- 07 Apr, 2020 40 commits
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Alexey Dobriyan authored
PT_INTERP ELF header can be spared if executable is static. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200219185012.GB4871@avx2Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Alexey Dobriyan authored
"loc" variable became just a wrapper for PT_INTERP ELF header after main ELF header was moved to "bprm->buf". Delete it. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200219184847.GA4871@avx2Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Jason Baron authored
Davidlohr Bueso pointed out that when CONFIG_DEBUG_LOCK_ALLOC is set ep_poll_safewake() can take several non-raw spinlocks after disabling interrupts. Since a spinlock can block in the -rt kernel, we can't take a spinlock after disabling interrupts. So let's re-work how we determine the nesting level such that it plays nicely with the -rt kernel. Let's introduce a 'nests' field in struct eventpoll that records the current nesting level during ep_poll_callback(). Then, if we nest again we can find the previous struct eventpoll that we were called from and increase our count by 1. The 'nests' field is protected by ep->poll_wait.lock. I've also moved the visited field to reduce the size of struct eventpoll from 184 bytes to 176 bytes on x86_64 for !CONFIG_DEBUG_LOCK_ALLOC, which is typical for a production config. Reported-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Jason Baron <jbaron@akamai.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Cc: Roman Penyaev <rpenyaev@suse.de> Cc: Eric Wong <normalperson@yhbt.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Link: http://lkml.kernel.org/r/1582739816-13167-1-git-send-email-jbaron@akamai.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Roman Penyaev authored
This testcase repeats epollbug.c from the bug: https://bugzilla.kernel.org/show_bug.cgi?id=205933 What it tests? It tests the race between epoll_ctl() and epoll_wait(). New event mask passed to epoll_ctl() triggers wake up, which can be missed because of the bug described in the link. Reproduction is 100%, so easy to fix. Kudos, Max, for wonderful test case. Signed-off-by: Roman Penyaev <rpenyaev@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Max Neunhoeffer <max@arangodb.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Christopher Kohlhoff <chris.kohlhoff@clearpool.io> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Jason Baron <jbaron@akamai.com> Cc: Jes Sorensen <jes.sorensen@gmail.com> Link: http://lkml.kernel.org/r/20200214170211.561524-2-rpenyaev@suse.deSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
WARNING: function definition argument 'flags' should also have an identifier name #26: FILE: drivers/tty/serial/sh-sci.c:1348: + unsigned long uninitialized_var(flags); Special-case uninitialized_var() to prevent this. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/7db7944761b0bd88c70eb17d4b7f40fe589e14ed.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Lubomir Rintel authored
According to Devicetree maintainers (see Link: below), the Devicetree binding documents are preferrably licensed (GPL-2.0-only OR BSD-2-Clause). Let's check that. The actual check is a bit more relaxed, to allow more liberal but compatible licensing (e.g. GPL-2.0-or-later OR BSD-2-Clause). Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Joe Perches <joe@perches.com> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Cc: Rob Herring <robh@kernel.org> Cc: Neil Armstrong <narmstrong@baylibre.com> Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>, Cc: Jonas Karlman <jonas@kwiboo.se>, Cc: Jernej Skrabec <jernej.skrabec@siol.net>, Cc: Mark Rutland <mark.rutland@arm.com>, Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch>, Link: https://lore.kernel.org/lkml/20200108142132.GA4830@bogus/ Link: http://lkml.kernel.org/r/20200309215153.38824-1-lkundrak@v3.skSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
The Gerrit Change-Id: entry is sometimes placed after a Signed-off-by: line. When this occurs, the Gerrit warning is not currently emitted as the first Signed-off-by: signature sets a flag to stop looking. Change the test to add a test for the --- patch separator and emit the warning before any before the --- and also before any diff file name. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/2f6d5f8766fe7439a116c77ea8cc721a3f2d77a2.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Antonio Borneo authored
Linux kernel coding style requires a size of 8 characters for both TAB and indentation, and such value is embedded as magic value allover the checkpatch script. This makes hard to reuse the script by other projects with different requirements in their coding style (e.g. OpenOCD [1] requires TAB size of 4 characters [2]). Replace the magic value 8 with a variable. Add a command-line option "--tab-size" to let the user select a TAB size value other than 8. [1] http://openocd.org/ [2] http://openocd.org/doc/doxygen/html/stylec.html#styleformatSigned-off-by: Antonio Borneo <borneo.antonio@gmail.com> Signed-off-by: Erik Ahlén <erik.ahlen@avalonenterprise.com> Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Link: http://lkml.kernel.org/r/20200122163852.124417-3-borneo.antonio@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Antonio Borneo authored
