- 09 May, 2017 40 commits
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Laura Abbott authored
set_memory_* functions have moved to set_memory.h. Switch to this explicitly. Link: http://lkml.kernel.org/r/1488920133-27229-14-git-send-email-labbott@redhat.comSigned-off-by:
Laura Abbott <labbott@redhat.com> Acked-by:
Takashi Iwai <tiwai@suse.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Laura Abbott authored
set_memory_* functions have moved to set_memory.h. Switch to this explicitly. Link: http://lkml.kernel.org/r/1488920133-27229-13-git-send-email-labbott@redhat.comSigned-off-by:
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Laura Abbott authored
set_memory_* functions have moved to set_memory.h. Switch to this explicitly. Link: http://lkml.kernel.org/r/1488920133-27229-12-git-send-email-labbott@redhat.comSigned-off-by:
Jessica Yu <jeyu@redhat.com> Signed-off-by:
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Laura Abbott authored
set_memory_* functions have moved to set_memory.h. Switch to this explicitly. Link: http://lkml.kernel.org/r/1488920133-27229-11-git-send-email-labbott@redhat.comSigned-off-by:
Daniel Borkmann <daniel@iogearbox.net> Signed-off-by:
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Laura Abbott authored
set_memory_* functions have moved to set_memory.h. Switch to this explicitly. Link: http://lkml.kernel.org/r/1488920133-27229-10-git-send-email-labbott@redhat.comSigned-off-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
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Laura Abbott authored
set_memory_* functions have moved to set_memory.h. Switch to this explicitly. Link: http://lkml.kernel.org/r/1488920133-27229-9-git-send-email-labbott@redhat.comSigned-off-by:
Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by:
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Laura Abbott authored
set_memory_* functions have moved to set_memory.h. Switch to this explicitly. [akpm@linux-foundation.org: track drivers/gpu/drm/i915/i915_gem_gtt.c linux-next changes] Link: http://lkml.kernel.org/r/1488920133-27229-8-git-send-email-labbott@redhat.comSigned-off-by:
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Laura Abbott authored
set_memory_* functions have moved to set_memory.h. Switch to this explicitly. Link: http://lkml.kernel.org/r/1488920133-27229-7-git-send-email-labbott@redhat.comSigned-off-by:
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Laura Abbott authored
set_memory_* functions have moved to set_memory.h. Switch to this explicitly. Link: http://lkml.kernel.org/r/1488920133-27229-6-git-send-email-labbott@redhat.comSigned-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Laura Abbott authored
set_memory_* functions have moved to set_memory.h. Switch to this explicitly Link: http://lkml.kernel.org/r/1488920133-27229-5-git-send-email-labbott@redhat.comSigned-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:
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Laura Abbott authored
The set_memory_* functions have moved to set_memory.h. Use that header explicitly. Link: http://lkml.kernel.org/r/1488920133-27229-4-git-send-email-labbott@redhat.comSigned-off-by:
Catalin Marinas <catalin.marinas@arm.com> Acked-by:
Mark Rutland <mark.rutland@arm.com> Signed-off-by:
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Laura Abbott authored
set_memory_* functions have moved to set_memory.h. Switch to this explicitly Link: http://lkml.kernel.org/r/1488920133-27229-3-git-send-email-labbott@redhat.comSigned-off-by:
Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by:
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Laura Abbott authored
Patch series "set_memory_* functions header refactor", v3. The set_memory_* APIs came out of a desire to have a better way to change memory attributes. Many of these attributes were linked to cache functionality so the prototypes were put in cacheflush.h. These days, the APIs have grown and have a much wider use than just cache APIs. To support this growth, split off set_memory_* and friends into a separate header file to avoid growing cacheflush.h for APIs that have nothing to do with caches. Link: http://lkml.kernel.org/r/1488920133-27229-2-git-send-email-labbott@redhat.comSigned-off-by:
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Joe Perches authored
