.32402-1-jani.nikula@intel.com
Link: https://lkml.kernel.org/r/cc3ff292e4eb4fdc56bee3d690c7b8e39209cd37.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All clients provide create_buf_file and remove_buf_file callbacks, and
they're required for relay to make sense. There is no point in them being
optional.
Also document whether each callback is mandatory/optional.
Link: https://lkml.kernel.org/r/88003c1527386b93036e286e7917f1e33aec84ac.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are no clients passing NULL callbacks, which makes sense as it
wouldn't even create a file. Require non-NULL callbacks, and throw away
the handling for NULL callbacks.
Link: https://lkml.kernel.org/r/e40642f3b027d2bb6bc851ddb60e0a61ea51f5f8.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "relay: cleanup and const callbacks", v2.
None of the relay users require the use of mutable structs for callbacks,
however the relay code does. Instead of assigning default callbacks when
there is none, add callback wrappers to conditionally call the client
callbacks if available, and fall back to default behaviour (typically
no-op) otherwise.
This lets all relay users make their struct rchan_callbacks const data.
This series starts with a number of cleanups first based on Christoph's
feedback.
This patch (of 9):
No relay client uses the buf_mapped or buf_unmapped callbacks. Remove
them. This makes relay's vm_operations_struct close callback a dummy,
remove it as well.
Link: https://lkml.kernel.org/r/cover.1606153547.git.jani.nikula@intel.com
Link: https://lkml.kernel.org/r/c69fff6e0cd485563604240bbfcc028434983bec.1606153547.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the printk() [bfs "printf" macro] seem less severe by changing
"WARNING:" to "NOTE:".
<asm-generic/bug.h> warns us about using WARNING or BUG in a format string
other than in WARN() or BUG() family macros. bfs/inode.c is doing just
that in a normal printk() call, so change the "WARNING" string to be
"NOTE".
Link: https://lkml.kernel.org/r/20201203212634.17278-1-rdunlap@infradead.org
Reported-by: syzbot+3fd34060f26e766536ff@syzkaller.appspotmail.com
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: "Tigran A. Aivazian" <aivazian.tigran@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following kernel-doc issue in gcov:
kernel/gcov/gcc_4_7.c:238: warning: Function parameter or member 'dst' not described in 'gcov_info_add'
kernel/gcov/gcc_4_7.c:238: warning: Function parameter or member 'src' not described in 'gcov_info_add'
kernel/gcov/gcc_4_7.c:238: warning: Excess function parameter 'dest' description in 'gcov_info_add'
kernel/gcov/gcc_4_7.c:238: warning: Excess function parameter 'source' description in 'gcov_info_add'
Link: https://lkml.kernel.org/r/1605252352-63983-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 0bddd227f3 ("Documentation: update for gcc 4.9
requirement") the minimum supported version of GCC is gcc-4.9. It's now
safe to remove this code.
Similar to commit 10415533a9 ("gcov: Remove old GCC 3.4 support") but
that was for GCC 4.8 and this is for GCC 4.9.
Link: https://github.com/ClangBuiltLinux/linux/issues/427
Link: https://lkml.kernel.org/r/20201111030557.2015680-1-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The functions rio_get_asm() and rio_get_device() are globally exported
but have almost no users in tree. The only user is rio_init_mports()
which invokes it via rio_init().
rio_init() iterates over every registered device and invokes
rio_fixup_device(). It looks like a fixup function which should perform a
"change" to the device but does nothing. It has been like this since its
introduction in commit 394b701ce4 ("[PATCH] RapidIO support: core
base") which was merged into v2.6.15-rc1.
Remove rio_init() because the performed fixup function
(rio_fixup_device()) does nothing. Remove rio_get_asm() and
rio_get_device() which have no callers now.
Link: https://lkml.kernel.org/r/20201116170004.420143-1-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The offset of the field 'init_uts_ns.name' has changed since commit
9a56493f69 ("uts: Use generic ns_common::count").
