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2017-11-17include/asm-generic/topology.h: remove unused parent_node() macroDou Liyang1-3/+0
Commit a7be6e5a7f8d ("mm: drop useless local parameters of __register_one_node()") removed the last user of parent_node(). The parent_node() macro in generic situation is unnecessary. Remove it for cleanup. Link: http://lkml.kernel.org/r/1504234599-29533-8-git-send-email-douly.fnst@cn.fujitsu.com Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17arch/tile/include/asm/topology.h: remove unused parent_node() macroDou Liyang1-6/+0
Commit a7be6e5a7f8d ("mm: drop useless local parameters of __register_one_node()") removed the last user of parent_node(). The parent_node() macro in tile platform is unnecessary. Remove it for cleanup. Link: http://lkml.kernel.org/r/1504234599-29533-7-git-send-email-douly.fnst@cn.fujitsu.com Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Chris Metcalf <cmetcalf@mellanox.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17arch/sparc/include/asm/topology_64.h: remove unused parent_node() macroDou Liyang1-2/+0
Commit a7be6e5a7f8d ("mm: drop useless local parameters of __register_one_node()") removed the last user of parent_node(). The parent_node() macro in SPARC64 platform is unnecessary. Remove it for cleanup. Link: http://lkml.kernel.org/r/1504234599-29533-6-git-send-email-douly.fnst@cn.fujitsu.com Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17arch/sh/include/asm/topology.h: remove unused parent_node() macroDou Liyang1-1/+0
Commit a7be6e5a7f8d ("mm: drop useless local parameters of __register_one_node()") removed the last user of parent_node(). The parent_node() macro in SUPERH platform is unnecessary. Remove it for cleanup. Link: http://lkml.kernel.org/r/1504234599-29533-5-git-send-email-douly.fnst@cn.fujitsu.com Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17arch/ia64/include/asm/topology.h: remove unused parent_node() macroDou Liyang1-7/+0
Commit a7be6e5a7f8d ("mm: drop useless local parameters of __register_one_node()") removed the last user of parent_node(). The parent_node() macro in IA64(Itanium) platform is unnecessary. Remove it for cleanup. Link: http://lkml.kernel.org/r/1504234599-29533-2-git-send-email-douly.fnst@cn.fujitsu.com Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Reported-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17drivers/pcmcia/sa1111_badge4.c: avoid unused function warningArnd Bergmann1-0/+2
pcmv_setup() is only used when the badge4 driver is built-in, but not when it is a loadable module: drivers/pcmcia/sa1111_badge4.c:153:122: error: 'pcmv_setup' defined but not used [-Werror=unused-function] This adds an #ifdef to avoid the definition of the unused function in the modular case. Link: http://lkml.kernel.org/r/20170911201133.3421636-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <rmk@armlinux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17mm: add infrastructure for get_user_pages_fast() benchmarkingKirill A. Shutemov5-0/+202
Performance of get_user_pages_fast() is critical for some workloads, but it's tricky to test it directly. This patch provides /sys/kernel/debug/gup_benchmark that helps with testing performance of it. See tools/testing/selftests/vm/gup_benchmark.c for userspace counterpart. Link: http://lkml.kernel.org/r/20170908215603.9189-2-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Huang Ying <ying.huang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17sysvipc: make get_maxid O(1) againDavidlohr Bueso3-33/+32
For a custom microbenchmark on a 3.30GHz Xeon SandyBridge, which calls IPC_STAT over and over, it was calculated that, on avg the cost of ipc_get_maxid() for increasing amounts of keys was: 10 keys: ~900 cycles 100 keys: ~15000 cycles 1000 keys: ~150000 cycles 10000 keys: ~2100000 cycles This is unsurprising as maxid is currently O(n). By having the max_id available in O(1) we save all those cycles for each semctl(_STAT) command, the idr_find can be expensive -- which some real (customer) workloads actually poll on. Note that this used to be the case, until commit 7ca7e564e04 ("ipc: store ipcs into IDRs"). The cost is the extra idr_find when doing RMIDs, but we simply go backwards, and should not take too many iterations to find the new value. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20170831172049.14576-5-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17sysvipc: properly name ipc_addid() limit parameterDavidlohr Bueso1-5/+5
