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2017-11-18kernel/panic.c: add TAINT_AUXBorislav Petkov1-1/+2
This is the gist of a patch which we've been forward-porting in our kernels for a long time now and it probably would make a good sense to have such TAINT_AUX flag upstream which can be used by each distro etc, how they see fit. This way, we won't need to forward-port a distro-only version indefinitely. Add an auxiliary taint flag to be used by distros and others. This obviates the need to forward-port whatever internal solutions people have in favor of a single flag which they can map arbitrarily to a definition of their pleasing. The "X" mnemonic could also mean eXternal, which would be taint from a distro or something else but not the upstream kernel. We will use it to mark modules for which we don't provide support. I.e., a really eXternal module. Link: http://lkml.kernel.org/r/20170911134533.dp5mtyku5bongx4c@pd.tnic Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Kees Cook <keescook@chromium.org> Cc: Jessica Yu <jeyu@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Michal Marek <mmarek@suse.cz> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Takashi Iwai <tiwai@suse.de> Cc: Petr Mladek <pmladek@suse.com> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-14linux/kernel.h: add/correct kernel-doc notationRandy Dunlap1-16/+74
Add kernel-doc notation for some macros. Correct kernel-doc comments & typos for a few macros. Link: http://lkml.kernel.org/r/76fa1403-1511-be4c-e9c4-456b43edfad3@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-09linux/kernel.h: move DIV_ROUND_DOWN_ULL() macroMasahiro Yamada1-2/+5
This macro is useful to avoid link error on 32-bit systems. We have the same definition in two drivers, so move it to include/linux/kernel.h While we are here, refactor DIV_ROUND_UP_ULL() by using DIV_ROUND_DOWN_ULL(). Link: http://lkml.kernel.org/r/1500945156-12907-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Mark Brown <broonie@kernel.org> Cc: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Boris Brezillon <boris.brezillon@free-electrons.com> Cc: Marek Vasut <marek.vasut@gmail.com> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Richard Weinberger <richard@nod.at> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-17locking/refcounts, x86/asm: Implement fast refcount overflow protectionKees Cook1-0/+7
This implements refcount_t overflow protection on x86 without a noticeable performance impact, though without the fuller checking of REFCOUNT_FULL. This is done by duplicating the existing atomic_t refcount implementation but with normally a single instruction added to detect if the refcount has gone negative (e.g. wrapped past INT_MAX or below zero). When detected, the handler saturates the refcount_t to INT_MIN / 2. With this overflow protection, the erroneous reference release that would follow a wrap back to zero is blocked from happening, avoiding the class of refcount-overflow use-after-free vulnerabilities entirely. Only the overflow case of refcounting can be perfectly protected, since it can be detected and stopped before the reference is freed and left to be abused by an attacker. There isn't a way to block early decrements, and while REFCOUNT_FULL stops increment-from-zero cases (which would be the state _after_ an early decrement and stops potential double-free conditions), this fast implementation does not, since it would require the more expensive cmpxchg loops. Since the overflow case is much more common (e.g. missing a "put" during an error path), this protection provides real-world protection. For example, the two public refcount overflow use-after-free exploits published in 2016 would have been rendered unexploitable: http://perception-point.io/2016/01/14/analysis-and-exploitation-of-a-linux-kernel-vulnerability-cve-2016-0728/ http://cyseclabs.com/page?n=02012016 This implementation does, however, notice an unchecked decrement to zero (i.e. caller used refcount_dec() instead of refcount_dec_and_test() and it resulted in a zero). Decrements under zero are noticed (since they will have resulted in a negative value), though this only indicates that a use-after-free may have already happened. Such notifications are likely avoidable by an attacker that has already exploited a use-after-free vulnerability, but it's better to have them reported than allow such conditions to remain universally silent. On first overflow detection, the refcount value is reset to INT_MIN / 2 (which serves as a saturation value) and a report and stack trace are produced. When operations detect only negative value results (such as changing an already saturated value), saturation still happens but no notification is performed (since the value was already saturated). On the matter of races, since the entire range beyond INT_MAX but before 0 is negative, every operation at INT_MIN / 2 will trap, leaving no overflow-only race condition. As for performance, this implementation adds a single "js" instruction to the regular execution flow of a copy of the standard atomic_t refcount operations. (The non-"and_test" refcount_dec() function, which is uncommon in regular refcount design patterns, has an additional "jz" instruction to detect reaching exactly zero.) Since this is a forward jump, it is by default the non-predicted path, which will be reinforced by dynamic branch prediction. The result is this protection having virtually no measurable change in performance over standard atomic_t operations. The error path, located in .text.unlikely, saves the refcount location and then uses UD0 to fire a refcount exception handler, which resets the refcount, handles reporting, and returns to regular execution. This keeps the changes to .text size minimal, avoiding return jumps and open-coded calls to the error reporting routine. Example assembly comparison: refcount_inc() before: .text: ffffffff81546149: f0 ff 45 f4 lock incl -0xc(%rbp) refcount_inc() after: .text: ffffffff81546149: f0 ff 45 f4 lock incl -0xc(%rbp) ffffffff8154614d: 0f 88 80 d5 17 00 js ffffffff816c36d3 ... .text.unlikely: ffffffff816c36d3: 48 8d 4d f4 lea -0xc(%rbp),%rcx ffffffff816c36d7: 0f ff (bad) These are the cycle counts comparing a loop of refcount_inc() from 1 to INT_MAX and back down to 0 (via refcount_dec_and_test()), between unprotected refcount_t (atomic_t), fully protected REFCOUNT_FULL (refcount_t-full), and this overflow-protected refcount (refcount_t-fast): 2147483646 refcount_inc()s and 2147483647 refcount_dec_and_test()s: cycles protections atomic_t 82249267387 none refcount_t-fast 82211446892 overflow, untested dec-to-zero refcount_t-full 144814735193 overflow, untested dec-to-zero, inc-from-zero This code is a modified version of the x86 PAX_REFCOUNT atomic_t overflow defense from the last public patch of PaX/grsecurity, based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Thanks to PaX Team for various suggestions for improvement for repurposing this code to be a refcount-only protection. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Elena Reshetova <elena.reshetova@intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Hans Liljestrand <ishkamiel@gmail.com> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: Jann Horn <jannh@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Serge E. Hallyn <serge@hallyn.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: arozansk@redhat.com Cc: axboe@kernel.dk Cc: kernel-hardening@lists.openwall.com Cc: linux-arch <linux-arch@vger.kernel.org> Link: http://lkml.kernel.org/r/20170815161924.GA133115@beast Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-13kernel.h: handle pointers to arrays better in container_of()Ian Abbott1-3/+7