Make the offset of the field 'uts_namespace.name' available in VMCOREINFO
because tools like 'crash-utility' and 'makedumpfile' must be able to read
it from crash dumps.
Link: https://lore.kernel.org/r/159644978167.604812.1773586504374412107.stgit@localhost.localdomain
Link: https://lkml.kernel.org/r/20200930102328.396488-1-egorenar@linux.ibm.com
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Acked-by: lijiang <lijiang@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There some macros are unused and cause gcc warning. Remove them.
fs/nilfs2/segment.c:137:0: warning: macro "nilfs_cnt32_gt" is not used [-Wunused-macros]
fs/nilfs2/segment.c:144:0: warning: macro "nilfs_cnt32_le" is not used [-Wunused-macros]
fs/nilfs2/segment.c:143:0: warning: macro "nilfs_cnt32_lt" is not used [-Wunused-macros]
Link: https://lkml.kernel.org/r/1607552733-24292-1-git-send-email-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch reports a false TYPO_SPELLING warning for some words containing
an apostrophe when run with --codespell option.
A false positive is "doesn't". Occurrence of the word causes checkpatch
to emit the following warning:
"WARNING: 'doesn'' may be misspelled - perhaps 'doesn't'?"
Modify the regex pattern to be more in line with the codespell default
word matching regex. This fixes the word capture and avoids the false
warning.
In addition, highlight the misspelled word location by adding a caret
below the word.
[akpm@linux-foundation.org: make matched misspelling more obvious, per Joe]
Link: https://lkml.kernel.org/r/09c24ef1aa2f1c4fe909d76f5426f08780b9d81c.camel@perches.com
Link: https://lkml.kernel.org/r/20201201190729.169733-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Reported-by: Peilin Ye <yepeilin.cs@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit log lines starting with '#' are dropped by git as comments.
Add a check to emit a warning for these lines.
Also add a --fix option to insert a space before the leading '#' in
such lines.
Link: https://lkml.kernel.org/r/20201202205740.127986-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Peilin Ye <yepeilin.cs@gmail.com>
Tested-by: Peilin Ye <yepeilin.cs@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Modifiers %h and %hh should never be used.
Commit cbacb5ab0a ("docs: printk-formats: Stop encouraging use of
unnecessary %h[xudi] and %hh[xudi]") specifies that:
"Standard integer promotion is already done and %hx and %hhx is useless
so do not encourage the use of %hh[xudi] or %h[xudi]."
"The "h" and "hh" things should never be used. The only reason for them
being used if you have an "int", but you want to print it out as a
"char" (and honestly, that is a really bad reason, you'd be better off
just using a proper cast to make the code more obvious)."
Add a new check to emit a warning on finding an unneeded use of %h or
%hh modifier.
Also add a fix option to the check.
Link: https://lore.kernel.org/lkml/4910042649a4f3ab22fac93191b8c1fa0a2e17c3.camel@perches.com/
Link: https://lkml.kernel.org/r/20201128200046.78739-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently checkpatch warns for BAD_SIGN_OFF on non-standard signature
styles.
A large number of these warnings occur because of typo mistakes in
signature tags. An evaluation over v4.13..v5.8 showed that out of 539
warnings due to non-standard signatures, 87 are due to typo mistakes.
Following are the standard signature tags which are often incorrectly
used, along with their individual counts of incorrect use (over
v4.13..v5.8):
Reviewed-by: 42
Signed-off-by: 25
Reported-by: 6
Acked-by: 4
Tested-by: 4
Suggested-by: 4
Provide a fix by calculating levenshtein distance for the signature tag
with all the standard signatures and suggest a fix with a signature, whose
edit distance is less than or equal to 2 with the misspelled signature.
Out of the 86 mispelled signatures fixed with this approach, 85 were found
to be good corrections and 1 was bad correction.
Following was found to be a bad correction:
Tweeted-by (count: 1) => Tested-by
Link: https://lkml.kernel.org/r/20201128204333.7054-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, checkpatch warns if logical continuations are placed at the
start of a line and not at the end of previous line.
