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<title>user/sven/linux.git/ipc, branch v6.1.97</title>
<subtitle>Linux Kernel
</subtitle>
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<updated>2022-12-31T12:32:01Z</updated>
<entry>
<title>ipc: fix memory leak in init_mqueue_fs()</title>
<updated>2022-12-31T12:32:01Z</updated>
<author>
<name>Zhengchao Shao</name>
<email>shaozhengchao@huawei.com</email>
</author>
<published>2022-12-09T09:29:29Z</published>
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<id>urn:sha1:28dad915abe46d38c5799a0c8130e9a2a1540385</id>
<content type='text'>
[ Upstream commit 12b677f2c697d61e5ddbcb6c1650050a39392f54 ]

When setup_mq_sysctls() failed in init_mqueue_fs(), mqueue_inode_cachep is
not released.  In order to fix this issue, the release path is reordered.

Link: https://lkml.kernel.org/r/20221209092929.1978875-1-shaozhengchao@huawei.com
Fixes: dc55e35f9e81 ("ipc: Store mqueue sysctls in the ipc namespace")
Signed-off-by: Zhengchao Shao &lt;shaozhengchao@huawei.com&gt;
Cc: Alexey Gladkov &lt;legion@kernel.org&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Cc: Jingyu Wang &lt;jingyuwang_vip@163.com&gt;
Cc: Muchun Song &lt;songmuchun@bytedance.com&gt;
Cc: Roman Gushchin &lt;roman.gushchin@linux.dev&gt;
Cc: Waiman Long &lt;longman@redhat.com&gt;
Cc: Wei Yongjun &lt;weiyongjun1@huawei.com&gt;
Cc: YueHaibing &lt;yuehaibing@huawei.com&gt;
Cc: Yu Zhe &lt;yuzhe@nfschina.com&gt;
Cc: Manfred Spraul &lt;manfred@colorfullife.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ipc/sem: Fix dangling sem_array access in semtimedop race</title>
<updated>2022-12-05T18:54:44Z</updated>
<author>
<name>Jann Horn</name>
<email>jannh@google.com</email>
</author>
<published>2022-12-05T16:59:27Z</published>
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<id>urn:sha1:b52be557e24c47286738276121177a41f54e3b83</id>
<content type='text'>
When __do_semtimedop() goes to sleep because it has to wait for a
semaphore value becoming zero or becoming bigger than some threshold, it
links the on-stack sem_queue to the sem_array, then goes to sleep
without holding a reference on the sem_array.

When __do_semtimedop() comes back out of sleep, one of two things must
happen:

 a) We prove that the on-stack sem_queue has been disconnected from the
    (possibly freed) sem_array, making it safe to return from the stack
    frame that the sem_queue exists in.

 b) We stabilize our reference to the sem_array, lock the sem_array, and
    detach the sem_queue from the sem_array ourselves.

sem_array has RCU lifetime, so for case (b), the reference can be
stabilized inside an RCU read-side critical section by locklessly
checking whether the sem_queue is still connected to the sem_array.

However, the current code does the lockless check on sem_queue before
starting an RCU read-side critical section, so the result of the
lockless check immediately becomes useless.

Fix it by doing rcu_read_lock() before the lockless check.  Now RCU
ensures that if we observe the object being on our queue, the object
can't be freed until rcu_read_unlock().

This bug is only hittable on kernel builds with full preemption support
(either CONFIG_PREEMPT or PREEMPT_DYNAMIC with preempt=full).

Fixes: 370b262c896e ("ipc/sem: avoid idr tree lookup for interrupted semop")
Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn &lt;jannh@google.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>ipc/shm: call underlying open/close vm_ops</title>
<updated>2022-11-23T02:50:42Z</updated>
<author>
<name>Mike Kravetz</name>
<email>mike.kravetz@oracle.com</email>
</author>
<published>2022-11-14T21:00:18Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b6305049f30652f1efcf78d627fc6656151a7929'/>
<id>urn:sha1:b6305049f30652f1efcf78d627fc6656151a7929</id>
<content type='text'>
Shared memory segments can be created that are backed by hugetlb pages. 
When this happens, the vmas associated with any mappings (shmat) are
marked VM_HUGETLB, yet the vm_ops for such mappings are provided by
ipc/shm (shm_vm_ops).  There is a mechanism to call the underlying hugetlb
vm_ops, and this is done for most operations.  However, it is not done for
open and close.