If the first parameter of container_of() is a pointer to a non-const-qualified array type (and the third parameter names a non-const-qualified array member), the local variable __mptr will be defined with a const-qualified array type. In ISO C, these types are incompatible. They work as expected in GNU C, but some versions will issue warnings. For example, GCC 4.9 produces the warning "initialization from incompatible pointer type". Here is an example of where the problem occurs: ------------------------------------------------------- #include <linux/kernel.h> #include <linux/module.h> MODULE_LICENSE("GPL"); struct st { int a; char b[16]; }; static int __init example_init(void) { struct st t = { .a = 101, .b = "hello" }; char (*p)[16] = &t.b; struct st *x = container_of(p, struct st, b); printk(KERN_DEBUG "%p %p\n", (void *)&t, (void *)x); return 0; } static void __exit example_exit(void) { } module_init(example_init); module_exit(example_exit); ------------------------------------------------------- Building the module with gcc-4.9 results in these warnings (where '{m}' is the module source and '{k}' is the kernel source): ------------------------------------------------------- In file included from {m}/example.c:1:0: {m}/example.c: In function `example_init': {k}/include/linux/kernel.h:854:48: warning: initialization from incompatible pointer type const typeof( ((type *)0)->member ) *__mptr = (ptr); \ ^ {m}/example.c:14:17: note: in expansion of macro `container_of' struct st *x = container_of(p, struct st, b); ^ {k}/include/linux/kernel.h:854:48: warning: (near initialization for `x') const typeof( ((type *)0)->member ) *__mptr = (ptr); \ ^ {m}/example.c:14:17: note: in expansion of macro `container_of' struct st *x = container_of(p, struct st, b); ^ ------------------------------------------------------- Replace the type checking performed by the macro to avoid these warnings. Make sure `*(ptr)` either has type compatible with the member, or has type compatible with `void`, ignoring qualifiers. Raise compiler errors if this is not true. This is stronger than the previous behaviour, which only resulted in compiler warnings for a type mismatch. [arnd@arndb.de: fix new warnings for container_of()] Link: http://lkml.kernel.org/r/20170620200940.90557-1-arnd@arndb.de Link: http://lkml.kernel.org/r/20170525120316.24473-7-abbotti@mev.co.uk Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Borislav Petkov <bp@suse.de> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Johannes Berg <johannes.berg@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-23init: Introduce SYSTEM_SCHEDULING stateThomas Gleixner1-1/+5
might_sleep() debugging and smp_processor_id() debugging should be active right after the scheduler starts working. The init task can invoke smp_processor_id() from preemptible context as it is pinned on the boot cpu until sched_smp_init() removes the pinning and lets it schedule on all non isolated cpus. Add a new state which allows to enable those checks earlier and add it to the xen do_poweroff() function. No functional change. Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20170516184736.196214622@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-03Merge branch 'linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 Pull crypto updates from Herbert Xu: "Here is the crypto update for 4.12: API: - Add batch registration for acomp/scomp - Change acomp testing to non-unique compressed result - Extend algorithm name limit to 128 bytes - Require setkey before accept(2) in algif_aead Algorithms: - Add support for deflate rfc1950 (zlib) Drivers: - Add accelerated crct10dif for powerpc - Add crc32 in stm32 - Add sha384/sha512 in ccp - Add 3des/gcm(aes) for v5 devices in ccp - Add Queue Interface (QI) backend support in caam - Add new Exynos RNG driver - Add ThunderX ZIP driver - Add driver for hardware random generator on MT7623 SoC" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (101 commits) crypto: stm32 - Fix OF module alias information crypto: algif_aead - Require setkey before accept(2) crypto: scomp - add support for deflate rfc1950 (zlib) crypto: scomp - allow registration of multiple scomps crypto: ccp - Change ISR handler method for a v5 CCP crypto: ccp - Change ISR handler method for a v3 CCP crypto: crypto4xx - rename ce_ring_contol to ce_ring_control crypto: testmgr - Allow ecb(cipher_null) in FIPS mode Revert "crypto: arm64/sha - Add constant operand modifier to ASM_EXPORT" crypto: ccp - Disable interrupts early on unload crypto: ccp - Use only the relevant interrupt bits hwrng: mtk - Add driver for hardware random generator on MT7623 SoC dt-bindings: hwrng: Add Mediatek hardware random generator bindings crypto: crct10dif-vpmsum - Fix missing preempt_disable() crypto: testmgr - replace compression known answer test crypto: acomp - allow registration of multiple acomps hwrng: n2 - Use devm_kcalloc() in n2rng_probe() crypto: chcr - Fix error handling related to 'chcr_alloc_shash' padata: get_next is never NULL crypto: exynos - Add new Exynos RNG driver ...
2017-04-21linux/kernel.h: Add ALIGN_DOWN macroKrzysztof Kozlowski1-0/+1
Few parts of kernel define their own macro for aligning down so provide a common define for this, with the same usage and assumptions as existing ALIGN. Convert also three existing implementations to this one. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-04-18boot/param: Move next_arg() function to lib/cmdline.c for later reuseBaoquan He1-0/+1
next_arg() will be used to parse boot parameters in the x86/boot/compressed code, so move it to lib/cmdline.c for better code reuse. No change in functionality. Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Cc: Jens Axboe <axboe@fb.com> Cc: Jessica Yu <jeyu@redhat.com> Cc: Johannes Berg <johannes.berg@intel.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Larry Finger <Larry.Finger@lwfinger.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dan.j.williams@intel.com Cc: dave.jiang@intel.com Cc: dyoung@redhat.com Cc: keescook@chromium.org Cc: zijun_hu <zijun_hu@htc.com> Link: http://lkml.kernel.org/r/1492436099-4017-2-git-send-email-bhe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-25linux/kernel.h: fix DIV_ROUND_CLOSEST to support negative divisorsNiklas Söderlund1-4/+6
While working on a thermal driver I encounter a scenario where the divisor could be negative, instead of adding local code to handle this I though I first try to add support for this in DIV_ROUND_CLOSEST. Add support to DIV_ROUND_CLOSEST for negative divisors if both dividend and divisor variable types are signed. This should not alter current behavior for users of the macro as previously negative divisors where not supported. Before: DIV_ROUND_CLOSEST( 59, 4) = 15 DIV_ROUND_CLOSEST( 59, -4) = -14 DIV_ROUND_CLOSEST( -59, 4) = -15 DIV_ROUND_CLOSEST( -59, -4) = 14 After: DIV_ROUND_CLOSEST( 59, 4) = 15 DIV_ROUND_CLOSEST( 59, -4) = -15 DIV_ROUND_CLOSEST( -59, 4) = -15 DIV_ROUND_CLOSEST( -59, -4) = 15 [akpm@linux-foundation.org: fix comment, per Guenter] Link: http://lkml.kernel.org/r/20161222102217.29011-1-niklas.soderlund+renesas@ragnatech.se Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-17taint/module: Fix problems when out-of-kernel driver defines true or falseLarry Finger1-2/+2
Commit 7fd8329ba502 ("taint/module: Clean up global and module taint flags handling") used the key words true and false as character members of a new struct. These names cause problems when out-of-kernel modules such as VirtualBox include their own definitions of true and false. Fixes: 7fd8329ba502 ("taint/module: Clean up global and module taint flags handling") Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: Petr Mladek <pmladek@suse.com> Cc: Jessica Yu <jeyu@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jessica Yu <jeyu@redhat.com>
2016-12-15Merge tag 'modules-for-v4.10' of ↵Linus Torvalds1-0/+9
git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux Pull modules updates from Jessica Yu: "Summary of modules changes for the 4.10 merge window: - The rodata= cmdline parameter has been extended to additionally apply to module mappings - Fix a hard to hit race between module loader error/clean up handling and ftrace registration - Some code cleanups, notably panic.c and modules code use a unified taint_flags table now. This is much cleaner than duplicating the taint flag code in modules.c" * tag 'modules-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: module: fix DEBUG_SET_MODULE_RONX typo module: extend 'rodata=off' boot cmdline parameter to module mappings module: Fix a comment above strong_try_module_get() module: When modifying a module's text ignore modules which are going away too module: Ensure a module's state is set accordingly during module coming cleanup code module: remove trailing whitespace taint/module: Clean up global and module taint flags handling modpost: free allocated memory
2016-12-13Merge branch 'for-4.10' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu Pull percpu update from Tejun Heo: "This includes just one patch to reject non-power-of-2 alignments and trigger warning. Interestingly, this actually caught a bug in XEN ARM64" * 'for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: ensure the requested alignment is power of two
2016-11-26taint/module: Clean up global and module taint flags handlingPetr Mladek1-0/+9