E.g., running checkpatch on commit 3485507fc2 ("staging: bcm2835-camera:
Reduce length of enum names") reports:
CHECK:LOGICAL_CONTINUATIONS: Logical continuations should be on the previous line
+ if (!ret
+ && camera_port ==
Provide a simple fix by inserting logical operator at the last
non-comment, non-whitespace char of the previous line and removing from
current line, if both the lines are additions(ie start with '+')
Link: https://lkml.kernel.org/r/20201123102818.24364-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, checkpatch warns us if an assignment operator is placed at the
start of a line and not at the end of previous line.
E.g., running checkpatch on commit 8195b1396e ("hv_netvsc: fix
deadlock on hotplug") reports:
CHECK: Assignment operator '=' should be on the previous line
+ struct netvsc_device *nvdev
+ = container_of(w, struct netvsc_device, subchan_work);
Provide a simple fix by appending assignment operator to the previous
line and removing from the current line, if both the lines are additions
(ie start with '+')
Link: https://lkml.kernel.org/r/20201121120407.22942-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is an unescaped left brace in a regex in OPEN_BRACE check. This
throws a runtime error when checkpatch is run with --fix flag and the
OPEN_BRACE check is executed.
Fix it by escaping the left brace.
Link: https://lkml.kernel.org/r/20201115202928.81955-1-dwaipayanray1@gmail.com
Fixes: 8d1824780f ("checkpatch: add --fix option for a couple OPEN_BRACE misuses")
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently checkpatch warns us for long lines in commits even for signature
tag lines.
Generally these lines exceed the 75-character limit because of:
1) long names and long email address
2) some comments on scoped review and acknowledgement, i.e., for a
dedicated pointer on what was reported by the identity in
'Reported-by'
3) some additional comments on CC: stable@vger.org tags
Exclude signature tag lines from this class of warning.
There were 1896 COMMIT_LOG_LONG_LINE warnings in v5.6..v5.8 before this
patch application and 1879 afterwards.
A quick manual check found all the dropped warnings related to signature
tags.
Link: https://lkml.kernel.org/r/20201116083754.10629-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
checkpatch doesn't report warnings for many common mistakes in emails.
Some of which are trailing commas and incorrect use of email comments.
At the same time several false positives are reported due to incorrect
handling of mail comments. The most common of which is due to the
pattern:
<stable@vger.kernel.org> # X.X
Improve email parsing in checkpatch.
Some general email rules are defined:
- Multiple name comments should not be allowed.
- Comments inside address should not be allowed.
- In general comments should be enclosed within parentheses.
Relaxation is given to comments beginning with #.
- Stable addresses should not begin with a name.
- Comments in stable addresses should begin only
with a #.
Improvements to parsing:
- Detect and report unexpected content after email.
- Quoted names are excluded from comment parsing.
- Trailing dots, commas or quotes in email are removed during
formatting. Correspondingly a BAD_SIGN_OFF warning
is emitted.
- Improperly quoted email like '"name <address>"' are now
warned about.
In addition, added fixes for all the possible rules.
Link: https://lore.kernel.org/linux-kernel-mentees/6c275d95c3033422addfc256a30e6ae3dd37941d.camel@perches.com/
Link: https://lore.kernel.org/linux-kernel-mentees/20201105200857.GC1333458@kroah.com/
Link: https://lkml.kernel.org/r/20201108100632.75340-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add __alias and __weak to the suggested __attribute__((<foo>))
conversions.
Link: https://lkml.kernel.org/r/7b74137743c58ce0633ec4d575b94e2210e4dbe7.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, whenever a Gerrit Change-Id is present in a commit,
checkpatch.pl warns to remove the Change-Id before submitting the patch.