This was not an issue until the introduction of the hugetlb vma_lock. 
This lock structure is pointed to by vm_private_data and the open/close
vm_ops help maintain this structure.  The special hugetlb routine called
at fork took care of structure updates at fork time.  However,
vma_splitting is not properly handled for ipc shared memory mappings
backed by hugetlb pages.  This can result in a "kernel NULL pointer
dereference" BUG or use after free as two vmas point to the same lock
structure.

Update the shm open and close routines to always call the underlying open
and close routines.

Link: https://lkml.kernel.org/r/20221114210018.49346-1-mike.kravetz@oracle.com
Fixes: 8d9bfb260814 ("hugetlb: add vma based lock for pmd sharing")
Signed-off-by: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Reported-by: Doug Nelson &lt;doug.nelson@intel.com&gt;
Reported-by: &lt;syzbot+83b4134621b7c326d950@syzkaller.appspotmail.com&gt;
Cc: Alexander Mikhalitsyn &lt;alexander.mikhalitsyn@virtuozzo.com&gt;
Cc: "Eric W . Biederman" &lt;ebiederm@xmission.com&gt;
Cc: Manfred Spraul &lt;manfred@colorfullife.com&gt;
Cc: Matthew Wilcox &lt;willy@infradead.org&gt;
Cc: Miaohe Lin &lt;linmiaohe@huawei.com&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>ipc/msg.c: fix percpu_counter use after free</title>
<updated>2022-10-28T20:37:22Z</updated>
<author>
<name>Andrew Morton</name>
<email>akpm@linux-foundation.org</email>
</author>
<published>2022-10-21T04:19:22Z</published>
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<id>urn:sha1:64b4c411a6c7a5f27555bfc2d6310b87bde3db67</id>
<content type='text'>
These percpu counters are referenced in free_ipcs-&gt;freeque, so destroy
them later.

Fixes: 72d1e611082e ("ipc/msg: mitigate the lock contention with percpu counter")
Reported-by: syzbot+96e659d35b9d6b541152@syzkaller.appspotmail.com
Tested-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Jiebin Sun &lt;jiebin.sun@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2022-10-12T18:00:22Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-10-12T18:00:22Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=676cb4957396411fdb7aba906d5f950fc3de7cc9'/>
<id>urn:sha1:676cb4957396411fdb7aba906d5f950fc3de7cc9</id>
<content type='text'>
Pull non-MM updates from Andrew Morton:

 - hfs and hfsplus kmap API modernization (Fabio Francesco)

 - make crash-kexec work properly when invoked from an NMI-time panic
   (Valentin Schneider)

 - ntfs bugfixes (Hawkins Jiawei)

 - improve IPC msg scalability by replacing atomic_t's with percpu
   counters (Jiebin Sun)

 - nilfs2 cleanups (Minghao Chi)

 - lots of other single patches all over the tree!

* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
  proc: test how it holds up with mapping'less process
  mailmap: update Frank Rowand email address
  ia64: mca: use strscpy() is more robust and safer
  init/Kconfig: fix unmet direct dependencies
  ia64: update config files
  nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
  fork: remove duplicate included header files
  init/main.c: remove unnecessary (void*) conversions
  proc: mark more files as permanent
  nilfs2: remove the unneeded result variable
  nilfs2: delete unnecessary checks before brelse()
  checkpatch: warn for non-standard fixes tag style
  usr/gen_init_cpio.c: remove unnecessary -1 values from int file
  ipc/msg: mitigate the lock contention with percpu counter
  percpu: add percpu_counter_add_local and percpu_counter_sub_local
  fs/ocfs2: fix repeated words in comments
  relay: use kvcalloc to alloc page array in relay_alloc_page_array
  proc: make config PROC_CHILDREN depend on PROC_FS
  fs: uninline inode_maybe_inc_iversion()
  ...
</content>
</entry>
<entry>
<title>Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2022-10-11T00:53:04Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-10-11T00:53:04Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=27bc50fc90647bbf7b734c3fc306a5e61350da53'/>
<id>urn:sha1:27bc50fc90647bbf7b734c3fc306a5e61350da53</id>
<content type='text'>
Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP &amp; KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock-&gt;vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
</content>
</entry>
<entry>
<title>Merge tag 'retire_mq_sysctls-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace</title>
<updated>2022-10-09T23:10:22Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-10-09T23:10:22Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=86fb9c53d82f1dadf960553a3bd351de6173911f'/>
<id>urn:sha1:86fb9c53d82f1dadf960553a3bd351de6173911f</id>
<content type='text'>
Pull mqueue fix from Eric Biederman:
 "A fix for an unlikely but possible memory leak"