The commit 66cc69e34e86a231 ("Fix: module signature vs tracepoints: add new TAINT_UNSIGNED_MODULE") updated module_taint_flags() to potentially print one more character. But it did not increase the size of the corresponding buffers in m_show() and print_modules(). We have recently done the same mistake when adding a taint flag for livepatching, see https://lkml.kernel.org/r/cfba2c823bb984690b73572aaae1db596b54a082.1472137475.git.jpoimboe@redhat.com Also struct module uses an incompatible type for mod-taints flags. It survived from the commit 2bc2d61a9638dab670d ("[PATCH] list module taint flags in Oops/panic"). There was used "int" for the global taint flags at these times. But only the global tain flags was later changed to "unsigned long" by the commit 25ddbb18aae33ad2 ("Make the taint flags reliable"). This patch defines TAINT_FLAGS_COUNT that can be used to create arrays and buffers of the right size. Note that we could not use enum because the taint flag indexes are used also in assembly code. Then it reworks the table that describes the taint flags. The TAINT_* numbers can be used as the index. Instead, we add information if the taint flag is also shown per-module. Finally, it uses "unsigned long", bit operations, and the updated taint_flags table also for mod->taints. It is not optimal because only few taint flags can be printed by module_taint_flags(). But better be on the safe side. IMHO, it is not worth the optimization and this is a good compromise. Signed-off-by: Petr Mladek <pmladek@suse.com> Link: http://lkml.kernel.org/r/1474458442-21581-1-git-send-email-pmladek@suse.com [jeyu@redhat.com: fix broken lkml link in changelog] Signed-off-by: Jessica Yu <jeyu@redhat.com>
2016-11-01fs: decouple READ and WRITE from the block layer opsChristoph Hellwig1-0/+4
Move READ and WRITE to kernel.h and don't define them in terms of block layer ops; they are our generic data direction indicators these days and have no more resemblance with the block layer ops. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-19percpu: ensure the requested alignment is power of twozijun_hu1-0/+1
The percpu allocator expectedly assumes that the requested alignment is power of two but hasn't been veryfing the input. If the specified alignment isn't power of two, the allocator can malfunction. Add the sanity check. The following is detailed analysis of the effects of alignments which aren't power of two. The alignment must be a even at least since the LSB of a chunk->map element is used as free/in-use flag of a area; besides, the alignment must be a power of 2 too since ALIGN() doesn't work well for other alignment always but is adopted by pcpu_fit_in_area(). IOW, the current allocator only works well for a power of 2 aligned area allocation. See below opposite example for why an odd alignment doesn't work. Let's assume area [16, 36) is free but its previous one is in-use, we want to allocate a @size == 8 and @align == 7 area. The larger area [16, 36) is split to three areas [16, 21), [21, 29), [29, 36) eventually. However, due to the usage for a chunk->map element, the actual offset of the aim area [21, 29) is 21 but is recorded in relevant element as 20; moreover, the residual tail free area [29, 36) is mistook as in-use and is lost silently Unlike macro roundup(), ALIGN(x, a) doesn't work if @a isn't a power of 2 for example, roundup(10, 6) == 12 but ALIGN(10, 6) == 10, and the latter result isn't desired obviously. tj: Code style and patch description updates. Signed-off-by: zijun_hu <zijun_hu@htc.com> Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-10-08min/max: remove sparse warnings when they're nestedJohannes Berg1-20/+28
Currently, when min/max are nested within themselves, sparse will warn: warning: symbol '_min1' shadows an earlier one originally declared here warning: symbol '_min1' shadows an earlier one originally declared here warning: symbol '_min2' shadows an earlier one originally declared here This also immediately happens when min3() or max3() are used. Since sparse implements __COUNTER__, we can use __UNIQUE_ID() to generate unique variable names, avoiding this. Link: http://lkml.kernel.org/r/1471519773-29882-1-git-send-email-johannes@sipsolutions.net Signed-off-by: Johannes Berg <johannes.berg@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-09-22sched/core: Optimize __schedule()Peter Zijlstra1-6/+3
Oleg noted that by making do_exit() use __schedule() for the TASK_DEAD context switch, we can avoid the TASK_DEAD special case currently in __schedule() because that avoids the extra preempt_disable() from schedule(). In order to facilitate this, create a do_task_dead() helper which we place in the scheduler code, such that it can access __schedule(). Also add some __noreturn annotations to the functions, there's no coming back from do_exit(). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Cheng Chao <cs.os.kernel@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: chris@chris-wilson.co.uk Cc: tj@kernel.org Link: http://lkml.kernel.org/r/20160913163729.GB5012@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-03dynamic_debug: only add header when usedLuis de Bethencourt1-1/+0
kernel.h header doesn't directly use dynamic debug, instead we can include it in module.c (which used it via kernel.h). printk.h only uses it if CONFIG_DYNAMIC_DEBUG is on, changing the inclusion to only happen in that case. Link: http://lkml.kernel.org/r/1468429793-16917-1-git-send-email-luisbg@osg.samsung.com [luisbg@osg.samsung.com: include dynamic_debug.h in drb_int.h] Link: http://lkml.kernel.org/r/1468447828-18558-2-git-send-email-luisbg@osg.samsung.com Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-16rcu: sysctl: Panic on RCU StallDaniel Bristot de Oliveira1-0/+1
It is not always easy to determine the cause of an RCU stall just by analysing the RCU stall messages, mainly when the problem is caused by the indirect starvation of rcu threads. For example, when preempt_rcu is not awakened due to the starvation of a timer softirq. We have been hard coding panic() in the RCU stall functions for some time while testing the kernel-rt. But this is not possible in some scenarios, like when supporting customers. This patch implements the sysctl kernel.panic_on_rcu_stall. If set to 1, the system will panic() when an RCU stall takes place, enabling the capture of a vmcore. The vmcore provides a way to analyze all kernel/tasks states, helping out to point to the culprit and the solution for the stall. The kernel.panic_on_rcu_stall sysctl is disabled by default. Changes from v1: - Fixed a typo in the git log - The if(sysctl_panic_on_rcu_stall) panic() is in a static function - Fixed the CONFIG_TINY_RCU compilation issue - The var sysctl_panic_on_rcu_stall is now __read_mostly Cc: Jonathan Corbet <corbet@lwn.net> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Arnaldo Carvalho de Melo <acme@kernel.org> Tested-by: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-05-21Merge tag 'staging-4.7-rc1' of ↵Linus Torvalds1-0/+7
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging Pull staging and IIO driver updates from Greg KH: "Here's the big staging and iio driver update for 4.7-rc1. I think we almost broke even with this release, only adding a few more lines than we removed, which isn't bad overall given that there's a bunch of new iio drivers added. The Lustre developers seem to have woken up from their sleep and have been doing a great job in cleaning up the code and pruning unused or old cruft, the filesystem is almost readable :) Other than that, just a lot of basic coding style cleanups in the churn. All have been in linux-next for a while with no reported issues" * tag 'staging-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (938 commits) Staging: emxx_udc: emxx_udc: fixed coding style issue staging/gdm724x: fix "alignment should match open parenthesis" issues staging/gdm724x: Fix avoid CamelCase staging: unisys: rename misleading var ii with frag staging: unisys: visorhba: switch success handling to error handling staging: unisys: visorhba: main path needs to flow down the left margin staging: unisys: visorinput: handle_locking_key() simplifications staging: unisys: visorhba: fail gracefully for thread creation failures staging: unisys: visornic: comment restructuring and removing bad diction staging: unisys: fix format string %Lx to %llx for u64 staging: unisys: remove unused struct members staging: unisys: visorchannel: correct variable misspelling staging: unisys: visorhba: replace functionlike macro with function staging: dgnc: Need to check for NULL of ch staging: dgnc: remove redundant condition check staging: dgnc: fix 'line over 80 characters' staging: dgnc: clean up the dgnc_get_modem_info() staging: lustre: lnet: enable configuration per NI interface staging: lustre: o2iblnd: properly set ibr_why staging: lustre: o2iblnd: remove last of kiblnd_tunables_fini ...
