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2018-08-22checkpatch: DT bindings should be a separate patchRob Herring1-0/+14
Devicetree bindings should be their own patch as documented in Documentation/devicetree/bindings/submitting-patches.txt section I.1. This is because bindings are logically independent from a driver implementation, they have a different maintainer (even though they often are applied via the same tree), and it makes for a cleaner history in the DT only tree created with git-filter-branch. [robh@kernel.org: add doc pointer to warning, simplify logic] Link: http://lkml.kernel.org/r/20180810170513.26284-1-robh@kernel.org [robh@kernel.org: v3] Link: http://lkml.kernel.org/r/20180810225049.20452-1-robh@kernel.org Link: http://lkml.kernel.org/r/20180809205032.22205-1-robh@kernel.org Signed-off-by: Rob Herring <robh@kernel.org> Acked-by: Joe Perches <joe@perches.com> Cc: Andy Whitcroft <apw@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: warn on unnecessary int declarationsJoe Perches1-0/+20
On Sun, 2018-08-05 at 08:52 -0700, Linus Torvalds wrote: > "long unsigned int" isn't _technically_ wrong. But we normally > call that type "unsigned long". So add a checkpatch test for it. Link: http://lkml.kernel.org/r/7bbd97dc0a1e5896a0251fada7bb68bb33643f77.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: check for space after "else" keywordMichal Zylowski1-2/+2
Current checkpatch implementation permits notation like } else{ in kernel code. It looks like oversight and inconsistency in checkpatch rules (e.g. instruction like 'do' is tested). Add regex for checking space after 'else' keyword and trigger error if space is not present. Link: http://lkml.kernel.org/r/1533545753-8870-1-git-send-email-michal.zylowski@intel.com Signed-off-by: Michal Zylowski <michal.zylowski@intel.com> Acked-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: fix SPDX license check with --root=<path>Joe Perches1-2/+3
checkpatch uses the in-kernel script spdxcheck.py to validate the specific license in a file or script. This check can currently fail for a couple reasons: o spdxcheck.py assumes the existence of git tree that may not exist for a bare source tree from something like a tarball o the spdxcheck.py must be run from the top level root directory So add a git existence test and set the subprocess subdirectory. Link: http://lkml.kernel.org/r/2b32864324ae9c92948b002ec4c0c22409ed98f1.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Reported-by: Charlemagne Lasse <charlemagnelasse@gmail.com> Tested-by: Charlemagne Lasse <charlemagnelasse@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: warn when a patch doesn't have a descriptionJoe Perches1-0/+13
Potential patches should have a commit description. Emit a warning when there isn't one. [akpm@linux-foundation.org: s/else if/elsif/] Link: http://lkml.kernel.org/r/1b099f4d8373aa583a17011992676bf0f3f09eee.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Prakruthi Deepak Heragu <pheragu@codeaurora.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: check for #if 0/#if 1Prakruthi Deepak Heragu1-3/+8
The #if 0 or #if 1 is used to toggle features. Warn if #if 0 or #if 1 is present and suggest that they can be removed. [akpm@linux-foundation.org: fix spacing around periods, per Joe\ Link: http://lkml.kernel.org/r/1532625218-24321-1-git-send-email-pheragu@codeaurora.org Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org> Signed-off-by: Prakruthi Deepak Heragu <pheragu@codeaurora.org> Acked-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: fix krealloc reuse testJoe Perches1-1/+2
The current krealloc test does not function correctly when the temporary pointer return name contains the original pointer name. Fix that by maximally matching the return pointer name and the original pointer name and doing a separate comparison of the both names. Link: http://lkml.kernel.org/r/e617ecb8c019a9c4c56540a1bec16c8aed43a4e4.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Reported-by: Lars-Peter Clausen <lars@metafoo.de> Cc: Manish Narani <manish.narani@xilinx.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: validate SPDX license with spdxcheck.pyJoe Perches1-2/+18
Use the existing scripts/spdxcheck.py to validate any SPDX-License-Identifier found in line 1 or 2 of patches or files. Miscellanea: o Properly indent the existing SPDX-License-Identifier block. Link: http://lkml.kernel.org/r/05b832407b24e0a27e419906187cd863bc1617c7.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Rob Herring <robh@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: fix macro argument reuse testJoe Perches1-0/+1