This is better understood as a limit, instead of size; exactly like the function comment indicates. Rename it. Link: http://lkml.kernel.org/r/20170831172049.14576-4-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17sysvipc: duplicate lock comments wrt ipc_addid()Davidlohr Bueso2-0/+2
The comment in msgqueues when using ipc_addid() is quite useful imo. Duplicate it for shm and semaphores. Link: http://lkml.kernel.org/r/20170831172049.14576-3-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17sysvipc: unteach ids->next_id for !CHECKPOINT_RESTOREDavidlohr Bueso3-20/+47
Patch series "sysvipc: ipc-key management improvements". Here are a few improvements I spotted while eyeballing Guillaume's rhashtable implementation for ipc keys. The first and fourth patches are the interesting ones, the middle two are trivial. This patch (of 4): The next_id object-allocation functionality was introduced in commit 03f595668017 ("ipc: add sysctl to specify desired next object id"). Given that these new entries are _only_ exported under the CONFIG_CHECKPOINT_RESTORE option, there is no point for the common case to even know about ->next_id. As such rewrite ipc_buildid() such that it can do away with the field as well as unnecessary branches when adding a new identifier. The end result also better differentiates both cases, so the code ends up being cleaner; albeit the small duplications regarding the default case. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20170831172049.14576-2-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17initramfs: use time64_t timestampsArnd Bergmann1-5/+5
The cpio format uses a 32-bit number to encode file timestamps, which breaks initramfs support in 2038. This reinterprets the timestamp as unsigned, to give us another 68 years and avoids breaking until 2106. Link: http://lkml.kernel.org/r/20171019095536.801199-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Deepa Dinamani <deepa.kernel@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Daniel Thompson <daniel.thompson@linaro.org> Cc: Lokesh Vutla <lokeshvutla@ti.com> Cc: Stafford Horne <shorne@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17drivers/watchdog: make use of devm_register_reboot_notifier()Andrey Smirnov2-35/+32
Save a bit of cleanup code by leveraging newly added devm_register_reboot_notifier(). [akpm@linux-foundation.org: small cleanup: avoid 80-col tricks] Link: http://lkml.kernel.org/r/20170411160615.9784-1-andrew.smirnov@gmail.com Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Acked-by: Guenter Roeck <linux@roeck-us.net> Cc: Chris Healy <cphealy@gmail.com> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17kernel/reboot.c: add devm_register_reboot_notifier()Andrey Smirnov2-0/+31
Add devm_* wrapper around register_reboot_notifier to simplify device specific reboot notifier registration/unregistration. [akpm@linux-foundation.org: move `struct device' forward decl to top-of-file] Link: http://lkml.kernel.org/r/20170320171753.1705-1-andrew.smirnov@gmail.com Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17kcov: update documentationVictor Chibotaru1-4/+95
The updated documentation describes new KCOV mode for collecting comparison operands. Link: http://lkml.kernel.org/r/20171011095459.70721-3-glider@google.com Signed-off-by: Victor Chibotaru <tchibo@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Popov <alex.popov@linux.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Kees Cook <keescook@chromium.org> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: <syzkaller@googlegroups.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17Makefile: support flag -fsanitizer-coverage=trace-cmpVictor Chibotaru3-2/+18
The flag enables Clang instrumentation of comparison operations (currently not supported by GCC). This instrumentation is needed by the new KCOV device to collect comparison operands. Link: http://lkml.kernel.org/r/20171011095459.70721-2-glider@google.com Signed-off-by: Victor Chibotaru <tchibo@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Popov <alex.popov@linux.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Kees Cook <keescook@chromium.org> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: <syzkaller@googlegroups.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17kcov: support comparison operands collectionVictor Chibotaru3-39/+211
