- 07 Feb, 2018 40 commits
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Joe Perches authored
Declarations should start on a tabstop too. Link: http://lkml.kernel.org/r/1b5f97673f36595956ad43329f77bf1a5546d2ff.1513976662.git.joe@perches.comSigned-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>
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Joe Perches authored
DEVICE_ATTR is a declaration macro that has a few alternate and preferred forms like DEVICE_ATTR_RW, DEVICE_ATTR_RO, and DEVICE_ATTR. As well, many uses of DEVICE_ATTR could use the preferred forms when the show or store functions are also named in a regular form. Suggest the preferred forms when appropriate. Also emit a permissions warning if the the permissions are not the typical 0644, 0444, or 0200. Link: http://lkml.kernel.org/r/725864f363d91d1e1e6894a39fb57662eabd6d65.1513803306.git.joe@perches.comSigned-off-by:
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Joe Perches authored
Given this patch context, +#define EFI_ST_DISK_IMG { \ + 0x00000240, "\xbe\x5b\x7c\xac\x22\xc0\x74\x0b" /* .[|.".t. */ \ + } the current code misreports a quoted string line continuation defect as there is a single quote in comment. The 'raw' line should not be tested for quote count, the comment substituted line should be instead. Link: http://lkml.kernel.org/r/13f2735df10c33ca846e26f42f5cce6618157200.1513698599.git.joe@perches.comSigned-off-by:Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by:
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Joe Perches authored
module_param and create_proc uses with a permissions use of a single 0 are "special" and should not emit any warning. module_param uses with permission 0 are not visible in sysfs create_proc uses with permission 0 use a default permission Link: http://lkml.kernel.org/r/b6583611bb529ea6f6d43786827fddbabbab0a71.1513190059.git.joe@perches.comSigned-off-by:
Bartosz Golaszewski <brgl@bgdev.pl> Signed-off-by:
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Andreas Brauchli authored
Allow lines with URL to exceed the 80 char limit for improved interaction in adaption to ongoing but undocumented practice. $ git grep -E '://\S{77}.*' -- '*.[ch]' As per RFC3986 [1], the URL format allows for alphanum, +, - and . characters in the scheme before the separator :// as long as it starts with a letter (e.g. https, git, f.-+). Recognition of URIs without more context information is prone to false positives and thus currently left out of the heuristics. $rawline is used in the check as comments are removed from $line. [1] https://tools.ietf.org/html/rfc3986#section-3.1 Link: http://lkml.kernel.org/r/1511355432.12667.15.camel@elementarea.netSigned-off-by:Andreas Brauchli <andreas.brauchli@sensirion.com> Acked-by:
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Pravin Shedge authored
test_sort.c performs array-based and linked list sort test. Code allows to compile either as a loadable modules or builtin into the kernel. Current code is not allow to unload the test_sort.ko module after successful completion. This patch adds support to unload the "test_sort.ko" module by adding module_exit support. Previous patch was implemented auto unload support by returning -EAGAIN from module_init() function on successful case, but this approach is not ideal. The auto-unload might seem like a nice optimization, but it encourages inconsistent behaviour. And behaviour that is different from all other normal modules. Link: http://lkml.kernel.org/r/1513967133-6843-1-git-send-email-pravin.shedge4linux@gmail.comSigned-off-by:
Pravin Shedge <pravin.shedge4linux@gmail.com> Cc: Kostenzer Felix <fkostenzer@live.at> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by:
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Vincent Legoll authored
No need to get into the submenu to disable all related config entries. This makes it easier to disable all RUNTIME_TESTS config options without entering the submenu. It will also enable one to see that en/dis-abled state from the outside menu. This is only intended to change menuconfig UI, not change the config dependencies. Link: http://lkml.kernel.org/r/20171209162742.7363-1-vincent.legoll@gmail.comSigned-off-by:
Vincent Legoll <vincent.legoll@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Clement Courbet authored