Multiple line macro definitions where the arguments are separated by line continuations can cause checkpatch to emit invalid syntax regex tests. This can occur when a single argument is modified in a part of a patch. For example: (to not add a diff in the commit message) $ ./scripts/checkpatch.pl --git db023296f0115d2fe01fdabad54678f2b806da23 Unterminated \g... pattern in regex; <very long regex omitted> And, the test does not work correctly when these arguments are all new as the initial patch line addition "+" is used in the argument name. Fix this by stripping the line continuations and any "+" from the list of arguments. Link: http://lkml.kernel.org/r/86cdb43a4db70670c102020093f7fb4eb3003e01.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: warn if missing author Signed-off-byGeert Uytterhoeven1-3/+25
Print a warning if none of the Signed-off-by lines cover the patch author. Non-ASCII quoted printable encoding in From: headers and (lack of) double quotes are handled. Split From: headers are not fully handled: only the first part is compared. [geert+renesas@glider.be: only encode UTF-8 quoted printable mail headers] Link: http://lkml.kernel.org/r/20180718145254.4770-1-geert+renesas@glider.be Link: http://lkml.kernel.org/r/20180712100323.26684-1-geert+renesas@glider.be Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Joe Perches <joe@perches.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: update section keywordsGeert Uytterhoeven1-1/+2
As of commit bd721ea73e1f ("treewide: replace obsolete _refok by __ref"), __init_refok no longer exists, so it can be removed. While at it, add the modern variants that were still missing. Link: http://lkml.kernel.org/r/20180706084205.26367-1-geert+renesas@glider.be Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: improve runtime execution speed a littleJoe Perches1-33/+33
checkpatch repeatedly uses a runtime minimum version check that validates the minimum perl version required for a regex match by using a "$^V ge 5.10.0" runtime string match. Only perform that minimum version test once and store the result to reduce string matching time. This reduces runtime execution time for patches or files with high line counts. An example runtime improvement: new: $ time ./scripts/checkpatch.pl -f drivers/net/ethernet/intel/i40e/i40e_main.c > /dev/null real 0m11.856s user 0m11.831s sys 0m0.025s old: $ time ./scripts/checkpatch.pl -f drivers/net/ethernet/intel/i40e/i40e_main.c > /dev/null real 0m13.330s user 0m13.282s sys 0m0.049s Link: http://lkml.kernel.org/r/db21aa9703833bad65ab70cc4e8a78da5b399138.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: add --fix for CONCATENATED_STRING and STRING_FRAGMENTSJoe Perches1-5/+18
Add the ability to --fix these string issues. e.g.: printk(KERN_INFO"bar" "baz"QUX); converts to printk(KERN_INFO "barbaz" QUX); Link: http://lkml.kernel.org/r/a9fb505ccfedffc5869d08832a7ff05a21d85621.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22checkpatch: add a --strict test for structs with bool member definitionsJoe Perches1-0/+7
A struct with a bool member can have different sizes on various architectures because neither bool size nor alignment is standardized. So emit a message on the use of bool in structs only in .h files and not .c files. There is the real possibility that this test could have a false positive when a bool is declared as an automatic, so limit the test to .h files where the only false positive is for declarations in static inline functions. Link: http://lkml.kernel.org/r/95477c93db187bab6da8a8ba7c57836868446179.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22lib/test_hexdump.c: fix failure on big endian cpuChristophe Leroy1-5/+23
On a big endian cpu, test_hexdump fails as follows. The logs show that bytes are expected in reversed order. [...] test_hexdump: Len: 24 buflen: 130 strlen: 97 test_hexdump: Result: 97 'be32db7b 0a1893b2 70bac424 7d83349b a69c31ad 9c0face9 .2.{....p..$}.4...1.....' test_hexdump: Expect: 97 '7bdb32be b293180a 24c4ba70 9b34837d ad319ca6 e9ac0f9c .2.{....p..$}.4...1.....' test_hexdump: Len: 8 buflen: 130 strlen: 77 test_hexdump: Result: 77 'be32db7b0a1893b2 .2.{....' test_hexdump: Expect: 77 'b293180a7bdb32be .2.{....' test_hexdump: Len: 6 buflen: 131 strlen: 87 test_hexdump: Result: 87 'be32 db7b 0a18 .2.{..' test_hexdump: Expect: 87 '32be 7bdb 180a .2.{..' test_hexdump: Len: 24 buflen: 131 strlen: 97 test_hexdump: Result: 97 'be32db7b 0a1893b2 70bac424 7d83349b a69c31ad 9c0face9 .2.{....p..$}.4...1.....' test_hexdump: Expect: 97 '7bdb32be b293180a 24c4ba70 9b34837d ad319ca6 e9ac0f9c .2.{....p..$}.4...1.....' test_hexdump: Len: 32 buflen: 131 strlen: 101 test_hexdump: Result: 101 'be32db7b0a1893b2 70bac4247d83349b a69c31ad9c0face9 4cd1199943b1af0c .2.{....p..$}.4...1.....L...C...' test_hexdump: Expect: 101 'b293180a7bdb32be 9b34837d24c4ba70 e9ac0f9cad319ca6 0cafb1439919d14c .2.{....p..$}.4...1.....L...C...' test_hexdump: failed 801 out of 1184 tests This patch fixes it. Link: http://lkml.kernel.org/r/f3112437f62c2f48300535510918e8be1dceacfb.1533610877.git.christophe.leroy@c-s.fr Fixes: 64d1d77a44697 ("hexdump: introduce test suite") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: rashmica <rashmicy@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22lib/Kconfig: remove 'default n' for testsAndy Shevchenko2-18/+0