Enables kcov to collect comparison operands from instrumented code. This is done by using Clang's -fsanitize=trace-cmp instrumentation (currently not available for GCC). The comparison operands help a lot in fuzz testing. E.g. they are used in Syzkaller to cover the interiors of conditional statements with way less attempts and thus make previously unreachable code reachable. To allow separate collection of coverage and comparison operands two different work modes are implemented. Mode selection is now done via a KCOV_ENABLE ioctl call with corresponding argument value. Link: http://lkml.kernel.org/r/20171011095459.70721-1-glider@google.com Signed-off-by: Victor Chibotaru <tchibo@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Popov <alex.popov@linux.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Kees Cook <keescook@chromium.org> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: <syzkaller@googlegroups.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17kcov: remove pointless current != NULL checkAndrey Ryabinin1-1/+1
__sanitizer_cov_trace_pc() is a hot code, so it's worth to remove pointless '!current' check. Current is never NULL. Link: http://lkml.kernel.org/r/20170929162221.32500-1-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17kernel/panic.c: add TAINT_AUXBorislav Petkov2-1/+4
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>
2017-11-17pid: remove pidhashGargi Sharma8-50/+18
pidhash is no longer required as all the information can be looked up from idr tree. nr_hashed represented the number of pids that had been hashed. Since, nr_hashed and PIDNS_HASH_ADDING are no longer relevant, it has been renamed to pid_allocated and PIDNS_ADDING respectively. [gs051095@gmail.com: v6] Link: http://lkml.kernel.org/r/1507760379-21662-3-git-send-email-gs051095@gmail.com Link: http://lkml.kernel.org/r/1507583624-22146-3-git-send-email-gs051095@gmail.com Signed-off-by: Gargi Sharma <gs051095@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Tested-by: Tony Luck <tony.luck@intel.com> [ia64] Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: Ingo Molnar <mingo@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17pid: replace pid bitmap implementation with IDR APIGargi Sharma6-209/+65
Patch series "Replacing PID bitmap implementation with IDR API", v4. This series replaces kernel bitmap implementation of PID allocation with IDR API. These patches are written to simplify the kernel by replacing custom code with calls to generic code. The following are the stats for pid and pid_namespace object files before and after the replacement. There is a noteworthy change between the IDR and bitmap implementation. Before text data bss dec hex filename 8447 3894 64 12405 3075 kernel/pid.o After text data bss dec hex filename 3397 304 0 3701 e75 kernel/pid.o Before text data bss dec hex filename 5692 1842 192 7726 1e2e kernel/pid_namespace.o After text data bss dec hex filename 2854 216 16 3086 c0e kernel/pid_namespace.o The following are the stats for ps, pstree and calling readdir on /proc for 10,000 processes. ps: With IDR API With bitmap real 0m1.479s 0m2.319s user 0m0.070s 0m0.060s sys 0m0.289s 0m0.516s pstree: With IDR API With bitmap real 0m1.024s 0m1.794s user 0m0.348s 0m0.612s sys 0m0.184s 0m0.264s proc: With IDR API With bitmap real 0m0.059s 0m0.074s user 0m0.000s 0m0.004s sys 0m0.016s 0m0.016s This patch (of 2): Replace the current bitmap implementation for Process ID allocation. Functions that are no longer required, for example, free_pidmap(), alloc_pidmap(), etc. are removed. The rest of the functions are modified to use the IDR API. The change was made to make the PID allocation less complex by replacing custom code with calls to generic API. [gs051095@gmail.com: v6] Link: http://lkml.kernel.org/r/1507760379-21662-2-git-send-email-gs051095@gmail.com [avagin@openvz.org: restore the old behaviour of the ns_last_pid sysctl] Link: http://lkml.kernel.org/r/20171106183144.16368-1-avagin@openvz.org Link: http://lkml.kernel.org/r/1507583624-22146-2-git-send-email-gs051095@gmail.com Signed-off-by: Gargi Sharma <gs051095@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: Ingo Molnar <mingo@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17kernel/sysctl.c: code cleanupsOla N. Kaldestad1-5/+3
Remove unnecessary else block, remove redundant return and call to kfree in if block. Link: http://lkml.kernel.org/r/1510238435-1655-1-git-send-email-mail@okal.no Signed-off-by: Ola N. Kaldestad <mail@okal.no> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17Documentation/sysctl/vm.txt: fix typoKangmin Park1-1/+1
Link: http://lkml.kernel.org/r/CAKW4uUyCi=PnKf3epgFVz8z=1tMtHSOHNm+fdNxrNw3-THvRCA@mail.gmail.com Signed-off-by: Kangmin Park <l4stpr0gr4m@gmail.com> Cc: Jiri Kosina <trivial@kernel.org> Cc: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17drivers/rapidio/devices/rio_mport_cdev.c: fix error handling in 'rio_dma_transfer()'Christophe JAILLET1-1/+1