Add these misspellings to scripts/spelling.txt too Link: http://lkml.kernel.org/r/962aace119675e5fe87be2a88ddac1a5486f8e60.1490931810.git.joe@perches.comSigned-off-by:
Joe Perches <joe@perches.com> Acked-by:
Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by:
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Masahiro Yamada authored
Fix typos and add the following to the scripts/spelling.txt: intialisation||initialisation intialised||initialised intialise||initialise This commit does not intend to change the British spelling itself. Link: http://lkml.kernel.org/r/1481573103-11329-18-git-send-email-yamada.masahiro@socionext.comSigned-off-by:
Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by:
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Stephen Boyd authored
This typo is quite common. Fix it and add it to the spelling file so that checkpatch catches it earlier. Link: http://lkml.kernel.org/r/20170317011131.6881-2-sboyd@codeaurora.orgSigned-off-by:
Stephen Boyd <sboyd@codeaurora.org> Signed-off-by:
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Stephen Boyd authored
Fix typos and add the following to the scripts/spelling.txt: momery||memory Link: http://lkml.kernel.org/r/20170317011131.6881-1-sboyd@codeaurora.orgSigned-off-by: -
Michal Hocko authored
__vmalloc* allows users to provide gfp flags for the underlying allocation. This API is quite popular $ git grep "=[[:space:]]__vmalloc\|return[[:space:]]*__vmalloc" | wc -l 77 The only problem is that many people are not aware that they really want to give __GFP_HIGHMEM along with other flags because there is really no reason to consume precious lowmemory on CONFIG_HIGHMEM systems for pages which are mapped to the kernel vmalloc space. About half of users don't use this flag, though. This signals that we make the API unnecessarily too complex. This patch simply uses __GFP_HIGHMEM implicitly when allocating pages to be mapped to the vmalloc space. Current users which add __GFP_HIGHMEM are simplified and drop the flag. Link: http://lkml.kernel.org/r/20170307141020.29107-1-mhocko@kernel.orgSigned-off-by:
Michal Hocko <mhocko@suse.com> Reviewed-by:
Matthew Wilcox <mawilcox@microsoft.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Cristopher Lameter <cl@linux.com> Signed-off-by:
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Huang Ying authored
Now vzalloc() is used in swap code to allocate various data structures, such as swap cache, swap slots cache, cluster info, etc. Because the size may be too large on some system, so that normal kzalloc() may fail. But using kzalloc() has some advantages, for example, less memory fragmentation, less TLB pressure, etc. So change the data structure allocation in swap code to use kvzalloc() which will try kzalloc() firstly, and fallback to vzalloc() if kzalloc() failed. In general, although kmalloc() will reduce the number of high-order pages in short term, vmalloc() will cause more pain for memory fragmentation in the long term. And the swap data structure allocation that is changed in this patch is expected to be long term allocation. From Dave Hansen: "for example, we have a two-page data structure. vmalloc() takes two effectively random order-0 pages, probably from two different 2M pages and pins them. That "kills" two 2M pages. kmalloc(), allocating two *contiguous* pages, will not cross a 2M boundary. That means it will only "kill" the possibility of a single 2M page. More 2M pages == less fragmentation. The allocation in this patch occurs during swap on time, which is usually done during system boot, so usually we have high opportunity to allocate the contiguous pages successfully. The allocation for swap_map[] in struct swap_info_struct is not changed, because that is usually quite large and vmalloc_to_page() is used for it. That makes it a little harder to change. Link: http://lkml.kernel.org/r/20170407064911.25447-1-ying.huang@intel.comSigned-off-by:
Huang Ying <ying.huang@intel.com> Acked-by:
Tim Chen <tim.c.chen@intel.com> Acked-by:
Rik van Riel <riel@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by:
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Michal Hocko authored
bcache_device_init uses kmalloc for small requests and vmalloc for those which are larger than 64 pages. This alone is a strange criterion. Moreover kmalloc can fallback to vmalloc on the failure. Let's simply use kvmalloc instead as it knows how to handle the fallback properly Link: http://lkml.kernel.org/r/20170306103327.2766-5-mhocko@kernel.orgSigned-off-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by:
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Michal Hocko authored
copy_params uses kmalloc with vmalloc fallback. We already have a helper for that - kvmalloc. This caller requires GFP_NOIO semantic so it hasn't been converted with many others by previous patches. All we need to achieve this semantic is to use the scope memalloc_noio_{save,restore} around kvmalloc. Link: http://lkml.kernel.org/r/20170306103327.2766-4-mhocko@kernel.orgSigned-off-by: -
Michal Hocko authored
fq_alloc_node, alloc_netdev_mqs and netif_alloc* open code kmalloc with vmalloc fallback. Use the kvmalloc variant instead. Keep the __GFP_REPEAT flag based on explanation from Eric: "At the time, tests on the hardware I had in my labs showed that vmalloc() could deliver pages spread all over the memory and that was a small penalty (once memory is fragmented enough, not at boot time)" The way how the code is constructed means, however, that we prefer to go and hit the OOM killer before we fall back to the vmalloc for requests <=32kB (with 4kB pages) in the current code. This is rather disruptive for something that can be achived with the fallback. On the other hand __GFP_REPEAT doesn't have any useful semantic for these requests. So the effect of this patch is that requests which fit into 32kB will fall back to vmalloc easier now. Link: http://lkml.kernel.org/r/20170306103327.2766-3-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
There are many code paths opencoding kvmalloc. Let's use the helper instead. The main difference to kvmalloc is that those users are usually not considering all the aspects of the memory allocator. E.g. allocation requests <= 32kB (with 4kB pages) are basically never failing and invoke OOM killer to satisfy the allocation. This sounds too disruptive for something that has a reasonable fallback - the vmalloc. On the other hand those requests might fallback to vmalloc even when the memory allocator would succeed after several more reclaim/compaction attempts previously. There is no guarantee something like that happens though. This patch converts many of those places to kv[mz]alloc* helpers because they are more conservative. Link: http://lkml.kernel.org/r/20170306103327.2766-2-mhocko@kernel.orgSigned-off-by:
Kees Cook <keescook@chromium.org> Acked-by:
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Michal Hocko authored
getxattr uses vmalloc to allocate memory if kzalloc fails. This is filled by vfs_getxattr and then copied to the userspace. vmalloc, however, doesn't zero out the memory so if the specific implementation of the xattr handler is sloppy we can theoretically expose a kernel memory. There is no real sign this is really the case but let's make sure this will not happen and use vzalloc instead. Fixes: 779302e6 ("fs/xattr.c:getxattr(): improve handling of allocation failures") Link: http://lkml.kernel.org/r/20170306103327.2766-1-mhocko@kernel.orgAcked-by:
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Michal Hocko authored
alloc_ila_locks seemed to c&p from alloc_bucket_locks allocation pattern which is quite unusual. The default allocation size is 320 * sizeof(spinlock_t) which is sub page unless lockdep is enabled when the performance benefit is really questionable and not worth the subtle code IMHO. Also note that the context when we call ila_init_net (modprobe or a task creating a net namespace) has to be properly configured. Let's just simplify the code and use kvmalloc helper which is a transparent way to use kmalloc with vmalloc fallback. Link: http://lkml.kernel.org/r/20170306103032.2540-5-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
alloc_bucket_locks allocation pattern is quite unusual. We are preferring vmalloc when CONFIG_NUMA is enabled. The rationale is that vmalloc will respect the memory policy of the current process and so the backing memory will get distributed over multiple nodes if the requester is configured properly. At least that is the intention, in reality rhastable is shrunk and expanded from a kernel worker so no mempolicy can be assumed. Let's just simplify the code and use kvmalloc helper, which is a transparent way to use kmalloc with vmalloc fallback, if the caller is allowed to block and use the flag otherwise. Link: http://lkml.kernel.org/r/20170306103032.2540-4-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