It seems contributors follow the style of Kconfig entries where explicit 'default n' is present. The default 'default' is 'n' already, thus, drop these lines from Kconfig to make it more clear. Link: http://lkml.kernel.org/r/20180719085131.79541-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Coly Li <colyli@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22bcache: use routines from lib/crc64.c for CRC64 calculationColy Li3-135/+18
Now we have crc64 calculation in lib/crc64.c, it is unnecessary for bcache to use its own version. This patch changes bcache code to use crc64 routines in lib/crc64.c. Link: http://lkml.kernel.org/r/20180718165545.1622-3-colyli@suse.de Signed-off-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Michael Lyle <mlyle@lyle.org> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Noah Massey <noah.massey@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22lib: add crc64 calculation routinesColy Li6-0/+156
Patch series "add crc64 calculation as kernel library", v5. This patchset adds basic implementation of crc64 calculation as a Linux kernel library. Since bcache already does crc64 by itself, this patchset also modifies bcache code to use the new crc64 library routine. Currently bcache is the only user of crc64 calculation, another potential user is bcachefs which is on the way to be in mainline kernel. Therefore it makes sense to make crc64 calculation to be a public library. bcache uses crc64 as storage checksum, if a change of crc lib routines results an inconsistent result, the unmatched checksum may make bcache 'think' the on-disk is corrupted, such a change should be avoided or detected as early as possible. Therefore a patch is being prepared which adds a crc test framework, to check consistency of different calculations. This patch (of 2): Add the re-write crc64 calculation routines for Linux kernel. The CRC64 polynomical arithmetic follows ECMA-182 specification, inspired by CRC paper of Dr. Ross N. Williams (see http://www.ross.net/crc/download/crc_v3.txt) and other public domain implementations. All the changes work in this way, - When Linux kernel is built, host program lib/gen_crc64table.c will be compiled to lib/gen_crc64table and executed. - The output of gen_crc64table execution is an array called as lookup table (a.k.a POLY 0x42f0e1eba9ea369) which contain 256 64-bit long numbers, this table is dumped into header file lib/crc64table.h. - Then the header file is included by lib/crc64.c for normal 64bit crc calculation. - Function declaration of the crc64 calculation routines is placed in include/linux/crc64.h Currently bcache is the only user of crc64_be(), another potential user is bcachefs which is on the way to be in mainline kernel. Therefore it makes sense to move crc64 calculation into lib/crc64.c as public code. [colyli@suse.de: fix review comments from v4] Link: http://lkml.kernel.org/r/20180726053352.2781-2-colyli@suse.de Link: http://lkml.kernel.org/r/20180718165545.1622-2-colyli@suse.de Signed-off-by: Coly Li <colyli@suse.de> Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Michael Lyle <mlyle@lyle.org> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Noah Massey <noah.massey@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22lib/test_debug_virtual.c: make struct pointer foo staticColin Ian King1-1/+1
The pointer foo is local to the source and does not need to be in global scope, so make it static. Cleans up sparse warning: symbol 'foo' was not declared. Should it be static? Link: http://lkml.kernel.org/r/20180624112206.5722-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22include/linux/bitops.h: introduce BITS_PER_TYPEChris Wilson2-2/+2
net_dim.h has a rather useful extension to BITS_PER_BYTE to compute the number of bits in a type (BITS_PER_BYTE * sizeof(T)), so promote the macro to bitops.h, alongside BITS_PER_BYTE, for wider usage. Link: http://lkml.kernel.org/r/20180706094458.14116-1-chris@chris-wilson.co.uk Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Andy Gospodarek <gospo@broadcom.com> Cc: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22lib/bitmap.c: drop unnecessary 0 check for u32 array operationsAndy Shevchenko1-8/+1
nbits == 0 is safe to be supplied to the function body, so remove unnecessary checks in bitmap_to_arr32() and bitmap_from_arr32(). Link: http://lkml.kernel.org/r/20180531131914.44352-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Yury Norov <ynorov@caviumnetworks.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22get_maintainer: allow option --mpath <directory> to read all files in ↵Joe Perches1-7/+6