In case of error, 'dma_map_sg()' returns 0, not a negative value. There is BUG_ON() in 'dma_map_sg_attrs()' which makes sure of that. Link: http://lkml.kernel.org/r/d4235bd2b9274e99f6c86ea71b1fa1c7bd8d0c08.1505687047.git.christophe.jaillet@wanadoo.fr Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Christian K_nig <christian.koenig@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17drivers/rapidio/devices/rio_mport_cdev.c: fix resource leak in error handling path in 'rio_dma_transfer()'Christophe JAILLET1-1/+2
If 'dma_map_sg()', we should branch to the existing error handling path to free some resources before returning. Link: http://lkml.kernel.org/r/61292a4f369229eee03394247385e955027283f8.1505687047.git.christophe.jaillet@wanadoo.fr Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Christian K_nig <christian.koenig@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17rapidio: constify rio_device_idArvind Yadav5-5/+5
rio_device_id are not supposed to change at runtime. rio driver is working with const 'id_table'. So mark the non-const rio_device_id structs as const. Link: http://lkml.kernel.org/r/1503734627-6058-2-git-send-email-arvind.yadav.cs@gmail.com Link: http://lkml.kernel.org/r/1503734627-6058-3-git-send-email-arvind.yadav.cs@gmail.com Link: http://lkml.kernel.org/r/1503734627-6058-4-git-send-email-arvind.yadav.cs@gmail.com Link: http://lkml.kernel.org/r/1503734627-6058-5-git-send-email-arvind.yadav.cs@gmail.com Link: http://lkml.kernel.org/r/1503734627-6058-6-git-send-email-arvind.yadav.cs@gmail.com Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Acked-by: Alexandre Bounine <alexandre.bounine@idt.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17kdump: print a message in case parse_crashkernel_mem resulted in zero bytesDave Young1-1/+2
parse_crashkernel_mem() silently returns if we get zero bytes in the parsing function. It is useful for debugging to add a message, especially if the kernel cannot boot correctly. Add a pr_info instead of pr_warn because it is expected behavior for size = 0, eg. crashkernel=2G-4G:128M, size will be 0 in case system memory is less than 2G. Link: http://lkml.kernel.org/r/20171114080129.GA6115@dhcp-128-65.nay.redhat.com Signed-off-by: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17kernel/signal.c: remove the no longer needed SIGNAL_UNKILLABLE check in complete_signal()Oleg Nesterov1-2/+2
complete_signal() checks SIGNAL_UNKILLABLE before it starts to destroy the thread group, today this is wrong in many ways. If nothing else, fatal_signal_pending() should always imply that the whole thread group (except ->group_exit_task if it is not NULL) is killed, this check breaks the rule. After the previous changes we can rely on sig_task_ignored(); sig_fatal(sig) && SIGNAL_UNKILLABLE can only be true if we actually want to kill this task and sig == SIGKILL OR it is traced and debugger can intercept the signal. This should hopefully fix the problem reported by Dmitry. This test-case static int init(void *arg) { for (;;) pause(); } int main(void) { char stack[16 * 1024]; for (;;) { int pid = clone(init, stack + sizeof(stack)/2, CLONE_NEWPID | SIGCHLD, NULL); assert(pid > 0); assert(ptrace(PTRACE_ATTACH, pid, 0, 0) == 0); assert(waitpid(-1, NULL, WSTOPPED) == pid); assert(ptrace(PTRACE_DETACH, pid, 0, SIGSTOP) == 0); assert(syscall(__NR_tkill, pid, SIGKILL) == 0); assert(pid == wait(NULL)); } } triggers the WARN_ON_ONCE(!(task->jobctl & JOBCTL_STOP_PENDING)) in task_participate_group_stop(). do_signal_stop()->signal_group_exit() checks SIGNAL_GROUP_EXIT and return false, but task_set_jobctl_pending() checks fatal_signal_pending() and does not set JOBCTL_STOP_PENDING. And his should fix the minor security problem reported by Kyle, SECCOMP_RET_TRACE can miss fatal_signal_pending() the same way if the task is the root of a pid namespace. Link: http://lkml.kernel.org/r/20171103184246.GD21036@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Kyle Huey <me@kylehuey.com> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Kyle Huey <me@kylehuey.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17kernel/signal.c: protect the SIGNAL_UNKILLABLE tasks from !sig_kernel_only() signalsOleg Nesterov1-1/+1
Change sig_task_ignored() to drop the SIG_DFL && !sig_kernel_only() signals even if force == T. This simplifies the next change and this matches the same check in get_signal() which will drop these signals anyway. Link: http://lkml.kernel.org/r/20171103184227.GC21036@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Kyle Huey <me@kylehuey.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17kernel/signal.c: protect the traced SIGNAL_UNKILLABLE tasks from SIGKILLOleg Nesterov1-5/+7