vhost code uses __GFP_REPEAT when allocating vhost_virtqueue resp. vhost_vsock because it would really like to prefer kmalloc to the vmalloc fallback - see 23cc5a99 ("vhost-net: extend device allocation to vmalloc") for more context. Michael Tsirkin has also noted: "__GFP_REPEAT overhead is during allocation time. Using vmalloc means all accesses are slowed down. Allocation is not on data path, accesses are." The similar applies to other vhost_kvzalloc users. Let's teach kvmalloc_node to handle __GFP_REPEAT properly. There are two things to be careful about. First we should prevent from the OOM killer and so have to involve __GFP_NORETRY by default and secondly override __GFP_REPEAT for !costly order requests as the __GFP_REPEAT is ignored for !costly orders. Supporting __GFP_REPEAT like semantic for !costly request is possible it would require changes in the page allocator. This is out of scope of this patch. This patch shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170306103032.2540-3-mhocko@kernel.orgSigned-off-by:
Michael S. Tsirkin <mst@redhat.com> Cc: David Miller <davem@davemloft.net> Signed-off-by:
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Michal Hocko authored
__vmalloc_node_flags used to be static inline but this has changed by "mm: introduce kv[mz]alloc helpers" because kvmalloc_node needs to use it as well and the code is outside of the vmalloc proper. I haven't realized that changing this will lead to a subtle bug though. The function is responsible to track the caller as well. This caller is then printed by /proc/vmallocinfo. If __vmalloc_node_flags is not inline then we would get only direct users of __vmalloc_node_flags as callers (e.g. v[mz]alloc) which reduces usefulness of this debugging feature considerably. It simply doesn't help to see that the given range belongs to vmalloc as a caller: 0xffffc90002c79000-0xffffc90002c7d000 16384 vmalloc+0x16/0x18 pages=3 vmalloc N0=3 0xffffc90002c81000-0xffffc90002c85000 16384 vmalloc+0x16/0x18 pages=3 vmalloc N1=3 0xffffc90002c8d000-0xffffc90002c91000 16384 vmalloc+0x16/0x18 pages=3 vmalloc N1=3 0xffffc90002c95000-0xffffc90002c99000 16384 vmalloc+0x16/0x18 pages=3 vmalloc N1=3 We really want to catch the _caller_ of the vmalloc function. Fix this issue by making __vmalloc_node_flags static inline again. Link: http://lkml.kernel.org/r/20170502134657.12381-1-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
Patch series "kvmalloc", v5. There are many open coded kmalloc with vmalloc fallback instances in the tree. Most of them are not careful enough or simply do not care about the underlying semantic of the kmalloc/page allocator which means that a) some vmalloc fallbacks are basically unreachable because the kmalloc part will keep retrying until it succeeds b) the page allocator can invoke a really disruptive steps like the OOM killer to move forward which doesn't sound appropriate when we consider that the vmalloc fallback is available. As it can be seen implementing kvmalloc requires quite an intimate knowledge if the page allocator and the memory reclaim internals which strongly suggests that a helper should be implemented in the memory subsystem proper. Most callers, I could find, have been converted to use the helper instead. This is patch 6. There are some more relying on __GFP_REPEAT in the networking stack which I have converted as well and Eric Dumazet was not opposed [2] to convert them as well. [1] http://lkml.kernel.org/r/20170130094940.13546-1-mhocko@kernel.org [2] http://lkml.kernel.org/r/1485273626.16328.301.camel@edumazet-glaptop3.roam.corp.google.com This patch (of 9): Using kmalloc with the vmalloc fallback for larger allocations is a common pattern in the kernel code. Yet we do not have any common helper for that and so users have invented their own helpers. Some of them are really creative when doing so. Let's just add kv[mz]alloc and make sure it is implemented properly. This implementation makes sure to not make a large memory pressure for > PAGE_SZE requests (__GFP_NORETRY) and also to not warn about allocation failures. This also rules out the OOM killer as the vmalloc is a more approapriate fallback than a disruptive user visible action. This patch also changes some existing users and removes helpers which are specific for them. In some cases this is not possible (e.g. ext4_kvmalloc, libcfs_kvzalloc) because those seems to be broken and require GFP_NO{FS,IO} context which is not vmalloc compatible in general (note that the page table allocation is GFP_KERNEL). Those need to be fixed separately. While we are at it, document that __vmalloc{_node} about unsupported gfp mask because there seems to be a lot of confusion out there. kvmalloc_node will warn about GFP_KERNEL incompatible (which are not superset) flags to catch new abusers. Existing ones would have to die slowly. [sfr@canb.auug.org.au: f2fs fixup] Link: http://lkml.kernel.org/r/20170320163735.332e64b7@canb.auug.org.au Link: http://lkml.kernel.org/r/20170306103032.2540-2-mhocko@kernel.orgSigned-off-by:
Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by: Andreas Dilger <adilger@dilger.ca> [ext4 part] Acked-by:
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Davidlohr Bueso authored
Assign 'struct kern_ipc_perm' its own cacheline to avoid false sharing with sysv ipc calls. While the structure itself is rather read-mostly throughout the lifespan of ipc, the spinlock causes most of the invalidations. One example is commit 31a7c474 ("ipc/sem.c: cacheline align the ipc spinlock for semaphores"). Therefore, extend this to all ipc. The effect of cacheline alignment on sems can be seen in sembench, which deals mostly with semtimedop wait/wakes is seen to improve raw throughput (worker loops) between 8 to 12% on a 24-core x86 with over 4 threads. Link: http://lkml.kernel.org/r/1486673582-6979-4-git-send-email-dave@stgolabs.netSigned-off-by:
Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by:
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Davidlohr Bueso authored
Clean up early flag and address some minutia. Link: http://lkml.kernel.org/r/1486673582-6979-3-git-send-email-dave@stgolabs.netSigned-off-by:
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Arnd Bergmann authored
sys_newlstat is a system call implementation that is meant for user space, and that copies kernel-internal data structure to the user format, which is not needed for in-kernel users. Further, as we rearrange the system call implementation so we can extend it with 64-bit time_t, the prototype for sys_newlstat changes. This changes the initramfs code to use vfs_lstat directly, to get it out of the way of the time_t changes, and make it slightly more efficient in the process. Along the same lines we also replace sys_stat and sys_stat64 with vfs_stat. Link: http://lkml.kernel.org/r/20170314214932.4052842-1-arnd@arndb.deSigned-off-by:
Arnd Bergmann <arnd@arndb.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Daniel Thompson authored
Many "embedded" architectures provide CMDLINE_FORCE to allow the kernel to override the command line provided by an inflexible bootloader. However there is currrently no way for the kernel to override the initramfs image provided by the bootloader meaning there are still ways for bootloaders to make things difficult for us. Fix this by introducing INITRAMFS_FORCE which can prevent the kernel from loading the bootloader supplied image. We use CMDLINE_FORCE (and its friend CMDLINE_EXTEND) to imply that the system has an inflexible bootloader. This allow us to avoid presenting this config option to users of systems where inflexible bootloaders aren't usually a problem. Link: http://lkml.kernel.org/r/20170217121940.30126-1-daniel.thompson@linaro.orgSigned-off-by:
Daniel Thompson <daniel.thompson@linaro.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Guenter Roeck authored
smatch says: WARNING: please, no spaces at the start of a line #30: FILE: lib/zlib_inflate/inftrees.c:112: + for (min = 1; min < MAXBITS; min++)$ total: 0 errors, 1 warnings, 8 lines checked NOTE: For some of the reported defects, checkpatch may be able to mechanically convert to the typical style using --fix or --fix-inplace. ./patches/zlib-inflate-fix-potential-buffer-overflow.patch has style problems, please review. NOTE: If any of the errors are false positives, please report them to the maintainer, see CHECKPATCH in MAINTAINERS. Please run checkpatch prior to sending patches Signed-off-by: -
Dmitry Vyukov authored
in_interrupt() also returns true when bh is disabled in task context. That's not what fail_task() wants to check. Use the new in_task() predicate that does the right thing. Link: http://lkml.kernel.org/r/20170321091805.140676-1-dvyukov@google.comSigned-off-by:
Dmitry Vyukov <dvyukov@google.com> Reviewed-by:
Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by:
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Dmitry Vyukov authored
in_interrupt() semantics are confusing and wrong for most users as it also returns true when bh is disabled. Thus we open coded a proper check for interrupts in __sanitizer_cov_trace_pc() with a lengthy explanatory comment. Use the new in_task() predicate instead. Link: http://lkml.kernel.org/r/20170321091026.139655-1-dvyukov@google.comSigned-off-by:
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Zhang Xiao authored
The elapsed time, user CPU time and system CPU time for the thread group status request are presently left at zero. Fill these in. [akpm@linux-foundation.org: run ktime_get_ns() a single time] [akpm@linux-foundation.org: include linux/sched/cputime.h for task_cputime()] Link: http://lkml.kernel.org/r/1488508424-12322-1-git-send-email-xiao.zhang@windriver.comSigned-off-by:
Zhang Xiao <xiao.zhang@windriver.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by:
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Kirill Tkhai authored
pid_ns_for_children set by a task is known only to the task itself, and it's impossible to identify it from outside. It's a big problem for checkpoint/restore software like CRIU, because it can't correctly handle tasks, that do setns(CLONE_NEWPID) in proccess of their work. This patch solves the problem, and it exposes pid_ns_for_children to ns directory in standard way with the name "pid_for_children": ~# ls /proc/5531/ns -l | grep pid lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid -> pid:[4026531836] lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid_for_children -> pid:[4026532286] Link: http://lkml.kernel.org/r/149201123914.6007.2187327078064239572.stgit@localhost.localdomainSigned-off-by:
Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Andrei Vagin <avagin@virtuozzo.com> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Serge Hallyn <serge@hallyn.com> Signed-off-by:
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Kirill Tkhai authored
Patch series "Expose task pid_ns_for_children to userspace". pid_ns_for_children set by a task is known only to the task itself, and it's impossible to identify it from outside. It's a big problem for checkpoint/restore software like CRIU, because it can't correctly handle tasks, that do setns(CLONE_NEWPID) in proccess of their work. If they have a custom pid_ns_for_children before dump, they must have the same ns after restore. Otherwise, restored task bumped into enviroment it does not expect. This patchset solves the problem. It exposes pid_ns_for_children to ns directory in standard way with the name "pid_for_children": ~# ls /proc/5531/ns -l | grep pid lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid -> pid:[4026531836] lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid_for_children -> pid:[4026532286] This patch (of 2): Make possible to have link content prefix yyy different from the link name xxx: $ readlink /proc/[pid]/ns/xxx yyy:[4026531838] This will be used in next patch. Link: http://lkml.kernel.org/r/149201120318.6007.7362655181033883000.stgit@localhost.localdomainSigned-off-by:
Cyrill Gorcunov <gorcunov@openvz.org> Acked-by:
Andrei Vagin <avagin@virtuozzo.com> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Serge Hallyn <serge@hallyn.com> Signed-off-by:
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Kirill Tkhai authored
alloc_pidmap() advances pid_namespace::last_pid. When first pid allocation fails, then next created process will have pid 2 and pid_ns_prepare_proc() won't be called. So, pid_namespace::proc_mnt will never be initialized (not to mention that there won't be a child reaper). I saw crash stack of such case on kernel 3.10: BUG: unable to handle kernel NULL pointer dereference at (null) IP: proc_flush_task+0x8f/0x1b0 Call Trace: release_task+0x3f/0x490 wait_consider_task.part.10+0x7ff/0xb00 do_wait+0x11f/0x280 SyS_wait4+0x7d/0x110 We may fix this by restore of last_pid in 0 or by prohibiting of futher allocations. Since there was a similar issue in Oleg Nesterov's commit 314a8ad0 ("pidns: fix free_pid() to handle the first fork failure"). and it was fixed via prohibiting allocation, let's follow this way, and do the same. Link: http://lkml.kernel.org/r/149201021004.4863.6762095011554287922.stgit@localhost.localdomainSigned-off-by:
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