<directory> There is an external use case for multiple private MAINTAINER style files in a separate directory. Allow it. --mpath has a default of "./MAINTAINERS". The value entered can be either a file or a directory. The behaviors are now: --mpath <file> Read only the specific file as <MAINTAINER_TYPE> file --mpath <directory> Read all files in <directory> as <MAINTAINER_TYPE> files --mpath <directory> --find-maintainer-files Recurse through <directory> and read all files named MAINTAINERS Link: http://lkml.kernel.org/r/991b2f20112d53863cd79e61d908f1d26d3e1971.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Tested-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22get_maintainer.pl: add -mpath=<path or file> for MAINTAINERS file locationJoe Perches1-18/+30
Add the ability to have an override for the location of the MAINTAINERS file. Miscellanea: o Properly indent a few lines with leading spaces Link: http://lkml.kernel.org/r/a86e69195076ed3c4c526fddc76b86c28e0a1e37.camel@perches.com Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Don Zickus <dzickus@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22get_maintainer: allow usage outside of kernel treeAntonio Nino Diaz1-3/+6
Add option '--no-tree' to get_maintainer.pl script to allow using this script in projects that aren't the Linux kernel if they use the same format for their MAINTAINERS file. This command is also available in checkpatch.pl, for example. Link: http://lkml.kernel.org/r/04452ac6-1575-f612-72c6-6ea88e70a9d5@arm.com Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.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>
2018-08-22s/epoll: robustify irq safety with lockdep_assert_irqs_enabled()Davidlohr Bueso1-0/+8
Sprinkle lockdep_assert_irqs_enabled() checks in the functions that do not save and restore interrupts when dealing with the ep->wq.lock. These are ep_scan_ready_list() and those called by epoll_ctl(): ep_insert, ep_modify and ep_remove. [akpm@linux-foundation.org: remove too-obvious comments] Link: http://lkml.kernel.org/r/20180721183127.3busfa335zlcjeox@linux-r8p5 Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22fs/epoll: loosen irq safety in epoll_insert() and epoll_remove()Davidlohr Bueso1-8/+6
Both functions are similar to the context of ep_modify(), called via epoll_ctl(2). Just like ep_modify(), saving and restoring interrupts is an overkill in these calls as it will never be called with irqs disabled. While ep_remove() can be called directly from EPOLL_CTL_DEL, it can also be called when releasing the file, but this also complies with the above. Link: http://lkml.kernel.org/r/20180720172956.2883-3-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Jason Baron <jbaron@akamai.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22fs/epoll: loosen irq safety in ep_scan_ready_list()Davidlohr Bueso1-5/+4
Patch series "fs/epoll: loosen irq safety when possible". Both patches replace saving+restoring interrupts when taking the ep->lock (now the waitqueue lock), with just disabling local irqs. This shows immediate performance benefits in patch 1 for an epoll workload running on Xen. The main concern we need to have with this sort of changes in epoll is the ep_poll_callback() which is passed to the wait queue wakeup and is done very often under irq context, this patch does not touch this call. Patches have been tested pretty heavily with the customer workload, microbenchmarks, ltp testcases and two high level workloads that use epoll under the hood: nginx and libevent benchmarks. This patch (of 2): Saving and restoring interrupts in ep_scan_ready_list() is an overkill as it is never called with interrupts disabled. Loosen this to simply disabling local irqs such that archs where managing irqs is expensive or virtual environments. This patch yields some throughput improvements on a workload that is epoll intensive running on a single Xen DomU. 1 Job 7500 --> 8800 enq/s (+17%) 2 Jobs 14000 --> 15200 enq/s (+8%) 3 Jobs 20500 --> 22300 enq/s (+8%) 4 Jobs 25000 --> 28000 enq/s (+8-12)% On bare metal: For a 2-socket 40-core (ht) IvyBridge on a few workloads, unfortunately I don't have a xen environment and the results for Xen I do have (which numbers are in patch 1) I don't have the actual workload, so cannot compare them directly. 1) Different configurations were used for a epoll_wait (pipes io) microbench (http://linux-scalability.org/epoll/epoll-test.c) and shows around a 7-10% improvement in overall total number of times the epoll_wait() loops when using both regular and nested epolls, so very raw numbers, but measurable nonetheless. # threads vanilla dirty 1 1677717 1805587 2 1660510 1854064 4 1610184 1805484 8 1577696 1751222 16 1568837 1725299 32 1291532 1378463 64 752584 787368 Note that stddev is pretty small. 2) Another pipe test, which shows no real measurable improvement. (http://www.xmailserver.org/linux-patches/pipetest.c) Link: http://lkml.kernel.org/r/20180720172956.2883-2-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Jason Baron <jbaron@akamai.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22sched/wait: assert the wait_queue_head lock is held in __wake_up_commonChristoph Hellwig1-0/+2