The comment in sig_ignored() says "Tracers may want to know about even ignored signals" but SIGKILL can not be reported to debugger and it is just wrong to return 0 in this case: SIGKILL should only kill the SIGNAL_UNKILLABLE task if it comes from the parent ns. Change sig_ignored() to ignore ->ptrace if sig == SIGKILL and rely on sig_task_ignored(). SISGTOP coming from within the namespace is not really right too but at least debugger can intercept it, and we can't drop it here because this will break "gdb -p 1": ptrace_attach() won't work. Perhaps we will add another ->ptrace check later, we will see. Link: http://lkml.kernel.org/r/20171103184206.GB21036@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Kyle Huey <me@kylehuey.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17fat: remove redundant assignment of 0 to slotsColin Ian King1-1/+0
The variable slots is being assigned a value of zero that is never read, slots is being updated again a few lines later. Remove this redundant assignment. Cleans clang warning: Value stored to 'slots' is never read Link: http://lkml.kernel.org/r/20171017140258.22536-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17hfs/hfsplus: clean up unused variables in bnode.cChristos Gkekas2-8/+0
Delete variables 'tree' and 'sb', which are set but never used. Link: http://lkml.kernel.org/r/1507977146-15875-1-git-send-email-chris.gekas@gmail.com Signed-off-by: Christos Gkekas <chris.gekas@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17nilfs2: remove inode->i_version initializationJeff Layton1-1/+0
It's never used in nilfs2. Link: http://lkml.kernel.org/r/1510064486-1728-2-git-send-email-konishi.ryusuke@lab.ntt.co.jp Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17nilfs2: use octal for unreadable permission macroRyusuke Konishi1-1/+1
Replace S_IRWXUGO with 0777 because symbolic permissions are considered harmful: https://lwn.net/Articles/696229/ Link: http://lkml.kernel.org/r/1509367935-3086-5-git-send-email-konishi.ryusuke@lab.ntt.co.jp Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17nilfs2: align block comments of nilfs_sufile_truncate_range() at *Ryusuke Konishi1-16/+16
Fix the following checkpatch warning: WARNING: Block comments should align the * on each line #633: FILE: sufile.c:633: +/** + * nilfs_sufile_truncate_range - truncate range of segment array Link: http://lkml.kernel.org/r/1509367935-3086-4-git-send-email-konishi.ryusuke@lab.ntt.co.jp Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17fs, nilfs: convert nilfs_root.count from atomic_t to refcount_tElena Reshetova2-6/+7
atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable nilfs_root.count is used as pure reference counter. Convert it to refcount_t and fix up the operations. Link: http://lkml.kernel.org/r/1509367935-3086-3-git-send-email-konishi.ryusuke@lab.ntt.co.jp Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17nilfs2: fix race condition that causes file system corruptionAndreas Rohner1-2/+4
There is a race condition between nilfs_dirty_inode() and nilfs_set_file_dirty(). When a file is opened, nilfs_dirty_inode() is called to update the access timestamp in the inode. It calls __nilfs_mark_inode_dirty() in a separate transaction. __nilfs_mark_inode_dirty() caches the ifile buffer_head in the i_bh field of the inode info structure and marks it as dirty. After some data was written to the file in another transaction, the function nilfs_set_file_dirty() is called, which adds the inode to the ns_dirty_files list. Then the segment construction calls nilfs_segctor_collect_dirty_files(), which goes through the ns_dirty_files list and checks the i_bh field. If there is a cached buffer_head in i_bh it is not marked as dirty again. Since nilfs_dirty_inode() and nilfs_set_file_dirty() use separate transactions, it is possible that a segment construction that writes out the ifile occurs in-between the two. If this happens the inode is not on the ns_dirty_files list, but its ifile block is still marked as dirty and written out. In the next segment construction, the data for the file is written out and nilfs_bmap_propagate() updates the b-tree. Eventually the bmap root is written into the i_bh block, which is not dirty, because it was written out in another segment construction. As a result the bmap update can be lost, which leads to file system corruption. Either the virtual block address points to an unallocated DAT block, or the DAT entry will be reused for something different. The error can remain undetected for a long time. A typical error message would be one of the "bad btree" errors or a warning that a DAT entry could not be found. This bug can be reproduced reliably by a simple benchmark that creates and overwrites millions of 4k files. Link: http://lkml.kernel.org/r/1509367935-3086-2-git-send-email-konishi.ryusuke@lab.ntt.co.jp Signed-off-by: Andreas Rohner <andreas.rohner@gmx.net> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Tested-by: Andreas Rohner <andreas.rohner@gmx.net> Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17fs/nilfs2: convert timers to use timer_setup()Kees Cook2-6/+6