E.g., running checkpatch on commit adc311a5bb ("iwlwifi: bump FW
API to 53 for 22000 series") reports this error:
ERROR: Remove Gerrit Change-Id's before submitting upstream
Change-Id: I5725e46394f3f53c3069723fd513cc53c7df383d
Provide a simple fix option by simply deleting the indicated line.
Link: https://lkml.kernel.org/r/20201030114447.24199-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 33def8498f ("treewide: Convert macro and uses of
__section(foo) to __section("foo")") removed the stringification of the
section name and now requires quotes around the named section.
Update checkpatch to not remove any quotes when suggesting conversion
of __attribute__((section("name"))) to __section("name")
Miscellanea:
o Add section to the hash with __section replacement
o Remove separate test for __attribute__((section
o Remove the limitation on converting attributes containing only
known, possible conversions. Any unknown attribute types are now
left as-is and known types are converted and moved before
__attribute__ and removed from within the __attribute__((list...)).
[joe@perches.com: eliminate the separate test below the possible conversions loop]
Link: https://lkml.kernel.org/r/58e9d55e933dc8fdc6af489f2ad797fa8eb13e44.camel@perches.com
Link: https://lkml.kernel.org/r/c04dd1c810e8d6a68e6a632e3191ae91651c8edf.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the trailing error message from the fixed lines.
Link: https://lkml.kernel.org/r/20201017142546.28988-1-trix@redhat.com
Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is generally preferred that the macros from
include/linux/compiler_attributes.h are used, unless there is a reason not
to.
checkpatch currently checks __attribute__ for each of packed, aligned,
section, printf, scanf, and weak. Other declarations in
compiler_attributes.h are not handled.
Add a generic test to check the presence of such attributes. Some
attributes require more specific handling and are kept separate.
Also add fixes to the generic attributes check to substitute the correct
conversions.
New attributes which are now handled are:
__always_inline__
__assume_aligned__(a, ## __VA_ARGS__)
__cold__
__const__
__copy__(symbol)
__designated_init__
__externally_visible__
__gnu_inline__
__malloc__
__mode__(x)
__no_caller_saved_registers__
__noclone__
__noinline__
__nonstring__
__noreturn__
__pure__
__unused__
__used__
Declarations which contain multiple attributes like
__attribute__((__packed__, __cold__)) are also handled except when proper
conversions for one or more attributes of the list cannot be determined.
Link: https://lore.kernel.org/linux-kernel-mentees/3ec15b41754b01666d94b76ce51b9832c2dd577a.camel@perches.com/
Link: https://lkml.kernel.org/r/20201025193103.23223-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
switch/case use of break after a return, goto or break is unnecessary.
There is an existing warning for the return and goto uses, so add
break and a --fix option too.
Link: https://lkml.kernel.org/r/d9ea654104d55f590fb97d252d64a66b23c1a096.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are about 100,000 uses of 'static const <type>' but about 400 uses
of 'static <type> const' in the kernel where type is not a pointer.
The kernel almost always uses "static const" over "const static" as there
is a compiler warning for that declaration style.
But there is no compiler warning for "static <type> const".
So add a checkpatch warning for the atypical declaration uses of.
const static <type> <foo>
and
static <type> const <foo>
For example:
$ ./scripts/checkpatch.pl -f --emacs --quiet --nosummary -types=static_const arch/arm/crypto/aes-ce-glue.c
arch/arm/crypto/aes-ce-glue.c:75: WARNING: Move const after static - use 'static const u8'
#75: FILE: arch/arm/crypto/aes-ce-glue.c:75:
+ static u8 const rcon[] = {
Link: https://lkml.kernel.org/r/4b863be68e679546b40d50b97a4a806c03056a1c.camel@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Presence of hexadecimal address or symbol results in false warning
message by checkpatch.pl.
For example, running checkpatch on commit b8ad540dd4 ("mptcp: fix
memory leak in mptcp_subflow_create_socket()") results in warning:
WARNING:REPEATED_WORD: Possible repeated word: 'ff'
00 00 00 00 00 00 00 00 00 2f 30 0a 81 88 ff ff ........./0.....