Better ensure we actually hold the lock using lockdep than just commenting on it. Due to the various exported _locked interfaces it is far too easy to get the locking wrong. Link: http://lkml.kernel.org/r/20171214152344.6880-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22userfaultfd: use fault_wqh lockMatthew Wilcox1-3/+3
The userfaultfd code currently uses the unlocked waitqueue helpers for managing fault_wqh, but instead of holding the waitqueue lock for this waitqueue around these calls, it the waitqueue lock of fault_pending_wq, which is a different waitqueue instance. Given that the waitqueue is not exposed to the rest of the kernel this actually works ok at the moment, but prevents the userfaultfd locking rules from being enforced using lockdep. Switch to the internally locked waitqueue helpers instead. This means that the lock inside fault_wqh now nests inside the fault_pending_wqh lock, but that's not a problem since it was entirely unused before. [hch@lst.de: slight changelog updates] [rppt@linux.vnet.ibm.com: spotted changelog spellos] Link: http://lkml.kernel.org/r/20171214152344.6880-3-hch@lst.de Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22epoll: use the waitqueue lock to protect ep->wqChristoph Hellwig1-36/+29
Patch series "waitqueue lockdep annotation", v3. This series adds a strategic lockdep_assert_held to __wake_up_common to ensure callers really do hold the wait_queue_head lock when calling the unlocked wake_up variants. It turns out epoll did not do this for a fairly common path (hit all the time by systemd during bootup), so the second patch fixed this instance as well. This patch (of 3): The epoll code currently uses the unlocked waitqueue helpers for managing ep->wq, but instead of holding the waitqueue lock around these calls, it uses its own ep->lock spinlock. Given that the waitqueue is not exposed to the rest of the kernel this actually works ok at the moment, but prevents the epoll locking rules from being enforced using lockdep. Remove ep->lock and use the waitqueue lock to not only reduce the size of struct eventpoll but also to make sure we can assert locking invariants in the waitqueue code. Link: http://lkml.kernel.org/r/20171214152344.6880-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Baron <jbaron@akamai.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22kernel: tracepoints: add support for relative referencesArd Biesheuvel2-27/+41
To avoid the need for relocating absolute references to tracepoint structures at boot time when running relocatable kernels (which may take a disproportionate amount of space), add the option to emit these tables as relative references instead. Link: http://lkml.kernel.org/r/20180704083651.24360-7-ard.biesheuvel@linaro.org Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <james.morris@microsoft.com> Cc: James Morris <jmorris@namei.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22PCI: Add support for relative addressing in quirk tablesArd Biesheuvel2-3/+29
Allow the PCI quirk tables to be emitted in a way that avoids absolute references to the hook functions. This reduces the size of the entries, and, more importantly, makes them invariant under runtime relocation (e.g., for KASLR) Link: http://lkml.kernel.org/r/20180704083651.24360-6-ard.biesheuvel@linaro.org Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <james.morris@microsoft.com> Cc: James Morris <jmorris@namei.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22init: allow initcall tables to be emitted using relative referencesArd Biesheuvel4-41/+68
Allow the initcall tables to be emitted using relative references that are only half the size on 64-bit architectures and don't require fixups at runtime on relocatable kernels. Link: http://lkml.kernel.org/r/20180704083651.24360-5-ard.biesheuvel@linaro.org Acked-by: James Morris <james.morris@microsoft.com> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Petr Mladek <pmladek@suse.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <jmorris@namei.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22module: use relative references for __ksymtab entriesArd Biesheuvel6-24/+91