We've measured that we spend ~0.6% of sys cpu time in cpumask_next_and(). It's essentially a joined iteration in search for a non-zero bit, which is currently implemented as a lookup join (find a nonzero bit on the lhs, lookup the rhs to see if it's set there). Implement a direct join (find a nonzero bit on the incrementally built join). Also add generic bitmap benchmarks in the new `test_find_bit` module for new function (see `find_next_and_bit` in [2] and [3] below). For cpumask_next_and, direct benchmarking shows that it's 1.17x to 14x faster with a geometric mean of 2.1 on 32 CPUs [1]. No impact on memory usage. Note that on Arm, the new pure-C implementation still outperforms the old one that uses a mix of C and asm (`find_next_bit`) [3]. [1] Approximate benchmark code: ``` unsigned long src1p[nr_cpumask_longs] = {pattern1}; unsigned long src2p[nr_cpumask_longs] = {pattern2}; for (/*a bunch of repetitions*/) { for (int n = -1; n <= nr_cpu_ids; ++n) { asm volatile("" : "+rm"(src1p)); // prevent any optimization asm volatile("" : "+rm"(src2p)); unsigned long result = cpumask_next_and(n, src1p, src2p); asm volatile("" : "+rm"(result)); } } ``` Results: pattern1 pattern2 time_before/time_after 0x0000ffff 0x0000ffff 1.65 0x0000ffff 0x00005555 2.24 0x0000ffff 0x00001111 2.94 0x0000ffff 0x00000000 14.0 0x00005555 0x0000ffff 1.67 0x00005555 0x00005555 1.71 0x00005555 0x00001111 1.90 0x00005555 0x00000000 6.58 0x00001111 0x0000ffff 1.46 0x00001111 0x00005555 1.49 0x00001111 0x00001111 1.45 0x00001111 0x00000000 3.10 0x00000000 0x0000ffff 1.18 0x00000000 0x00005555 1.18 0x00000000 0x00001111 1.17 0x00000000 0x00000000 1.25 ----------------------------- geo.mean 2.06 [2] test_find_next_bit, X86 (skylake) [ 3913.477422] Start testing find_bit() with random-filled bitmap [ 3913.477847] find_next_bit: 160868 cycles, 16484 iterations [ 3913.477933] find_next_zero_bit: 169542 cycles, 16285 iterations [ 3913.478036] find_last_bit: 201638 cycles, 16483 iterations [ 3913.480214] find_first_bit: 4353244 cycles, 16484 iterations [ 3913.480216] Start testing find_next_and_bit() with random-filled bitmap [ 3913.481074] find_next_and_bit: 89604 cycles, 8216 iterations [ 3913.481075] Start testing find_bit() with sparse bitmap [ 3913.481078] find_next_bit: 2536 cycles, 66 iterations [ 3913.481252] find_next_zero_bit: 344404 cycles, 32703 iterations [ 3913.481255] find_last_bit: 2006 cycles, 66 iterations [ 3913.481265] find_first_bit: 17488 cycles, 66 iterations [ 3913.481266] Start testing find_next_and_bit() with sparse bitmap [ 3913.481272] find_next_and_bit: 764 cycles, 1 iterations [3] test_find_next_bit, arm (v7 odroid XU3). [ 267.206928] Start testing find_bit() with random-filled bitmap [ 267.214752] find_next_bit: 4474 cycles, 16419 iterations [ 267.221850] find_next_zero_bit: 5976 cycles, 16350 iterations [ 267.229294] find_last_bit: 4209 cycles, 16419 iterations [ 267.279131] find_first_bit: 1032991 cycles, 16420 iterations [ 267.286265] Start testing find_next_and_bit() with random-filled bitmap [ 267.302386] find_next_and_bit: 2290 cycles, 8140 iterations [ 267.309422] Start testing find_bit() with sparse bitmap [ 267.316054] find_next_bit: 191 cycles, 66 iterations [ 267.322726] find_next_zero_bit: 8758 cycles, 32703 iterations [ 267.329803] find_last_bit: 84 cycles, 66 iterations [ 267.336169] find_first_bit: 4118 cycles, 66 iterations [ 267.342627] Start testing find_next_and_bit() with sparse bitmap [ 267.356919] find_next_and_bit: 91 cycles, 1 iterations [courbet@google.com: v6] Link: http://lkml.kernel.org/r/20171129095715.23430-1-courbet@google.com [geert@linux-m68k.org: m68k/bitops: always include <asm-generic/bitops/find.h>] Link: http://lkml.kernel.org/r/1512556816-28627-1-git-send-email-geert@linux-m68k.org Link: http://lkml.kernel.org/r/20171128131334.23491-1-courbet@google.comSigned-off-by:Clement Courbet <courbet@google.com> Signed-off-by:
Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yury Norov <ynorov@caviumnetworks.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by:
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Yury Norov authored