2016-05-20include/linux: apply __malloc attributeRasmus Villemoes1-2/+2
Attach the malloc attribute to a few allocation functions. This helps gcc generate better code by telling it that the return value doesn't alias any existing pointers (which is even more valuable given the pessimizations implied by -fno-strict-aliasing). A simple example of what this allows gcc to do can be seen by looking at the last part of drm_atomic_helper_plane_reset: plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL); if (plane->state) { plane->state->plane = plane; plane->state->rotation = BIT(DRM_ROTATE_0); } which compiles to e8 99 bf d6 ff callq ffffffff8116d540 <kmem_cache_alloc_trace> 48 85 c0 test %rax,%rax 48 89 83 40 02 00 00 mov %rax,0x240(%rbx) 74 11 je ffffffff814015c4 <drm_atomic_helper_plane_reset+0x64> 48 89 18 mov %rbx,(%rax) 48 8b 83 40 02 00 00 mov 0x240(%rbx),%rax [*] c7 40 40 01 00 00 00 movl $0x1,0x40(%rax) With this patch applied, the instruction at [*] is elided, since the store to plane->state->plane is known to not alter the value of plane->state. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-30kernel.h: add u64_to_user_ptr()Gustavo Padovan1-0/+7
This function had copies in 3 different files. Unify them in kernel.h. Cc: Joe Perches <joe@perches.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Rob Clark <robdclark@gmail.com> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Acked-by: Daniel Vetter <daniel.vetter@intel.com> [drm/i915/] Acked-by: Rob Clark <robdclark@gmail.com> [drm/msm/] Acked-by: Lucas Stach <l.stach@pengutronix.de> [drm/etinav/] Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-24Merge tag 'trace-v4.6' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Nothing major this round. Mostly small clean ups and fixes. Some visible changes: - A new flag was added to distinguish traces done in NMI context. - Preempt tracer now shows functions where preemption is disabled but interrupts are still enabled. Other notes: - Updates were done to function tracing to allow better performance with perf. - Infrastructure code has been added to allow for a new histogram feature for recording live trace event histograms that can be configured by simple user commands. The feature itself was just finished, but needs a round in linux-next before being pulled. This only includes some infrastructure changes that will be needed" * tag 'trace-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (22 commits) tracing: Record and show NMI state tracing: Fix trace_printk() to print when not using bprintk() tracing: Remove redundant reset per-CPU buff in irqsoff tracer x86: ftrace: Fix the misleading comment for arch/x86/kernel/ftrace.c tracing: Fix crash from reading trace_pipe with sendfile tracing: Have preempt(irqs)off trace preempt disabled functions tracing: Fix return while holding a lock in register_tracer() ftrace: Use kasprintf() in ftrace_profile_tracefs() ftrace: Update dynamic ftrace calls only if necessary ftrace: Make ftrace_hash_rec_enable return update bool tracing: Fix typoes in code comment and printk in trace_nop.c tracing, writeback: Replace cgroup path to cgroup ino tracing: Use flags instead of bool in trigger structure tracing: Add an unreg_all() callback to trigger commands tracing: Add needs_rec flag to event triggers tracing: Add a per-event-trigger 'paused' field tracing: Add get_syscall_name() tracing: Add event record param to trigger_ops.func() tracing: Make event trigger functions available tracing: Make ftrace_event_field checking functions available ...
2016-03-23panic: change nmi_panic from macro to functionHidehiro Kawai1-20/+1
Commit 1717f2096b54 ("panic, x86: Fix re-entrance problem due to panic on NMI") and commit 58c5661f2144 ("panic, x86: Allow CPUs to save registers even if looping in NMI context") introduced nmi_panic() which prevents concurrent/recursive execution of panic(). It also saves registers for the crash dump on x86. However, there are some cases where NMI handlers still use panic(). This patch set partially replaces them with nmi_panic() in those cases. Even this patchset is applied, some NMI or similar handlers (e.g. MCE handler) continue to use panic(). This is because I can't test them well and actual problems won't happen. For example, the possibility that normal panic and panic on MCE happen simultaneously is very low. This patch (of 3): Convert nmi_panic() to a proper function and export it instead of exporting internal implementation details to modules, for obvious reasons. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Acked-by: Borislav Petkov <bp@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Javi Merino <javi.merino@arm.com> Cc: Gobinda Charan Maji <gobinda.cemk07@gmail.com> Cc: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-23tracing: Fix trace_printk() to print when not using bprintk()Steven Rostedt (Red Hat)1-3/+3
The trace_printk() code will allocate extra buffers if the compile detects that a trace_printk() is used. To do this, the format of the trace_printk() is saved to the __trace_printk_fmt section, and if that section is bigger than zero, the buffers are allocated (along with a message that this has happened). If trace_printk() uses a format that is not a constant, and thus something not guaranteed to be around when the print happens, the compiler optimizes the fmt out, as it is not used, and the __trace_printk_fmt section is not filled. This means the kernel will not allocate the special buffers needed for the trace_printk() and the trace_printk() will not write anything to the tracing buffer. Adding a "__used" to the variable in the __trace_printk_fmt section will keep it around, even though it is set to NULL. This will keep the string from being printed in the debugfs/tracing/printk_formats section as it is not needed. Reported-by: Vlastimil Babka <vbabka@suse.cz> Fixes: 07d777fe8c398 "tracing: Add percpu buffers for trace_printk()" Cc: stable@vger.kernel.org # v3.5+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds1-1/+1
Pull networking updates from David Miller: "Highlights: 1) Support more Realtek wireless chips, from Jes Sorenson. 2) New BPF types for per-cpu hash and arrap maps, from Alexei Starovoitov. 3) Make several TCP sysctls per-namespace, from Nikolay Borisov. 4) Allow the use of SO_REUSEPORT in order to do per-thread processing of incoming TCP/UDP connections. The muxing can be done using a BPF program which hashes the incoming packet. From Craig Gallek. 5) Add a multiplexer for TCP streams, to provide a messaged based interface. BPF programs can be used to determine the message boundaries. From Tom Herbert. 6) Add 802.1AE MACSEC support, from Sabrina Dubroca. 7) Avoid factorial complexity when taking down an inetdev interface with lots of configured addresses. We were doing things like traversing the entire address less for each address removed, and flushing the entire netfilter conntrack table for every address as well. 8) Add and use SKB bulk free infrastructure, from Jesper Brouer. 9) Allow offloading u32 classifiers to hardware, and implement for ixgbe, from John Fastabend. 10) Allow configuring IRQ coalescing parameters on a per-queue basis, from Kan Liang. 11) Extend ethtool so that larger link mode masks can be supported. From David Decotigny. 12) Introduce devlink, which can be used to configure port link types (ethernet vs Infiniband, etc.), port splitting, and switch device level attributes as a whole. From Jiri Pirko. 13) Hardware offload support for flower classifiers, from Amir Vadai. 14) Add "Local Checksum Offload". Basically, for a tunneled packet the checksum of the outer header is 'constant' (because with the checksum field filled into the inner protocol header, the payload of the outer frame checksums to 'zero'), and we can take advantage of that in various ways. From Edward Cree" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1548 commits) bonding: fix bond_get_stats() net: bcmgenet: fix dma api length mismatch net/mlx4_core: Fix backward compatibility on VFs phy: mdio-thunder: Fix some Kconfig typos lan78xx: add ndo_get_stats64 lan78xx: handle statistics counter rollover RDS: TCP: Remove unused constant RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket net: smc911x: convert pxa dma to dmaengine team: remove duplicate set of flag IFF_MULTICAST bonding: remove duplicate set of flag IFF_MULTICAST net: fix a comment typo ethernet: micrel: fix some error codes ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it bpf, dst: add and use dst_tclassid helper bpf: make skb->tc_classid also readable net: mvneta: bm: clarify dependencies cls_bpf: reset class and reuse major in da ldmvsw: Checkpatch sunvnet.c and sunvnet_common.c ldmvsw: Add ldmvsw.c driver code ...