* tag 'retire_mq_sysctls-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ipc: mqueue: fix possible memory leak in init_mqueue_fs()
</content>
</entry>
<entry>
<title>ipc/msg: mitigate the lock contention with percpu counter</title>
<updated>2022-10-03T21:21:44Z</updated>
<author>
<name>Jiebin Sun</name>
<email>jiebin.sun@intel.com</email>
</author>
<published>2022-09-13T19:25:38Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=72d1e611082eda18689106a0c192f2827072713c'/>
<id>urn:sha1:72d1e611082eda18689106a0c192f2827072713c</id>
<content type='text'>
The msg_bytes and msg_hdrs atomic counters are frequently updated when IPC
msg queue is in heavy use, causing heavy cache bounce and overhead. 
Change them to percpu_counter greatly improve the performance.  Since
there is one percpu struct per namespace, additional memory cost is
minimal.  Reading of the count done in msgctl call, which is infrequent. 
So the need to sum up the counts in each CPU is infrequent.

Apply the patch and test the pts/stress-ng-1.4.0
-- system v message passing (160 threads).

Score gain: 3.99x

CPU: ICX 8380 x 2 sockets
Core number: 40 x 2 physical cores
Benchmark: pts/stress-ng-1.4.0
-- system v message passing (160 threads)

[akpm@linux-foundation.org: coding-style cleanups]
[jiebin.sun@intel.com: avoid negative value by overflow in msginfo]
  Link: https://lkml.kernel.org/r/20220920150809.4014944-1-jiebin.sun@intel.com
[akpm@linux-foundation.org: fix min() warnings]
Link: https://lkml.kernel.org/r/20220913192538.3023708-3-jiebin.sun@intel.com
Signed-off-by: Jiebin Sun &lt;jiebin.sun@intel.com&gt;
Reviewed-by: Tim Chen &lt;tim.c.chen@linux.intel.com&gt;
Cc: Alexander Mikhalitsyn &lt;alexander.mikhalitsyn@virtuozzo.com&gt;
Cc: Alexey Gladkov &lt;legion@kernel.org&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: Dennis Zhou &lt;dennis@kernel.org&gt;
Cc: "Eric W . Biederman" &lt;ebiederm@xmission.com&gt;
Cc: Manfred Spraul &lt;manfred@colorfullife.com&gt;
Cc: Shakeel Butt &lt;shakeelb@google.com&gt;
Cc: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Vasily Averin &lt;vasily.averin@linux.dev&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>ipc: mqueue: remove unnecessary conditionals</title>
<updated>2022-10-03T21:21:42Z</updated>
<author>
<name>Jingyu Wang</name>
<email>jingyuwang_vip@163.com</email>
</author>
<published>2022-09-08T18:54:52Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=5758478a3d3c42a78ee9ddc4b08db3e968a68058'/>
<id>urn:sha1:5758478a3d3c42a78ee9ddc4b08db3e968a68058</id>
<content type='text'>
iput() already handles null and non-null parameters, so there is no need
to use if().

Link: https://lkml.kernel.org/r/20220908185452.76590-1-jingyuwang_vip@163.com
Signed-off-by: Jingyu Wang &lt;jingyuwang_vip@163.com&gt;
Acked-by: Roman Gushchin &lt;roman.gushchin@linux.dev&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>ipc/shm: use VMA iterator instead of linked list</title>
<updated>2022-09-27T02:46:21Z</updated>
<author>
<name>Liam R. Howlett</name>
<email>Liam.Howlett@Oracle.com</email>
</author>
<published>2022-09-06T19:48:58Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=01293a62bae2fa55c09cebf5a771eab7219171c3'/>
<id>urn:sha1:01293a62bae2fa55c09cebf5a771eab7219171c3</id>
<content type='text'>
The VMA iterator is faster than the linked llist, and it can be walked
even when VMAs are being removed from the address space, so there's no
need to keep track of 'next'.

Link: https://lkml.kernel.org/r/20220906194824.2110408-46-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Liam R. Howlett &lt;Liam.Howlett@Oracle.com&gt;
Tested-by: Yu Zhao &lt;yuzhao@google.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: David Hildenbrand &lt;david@redhat.com&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: SeongJae Park &lt;sj@kernel.org&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
</entry>
</feed>