As suggested in review comments: * printk: align numbers using whitespaces instead of tabs; * return error value from init() to avoid calling rmmod if testing again; * use ktime_get instead of get_cycles as some arches don't support it; The output in dmesg (on QEMU arm64): [ 38.823430] Start testing find_bit() with random-filled bitmap [ 38.845358] find_next_bit: 20138448 ns, 163968 iterations [ 38.856217] find_next_zero_bit: 10615328 ns, 163713 iterations [ 38.863564] find_last_bit: 7111888 ns, 163967 iterations [ 40.944796] find_first_bit: 2081007216 ns, 163968 iterations [ 40.944975] [ 40.944975] Start testing find_bit() with sparse bitmap [ 40.945268] find_next_bit: 73216 ns, 656 iterations [ 40.967858] find_next_zero_bit: 22461008 ns, 327025 iterations [ 40.968047] find_last_bit: 62320 ns, 656 iterations [ 40.978060] find_first_bit: 9889360 ns, 656 iterations Link: http://lkml.kernel.org/r/20171124143040.a44jvhmnaiyedg2i@yury-thinkpadSigned-off-by:
Yury Norov <ynorov@caviumnetworks.com> Tested-by:
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Yury Norov authored
As suggested in review comments, rename test_find_bit.c to find_bit_benchmark.c. Link: http://lkml.kernel.org/r/20171124143040.a44jvhmnaiyedg2i@yury-thinkpadSigned-off-by:
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Alexander Potapenko authored
stackdepot used to call memcmp(), which compiler tools normally instrument, therefore every lookup used to unnecessarily call instrumented code. This is somewhat ok in the case of KASAN, but under KMSAN a lot of time was spent in the instrumentation. Link: http://lkml.kernel.org/r/20171117172149.69562-1-glider@google.comSigned-off-by:
Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by:
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Andy Shevchenko authored
Behaviour of bitmap_fill() differs from bitmap_zero() in a way how bits behind bitmap are handed. bitmap_zero() clears entire bitmap by unsigned long boundary, while bitmap_fill() mimics bitmap_set(). Here we change bitmap_fill() behaviour to be consistent with bitmap_zero() and add a note to documentation. The change might reveal some bugs in the code where unused bits are handled differently and in such cases bitmap_set() has to be used. Link: http://lkml.kernel.org/r/20180109172430.87452-4-andriy.shevchenko@linux.intel.comSigned-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Suggested-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yury Norov <ynorov@caviumnetworks.com> Signed-off-by:
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Andy Shevchenko authored
Since we have separate explicit test cases for bitmap_zero() / bitmap_clear() and bitmap_fill() / bitmap_set(), clean up test_zero_fill_copy() to only test bitmap_copy() functionality and thus rename a function to reflect the changes. While here, replace bitmap_fill() by bitmap_set() with proper values. Link: http://lkml.kernel.org/r/20180109172430.87452-3-andriy.shevchenko@linux.intel.comSigned-off-by:
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Andy Shevchenko authored
Explicitly test bitmap_fill() and bitmap_set() functions. For bitmap_fill() we expect a consistent behaviour as in bitmap_zero(), i.e. the trailing bits will be set up to unsigned long boundary. Link: http://lkml.kernel.org/r/20180109172430.87452-2-andriy.shevchenko@linux.intel.comSigned-off-by:
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Andy Shevchenko authored
Explicitly test bitmap_zero() and bitmap_clear() functions. Link: http://lkml.kernel.org/r/20180109172430.87452-1-andriy.shevchenko@linux.intel.comSigned-off-by:
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Yury Norov authored
with bitmap_{from,to}_arr32 over the kernel. Additionally to it: * __check_eq_bitmap() now takes single nbits argument. * __check_eq_u32_array is not used in new test but may be used in future. So I don't remove it here, but annotate as __used. Tested on arm64 and 32-bit BE mips. [arnd@arndb.de: perf: arm_dsu_pmu: convert to bitmap_from_arr32] Link: http://lkml.kernel.org/r/20180201172508.5739-2-ynorov@caviumnetworks.com [ynorov@caviumnetworks.com: fix net/core/ethtool.c] Link: http://lkml.kernel.org/r/20180205071747.4ekxtsbgxkj5b2fz@yury-thinkpad Link: http://lkml.kernel.org/r/20171228150019.27953-2-ynorov@caviumnetworks.comSigned-off-by:Arnd Bergmann <arnd@arndb.de> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: David Decotigny <decot@googlers.com>, Cc: David S. Miller <davem@davemloft.net>, Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by:
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Yury Norov authored