An ordinary arm64 defconfig build has ~64 KB worth of __ksymtab entries, each consisting of two 64-bit fields containing absolute references, to the symbol itself and to a char array containing its name, respectively. When we build the same configuration with KASLR enabled, we end up with an additional ~192 KB of relocations in the .init section, i.e., one 24 byte entry for each absolute reference, which all need to be processed at boot time. Given how the struct kernel_symbol that describes each entry is completely local to module.c (except for the references emitted by EXPORT_SYMBOL() itself), we can easily modify it to contain two 32-bit relative references instead. This reduces the size of the __ksymtab section by 50% for all 64-bit architectures, and gets rid of the runtime relocations entirely for architectures implementing KASLR, either via standard PIE linking (arm64) or using custom host tools (x86). Note that the binary search involving __ksymtab contents relies on each section being sorted by symbol name. This is implemented based on the input section names, not the names in the ksymtab entries, so this patch does not interfere with that. Given that the use of place-relative relocations requires support both in the toolchain and in the module loader, we cannot enable this feature for all architectures. So make it dependent on whether CONFIG_HAVE_ARCH_PREL32_RELOCATIONS is defined. Link: http://lkml.kernel.org/r/20180704083651.24360-4-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Jessica Yu <jeyu@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <james.morris@microsoft.com> Cc: James Morris <jmorris@namei.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22module: allow symbol exports to be disabledArd Biesheuvel3-5/+12
To allow existing C code to be incorporated into the decompressor or the UEFI stub, introduce a CPP macro that turns all EXPORT_SYMBOL_xxx declarations into nops, and #define it in places where such exports are undesirable. Note that this gets rid of a rather dodgy redefine of linux/export.h's header guard. Link: http://lkml.kernel.org/r/20180704083651.24360-3-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morris <james.morris@microsoft.com> Cc: James Morris <jmorris@namei.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Russell King <linux@armlinux.org.uk> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22arch: enable relative relocations for arm64, power and x86Ard Biesheuvel4-0/+13
Patch series "add support for relative references in special sections", v10. This adds support for emitting special sections such as initcall arrays, PCI fixups and tracepoints as relative references rather than absolute references. This reduces the size by 50% on 64-bit architectures, but more importantly, it removes the need for carrying relocation metadata for these sections in relocatable kernels (e.g., for KASLR) that needs to be fixed up at boot time. On arm64, this reduces the vmlinux footprint of such a reference by 8x (8 byte absolute reference + 24 byte RELA entry vs 4 byte relative reference) Patch #3 was sent out before as a single patch. This series supersedes the previous submission. This version makes relative ksymtab entries dependent on the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS rather than trying to infer from kbuild test robot replies for which architectures it should be blacklisted. Patch #1 introduces the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS, and sets it for the main architectures that are expected to benefit the most from this feature, i.e., 64-bit architectures or ones that use runtime relocations. Patch #2 add support for #define'ing __DISABLE_EXPORTS to get rid of ksymtab/kcrctab sections in decompressor and EFI stub objects when rebuilding existing C files to run in a different context. Patches #4 - #6 implement relative references for initcalls, PCI fixups and tracepoints, respectively, all of which produce sections with order ~1000 entries on an arm64 defconfig kernel with tracing enabled. This means we save about 28 KB of vmlinux space for each of these patches. [From the v7 series blurb, which included the jump_label patches as well]: For the arm64 kernel, all patches combined reduce the memory footprint of vmlinux by about 1.3 MB (using a config copied from Ubuntu that has KASLR enabled), of which ~1 MB is the size reduction of the RELA section in .init, and the remaining 300 KB is reduction of .text/.data. This patch (of 6): Before updating certain subsystems to use place relative 32-bit relocations in special sections, to save space and reduce the number of absolute relocations that need to be processed at runtime by relocatable kernels, introduce the Kconfig symbol and define it for some architectures that should be able to support and benefit from it. Link: http://lkml.kernel.org/r/20180704083651.24360-2-ard.biesheuvel@linaro.org Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Petr Mladek <pmladek@suse.com> Cc: James Morris <jmorris@namei.org> Cc: Nicolas Pitre <nico@linaro.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>, Cc: James Morris <james.morris@microsoft.com> Cc: Jessica Yu <jeyu@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22spelling.txt: add more spellings to spelling.txtColin Ian King1-0/+88
