- 07 Feb, 2018 40 commits
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Arnd Bergmann authored
We get a lot of very large stack frames using gcc-7.0.1 with the default -fsanitize-address-use-after-scope --param asan-stack=1 options, which can easily cause an overflow of the kernel stack, e.g. drivers/gpu/drm/i915/gvt/handlers.c:2434:1: warning: the frame size of 46176 bytes is larger than 3072 bytes drivers/net/wireless/ralink/rt2x00/rt2800lib.c:5650:1: warning: the frame size of 23632 bytes is larger than 3072 bytes lib/atomic64_test.c:250:1: warning: the frame size of 11200 bytes is larger than 3072 bytes drivers/gpu/drm/i915/gvt/handlers.c:2621:1: warning: the frame size of 9208 bytes is larger than 3072 bytes drivers/media/dvb-frontends/stv090x.c:3431:1: warning: the frame size of 6816 bytes is larger than 3072 bytes fs/fscache/stats.c:287:1: warning: the frame size of 6536 bytes is larger than 3072 bytes To reduce this risk, -fsanitize-address-use-after-scope is now split out into a separate CONFIG_KASAN_EXTRA Kconfig option, leading to stack frames that are smaller than 2 kilobytes most of the time on x86_64. An earlier version of this patch also prevented combining KASAN_EXTRA with KASAN_INLINE, but that is no longer necessary with gcc-7.0.1. All patches to get the frame size below 2048 bytes with CONFIG_KASAN=y and CONFIG_KASAN_EXTRA=n have been merged by maintainers now, so we can bring back that default now. KASAN_EXTRA=y still causes lots of warnings but now defaults to !COMPILE_TEST to disable it in allmodconfig, and it remains disabled in all other defconfigs since it is a new option. I arbitrarily raise the warning limit for KASAN_EXTRA to 3072 to reduce the noise, but an allmodconfig kernel still has around 50 warnings on gcc-7. I experimented a bit more with smaller stack frames and have another follow-up series that reduces the warning limit for 64-bit architectures to 1280 bytes (without CONFIG_KASAN). With earlier versions of this patch series, I also had patches to address the warnings we get with KASAN and/or KASAN_EXTRA, using a "noinline_if_stackbloat" annotation. That annotation now got replaced with a gcc-8 bugfix (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715) and a workaround for older compilers, which means that KASAN_EXTRA is now just as bad as before and will lead to an instant stack overflow in a few extreme cases. This reverts parts of commit 3f181b4d ("lib/Kconfig.debug: disable -Wframe-larger-than warnings with KASAN=y"). Two patches in linux-next should be merged first to avoid introducing warnings in an allmodconfig build: 3cd890db ("media: dvb-frontends: fix i2c access helpers for KASAN") 16c3ada8 ("media: r820t: fix r820t_write_reg for KASAN") Do we really need to backport this? I think we do: without this patch, enabling KASAN will lead to unavoidable kernel stack overflow in certain device drivers when built with gcc-7 or higher on linux-4.10+ or any version that contains a backport of commit c5caf21a. Most people are probably still on older compilers, but it will get worse over time as they upgrade their distros. The warnings we get on kernels older than this should all be for code that uses dangerously large stack frames, though most of them do not cause an actual stack overflow by themselves.The asan-stack option was added in linux-4.0, and commit 3f181b4d ("lib/Kconfig.debug: disable -Wframe-larger-than warnings with KASAN=y") effectively turned off the warning for allmodconfig kernels, so I would like to see this fix backported to any kernels later than 4.0. I have done dozens of fixes for individual functions with stack frames larger than 2048 bytes with asan-stack, and I plan to make sure that all those fixes make it into the stable kernels as well (most are already there). Part of the complication here is that asan-stack (from 4.0) was originally assumed to always require much larger stacks, but that turned out to be a combination of multiple gcc bugs that we have now worked around and fixed, but sanitize-address-use-after-scope (from v4.10) has a much higher inherent stack usage and also suffers from at least three other problems that we have analyzed but not yet fixed upstream, each of them makes the stack usage more severe than it should be. Link: http://lkml.kernel.org/r/20171221134744.2295529-1-arnd@arndb.deSigned-off-by:
Arnd Bergmann <arnd@arndb.de> Acked-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Yaowei Bai authored