This patchset replaces bitmap_{to,from}_u32array with more simple and standard looking copy-like functions. bitmap_from_u32array() takes 4 arguments (bitmap_to_u32array is similar): - unsigned long *bitmap, which is destination; - unsigned int nbits, the length of destination bitmap, in bits; - const u32 *buf, the source; and - unsigned int nwords, the length of source buffer in ints. In description to the function it is detailed like: * copy min(nbits, 32*nwords) bits from @buf to @bitmap, remaining * bits between nword and nbits in @bitmap (if any) are cleared. Having two size arguments looks unneeded and potentially dangerous. It is unneeded because normally user of copy-like function should take care of the size of destination and make it big enough to fit source data. And it is dangerous because function may hide possible error if user doesn't provide big enough bitmap, and data becomes silently dropped. That's why all copy-like functions have 1 argument for size of copying data, and I don't see any reason to make bitmap_from_u32array() different. One exception that comes in mind is strncpy() which also provides size of destination in arguments, but it's strongly argued by the possibility of taking broken strings in source. This is not the case of bitmap_{from,to}_u32array(). There is no many real users of bitmap_{from,to}_u32array(), and they all very clearly provide size of destination matched with the size of source, so additional functionality is not used in fact. Like this: bitmap_from_u32array(to->link_modes.supported, __ETHTOOL_LINK_MODE_MASK_NBITS, link_usettings.link_modes.supported, __ETHTOOL_LINK_MODE_MASK_NU32); Where: #define __ETHTOOL_LINK_MODE_MASK_NU32 \ DIV_ROUND_UP(__ETHTOOL_LINK_MODE_MASK_NBITS, 32) In this patch, bitmap_copy_safe and bitmap_{from,to}_arr32 are introduced. 'Safe' in bitmap_copy_safe() stands for clearing unused bits in bitmap beyond last bit till the end of last word. It is useful for hardening API when bitmap is assumed to be exposed to userspace. bitmap_{from,to}_arr32 functions are replacements for bitmap_{from,to}_u32array. They don't take unneeded nwords argument, and so simpler in implementation and understanding. This patch suggests optimization for 32-bit systems - aliasing bitmap_{from,to}_arr32 to bitmap_copy_safe. Other possible optimization is aliasing 64-bit LE bitmap_{from,to}_arr32 to more generic function(s). But I didn't end up with the function that would be helpful by itself, and can be used to alias 64-bit LE bitmap_{from,to}_arr32, like bitmap_copy_safe() does. So I preferred to leave things as is. The following patch switches kernel to new API and introduces test for it. Discussion is here: https://lkml.org/lkml/2017/11/15/592 [ynorov@caviumnetworks.com: rename bitmap_copy_safe to bitmap_copy_clear_tail] Link: http://lkml.kernel.org/r/20180201172508.5739-3-ynorov@caviumnetworks.com Link: http://lkml.kernel.org/r/20171228150019.27953-1-ynorov@caviumnetworks.comSigned-off-by: -
Stephen Boyd authored
Replace my codeaurora.org address with my kernel.org address so that emails don't bounce. Link: http://lkml.kernel.org/r/20180129173258.10643-1-sboyd@codeaurora.orgSigned-off-by:
Stephen Boyd <sboyd@codeaurora.org> Signed-off-by:
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Rasmus Villemoes authored
This reverts commit 92266d6e ("async: simplify lowest_in_progress()") which was simply wrong: In the case where domain is NULL, we now use the wrong offsetof() in the list_first_entry macro, so we don't actually fetch the ->cookie value, but rather the eight bytes located sizeof(struct list_head) further into the struct async_entry. On 64 bit, that's the data member, while on 32 bit, that's a u64 built from func and data in some order. I think the bug happens to be harmless in practice: It obviously only affects callers which pass a NULL domain, and AFAICT the only such caller is async_synchronize_full() -> async_synchronize_full_domain(NULL) -> async_synchronize_cookie_domain(ASYNC_COOKIE_MAX, NULL) and the ASYNC_COOKIE_MAX means that in practice we end up waiting for the async_global_pending list to be empty - but it would break if somebody happened to pass (void*)-1 as the data element to async_schedule, and of course also if somebody ever does a async_synchronize_cookie_domain(, NULL) with a "finite" cookie value. Maybe the "harmless in practice" means this isn't -stable material. But I'm not completely confident my quick git grep'ing is enough, and there might be affected code in one of the earlier kernels that has since been removed, so I'll leave the decision to the stable guys. Link: http://lkml.kernel.org/r/20171128104938.3921-1-linux@rasmusvillemoes.dk Fixes: 92266d6e "async: simplify lowest_in_progress()" Signed-off-by:
Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Adam Wallis <awallis@codeaurora.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: <stable@vger.kernel.org> [3.10+] Signed-off-by:
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Sergey Senozhatsky authored
Use a separate fd set for select()-s exception fds param to fix the following gcc warning: pager.c:36:12: error: passing argument 2 to restrict-qualified parameter aliases with argument 4 [-Werror=restrict] select(1, &in, NULL, &in, NULL); ^~~ ~~~ Link: http://lkml.kernel.org/r/20180101105626.7168-1-sergey.senozhatsky@gmail.comSigned-off-by:Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by:
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Alexey Dobriyan authored
Exported header doesn't use anything from <linux/string.h>, it is <linux/uuid.h> which uses memcmp(). Link: http://lkml.kernel.org/r/20171225171121.GA22754@avx2Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by:
Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by:
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Kees Cook authored
Nearly all modern compilers support a stack-protector option, and nearly all modern distributions enable the kernel stack-protector, so enabling this by default in kernel builds would make sense. However, Kconfig does not have knowledge of available compiler features, so it isn't safe to force on, as this would unconditionally break builds for the compilers or architectures that don't have support. Instead, this introduces a new option, CONFIG_CC_STACKPROTECTOR_AUTO, which attempts to discover the best possible stack-protector available, and will allow builds to proceed even if the compiler doesn't support any stack-protector. This option is made the default so that kernels built with modern compilers will be protected-by-default against stack buffer overflows, avoiding things like the recent BlueBorne attack. Selection of a specific stack-protector option remains available, including disabling it. Additionally, tiny.config is adjusted to use CC_STACKPROTECTOR_NONE, since that's the option with the least code size (and it used to be the default, so we have to explicitly choose it there now). Link: http://lkml.kernel.org/r/1510076320-69931-4-git-send-email-keescook@chromium.orgSigned-off-by:
Kees Cook <keescook@chromium.org> Tested-by:
Laura Abbott <labbott@redhat.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Josh Triplett <josh@joshtriplett.org> Signed-off-by:
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Kees Cook authored
Various portions of the kernel, especially per-architecture pieces, need to know if the compiler is building with the stack protector. This was done in the arch/Kconfig with 'select', but this doesn't allow a way to do auto-detected compiler support. In preparation for creating an on-if-available default, move the logic for the definition of CONFIG_CC_STACKPROTECTOR into the Makefile. Link: http://lkml.kernel.org/r/1510076320-69931-3-git-send-email-keescook@chromium.orgSigned-off-by:
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Kees Cook authored
In order to make stack-protector failures warn instead of unconditionally breaking the build, this moves the compiler output sanity-check earlier, and sets a flag for later testing. Future patches can choose to warn or fail, depending on the flag value. Link: http://lkml.kernel.org/r/1510076320-69931-2-git-send-email-keescook@chromium.orgSigned-off-by:
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Markus Elfring authored
A single character (line break) should be put into a sequence. Thus use the corresponding function "seq_putc". This issue was detected by using the Coccinelle software. Link: http://lkml.kernel.org/r/04fb69fe-d820-9141-820f-07e9a48f4635@users.sourceforge.netSigned-off-by:
Markus Elfring <elfring@users.sourceforge.net> Signed-off-by:
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Alexey Dobriyan authored