Here are some of the more common spelling mistakes and typos that I've found while fixing up spelling mistakes in the kernel over the past 6 months. Link: http://lkml.kernel.org/r/20180629150603.1159-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.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>
2018-08-22kernel/hung_task.c: allow to set checking interval separately from timeoutDmitry Vyukov6-3/+43
Currently task hung checking interval is equal to timeout, as the result hung is detected anywhere between timeout and 2*timeout. This is fine for most interactive environments, but this hurts automated testing setups (syzbot). In an automated setup we need to strictly order CPU lockup < RCU stall < workqueue lockup < task hung < silent loss, so that RCU stall is not detected as task hung and task hung is not detected as silent machine loss. The large variance in task hung detection timeout requires setting silent machine loss timeout to a very large value (e.g. if task hung is 3 mins, then silent loss need to be set to ~7 mins). The additional 3 minutes significantly reduce testing efficiency because usually we crash kernel within a minute, and this can add hours to bug localization process as it needs to do dozens of tests. Allow setting checking interval separately from timeout. This allows to set timeout to, say, 3 minutes, but checking interval to 10 secs. The interval is controlled via a new hung_task_check_interval_secs sysctl, similar to the existing hung_task_timeout_secs sysctl. The default value of 0 results in the current behavior: checking interval is equal to timeout. [akpm@linux-foundation.org: update hung_task_timeout_max's comment] Link: http://lkml.kernel.org/r/20180611111004.203513-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22kernel/crash_core.c: print timestamp using time64_tArnd Bergmann1-1/+1
The get_seconds() call returns a 32-bit timestamp on some architectures, and will overflow in the future. The newer ktime_get_real_seconds() always returns a 64-bit timestamp that does not suffer from this problem. Link: http://lkml.kernel.org/r/20180618150329.941903-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Marc-Andr Lureau <marcandre.lureau@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22linux/compiler.h: don't use boolRasmus Villemoes1-1/+1
Appararently, it's possible to have a non-trivial TU include a few headers, including linux/build_bug.h, without ending up with linux/types.h. So the 0day bot sent me config: um-x86_64_defconfig (attached as .config) >> include/linux/compiler.h:316:3: error: unknown type name 'bool'; did you mean '_Bool'? bool __cond = !(condition); \ for something I'm working on. Rather than contributing to the #include madness and including linux/types.h from compiler.h, just use int. Link: http://lkml.kernel.org/r/20180817101036.20969-1-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Christopher Li <sparse@chrisli.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22userns: use irqsave variant of refcount_dec_and_lock()Anna-Maria Gleixner1-4/+1
The irqsave variant of refcount_dec_and_lock handles irqsave/restore when taking/releasing the spin lock. With this variant the call of local_irq_save/restore is no longer required. [bigeasy@linutronix.de: s@atomic_dec_and_lock@refcount_dec_and_lock@g] Link: http://lkml.kernel.org/r/20180703200141.28415-7-bigeasy@linutronix.de Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22userns: use refcount_t for reference counting instead atomic_tSebastian Andrzej Siewior2-6/+7
refcount_t type and corresponding API should be used instead of atomic_t wh en the variable is used as a reference counter. This avoids accidental refcounter overflows that might lead to use-after-free situations. Link: http://lkml.kernel.org/r/20180703200141.28415-6-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Suggested-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22bdi: use irqsave variant of refcount_dec_and_lock()Anna-Maria Gleixner1-4/+1
The irqsave variant of refcount_dec_and_lock handles irqsave/restore when taking/releasing the spin lock. With this variant the call of local_irq_save/restore is no longer required. [bigeasy@linutronix.de: s@atomic_dec_and_lock@refcount_dec_and_lock@g] Link: http://lkml.kernel.org/r/20180703200141.28415-5-bigeasy@linutronix.de Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22bdi: use refcount_t for reference counting instead atomic_tSebastian Andrzej Siewior3-9/+10