Commit 1574a29f ("checkpatch: allow multiple const * types") claims to support repetition of pattern "const *", but it actually allows only one extra instance. Check the following lines int a(char const * const x[]); int b(char const * const *x); int c(char const * const * const x[]); int d(char const * const * const *x); with command ./scripts/checkpatch.pl --show-types -f filename to find that only the first line passes the test, while a warning is triggered by the other 3 lines: WARNING:FUNCTION_ARGUMENTS: function definition argument 'char const * const' should also have an identifier name The reason is that the pattern match halts at the second asterisk in the line, thus the remaining text starting with asterisk fails to match a valid name for a variable. Fixed by replacing "?" (Match 1 or 0 times) with "{0,4}" (Match no more than 4 times) in the regular expression. Fix also the similar test for types in unusual order. Fixes: 1574a29f ("checkpatch: allow multiple const * types") Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Link: http://lkml.kernel.org/r/20200122163852.124417-1-borneo.antonio@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Antonio Borneo authored
Fix spelling of "concatenation". Don't use tab after space in indentation. Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Link: http://lkml.kernel.org/r/20200122163852.124417-2-borneo.antonio@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
commit 294f69e6 ("compiler_attributes.h: Add 'fallthrough' pseudo keyword for switch/case use") added the pseudo keyword so add a test for it to checkpatch. Warn on a patch or use --strict for files. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/8b6c1b9031ab9f3cdebada06b8d46467f1492d68.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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John Hubbard authored
In order to support the get-lore-mbox.py tool described in [1], I ran: git format-patch --base=<commit> --cover-letter <revrange> ... which generated a "base-commit: <commit-hash>" tag at the end of the cover letter. However, checkpatch.pl generated an error upon encounting "base-commit:" in the cover letter: "ERROR: Please use git commit description style..." ... because it found the "commit" keyword, and failed to recognize that it was part of the "base-commit" phrase, and as such, should not be subjected to the same commit description style rules. Update checkpatch.pl to include a special case for "base-commit:" (at the start of the line, possibly with some leading whitespace) so that that tag no longer generates a checkpatch error. [1] https://lwn.net/Articles/811528/ "Better tools for kernel developers" Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Joe Perches <joe@perches.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Konstantin Ryabitsev <konstantin@linuxfoundation.org> Cc: Jonathan Corbet <corbet@lwn.net> Link: http://lkml.kernel.org/r/20200213055004.69235-2-jhubbard@nvidia.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Lubomir Rintel authored
This adds a warning when a YAML file is lacking a SPDX header on first line, or it uses incorrect commenting style. Currently the only YAML files in the tree are Devicetree binding documents. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Joe Perches <joe@perches.com> Cc: Rob Herring <robh@kernel.org> Link: http://lkml.kernel.org/r/20200129123356.388669-1-lkundrak@v3.skSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
About 2% of the last 100K commits have email addresses that include an RFC2822 compliant comment like: Peter Zijlstra (Intel) <peterz@infradead.org> checkpatch currently does a comparison of the complete name and address to the submitted author to determine if the author has signed-off and emits a warning if the exact email names and addresses do not match. Unfortunately, the author email address can be written without the comment like: Peter Zijlstra <peterz@infradead.org> Add logic to compare the comment stripped email addresses to avoid this warning. Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/ebaa2f7c8f94e25520981945cddcc1982e70e072.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Nathan Chancellor authored
Clang warns: ../lib/dynamic_debug.c:1034:24: warning: array comparison always evaluates to false [-Wtautological-compare] if (__start___verbose == __stop___verbose) { ^ 1 warning generated. These are not true arrays, they are linker defined symbols, which are just addresses. Using the address of operator silences the warning and does not change the resulting assembly with either clang/ld.lld or gcc/ld (tested with diff + objdump -Dr). Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Jason Baron <jbaron@akamai.com> Link: https://github.com/ClangBuiltLinux/linux/issues/894 Link: http://lkml.kernel.org/r/20200220051320.10739-1-natechancellor@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Rikard Falkeborn authored