Rearrange args for smaller code. lookup revolves around memcmp() which gets len 3rd arg, so propagate length as 3rd arg. readdir and lookup add additional arg to VFS ->readdir and ->lookup, so better add it to the end. Space savings on x86_64: add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-18 (-18) Function old new delta proc_readdir 22 13 -9 proc_lookup 18 9 -9 proc_match() is smaller if not inlined, I promise! Link: http://lkml.kernel.org/r/20180104175958.GB5204@avx2Signed-off-by:
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Alexey Dobriyan authored
use_pde() is used at every open/read/write/... of every random /proc file. Negative refcount happens only if PDE is being deleted by module (read: never). So it gets "likely". unuse_pde() gets "unlikely" for the same reason. close_pdeo() gets unlikely as the completion is filled only if there is a race between PDE removal and close() (read: never ever). It even saves code on x86_64 defconfig: add/remove: 0/0 grow/shrink: 1/2 up/down: 2/-20 (-18) Function old new delta close_pdeo 183 185 +2 proc_reg_get_unmapped_area 119 111 -8 proc_reg_poll 85 73 -12 Link: http://lkml.kernel.org/r/20180104175657.GA5204@avx2Signed-off-by:
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Alexey Dobriyan authored
/proc/self inode numbers, value of proc_inode_cache and st_nlink of /proc/$TGID are fixed constants. Link: http://lkml.kernel.org/r/20180103184707.GA31849@avx2Signed-off-by:
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Alexey Dobriyan authored
Document what ->pde_unload_lock actually does. Link: http://lkml.kernel.org/r/20180103185120.GB31849@avx2Signed-off-by:
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Alexey Dobriyan authored
struct proc_dir_entry became bit messy over years: * move 16-bit ->mode_t before namelen to get rid of padding * make ->in_use first field: it seems to be most used resulting in smaller code on x86_64 (defconfig): add/remove: 0/0 grow/shrink: 7/13 up/down: 24/-67 (-43) Function old new delta proc_readdir_de 451 455 +4 proc_get_inode 282 286 +4 pde_put 65 69 +4 remove_proc_subtree 294 297 +3 remove_proc_entry 297 300 +3 proc_register 295 298 +3 proc_notify_change 94 97 +3 unuse_pde 27 26 -1 proc_reg_write 89 85 -4 proc_reg_unlocked_ioctl 85 81 -4 proc_reg_read 89 85 -4 proc_reg_llseek 87 83 -4 proc_reg_get_unmapped_area 123 119 -4 proc_entry_rundown 139 135 -4 proc_reg_poll 91 85 -6 proc_reg_mmap 79 73 -6 proc_get_link 55 49 -6 proc_reg_release 108 101 -7 proc_reg_open 298 291 -7 close_pdeo 228 218 -10 * move writeable fields together to a first cacheline (on x86_64), those include * ->in_use: reference count, taken every open/read/write/close etc * ->count: reference count, taken at readdir on every entry * ->pde_openers: tracks (nearly) every open, dirtied * ->pde_unload_lock: spinlock protecting ->pde_openers * ->proc_iops, ->proc_fops, ->data: writeonce fields, used right together with previous group. * other rarely written fields go into 1st/2nd and 2nd/3rd cacheline on 32-bit and 64-bit respectively. Additionally on 32-bit, ->subdir, ->subdir_node, ->namelen, ->name go fully into 2nd cacheline, separated from writeable fields. They are all used during lookup. Link: http://lkml.kernel.org/r/20171220215914.GA7877@avx2Signed-off-by:
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Heiko Carstens authored
Commit df04abfd ("fs/proc/kcore.c: Add bounce buffer for ktext data") added a bounce buffer to avoid hardened usercopy checks. Copying to the bounce buffer was implemented with a simple memcpy() assuming that it is always valid to read from kernel memory iff the kern_addr_valid() check passed. A simple, but pointless, test case like "dd if=/proc/kcore of=/dev/null" now can easily crash the kernel, since the former execption handling on invalid kernel addresses now doesn't work anymore. Also adding a kern_addr_valid() implementation wouldn't help here. Most architectures simply return 1 here, while a couple implemented a page table walk to figure out if something is mapped at the address in question. With DEBUG_PAGEALLOC active mappings are established and removed all the time, so that relying on the result of kern_addr_valid() before executing the memcpy() also doesn't work. Therefore simply use probe_kernel_read() to copy to the bounce buffer. This also allows to simplify read_kcore(). At least on s390 this fixes the observed crashes and doesn't introduce warnings that were removed with df04abfd ("fs/proc/kcore.c: Add bounce buffer for ktext data"), even though the generic probe_kernel_read() implementation uses uaccess functions. While looking into this I'm also wondering if kern_addr_valid() could be completely removed...(?) Link: http://lkml.kernel.org/r/20171202132739.99971-1-heiko.carstens@de.ibm.com Fixes: df04abfd ("fs/proc/kcore.c: Add bounce buffer for ktext data") Fixes: f5509cc1 ("mm: Hardened usercopy") Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by:
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Alexey Dobriyan authored
It is 1:1 wrapper around seq_release(). Link: http://lkml.kernel.org/r/20171122171510.GA12161@avx2Signed-off-by:
Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by:
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Alexey Dobriyan authored
dentry name can be evaluated later, right before calling into VFS. Also, spend less time under ->mmap_sem. Link: http://lkml.kernel.org/r/20171110163034.GA2534@avx2Signed-off-by:
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Alexey Dobriyan authored
Iterators aren't necessary as you can just grab the first entry and delete it until no entries left. Link: http://lkml.kernel.org/r/20171121191121.GA20757@avx2Signed-off-by:
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Alexey Dobriyan authored
Current code does: if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) However sscanf() is broken garbage. It silently accepts whitespace between format specifiers (did you know that?). It silently accepts valid strings which result in integer overflow. Do not use sscanf() for any even remotely reliable parsing code. OK # readlink '/proc/1/map_files/55a23af39000-55a23b05b000' /lib/systemd/systemd broken # readlink '/proc/1/map_files/ 55a23af39000-55a23b05b000' /lib/systemd/systemd broken # readlink '/proc/1/map_files/55a23af39000-55a23b05b000 ' /lib/systemd/systemd very broken # readlink '/proc/1/map_files/1000000000000000055a23af39000-55a23b05b000' /lib/systemd/systemd Andrei said: : This patch breaks criu. It was a bug in criu. And this bug is on a minor : path, which works when memfd_create() isn't available. It is a reason why : I ask to not backport this patch to stable kernels. : : In CRIU this bug can be triggered, only if this patch will be backported : to a kernel which version is lower than v3.16. Link: http://lkml.kernel.org/r/20171120212706.GA14325@avx2Signed-off-by:
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Alexey Dobriyan authored
READ_ONCE and WRITE_ONCE are useless when there is only one read/write is being made. Link: http://lkml.kernel.org/r/20171120204033.GA9446@avx2Signed-off-by:
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Alexey Dobriyan authored
PROC_NUMBUF is 13 which is enough for "negative int + \n + \0". However PIDs and TGIDs are never negative and newline is not a concern, so use just 10 per integer. Link: http://lkml.kernel.org/r/20171120203005.GA27743@avx2Signed-off-by:
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Colin Ian King authored
Variable real_size is initialized with a value that is never read, it is re-assigned a new value later on, hence the initialization is redundant and can be removed. Cleans up clang warning: lib/test_kasan.c:422:21: warning: Value stored to 'real_size' during its initialization is never read Link: http://lkml.kernel.org/r/20180206144950.32457-1-colin.king@canonical.comSigned-off-by:
Colin Ian King <colin.king@canonical.com> Acked-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by:
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Andrey Konovalov authored
Right now the fact that KASAN uses a single shadow byte for 8 bytes of memory is scattered all over the code. This change defines KASAN_SHADOW_SCALE_SHIFT early in asm include files and makes use of this constant where necessary. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/34937ca3b90736eaad91b568edf5684091f662e3.1515775666.git.andreyknvl@google.comSigned-off-by:
Andrey Konovalov <andreyknvl@google.com> Acked-by:
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Andrey Konovalov authored
Use the new one. Link: http://lkml.kernel.org/r/de3b7ffc30a55178913a7d3865216aa7accf6c40.1515775666.git.andreyknvl@google.comSigned-off-by:
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