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This permits avoiding accidental refcounter overflows that might lead to use-after-free situations. Link: http://lkml.kernel.org/r/20180703200141.28415-4-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Suggested-by: Peter Zijlstra <peterz@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22kernel.h: documentation for roundup() vs round_up()Kees Cook1-1/+34
Things like 3619dec5103d ("dh key: fix rounding up KDF output length") expose the lack of explicit documentation for roundup() vs round_up(). At least we can try to document it better if anyone goes looking. Link: http://lkml.kernel.org/r/20180703041950.GA43464@beast Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22include/asm-generic/bug.h: clarify valid uses of WARN()Dmitry Vyukov1-3/+13
Explicitly state that WARN*() should be used only for recoverable kernel issues/bugs and that it should not be used for any kind of invalid external inputs or transient conditions. Motivation: it's a very useful capability to be able to understand if a particular kernel splat means a kernel bug or simply an invalid user-space program. For the former one wants to notify kernel developers, while notifying kernel developers for the latter is annoying. Even a kernel developer may not know what to do with a WARNING in an unfamiliar subsystem. This is especially critical for any automated testing systems that may use panic_on_warn and mail kernel developers. The clear separation also serves as an additional documentation: is it a condition that must never occur because of additional checks/logic elsewhere? or is it simply a check for invalid inputs or unfortunate conditions? Use of pr_err() for user messages also leads to better error messages. "Something is wrong in file foo on line X" is not particularly useful message for end user. pr_err() forces developers to write more meaningful error messages for user. As of now we are almost there. We are doing systematic kernel testing with panic_on_warn and are not seeing massive amounts of false positives. But every now and then another WARN on ENOMEM or invalid inputs pops up and leads to a lengthy argument each time. The goal of this change is to officially document the rules. Link: http://lkml.kernel.org/r/20180620103716.61636-1-dvyukov@gmail.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22proc/kcore: add vmcoreinfo note to /proc/kcoreOmar Sandoval4-4/+21
The vmcoreinfo information is useful for runtime debugging tools, not just for crash dumps. A lot of this information can be determined by other means, but this is much more convenient, and it only adds a page at most to the file. Link: http://lkml.kernel.org/r/fddbcd08eed76344863303878b12de1c1e2a04b6.1531953780.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22crash_core: use VMCOREINFO_SYMBOL_ARRAY() for swapper_pg_dirOmar Sandoval1-1/+1
This is preparation for allowing CRASH_CORE to be enabled for any architecture. swapper_pg_dir is always either an array or a macro expanding to NULL. In the latter case, VMCOREINFO_SYMBOL() won't work, as it tries to take the address of the given symbol: #define VMCOREINFO_SYMBOL(name) \ vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name) Instead, use VMCOREINFO_SYMBOL_ARRAY(), which uses the value: #define VMCOREINFO_SYMBOL_ARRAY(name) \ vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)name) This is the same thing for the array case but isn't an error for the macro case. Link: http://lkml.kernel.org/r/c05f9781ec204f40fc96f95086e7b6de6a3eb2c3.1532563124.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22proc/kcore: optimize multiple page readsOmar Sandoval1-3/+11
The current code does a full search of the segment list every time for every page. This is wasteful, since it's almost certain that the next page will be in the same segment. Instead, check if the previous segment covers the current page before doing the list search. Link: http://lkml.kernel.org/r/fd346c11090cf93d867e01b8d73a6567c5ac6361.1531953780.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22proc/kcore: clean up ELF header generationOmar Sandoval1-209/+141
Currently, the ELF file header, program headers, and note segment are allocated all at once, in some icky code dating back to 2.3. Programs tend to read the file header, then the program headers, then the note segment, all separately, so this is a waste of effort. It's cleaner and more efficient to handle the three separately. Link: http://lkml.kernel.org/r/19c92cbad0e11f6103ff3274b2e7a7e51a1eb74b.1531953780.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>