GENMASK() and GENMASK_ULL() are supposed to be called with the high bit as the first argument and the low bit as the second argument. Mixing them will return a mask with zero bits set. Recent commits show getting this wrong is not uncommon, see e.g. commit aa4c0c90 ("net: stmmac: Fix misuses of GENMASK macro") and commit 9bdd7bb3 ("clocksource/drivers/npcm: Fix misuse of GENMASK macro"). To prevent such mistakes from appearing again, add compile time sanity checking to the arguments of GENMASK() and GENMASK_ULL(). If both arguments are known at compile time, and the low bit is higher than the high bit, break the build to detect the mistake immediately. Since GENMASK() is used in declarations, BUILD_BUG_ON_ZERO() must be used instead of BUILD_BUG_ON(). __builtin_constant_p does not evaluate is argument, it only checks if it is a constant or not at compile time, and __builtin_choose_expr does not evaluate the expression that is not chosen. Therefore, GENMASK(x++, 0) does only evaluate x++ once. Commit 95b980d6 ("linux/bits.h: make BIT(), GENMASK(), and friends available in assembly") made the macros in linux/bits.h available in assembly. Since BUILD_BUG_OR_ZERO() is not asm compatible, disable the checks if the file is included in an asm file. Due to bugs in GCC versions before 4.9 [0], disable the check if building with a too old GCC compiler. [0]: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=19449Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Haren Myneni <haren@us.ibm.com> Cc: Joe Perches <joe@perches.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: lkml <linux-kernel@vger.kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200308193954.2372399-1-rikard.falkeborn@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Dan Carpenter authored
The "info" pointer has already been dereferenced so checking here is too late. Fortunately, we never pass NULL pointers to the test_kmod_put_module() function so the test can simply be removed. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Link: http://lkml.kernel.org/r/20200228092452.vwkhthsn77nrxdy6@kili.mountainSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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chenqiwu authored
Leave blank space between the right-hand and left-hand side of the assignment to meet the kernel coding style better. Signed-off-by: chenqiwu <chenqiwu@xiaomi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Michel Lespinasse <walken@google.com> Link: http://lkml.kernel.org/r/1582621140-25850-1-git-send-email-qiwuchen55@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Andy Shevchenko authored
Commit 30544ed5 ("lib/bitmap: introduce bitmap_replace() helper") introduced some new test cases to the test_bitmap.c module. Among these it also introduced an (unused) definition. Let's make use of EXP2_IN_BITS. Reported-by: Alex Shi <alex.shi@linux.alibaba.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com> Link: http://lkml.kernel.org/r/20200121151847.75223-1-andriy.shevchenko@linux.intel.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Qian Cai authored
"vm_committed_as.count" could be accessed concurrently as reported by KCSAN, BUG: KCSAN: data-race in __vm_enough_memory / percpu_counter_add_batch write to 0xffffffff9451c538 of 8 bytes by task 65879 on cpu 35: percpu_counter_add_batch+0x83/0xd0 percpu_counter_add_batch at lib/percpu_counter.c:91 __vm_enough_memory+0xb9/0x260 dup_mm+0x3a4/0x8f0 copy_process+0x2458/0x3240 _do_fork+0xaa/0x9f0 __do_sys_clone+0x125/0x160 __x64_sys_clone+0x70/0x90 do_syscall_64+0x91/0xb05 entry_SYSCALL_64_after_hwframe+0x49/0xbe read to 0xffffffff9451c538 of 8 bytes by task 66773 on cpu 19: __vm_enough_memory+0x199/0x260 percpu_counter_read_positive at include/linux/percpu_counter.h:81 (inlined by) __vm_enough_memory at mm/util.c:839 mmap_region+0x1b2/0xa10 do_mmap+0x45c/0x700 vm_mmap_pgoff+0xc0/0x130 ksys_mmap_pgoff+0x6e/0x300 __x64_sys_mmap+0x33/0x40 do_syscall_64+0x91/0xb05 entry_SYSCALL_64_after_hwframe+0x49/0xbe The read is outside percpu_counter::lock critical section which results in a data race. Fix it by adding a READ_ONCE() in percpu_counter_read_positive() which could also service as the existing compiler memory barrier. Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Marco Elver <elver@google.com> Link: http://lkml.kernel.org/r/1582302724-2804-1-git-send-email-cai@lca.pwSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Alexander Potapenko authored
filter_irq_stacks() can be used by other tools (e.g. KMSAN), so it needs to be moved to a common location. lib/stackdepot.c seems a good place, as filter_irq_stacks() is usually applied to the output of stack_trace_save(). This patch has been previously mailed as part of KMSAN RFC patch series. [glider@google.co: nds32: linker script: add SOFTIRQENTRY_TEXT\ Link: http://lkml.kernel.org/r/20200311121002.241430-1-glider@google.com [glider@google.com: add IRQENTRY_TEXT and SOFTIRQENTRY_TEXT to linker script] Link: http://lkml.kernel.org/r/20200311121124.243352-1-glider@google.comSigned-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: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Link: http://lkml.kernel.org/r/20200220141916.55455-3-glider@google.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Alexander Potapenko authored
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.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Alexander Potapenko authored