2016-03-18lib: move strtobool() to kstrtobool()Kees Cook1-0/+2
Create the kstrtobool_from_user() helper and move strtobool() logic into the new kstrtobool() (matching all the other kstrto* functions). Provides an inline wrapper for existing strtobool() callers. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Joe Perches <joe@perches.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Amitkumar Karwar <akarwar@marvell.com> Cc: Nishant Sarmukadam <nishants@marvell.com> Cc: Kalle Valo <kvalo@codeaurora.org> Cc: Steve French <sfrench@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-05uapi: define DIV_ROUND_UP for userlandNicolas Dichtel1-1/+1
DIV_ROUND_UP is defined in linux/kernel.h only for the kernel. When ethtool.h is included by a userland app, we got the following error: include/linux/ethtool.h:1218:8: error: variably modified 'queue_mask' at file scope __u32 queue_mask[DIV_ROUND_UP(MAX_NUM_QUEUE, 32)]; ^ Let's add a common definition in uapi and use it everywhere. Fixes: ac2c7ad0e5d6 ("net/ethtool: introduce a new ioctl for per queue setting") CC: Kan Liang <kan.liang@intel.com> Suggested-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-16include/linux/kernel.h: change abs() macro so it uses consistent return typeMichal Nazarewicz1-18/+18
Rewrite abs() so that its return type does not depend on the architecture and no unexpected type conversion happen inside of it. The only conversion is from unsigned to signed type. char is left as a return type but treated as a signed type regradless of it's actual signedness. With the old version, int arguments were promoted to long and depending on architecture a long argument might result in s64 or long return type (which may or may not be the same). This came after some back and forth with Nicolas. The current macro has different return type (for the same input type) depending on architecture which might be midly iritating. An alternative version would promote to int like so: #define abs(x) __abs_choose_expr(x, long long, \ __abs_choose_expr(x, long, \ __builtin_choose_expr( \ sizeof(x) <= sizeof(int), \ ({ int __x = (x); __x<0?-__x:__x; }), \ ((void)0)))) I have no preference but imagine Linus might. :] Nicolas argument against is that promoting to int causes iconsistent behaviour: int main(void) { unsigned short a = 0, b = 1, c = a - b; unsigned short d = abs(a - b); unsigned short e = abs(c); printf("%u %u\n", d, e); // prints: 1 65535 } Then again, no sane person expects consistent behaviour from C integer arithmetic. ;) Note: __builtin_types_compatible_p(unsigned char, char) is always false, and __builtin_types_compatible_p(signed char, char) is also always false. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-19panic, x86: Allow CPUs to save registers even if looping in NMI contextHidehiro Kawai1-4/+12
Currently, kdump_nmi_shootdown_cpus(), a subroutine of crash_kexec(), sends an NMI IPI to CPUs which haven't called panic() to stop them, save their register information and do some cleanups for crash dumping. However, if such a CPU is infinitely looping in NMI context, we fail to save its register information into the crash dump. For example, this can happen when unknown NMIs are broadcast to all CPUs as follows: CPU 0 CPU 1 =========================== ========================== receive an unknown NMI unknown_nmi_error() panic() receive an unknown NMI spin_trylock(&panic_lock) unknown_nmi_error() crash_kexec() panic() spin_trylock(&panic_lock) panic_smp_self_stop() infinite loop kdump_nmi_shootdown_cpus() issue NMI IPI -----------> blocked until IRET infinite loop... Here, since CPU 1 is in NMI context, the second NMI from CPU 0 is blocked until CPU 1 executes IRET. However, CPU 1 never executes IRET, so the NMI is not handled and the callback function to save registers is never called. In practice, this can happen on some servers which broadcast NMIs to all CPUs when the NMI button is pushed. To save registers in this case, we need to: a) Return from NMI handler instead of looping infinitely or b) Call the callback function directly from the infinite loop Inherently, a) is risky because NMI is also used to prevent corrupted data from being propagated to devices. So, we chose b). This patch does the following: 1. Move the infinite looping of CPUs which haven't called panic() in NMI context (actually done by panic_smp_self_stop()) outside of panic() to enable us to refer pt_regs. Please note that panic_smp_self_stop() is still used for normal context. 2. Call a callback of kdump_nmi_shootdown_cpus() directly to save registers and do some cleanups after setting waiting_for_crash_ipi which is used for counting down the number of CPUs which handled the callback Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Gobinda Charan Maji <gobinda.cemk07@gmail.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Javi Merino <javi.merino@arm.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: kexec@lists.infradead.org Cc: linux-doc@vger.kernel.org Cc: lkml <linux-kernel@vger.kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Seth Jennings <sjenning@redhat.com> Cc: Stefan Lippers-Hollmann <s.l-h@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Link: http://lkml.kernel.org/r/20151210014628.25437.75256.stgit@softrs [ Cleanup comments, fixup formatting. ] Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-19panic, x86: Fix re-entrance problem due to panic on NMIHidehiro Kawai1-0/+20
If panic on NMI happens just after panic() on the same CPU, panic() is recursively called. Kernel stalls, as a result, after failing to acquire panic_lock. To avoid this problem, don't call panic() in NMI context if we've already entered panic(). For that, introduce nmi_panic() macro to reduce code duplication. In the case of panic on NMI, don't return from NMI handlers if another CPU already panicked. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Don Zickus <dzickus@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Gobinda Charan Maji <gobinda.cemk07@gmail.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Javi Merino <javi.merino@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: kexec@lists.infradead.org Cc: linux-doc@vger.kernel.org Cc: lkml <linux-kernel@vger.kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Seth Jennings <sjenning@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Link: http://lkml.kernel.org/r/20151210014626.25437.13302.stgit@softrs [ Cleanup comments, fixup formatting. ] Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-11-10remove abs64()Andrew Morton1-3/+0