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. This requires adding a pointer to hold the timer's target task, as the lifetime of sc_task doesn't appear to match the timer's task. Link: http://lkml.kernel.org/r/20171016235900.GA102729@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17sysctl: check for UINT_MAX before unsigned int min/maxJoe Lawrence1-6/+8
Mikulas noticed in the existing do_proc_douintvec_minmax_conv() and do_proc_dopipe_max_size_conv() introduced in this patchset, that they inconsistently handle overflow and min/max range inputs: For example: 0 ... param->min - 1 ---> ERANGE param->min ... param->max ---> the value is accepted param->max + 1 ... 0x100000000L + param->min - 1 ---> ERANGE 0x100000000L + param->min ... 0x100000000L + param->max ---> EINVAL 0x100000000L + param->max + 1, 0x200000000L + param->min - 1 ---> ERANGE 0x200000000L + param->min ... 0x200000000L + param->max ---> EINVAL 0x200000000L + param->max + 1, 0x300000000L + param->min - 1 ---> ERANGE In do_proc_do*() routines which store values into unsigned int variables (4 bytes wide for 64-bit builds), first validate that the input unsigned long value (8 bytes wide for 64-bit builds) will fit inside the smaller unsigned int variable. Then check that the unsigned int value falls inside the specified parameter min, max range. Otherwise the unsigned long -> unsigned int conversion drops leading bits from the input value, leading to the inconsistent pattern Mikulas documented above. Link: http://lkml.kernel.org/r/1507658689-11669-5-git-send-email-joe.lawrence@redhat.com Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17pipe: add proc_dopipe_max_size() to safely assign pipe_max_sizeJoe Lawrence4-15/+56
pipe_max_size is assigned directly via procfs sysctl: static struct ctl_table fs_table[] = { ... { .procname = "pipe-max-size", .data = &pipe_max_size, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &pipe_proc_fn, .extra1 = &pipe_min_size, }, ... int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf, size_t *lenp, loff_t *ppos) { ... ret = proc_dointvec_minmax(table, write, buf, lenp, ppos) ... and then later rounded in-place a few statements later: ... pipe_max_size = round_pipe_size(pipe_max_size); ... This leaves a window of time between initial assignment and rounding that may be visible to other threads. (For example, one thread sets a non-rounded value to pipe_max_size while another reads its value.) Similar reads of pipe_max_size are potentially racy: pipe.c :: alloc_pipe_info() pipe.c :: pipe_set_size() Add a new proc_dopipe_max_size() that consolidates reading the new value from the user buffer, verifying bounds, and calling round_pipe_size() with a single assignment to pipe_max_size. Link: http://lkml.kernel.org/r/1507658689-11669-4-git-send-email-joe.lawrence@redhat.com Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17pipe: avoid round_pipe_size() nr_pages overflow on 32-bitJoe Lawrence1-2/+15
round_pipe_size() contains a right-bit-shift expression which may overflow, which would cause undefined results in a subsequent roundup_pow_of_two() call. static inline unsigned int round_pipe_size(unsigned int size) { unsigned long nr_pages; nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; return roundup_pow_of_two(nr_pages) << PAGE_SHIFT; } PAGE_SIZE is defined as (1UL << PAGE_SHIFT), so: - 4 bytes wide on 32-bit (0 to 0xffffffff) - 8 bytes wide on 64-bit (0 to 0xffffffffffffffff) That means that 32-bit round_pipe_size(), nr_pages may overflow to 0: size=0x00000000 nr_pages=0x0 size=0x00000001 nr_pages=0x1 size=0xfffff000 nr_pages=0xfffff size=0xfffff001 nr_pages=0x0 << ! size=0xffffffff nr_pages=0x0 << ! This is bad because roundup_pow_of_two(n) is undefined when n == 0! 64-bit is not a problem as the unsigned int size is 4 bytes wide (similar to 32-bit) and the larger, 8 byte wide unsigned long, is sufficient to handle the largest value of the bit shift expression: size=0xffffffff nr_pages=100000 Modify round_pipe_size() to return 0 if n == 0 and updates its callers to handle accordingly. Link: http://lkml.kernel.org/r/1507658689-11669-3-git-send-email-joe.lawrence@redhat.com Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17pipe: match pipe_max_size data type with procfsJoe Lawrence2-2/+2