Make is_kdump_kernel return bool due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1513308799-19232-8-git-send-email-baiyaowei@cmss.chinamobile.comSigned-off-by:
Yaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by:
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Yaowei Bai authored
Make mutex_is_locked return bool due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1513266622-15860-7-git-send-email-baiyaowei@cmss.chinamobile.comSigned-off-by:
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Yaowei Bai authored
Make module_is_live return bool due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1513266622-15860-6-git-send-email-baiyaowei@cmss.chinamobile.comSigned-off-by:
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Yaowei Bai authored
Make iomem_is_exclusive return bool due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1513266622-15860-5-git-send-email-baiyaowei@cmss.chinamobile.comSigned-off-by:
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Yaowei Bai authored
Make current_cpuset_is_being_rebound return bool due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1513266622-15860-4-git-send-email-baiyaowei@cmss.chinamobile.comSigned-off-by:
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Yaowei Bai authored
Make __lockref_is_dead return bool due to this function only using either true or false as its return value. No functional change. Link: http://lkml.kernel.org/r/1513266622-15860-3-git-send-email-baiyaowei@cmss.chinamobile.comSigned-off-by:
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Yaowei Bai authored
Make memblock_is_map/region_memory return bool due to these two functions only using either true or false as its return value. No functional change. Link: http://lkml.kernel.org/r/1513266622-15860-2-git-send-email-baiyaowei@cmss.chinamobile.comSigned-off-by:
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Sergey Senozhatsky authored
The file was converted from print_symbol() to %pf some time ago in commit ef26f20c ("genirq: Print threaded handler in spurious debug output"). kallsyms does not seem to be needed anymore. Link: http://lkml.kernel.org/r/20171208025616.16267-10-sergey.senozhatsky@gmail.comSigned-off-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Sergey Senozhatsky authored
hrtimer does not seem to use any of kallsyms functions/defines. Link: http://lkml.kernel.org/r/20171208025616.16267-9-sergey.senozhatsky@gmail.comSigned-off-by:
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Sergey Senozhatsky authored
The file was converted from print_symbol() to %pSR a while ago in commit 071361d3 ("mm: Convert print_symbol to %pSR"). kallsyms does not seem to be needed anymore. Link: http://lkml.kernel.org/r/20171208025616.16267-3-sergey.senozhatsky@gmail.comSigned-off-by:
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Pravin Shedge authored
These duplicate includes have been found with scripts/checkincludes.pl but they have been removed manually to avoid removing false positives. Link: http://lkml.kernel.org/r/1512580957-6071-1-git-send-email-pravin.shedge4linux@gmail.comSigned-off-by:
Pravin Shedge <pravin.shedge4linux@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by:
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Shakeel Butt authored
Commit 7994e6f7 ("vfs: Move waiting for inode writeback from end_writeback() to evict_inode()") removed inode_sync_wait() from end_writeback() and commit dbd5768f ("vfs: Rename end_writeback() to clear_inode()") renamed end_writeback() to clear_inode(). After these patches there is no sleeping operation in clear_inode(). So, remove might_sleep() from it. Link: http://lkml.kernel.org/r/20171108004354.40308-1-shakeelb@google.comSigned-off-by:
Shakeel Butt <shakeelb@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Greg Thelen <gthelen@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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Markus Elfring authored
Some data were printed into a sequence by two separate function calls. Print the same data by a single function call instead. This issue was detected by using the Coccinelle software. Link: http://lkml.kernel.org/r/ddcfff3a-9502-6ce0-b08a-365eb55ce958@users.sourceforge.netSigned-off-by:
Markus Elfring <elfring@users.sourceforge.net> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Lennox Wu <lennox.wu@gmail.com> Signed-off-by:
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Jonathan Haws authored