Switch everything to the new and more capable implementation of abs(). Mainly to give the new abs() a bit of a workout. Cc: Michal Nazarewicz <mina86@mina86.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-10kernel.h: make abs() work with 64-bit typesMichal Nazarewicz1-21/+24
For 64-bit arguments, the abs macro casts it to an int which leads to lost precision and may cause incorrect results. To deal with 64-bit types abs64 macro has been introduced but still there are places where abs macro is used incorrectly. To deal with the problem, expand abs macro such that it operates on s64 type when dealing with 64-bit types while still returning long when dealing with smaller types. This fixes one known bug (per John): The internal clocksteering done for fine-grained error correction uses a : logarithmic approximation, so any time adjtimex() adjusts the clock : steering, timekeeping_freqadjust() quickly approximates the correct clock : frequency over a series of ticks. : : Unfortunately, the logic in timekeeping_freqadjust(), introduced in commit : dc491596f639438 (Rework frequency adjustments to work better w/ nohz), : used the abs() function with a s64 error value to calculate the size of : the approximated adjustment to be made. : : Per include/linux/kernel.h: "abs() should not be used for 64-bit types : (s64, u64, long long) - use abs64()". : : Thus on 32-bit platforms, this resulted in the clocksteering to take a : quite dampended random walk trying to converge on the proper frequency, : which caused the adjustments to be made much slower then intended (most : easily observed when large adjustments are made). Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Reported-by: John Stultz <john.stultz@linaro.org> Tested-by: John Stultz <john.stultz@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-07lib/kasprintf.c: introduce kvasprintf_constRasmus Villemoes1-0/+2
This adds kvasprintf_const which tries to use kstrdup_const if possible: If the format string contains no % characters, or if the format string is exactly "%s", we delegate to kstrdup_const. Otherwise, we fall back to kvasprintf. Just as for kstrdup_const, the main motivation is to save memory by reusing .rodata when possible. The return value should be freed by kfree_const, just like for kstrdup_const. There is deliberately no kasprintf_const: In the vast majority of cases, the format string argument is a literal, so one can determine statically whether one could instead use kstrdup_const directly (which would also require one to change all corresponding kfree calls to kfree_const). Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-18include, lib: add __printf attributes to several function prototypesNicolas Iooss1-4/+5
Using __printf attributes helps to detect several format string issues at compile time (even though -Wformat-security is currently disabled in Makefile). For example it can detect when formatting a pointer as a number, like the issue fixed in commit a3fa71c40f18 ("wl18xx: show rx_frames_per_rates as an array as it really is"), or when the arguments do not match the format string, c.f. for example commit 5ce1aca81435 ("reiserfs: fix __RASSERT format string"). To prevent similar bugs in the future, add a __printf attribute to every function prototype which needs one in include/linux/ and lib/. These functions were mostly found by using gcc's -Wsuggest-attribute=format flag. Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Felipe Balbi <balbi@ti.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-02Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+3
Merge third patchbomb from Andrew Morton: - the rest of MM - scripts/gdb updates - ipc/ updates - lib/ updates - MAINTAINERS updates - various other misc things * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (67 commits) genalloc: rename of_get_named_gen_pool() to of_gen_pool_get() genalloc: rename dev_get_gen_pool() to gen_pool_get() x86: opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit MAINTAINERS: add zpool MAINTAINERS: BCACHE: Kent Overstreet has changed email address MAINTAINERS: move Jens Osterkamp to CREDITS MAINTAINERS: remove unused nbd.h pattern MAINTAINERS: update brcm gpio filename pattern MAINTAINERS: update brcm dts pattern MAINTAINERS: update sound soc intel patterns MAINTAINERS: remove website for paride MAINTAINERS: update Emulex ocrdma email addresses bcache: use kvfree() in various places libcxgbi: use kvfree() in cxgbi_free_big_mem() target: use kvfree() in session alloc and free IB/ehca: use kvfree() in ipz_queue_{cd}tor() drm/nouveau/gem: use kvfree() in u_free() drm: use kvfree() in drm_free_large() cxgb4: use kvfree() in t4_free_mem() cxgb3: use kvfree() in cxgb_free_mem() ...
2015-07-01Merge tag 'modules-next-for-linus' of ↵Linus Torvalds1-8/+10
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Main excitement here is Peter Zijlstra's lockless rbtree optimization to speed module address lookup. He found some abusers of the module lock doing that too. A little bit of parameter work here too; including Dan Streetman's breaking up the big param mutex so writing a parameter can load another module (yeah, really). Unfortunately that broke the usual suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were appended too" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits) modules: only use mod->param_lock if CONFIG_MODULES param: fix module param locks when !CONFIG_SYSFS. rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() module: add per-module param_lock module: make perm const params: suppress unused variable error, warn once just in case code changes. modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. kernel/module.c: avoid ifdefs for sig_enforce declaration kernel/workqueue.c: remove ifdefs over wq_power_efficient kernel/params.c: export param_ops_bool_enable_only kernel/params.c: generalize bool_enable_only kernel/module.c: use generic module param operaters for sig_enforce kernel/params: constify struct kernel_param_ops uses sysfs: tightened sysfs permission checks module: Rework module_addr_{min,max} module: Use __module_address() for module_address_lookup() module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING module: Optimize __module_address() using a latched RB-tree rbtree: Implement generic latch_tree seqlock: Introduce raw_read_seqcount_latch() ...