Avoid crashes on corrupted stack ids. Despite stack ID corruption may indicate other bugs in the program, we'd better fail gracefully on such IDs instead of crashing the kernel. This patch has been previously mailed as part of KMSAN RFC patch series. Link: http://lkml.kernel.org/r/20200220141916.55455-1-glider@google.comSigned-off-by: Alexander Potapenko <glider@google.com> 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: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> From: Dan Carpenter <dan.carpenter@oracle.com> Subject: lib/stackdepot.c: fix a condition in stack_depot_fetch() We should check for a NULL pointer first before adding the offset. Otherwise if the pointer is NULL and the offset is non-zero, it will lead to an Oops. Fixes: d45048e65a59 ("lib/stackdepot.c: check depot_index before accessing the stack slab") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Alexander Potapenko <glider@google.com> Link: http://lkml.kernel.org/r/20200312113006.GA20562@mwandaSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Kees Cook authored
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=44916Suggested-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@keescookSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Geert Uytterhoeven authored
Add the missing closing parenthesis to the description for the to_buffer parameter of sg_copy_buffer(). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Akinobu Mita <akinobu.mita@gmail.com Link: http://lkml.kernel.org/r/20200212084241.8778-1-geert+renesas@glider.beSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Gustavo A. R. Silva authored
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200211205948.GA26459@embeddedorSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Gustavo A. R. Silva authored
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200211205813.GA25602@embeddedorSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Gustavo A. R. Silva authored
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200211205620.GA24694@embeddedorSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Gustavo A. R. Silva authored
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200211205119.GA21234@embeddedorSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Konstantin Khlebnikov authored
file_path=<path> defines file or directory to open lock_inode=Y set lock_rwsem_ptr to inode->i_rwsem lock_mapping=Y set lock_rwsem_ptr to mapping->i_mmap_rwsem lock_sb_umount=Y set lock_rwsem_ptr to sb->s_umount This gives safe and simple way to see how system reacts to contention of common vfs locks and how syscalls depend on them directly or indirectly. For example to block s_umount for 60 seconds: # modprobe test_lockup file_path=. lock_sb_umount time_secs=60 state=S This is useful for checking/testing scalability issues like this: https://lore.kernel.org/lkml/158497590858.7371.9311902565121473436.stgit@buzz/Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Colin Ian King <colin.king@canonical.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Kees Cook <keescook@chromium.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Sasha Levin <sashal@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/158498153964.5621.83061779039255681.stgit@buzzSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Colin Ian King authored
There is a spelling mistake in a pr_notice message. Fix it. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Kees Cook <keescook@chromium.org> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Sasha Levin <sashal@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20200221155145.79522-1-colin.king@canonical.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Konstantin Khlebnikov authored
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.netSigned-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@buzzSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Josh Poimboeuf authored
With CONFIG_CC_OPTIMIZE_FOR_SIZE, objtool reports: drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool: i915_gem_execbuffer2_ioctl()+0x5b7: call to gen8_canonical_addr() with UACCESS enabled This means i915_gem_execbuffer2_ioctl() is calling gen8_canonical_addr() from the user_access_begin/end critical region (i.e, with SMAP disabled). While it's probably harmless in this case, in general we like to avoid extra function calls in SMAP-disabled regions because it can open up inadvertent security holes. Fix the warning by changing the sign extension helpers to __always_inline. This convinces GCC to inline gen8_canonical_addr(). The sign extension functions are trivial anyway, so it makes sense to always inline them. With my test optimize-for-size-based config, this actually shrinks the text size of i915_gem_execbuffer.o by 45 bytes -- and no change for vmlinux. Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Chris Wilson <chris@chris-wilson.co.uk> Link: http://lkml.kernel.org/r/740179324b2b18b750b16295c48357f00b5fa9ed.1582982020.git.jpoimboe@redhat.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Joe Perches authored