Previous behavior added tasks to the work queue using the static_prio value instead of the dynamic priority value in prio. This caused RT tasks to be added to the work queue in a FIFO manner rather than by priority. Normal tasks were handled by priority. This fix utilizes the dynamic priority of the task to ensure that both RT and normal tasks are added to the work queue in priority order. Utilizing the dynamic priority (prio) rather than the base priority (normal_prio) was chosen to ensure that if a task had a boosted priority when it was added to the work queue, it would be woken sooner to to ensure that it releases any other locks it may be holding in a more timely manner. It is understood that the task could have a lower priority when it wakes than when it was added to the queue in this (unlikely) case. Link: http://lkml.kernel.org/r/1513006652-7014-1-git-send-email-jhaws@sdl.usu.eduSigned-off-by:
Jonathan Haws <jhaws@sdl.usu.edu> Reviewed-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by:
Davidlohr Bueso <dbueso@suse.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Deepa Dinamani <deepa.kernel@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by:
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Philippe Mikoyan authored
As described in the title, this patch fixes <ipc>id_ds inconsistency when <ipc>ctl_stat executes concurrently with some ds-changing function, e.g. shmat, msgsnd or whatever. For instance, if shmctl(IPC_STAT) is running concurrently with shmat, following data structure can be returned: {... shm_lpid = 0, shm_nattch = 1, ...} Link: http://lkml.kernel.org/r/20171202153456.6514-1-philippe.mikoyan@skat.systemsSigned-off-by:Philippe Mikoyan <philippe.mikoyan@skat.systems> Reviewed-by:
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Andrey Ryabinin authored
Similarly to type mismatch checks, new GCC 8.x and Clang also changed for ABI for returns_nonnull checks. While we can update our code to conform the new ABI it's more reasonable to just remove it. Because it's just dead code, we don't have any single user of returns_nonnull attribute in the whole kernel. And AFAIU the advantage that this attribute could bring would be mitigated by -fno-delete-null-pointer-checks cflag that we use to build the kernel. So it's unlikely we will have a lot of returns_nonnull attribute in future. So let's just remove the code, it has no use. [aryabinin@virtuozzo.com: fix warning] Link: http://lkml.kernel.org/r/20180122165711.11510-1-aryabinin@virtuozzo.com Link: http://lkml.kernel.org/r/20180119152853.16806-2-aryabinin@virtuozzo.comSigned-off-by:
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Andrey Ryabinin authored
UBSAN=y fails to build with new GCC/clang: arch/x86/kernel/head64.o: In function `sanitize_boot_params': arch/x86/include/asm/bootparam_utils.h:37: undefined reference to `__ubsan_handle_type_mismatch_v1' because Clang and GCC 8 slightly changed ABI for 'type mismatch' errors. Compiler now uses new __ubsan_handle_type_mismatch_v1() function with slightly modified 'struct type_mismatch_data'. Let's add new 'struct type_mismatch_data_common' which is independent from compiler's layout of 'struct type_mismatch_data'. And make __ubsan_handle_type_mismatch[_v1]() functions transform compiler-dependent type mismatch data to our internal representation. This way, we can support both old and new compilers with minimal amount of change. Link: http://lkml.kernel.org/r/20180119152853.16806-1-aryabinin@virtuozzo.comSigned-off-by:Sodagudi Prasad <psodagud@codeaurora.org> Cc: <stable@vger.kernel.org> [4.5+] Signed-off-by:
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Andrew Morton authored
A vist from the spelling fairy. Cc: David Laight <David.Laight@ACULAB.COM> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by:
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Masahiro Yamada authored
This macro is only used by net/ipv6/mcast.c, but there is no reason why it must be BUILD_BUG_ON_NULL(). Replace it with BUILD_BUG_ON_ZERO(), and remove BUILD_BUG_ON_NULL() definition from <linux/build_bug.h>. Link: http://lkml.kernel.org/r/1515121833-3174-3-git-send-email-yamada.masahiro@socionext.comSigned-off-by:
Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Ian Abbott <abbotti@mev.co.uk> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by:
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Masahiro Yamada authored
Do not duplicate BUILD_BUG_ON*. Use ones from <linux/build_bug.h>. Link: http://lkml.kernel.org/r/1515121833-3174-2-git-send-email-yamada.masahiro@socionext.comSigned-off-by:
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Dmitry Vyukov authored