2015-07-01kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops pathHATAYAMA Daisuke1-0/+3
Commit f06e5153f4ae2e ("kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers") introduced "crash_kexec_post_notifiers" kernel boot option, which toggles wheather panic() calls crash_kexec() before panic_notifiers and dump kmsg or after. The problem is that the commit overlooks panic_on_oops kernel boot option. If it is enabled, crash_kexec() is called directly without going through panic() in oops path. To fix this issue, this patch adds a check to "crash_kexec_post_notifiers" in the condition of kexec_should_crash(). Also, put a comment in kexec_should_crash() to explain not obvious things on this patch. Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Baoquan He <bhe@redhat.com> Tested-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-27Merge tag 'trace-v4.2' of ↵Linus Torvalds1-6/+0
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "This patch series contains several clean ups and even a new trace clock "monitonic raw". Also some enhancements to make the ring buffer even faster. But the biggest and most noticeable change is the renaming of the ftrace* files, structures and variables that have to deal with trace events. Over the years I've had several developers tell me about their confusion with what ftrace is compared to events. Technically, "ftrace" is the infrastructure to do the function hooks, which include tracing and also helps with live kernel patching. But the trace events are a separate entity altogether, and the files that affect the trace events should not be named "ftrace". These include: include/trace/ftrace.h -> include/trace/trace_events.h include/linux/ftrace_event.h -> include/linux/trace_events.h Also, functions that are specific for trace events have also been renamed: ftrace_print_*() -> trace_print_*() (un)register_ftrace_event() -> (un)register_trace_event() ftrace_event_name() -> trace_event_name() ftrace_trigger_soft_disabled() -> trace_trigger_soft_disabled() ftrace_define_fields_##call() -> trace_define_fields_##call() ftrace_get_offsets_##call() -> trace_get_offsets_##call() Structures have been renamed: ftrace_event_file -> trace_event_file ftrace_event_{call,class} -> trace_event_{call,class} ftrace_event_buffer -> trace_event_buffer ftrace_subsystem_dir -> trace_subsystem_dir ftrace_event_raw_##call -> trace_event_raw_##call ftrace_event_data_offset_##call-> trace_event_data_offset_##call ftrace_event_type_funcs_##call -> trace_event_type_funcs_##call And a few various variables and flags have also been updated. This has been sitting in linux-next for some time, and I have not heard a single complaint about this rename breaking anything. Mostly because these functions, variables and structures are mostly internal to the tracing system and are seldom (if ever) used by anything external to that" * tag 'trace-v4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) ring_buffer: Allow to exit the ring buffer benchmark immediately ring-buffer-benchmark: Fix the wrong type ring-buffer-benchmark: Fix the wrong param in module_param ring-buffer: Add enum names for the context levels ring-buffer: Remove useless unused tracing_off_permanent() ring-buffer: Give NMIs a chance to lock the reader_lock ring-buffer: Add trace_recursive checks to ring_buffer_write() ring-buffer: Allways do the trace_recursive checks ring-buffer: Move recursive check to per_cpu descriptor ring-buffer: Add unlikelys to make fast path the default tracing: Rename ftrace_get_offsets_##call() to trace_event_get_offsets_##call() tracing: Rename ftrace_define_fields_##call() to trace_event_define_fields_##call() tracing: Rename ftrace_event_type_funcs_##call to trace_event_type_funcs_##call tracing: Rename ftrace_data_offset_##call to trace_event_data_offset_##call tracing: Rename ftrace_raw_##call event structures to trace_event_raw_##call tracing: Rename ftrace_trigger_soft_disabled() to trace_trigger_soft_disabled() tracing: Rename FTRACE_EVENT_FL_* flags to EVENT_FILE_FL_* tracing: Rename struct ftrace_subsystem_dir to trace_subsystem_dir tracing: Rename ftrace_event_name() to trace_event_name() tracing: Rename FTRACE_MAX_EVENT to TRACE_EVENT_TYPE_MAX ...
2015-05-28ring-buffer: Remove useless unused tracing_off_permanent()Steven Rostedt (Red Hat)1-6/+0
The tracing_off_permanent() call is a way to disable all ring_buffers. Nothing uses it and nothing should use it, as tracing_off() and friends are better, as they disable the ring buffers related to tracing. The tracing_off_permanent() even disabled non tracing ring buffers. This is a bit drastic, and was added to handle NMIs doing outputs that could corrupt the ring buffer when only tracing used them. It is now obsolete and adds a little overhead, it should be removed. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-28sysfs: tightened sysfs permission checksGobinda Charan Maji1-8/+10
There were some inconsistency in restriction to VERIFY_OCTAL_PERMISSIONS(). Previously the test was "User perms >= group perms >= other perms". The permission field of User, Group or Other consists of three bits. LSB is EXECUTE permission, MSB is READ permission and the middle bit is WRITE permission. But logically WRITE is "more privileged" than READ. Say for example, permission value is "0430". Here User has only READ permission whereas Group has both WRITE and EXECUTE permission. So, the checks could be tightened and the tests are separated to USER_READABLE >= GROUP_READABLE >= OTHER_READABLE, USER_WRITABLE >= GROUP_WRITABLE and OTHER_WRITABLE is not permitted. Signed-off-by: Gobinda Charan Maji <gobinda.cemk07@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-19sched/preempt, mm/fault: Trigger might_sleep() in might_fault() with ↵David Hildenbrand1-1/+2
disabled pagefaults Commit 662bbcb2747c ("mm, sched: Allow uaccess in atomic with pagefault_disable()") removed might_sleep() checks for all user access code (that uses might_fault()). The reason was to disable wrong "sleep in atomic" warnings in the following scenario: pagefault_disable() rc = copy_to_user(...) pagefault_enable() Which is valid, as pagefault_disable() increments the preempt counter and therefore disables the pagefault handler. copy_to_user() will not sleep and return an error code if a page is not available. However, as all might_sleep() checks are removed, CONFIG_DEBUG_ATOMIC_SLEEP would no longer detect the following scenario: spin_lock(&lock); rc = copy_to_user(...) spin_unlock(&lock) If the kernel is compiled with preemption turned on, preempt_disable() will make in_atomic() detect disabled preemption. The fault handler would correctly never sleep on user access. However, with preemption turned off, preempt_disable() is usually a NOP (with !CONFIG_PREEMPT_COUNT), therefore in_atomic() will not be able to detect disabled preemption nor disabled pagefaults. The fault handler could sleep. We really want to enable CONFIG_DEBUG_ATOMIC_SLEEP checks for user access functions again, otherwise we can end up with horrible deadlocks. Root of all evil is that pagefault_disable() acts almost as preempt_disable(), depending on preemption being turned on/off. As we now have pagefault_disabled(), we can use it to distinguish whether user acces functions might sleep. Convert might_fault() into a makro that calls __might_fault(), to allow proper file + line messages in case of a might_sleep() warning. Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David.Laight@ACULAB.COM Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: airlied@linux.ie Cc: akpm@linux-foundation.org Cc: benh@kernel.crashing.org Cc: bigeasy@linutronix.de Cc: borntraeger@de.ibm.com Cc: daniel.vetter@intel.com Cc: heiko.carstens@de.ibm.com Cc: herbert@gondor.apana.org.au Cc: hocko@suse.cz Cc: hughd@google.com Cc: mst@redhat.com Cc: paulus@samba.org Cc: ralf@linux-mips.org Cc: schwidefsky@de.ibm.com Cc: yang.shi@windriver.com Link: http://lkml.kernel.org/r/1431359540-32227-3-git-send-email-dahi@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-17kernel.h: implement DIV_ROUND_CLOSEST_ULLJavi Merino1-0/+12
We have grown a number of different implementations of DIV_ROUND_CLOSEST_ULL throughout the kernel. Move the i915 one to kernel.h so that it can be reused. Signed-off-by: Javi Merino <javi.merino@arm.com> Reviewed-by: Jeff Epler <jepler@unpythonic.net> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: David Airlie <airlied@linux.ie> Cc: Guenter Roeck <linux@roeck-us.net> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Alex Elder <elder@linaro.org> Cc: Antti Palosaari <crope@iki.fi> Cc: Javi Merino <javi.merino@arm.com> Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Turquette <mturquette@linaro.org> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13kernel.h: remove ancient __FUNCTION__ hackRasmus Villemoes1-3/+0