Patch series "A few round_pipe_size() and pipe-max-size fixups", v3. While backporting Michael's "pipe: fix limit handling" patchset to a distro-kernel, Mikulas noticed that current upstream pipe limit handling contains a few problems: 1 - procfs signed wrap: echo'ing a large number into /proc/sys/fs/pipe-max-size and then cat'ing it back out shows a negative value. 2 - round_pipe_size() nr_pages overflow on 32bit: this would subsequently try roundup_pow_of_two(0), which is undefined. 3 - visible non-rounded pipe-max-size value: there is no mutual exclusion or protection between the time pipe_max_size is assigned a raw value from proc_dointvec_minmax() and when it is rounded. 4 - unsigned long -> unsigned int conversion makes for potential odd return errors from do_proc_douintvec_minmax_conv() and do_proc_dopipe_max_size_conv(). This version underwent the same testing as v1: https://marc.info/?l=linux-kernel&m=150643571406022&w=2 This patch (of 4): pipe_max_size is defined as an unsigned int: unsigned int pipe_max_size = 1048576; but its procfs/sysctl representation is an integer: static struct ctl_table fs_table[] = { ... { .procname = "pipe-max-size", .data = &pipe_max_size, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &pipe_proc_fn, .extra1 = &pipe_min_size, }, ... that is signed: int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf, size_t *lenp, loff_t *ppos) { ... ret = proc_dointvec_minmax(table, write, buf, lenp, ppos) This leads to signed results via procfs for large values of pipe_max_size: % echo 2147483647 >/proc/sys/fs/pipe-max-size % cat /proc/sys/fs/pipe-max-size -2147483648 Use unsigned operations on this variable to avoid such negative values. Link: http://lkml.kernel.org/r/1507658689-11669-2-git-send-email-joe.lawrence@redhat.com Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17autofs: don't fail mount for transient errorNeilBrown1-1/+14
Currently if the autofs kernel module gets an error when writing to the pipe which links to the daemon, then it marks the whole moutpoint as catatonic, and it will stop working. It is possible that the error is transient. This can happen if the daemon is slow and more than 16 requests queue up. If a subsequent process tries to queue a request, and is then signalled, the write to the pipe will return -ERESTARTSYS and autofs will take that as total failure. So change the code to assess -ERESTARTSYS and -ENOMEM as transient failures which only abort the current request, not the whole mountpoint. It isn't a crash or a data corruption, but having autofs mountpoints suddenly stop working is rather inconvenient. Ian said: : And given the problems with a half dozen (or so) user space applications : consuming large amounts of CPU under heavy mount and umount activity this : could happen more easily than we expect. Link: http://lkml.kernel.org/r/87y3norvgp.fsf@notabene.neil.brown.name Signed-off-by: NeilBrown <neilb@suse.com> Acked-by: Ian Kent <raven@themaw.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17init/version.c: include <linux/export.h> instead of <linux/module.h>Masahiro Yamada1-1/+1
init/version.c has nothing to do with modules, so remove the <linux/modude.h>. Instead, include <linux/export.h> for EXPORT_SYMBOL_GPL. This cuts off a lot of unnecessary header parsing. Link: http://lkml.kernel.org/r/1505920984-8523-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17epoll: remove ep_call_nested() from ep_eventpoll_poll()Jason Baron1-45/+35
The use of ep_call_nested() in ep_eventpoll_poll(), which is the .poll routine for an epoll fd, is used to prevent excessively deep epoll nesting, and to prevent circular paths. However, we are already preventing these conditions during EPOLL_CTL_ADD. In terms of too deep epoll chains, we do in fact allow deep nesting of the epoll fds themselves (deeper than EP_MAX_NESTS), however we don't allow more than EP_MAX_NESTS when an epoll file descriptor is actually connected to a wakeup source. Thus, we do not require the use of ep_call_nested(), since ep_eventpoll_poll(), which is called via ep_scan_ready_list() only continues nesting if there are events available. Since ep_call_nested() is implemented using a global lock, applications that make use of nested epoll can see large performance improvements with this change. Davidlohr said: : Improvements are quite obscene actually, such as for the following : epoll_wait() benchmark with 2 level nesting on a 80 core IvyBridge: : : ncpus vanilla dirty delta : 1 2447092 3028315 +23.75% : 4 231265 2986954 +1191.57% : 8 121631 2898796 +2283.27% : 16 59749 2902056 +4757.07% : 32 26837 2326314 +8568.30% : 64 12926 1341281 +10276.61% : : (http://linux-scalability.org/epoll/epoll-test.c) Link: http://lkml.kernel.org/r/1509430214-5599-1-git-send-email-jbaron@akamai.com Signed-off-by: Jason Baron <jbaron@akamai.