Currently KCOV_ENABLE does not check if the current task is already associated with another kcov descriptor. As the result it is possible to associate a single task with more than one kcov descriptor, which later leads to a memory leak of the old descriptor. This relation is really meant to be one-to-one (task has only one back link). Extend validation to detect such misuse. Link: http://lkml.kernel.org/r/20180122082520.15716-1-dvyukov@google.com Fixes: 5c9a8750 ("kernel: add kcov code coverage") Signed-off-by:
Dmitry Vyukov <dvyukov@google.com> Reported-by:
Shankara Pailoor <sp3485@columbia.edu> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: syzbot <syzkaller@googlegroups.com> Signed-off-by:
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Eric Biggers authored
This reverts commit ba62bafe ("kernel/relay.c: fix potential memory leak"). This commit introduced a double free bug, because 'chan' is already freed by the line: kref_put(&chan->kref, relay_destroy_channel); This bug was found by syzkaller, using the BLKTRACESETUP ioctl. Link: http://lkml.kernel.org/r/20180127004759.101823-1-ebiggers3@gmail.com Fixes: ba62bafe ("kernel/relay.c: fix potential memory leak") Signed-off-by:
Eric Biggers <ebiggers@google.com> Reported-by:
syzbot <syzkaller@googlegroups.com> Reviewed-by:
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Arnd Bergmann authored
getnstimeofday() is deprecated, so I'm converting this to use ktime_get_real_ts64() as a safe replacement. I considered using ktime_get_real() instead, but since the algorithm here depends on the exact timing, I decided to introduce fewer changes and leave the code that determines the nanoseconds since the last seconds wrap untouched. It's not entirely clear to me whether we should also change the time base to CLOCK_BOOTTIME or CLOCK_TAI. With boottime, we would be independent of changes due to settimeofday() and only see the speed adjustment from the upstream clock source, with the downside of having the signal be at an arbirary offset from the start of the UTC second signal. With CLOCK_TAI, we would use the same offset from the UTC second as before and still suffer from settimeofday() adjustments, but would be less confused during leap seconds. Both boottime and tai only offer usable (i.e. avoiding ktime_t to timespec64 conversion) interfaces for ktime_t though, so either way, changing it wouldn't take significantly more work. CLOCK_MONOTONIC could be used with ktime_get_ts64(), but would lose synchronization across a suspend/resume cycle, which seems worse. Link: http://lkml.kernel.org/r/20180116171451.3095620-1-arnd@arndb.deSigned-off-by:
Rodolfo Giometti <giometti@enneenne.com> Signed-off-by:
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Mike Rapoport authored
There are several functions that do find_task_by_vpid() followed by get_task_struct(). We can use a helper function instead. Link: http://lkml.kernel.org/r/1509602027-11337-1-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by:
Oleg Nesterov <oleg@redhat.com> Signed-off-by:
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Markus Elfring authored
checkpatch pointed out the following: Comparison to NULL could be written !... Thus fix the affected source code places. Link: http://lkml.kernel.org/r/c3e79a1a-891e-cb62-990f-bd99839311b9@users.sourceforge.netSigned-off-by:
Alexandre Bounine <alexandre.bounine@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Signed-off-by:
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Markus Elfring authored
drivers/rapidio/devices/tsi721_dma.c: delete an unnecessary variable initialisation in tsi721_alloc_chan_resources() The local variable "desc" will eventually be set to an appropriate pointer a bit later. Thus omit the explicit initialisation at the beginning. Link: http://lkml.kernel.org/r/728d8e20-4ae9-d661-d932-2d99ce67e71f@users.sourceforge.netSigned-off-by:
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Markus Elfring authored
drivers/rapidio/devices/tsi721_dma.c: delete an error message for a failed memory allocation in tsi721_alloc_chan_resources() Omit an extra message for a memory allocation failure in this function. This issue was detected by using the Coccinelle software. Link: http://lkml.kernel.org/r/a96fcaf8-ea24-bcac-0214-273620349d42@users.sourceforge.netSigned-off-by:
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Markus Elfring authored