The MAINTAINERS file header has never shown a preferred order for the section entries but scripts/parse-maintainers.pl added a preferred order with commit 61f74164 ("parse-maintainers: Add section pattern sorting") Commit 5cdbec10 ("parse-maintainers: Do not sort section content by default") changed the preferred order to be a bit more sensible. Update the MAINTAINERS section description block to use this preferred section entry ordering. Add a slightly better description for the N: entry too. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Link: http://lkml.kernel.org/r/5aa5aad6fb1678230c260337dc066cd449a2bf32.camel@perches.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Vegard Nossum authored
compiletime_assert() uses __LINE__ to create a unique function name. This means that if you have more than one BUILD_BUG_ON() in the same source line (which can happen if they appear e.g. in a macro), then the error message from the compiler might output the wrong condition. For this source file: #include <linux/build_bug.h> #define macro() \ BUILD_BUG_ON(1); \ BUILD_BUG_ON(0); void foo() { macro(); } gcc would output: ./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_9' declared with attribute error: BUILD_BUG_ON failed: 0 _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) However, it was not the BUILD_BUG_ON(0) that failed, so it should say 1 instead of 0. With this patch, we use __COUNTER__ instead of __LINE__, so each BUILD_BUG_ON() gets a different function name and the correct condition is printed: ./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_0' declared with attribute error: BUILD_BUG_ON failed: 1 _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Daniel Santos <daniel.santos@pobox.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Ian Abbott <abbotti@mev.co.uk> Cc: Joe Perches <joe@perches.com> Link: http://lkml.kernel.org/r/20200331112637.25047-1-vegard.nossum@oracle.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Masahiro Yamada authored
Commit ac7c3e4f ("compiler: enable CONFIG_OPTIMIZE_INLINING forcibly") made this always-on option. We released v5.4 and v5.5 including that commit. Remove the CONFIG option and clean up the code now. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: David Miller <davem@davemloft.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20200220110807.32534-2-masahiroy@kernel.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Masahiro Yamada authored
The code, #undef CONFIG_OPTIMIZE_INLINING, is not working as expected because <linux/compiler_types.h> is parsed before vclock_gettime.c since 28128c61 ("kconfig.h: Include compiler types to avoid missed struct attributes"). Since then, <linux/compiler_types.h> is included really early by using the '-include' option. So, you cannot negate the decision of <linux/compiler_types.h> in this way. You can confirm it by checking the pre-processed code, like this: $ make arch/x86/entry/vdso/vdso32/vclock_gettime.i There is no difference with/without CONFIG_CC_OPTIMIZE_FOR_SIZE. It is about two years since 28128c61. Nobody has reported a problem (or, nobody has even noticed the fact that this code is not working). It is ugly and unreliable to attempt to undefine a CONFIG option from C files, and anyway the inlining heuristic is up to the compiler. Just remove the broken code. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: David Miller <davem@davemloft.net> Link: http://lkml.kernel.org/r/20200220110807.32534-1-masahiroy@kernel.orgSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Nathan Chancellor authored
Clang warns: ../kernel/extable.c:37:52: warning: array comparison always evaluates to a constant [-Wtautological-compare] if (main_extable_sort_needed && __stop___ex_table > __start___ex_table) { ^ 1 warning generated. These are not true arrays, they are linker defined symbols, which are just addresses. Using the address of operator silences the warning and does not change the resulting assembly with either clang/ld.lld or gcc/ld (tested with diff + objdump -Dr). Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: https://github.com/ClangBuiltLinux/linux/issues/892 Link: http://lkml.kernel.org/r/20200219202036.45702-1-natechancellor@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Michal Simek authored
Generated files are also checked by sparse that's why add newline to remove sparse (C=1) warning. The issue was found on Microblaze and reported like this: ./arch/microblaze/include/generated/uapi/asm/unistd_32.h:438:45: warning: no newline at end of file Mips and PowerPC have it already but let's align with style used by m68k. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Stefan Asserhall <stefan.asserhall@xilinx.com> Acked-by: Max Filippov <jcmvbkbc@gmail.com> (xtensa) Cc: Arnd Bergmann <arnd@arndb.de> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Zankel <chris@zankel.net> Cc: David S. Miller <davem@davemloft.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Burton <paulburton@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Tony Luck <tony.luck@intel.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/4d32ab4e1fb2edb691d2e1687e8fb303c09fd023.1581504803.git.michal.simek@xilinx.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
It's clearer to just put this inline. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200317193201.9924-5-adobriyan@gmail.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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