__FUNCTION__ hasn't been treated as a string literal since gcc 3.4, so this only helps people who only test-compile using 3.3 (compiler-gcc3.h barks at anything older than that). Besides, there are almost no occurrences of __FUNCTION__ left in the tree. [akpm@linux-foundation.org: convert remaining __FUNCTION__ references] Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11Merge branch 'for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching Pull live patching infrastructure from Jiri Kosina: "Let me provide a bit of history first, before describing what is in this pile. Originally, there was kSplice as a standalone project that implemented stop_machine()-based patching for the linux kernel. This project got later acquired, and the current owner is providing live patching as a proprietary service, without any intentions to have their implementation merged. Then, due to rising user/customer demand, both Red Hat and SUSE started working on their own implementation (not knowing about each other), and announced first versions roughly at the same time [1] [2]. The principle difference between the two solutions is how they are making sure that the patching is performed in a consistent way when it comes to different execution threads with respect to the semantic nature of the change that is being introduced. In a nutshell, kPatch is issuing stop_machine(), then looking at stacks of all existing processess, and if it decides that the system is in a state that can be patched safely, it proceeds insterting code redirection machinery to the patched functions. On the other hand, kGraft provides a per-thread consistency during one single pass of a process through the kernel and performs a lazy contignuous migration of threads from "unpatched" universe to the "patched" one at safe checkpoints. If interested in a more detailed discussion about the consistency models and its possible combinations, please see the thread that evolved around [3]. It pretty quickly became obvious to the interested parties that it's absolutely impractical in this case to have several isolated solutions for one task to co-exist in the kernel. During a dedicated Live Kernel Patching track at LPC in Dusseldorf, all the interested parties sat together and came up with a joint aproach that would work for both distro vendors. Steven Rostedt took notes [4] from this meeting. And the foundation for that aproach is what's present in this pull request. It provides a basic infrastructure for function "live patching" (i.e. code redirection), including API for kernel modules containing the actual patches, and API/ABI for userspace to be able to operate on the patches (look up what patches are applied, enable/disable them, etc). It's relatively simple and minimalistic, as it's making use of existing kernel infrastructure (namely ftrace) as much as possible. It's also self-contained, in a sense that it doesn't hook itself in any other kernel subsystem (it doesn't even touch any other code). It's now implemented for x86 only as a reference architecture, but support for powerpc, s390 and arm is already in the works (adding arch-specific support basically boils down to teaching ftrace about regs-saving). Once this common infrastructure gets merged, both Red Hat and SUSE have agreed to immediately start porting their current solutions on top of this, abandoning their out-of-tree code. The plan basically is that each patch will be marked by flag(s) that would indicate which consistency model it is willing to use (again, the details have been sketched out already in the thread at [3]). Before this happens, the current codebase can be used to patch a large group of secruity/stability problems the patches for which are not too complex (in a sense that they don't introduce non-trivial change of function's return value semantics, they don't change layout of data structures, etc) -- this corresponds to LEAVE_FUNCTION && SWITCH_FUNCTION semantics described at [3]. This tree has been in linux-next since December. [1] https://lkml.org/lkml/2014/4/30/477 [2] https://lkml.org/lkml/2014/7/14/857 [3] https://lkml.org/lkml/2014/11/7/354 [4] http://linuxplumbersconf.org/2014/wp-content/uploads/2014/10/LPC2014_LivePatching.txt [ The core code is introduced by the three commits authored by Seth Jennings, which got a lot of changes incorporated during numerous respins and reviews of the initial implementation. All the followup commits have materialized only after public tree has been created, so they were not folded into initial three commits so that the public tree doesn't get rebased ]" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: add missing newline to error message livepatch: rename config to CONFIG_LIVEPATCH livepatch: fix uninitialized return value livepatch: support for repatching a function livepatch: enforce patch stacking semantics livepatch: change ARCH_HAVE_LIVE_PATCHING to HAVE_LIVE_PATCHING livepatch: fix deferred module patching order livepatch: handle ancient compilers with more grace livepatch: kconfig: use bool instead of boolean livepatch: samples: fix usage example comments livepatch: MAINTAINERS: add git tree location livepatch: use FTRACE_OPS_FL_IPMODIFY livepatch: move x86 specific ftrace handler code to arch/x86 livepatch: samples: add sample live patching module livepatch: kernel: add support for live patching livepatch: kernel: add TAINT_LIVEPATCH
2015-02-01sched: don't cause task state changes in nested sleep debuggingLinus Torvalds1-1/+1
Commit 8eb23b9f35aa ("sched: Debug nested sleeps") added code to report on nested sleep conditions, which we generally want to avoid because the inner sleeping operation can re-set the thread state to TASK_RUNNING, but that will then cause the outer sleep loop not actually sleep when it calls schedule. However, that's actually valid traditional behavior, with the inner sleep being some fairly rare case (like taking a sleeping lock that normally doesn't actually need to sleep). And the debug code would actually change the state of the task to TASK_RUNNING internally, which makes that kind of traditional and working code not work at all, because now the nested sleep doesn't just sometimes cause the outer one to not block, but will cause it to happen every time. In particular, it will cause the cardbus kernel daemon (pccardd) to basically busy-loop doing scheduling, converting a laptop into a heater, as reported by Bruno Prémont. But there may be other legacy uses of that nested sleep model in other drivers that are also likely to never get converted to the new model. This fixes both cases: - don't set TASK_RUNNING when the nested condition happens (note: even if WARN_ONCE() only _warns_ once, the return value isn't whether the warning happened, but whether the condition for the warning was true. So despite the warning only happening once, the "if (WARN_ON(..))" would trigger for every nested sleep. - in the cases where we knowingly disable the warning by using "sched_annotate_sleep()", don't change the task state (that is used for all core scheduling decisions), instead use '->task_state_change' that is used for the debugging decision itself. (Credit for the second part of the fix goes to Oleg Nesterov: "Can't we avoid this subtle change in behaviour DEBUG_ATOMIC_SLEEP adds?" with the suggested change to use 'task_state_change' as part of the test) Reported-and-bisected-by: Bruno Prémont <bonbons@linux-vserver.org> Tested-by: Rafael J Wysocki <rjw@rjwysocki.net> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de>, Cc: Ilya Dryomov <ilya.dryomov@inktank.com>, Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Hurley <peter@hurleysoftware.com>, Cc: Davidlohr Bueso <dave@stgolabs.net>, Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-22livepatch: kernel: add TAINT_LIVEPATCHSeth Jennings1-0/+1
This adds a new taint flag to indicate when the kernel or a kernel module has been live patched. This will provide a clean indication in bug reports that live patching was used. Additionally, if the crash occurs in a live patched function, the live patch module will appear beside the patched function in the backtrace. Signed-off-by: Seth Jennings <sjenning@redhat.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-12-15Merge tag 'tty-3.19-rc1' of ↵Linus Torvalds1-3/+0
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here's the big tty/serial driver update for 3.19-rc1. There are a number of TTY core changes/fixes in here from Peter Hurley that have all been teted in linux-next for a long time now. There are also the normal serial driver updates as well, full details in the changelog below" * tag 'tty-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (219 commits) serial: pxa: hold port.lock when reporting modem line changes tty-hvsi_lib: Deletion of an unnecessary check before the function call "tty_kref_put" tty: Deletion of unnecessary checks before two function calls n_tty: Fix read_buf race condition, increment read_head after pushing data serial: of-serial: add PM suspend/resume support Revert "serial: of-serial: add PM suspend/resume support" Revert "serial: of-serial: fix up PM ops on no_console_suspend and port type" serial: 8250: don't attempt a trylock if in sysrq serial: core: Add big-endian iotype serial: samsung: use port->fifosize instead of hardcoded values serial: samsung: prefer to use fifosize from driver data serial: samsung: fix style problems serial: samsung: wait for transfer completion before clock disable serial: icom: fix error return code serial: tegra: clean up tty-flag assignments serial: Fix io address assign flow with Fintek PCI-to-UART Product serial: mxs-auart: fix tx_empty against shift register serial: mxs-auart: fix gpio change detection on interrupt serial: mxs-auart: Fix mxs_auart_set_ldisc() serial: 8250_dw: Use 64-bit access for OCTEON. ...