checkpatch pointed information out like the following. WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable Thus fix the affected source code places. Link: http://lkml.kernel.org/r/5f51f606-ece8-7bff-bb86-81d182c49b98@users.sourceforge.netSigned-off-by:
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Markus Elfring authored
* Return an error code without storing it in an intermediate variable. * Delete the label "out" and local variable "rc" which became unnecessary with this refactoring. Link: http://lkml.kernel.org/r/8db441e1-c227-64e7-4747-095da63d7a2e@users.sourceforge.netSigned-off-by:
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Markus Elfring authored
The local variable "rc" will be set to an appropriate value a bit later. Thus omit the explicit initialisation at the beginning. Link: http://lkml.kernel.org/r/ed729e8c-815c-8b56-a48f-1be579d0cc2b@users.sourceforge.netSigned-off-by:
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Markus Elfring authored
Replace the specification of data structures by pointer dereferences as the parameter for the operator "sizeof" to make the corresponding size determination a bit safer according to the Linux coding style convention. This issue was detected by using the Coccinelle software. Link: http://lkml.kernel.org/r/495f571c-fb4d-b1d5-a6e5-494f2c537a8d@users.sourceforge.netSigned-off-by:
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Markus Elfring authored
checkpatch pointed information out like the following. ERROR: do not use assignment in if condition Thus fix the affected source code places. Link: http://lkml.kernel.org/r/6f5631ed-ec3e-503d-850a-ab09b5736dbe@users.sourceforge.netSigned-off-by:
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Markus Elfring authored
checkpatch pointed information out like the following. Comparison to NULL could be written ... Thus fix the affected source code places. Link: http://lkml.kernel.org/r/739f9f1c-3ebe-c21b-c5e2-31976cfbc0ee@users.sourceforge.netSigned-off-by:
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Markus Elfring authored
Patch series "RapidIO: Adjustments for some function implementations". This patch (of 7): Omit an extra message for a memory allocation failure in this function. This issue was detected by using the Coccinelle software. Link: http://lkml.kernel.org/r/dfd6887b-2521-cbf2-af5b-e70b5fa4c33c@users.sourceforge.netSigned-off-by:
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Alexey Dobriyan authored
CPUmasks are never big enough to warrant 64-bit code. Space savings: add/remove: 0/0 grow/shrink: 1/4 up/down: 3/-17 (-14) Function old new delta sched_init_numa 1530 1533 +3 compat_sys_sched_setaffinity 160 159 -1 sys_sched_getaffinity 197 195 -2 sys_sched_setaffinity 183 176 -7 compat_sys_sched_getaffinity 179 172 -7 Link: http://lkml.kernel.org/r/20171204165531.GA8221@avx2Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by:
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Marcos Paulo de Souza authored
All other places that deals with namespaces have an explanation of why the restriction is there. The description added in this commit was based on commit e66eded8 ("userns: Don't allow CLONE_NEWUSER | CLONE_FS"). Link: http://lkml.kernel.org/r/20171112151637.13258-1-marcos.souza.org@gmail.comSigned-off-by:
Marcos Paulo de Souza <marcos.souza.org@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by:
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Marcos Paulo de Souza authored
Thus reducing one indentation level while maintaining the same rationale. Link: http://lkml.kernel.org/r/20171117002929.5155-1-marcos.souza.org@gmail.comSigned-off-by:
Michal Hocko <mhocko@suse.com> Signed-off-by:
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Randy Dunlap authored
Fix grammar and add an omitted word. Link: http://lkml.kernel.org/r/1a5a021c-0207-f793-7f07-addca26772d5@infradead.org Fixes: f9886bc5 ("signal: Document the strange si_codes used by ptrace event stops") Signed-off-by:
Randy Dunlap <rdunlap@infradead.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by:
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Ernesto A. Fernandez authored
When creating a file inside a directory that has the setgid flag set, give the new file the group ID of the parent, and also the setgid flag if it is a directory itself. Link: http://lkml.kernel.org/r/20171204192705.GA6101@debian.homeSigned-off-by:
Ernesto A. Fernandez <ernesto.mnd.fernandez@gmail.com> Reviewed-by:
Vyacheslav Dubeyko <slava@dubeyko.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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