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Salman Qazi <sqazi@google.com> Cc: Hou Tao <houtao1@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17epoll: avoid calling ep_call_nested() from ep_poll_safewake()Jason Baron1-29/+18
ep_poll_safewake() is used to wakeup potentially nested epoll file descriptors. The function uses ep_call_nested() to prevent entering the same wake up queue more than once, and to prevent excessively deep wakeup paths (deeper than EP_MAX_NESTS). However, this is not necessary since we are already preventing these conditions during EPOLL_CTL_ADD. This saves extra function calls, and avoids taking a global lock during the ep_call_nested() calls. I have, however, left ep_call_nested() for the CONFIG_DEBUG_LOCK_ALLOC case, since ep_call_nested() keeps track of the nesting level, and this is required by the call to spin_lock_irqsave_nested(). It would be nice to remove the ep_call_nested() calls for the CONFIG_DEBUG_LOCK_ALLOC case as well, however its not clear how to simply pass the nesting level through multiple wake_up() levels without more surgery. In any case, I don't think CONFIG_DEBUG_LOCK_ALLOC is generally used for production. This patch, also apparently fixes a workload at Google that Salman Qazi reported by completely removing the poll_safewake_ncalls->lock from wakeup paths. Link: http://lkml.kernel.org/r/1507920533-8812-1-git-send-email-jbaron@akamai.com Signed-off-by: Jason Baron <jbaron@akamai.com> Acked-by: Davidlohr Bueso <dbueso@suse.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Salman Qazi <sqazi@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17epoll: account epitem and eppoll_entry to kmemcgShakeel Butt1-2/+2
A userspace application can directly trigger the allocations from eventpoll_epi and eventpoll_pwq slabs. A buggy or malicious application can consume a significant amount of system memory by triggering such allocations. Indeed we have seen in production where a buggy application was leaking the epoll references and causing a burst of eventpoll_epi and eventpoll_pwq slab allocations. This patch opt-in the charging of eventpoll_epi and eventpoll_pwq slabs. There is a per-user limit (~4% of total memory if no highmem) on these caches. I think it is too generous particularly in the scenario where jobs of multiple users are running on the system and the administrator is reducing cost by overcomitting the memory. This is unaccounted kernel memory and will not be considered by the oom-killer. I think by accounting it to kmemcg, for systems with kmem accounting enabled, we can provide better isolation between jobs of different users. Link: http://lkml.kernel.org/r/20171003021519.23907-1-shakeelb@google.com Signed-off-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Greg Thelen <gthelen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17checkpatch: do not check missing blank line before builtin_*_driverMasahiro Yamada1-0/+1
checkpatch.pl does not check missing blank line before module_*_driver. I want it to behave likewise for builtin_*_driver. Link: http://lkml.kernel.org/r/1505700081-12854-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.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>
2017-11-17checkpatch: add --strict test for lines ending in [ or (Joe Perches1-0/+6
Lines that end in an open bracket or open parenthesis are generally hard to follow. Lines following those ending with open parenthesis are also rarely aligned to that open parenthesis. Suggest not ending lines with '[' or '(' Link: http://lkml.kernel.org/r/8fd0b2b4a7482064254e37931eb9302a81d5aa2f.1508340786.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-17checkpatch: add TP_printk to list of logging functionsJoe Perches1-0/+1
So the line length check can be bypassed by its callers. Link: http://lkml.kernel.org/r/7de542c08a6e79f2ebe7c1416c9f403c23fdcc09.1508282823.git.joe@perches.com Signed-off-by: Joe Perches <joe@perches.com> Reported-by: Song Liu <songliubraving@fb.com> Tested-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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