Similarly, the presence of list command output in commit results in
an unnecessary warning.
For example, running checkpatch on commit 899e5ffbf2 ("perf record:
Introduce --switch-output-event") gives:
WARNING:REPEATED_WORD: Possible repeated word: 'root'
dr-xr-x---. 12 root root 4096 Apr 27 17:46 ..
Here, it reports 'ff' and 'root' to be repeated, but it is in fact part
of some address or code, where it has to be repeated.
In these cases, the intent of the warning to find stylistic issues in
commit messages is not met and the warning is just completely wrong in
this case.
To avoid these warnings, add an additional regex check for the directory
permission pattern and avoid checking the line for this class of
warning. Similarly, to avoid hex pattern, check if the word consists of
hex symbols and skip this warning if it is not among the common english
words formed using hex letters.
A quick evaluation on v5.6..v5.8 showed that this fix reduces
REPEATED_WORD warnings by the frequency of 1890.
A quick manual check found all cases are related to hex output or list
command outputs in commit messages.
Link: https://lkml.kernel.org/r/20201024102253.13614-1-yashsri421@gmail.com
Signed-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Recently, commit 4f6ad8aa1eac ("checkpatch: move repeated word test")
moved the repeated word test to check for more file types. But after
this, if checkpatch.pl is run on MAINTAINERS, it generates several
new warnings of the type:
WARNING: Possible repeated word: 'git'
For example:
WARNING: Possible repeated word: 'git'
+T: git git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml.git
So, the pattern "git git://..." is a false positive in this case.
There are several other combinations which may produce a wrong warning
message, such as "@size size", ":Begin begin", etc.
Extend repeated word check to compare the characters before and after
the word matches.
If there is a non whitespace character before the first word or a non
whitespace character excluding punctuation characters after the second
word, then the check is skipped and the warning is avoided.
Also add case insensitive word matching to the repeated word check.
Link: https://lore.kernel.org/linux-kernel-mentees/81b6a0bb2c7b9256361573f7a13201ebcd4876f1.camel@perches.com/
Link: https://lkml.kernel.org/r/20201017162732.152351-1-dwaipayanray1@gmail.com
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Aditya Srivastava <yashsri421@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
LZ4 final literal copy could be overlapped when doing
in-place decompression, so it's unsafe to just use memcpy()
on an optimized memcpy approach but memmove() instead.
Upstream LZ4 has updated this years ago [1] (and the impact
is non-sensible [2] plus only a few bytes remain), this commit
just synchronizes LZ4 upstream code to the kernel side as well.
It can be observed as EROFS in-place decompression failure
on specific files when X86_FEATURE_ERMS is unsupported,
memcpy() optimization of commit 59daa706fb ("x86, mem:
Optimize memcpy by avoiding memory false dependece") will
be enabled then.
Currently most modern x86-CPUs support ERMS, these CPUs just
use "rep movsb" approach so no problem at all. However, it can
still be verified with forcely disabling ERMS feature...
arch/x86/lib/memcpy_64.S:
ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \
- "jmp memcpy_erms", X86_FEATURE_ERMS
+ "jmp memcpy_orig", X86_FEATURE_ERMS
We didn't observe any strange on arm64/arm/x86 platform before
since most memcpy() would behave in an increasing address order
("copy upwards" [3]) and it's the correct order of in-place
decompression but it really needs an update to memmove() for sure
considering it's an undefined behavior according to the standard
and some unique optimization already exists in the kernel.
[1] 33cb8518ac
[2] https://github.com/lz4/lz4/pull/717#issuecomment-497818921
[3] https://sourceware.org/bugzilla/show_bug.cgi?id=12518
Link: https://lkml.kernel.org/r/20201122030749.2698994-1-hsiangkao@redhat.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Reviewed-by: Nick Terrell <terrelln@fb.com>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Li Guifu <bluce.liguifu@huawei.com>
Cc: Guo Xuenan <guoxuenan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
