linux.git/kernel/workqueue.c, branch v5.11-rc2 Linux kernel source tree Merge branch 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2020-12-28T19:23:02+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-12-28T19:23:02+00:00 c76e02c59e13ae6c22cc091786d16c01bee23a14 Pull workqueue update from Tejun Heo: "The same as the cgroup tree - one commit which was scheduled for the 5.11 merge window. All the commit does is avoding spurious worker wakeups from workqueue allocation / config change path to help cpuisol use cases" * 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Kick a worker based on the actual activation of delayed works 
Pull workqueue update from Tejun Heo:
 "The same as the cgroup tree - one commit which was scheduled for the
  5.11 merge window.

  All the commit does is avoding spurious worker wakeups from workqueue
  allocation / config change path to help cpuisol use cases"

* 'for-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Kick a worker based on the actual activation of delayed works
Merge branch 'akpm' (patches from Andrew) 2020-12-15T20:53:37+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-12-15T20:53:37+00:00 ac73e3dc8acd0a3be292755db30388c3580f5674 Merge misc updates from Andrew Morton: - a few random little subsystems - almost all of the MM patches which are staged ahead of linux-next material. I'll trickle to post-linux-next work in as the dependents get merged up. Subsystems affected by this patch series: kthread, kbuild, ide, ntfs, ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation, kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction, oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc, uaccess, zram, and cleanups). * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits) mm: cleanup kstrto*() usage mm: fix fall-through warnings for Clang mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at mm: shmem: convert shmem_enabled_show to use sysfs_emit_at mm:backing-dev: use sysfs_emit in macro defining functions mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening mm: use sysfs_emit for struct kobject * uses mm: fix kernel-doc markups zram: break the strict dependency from lzo zram: add stat to gather incompressible pages since zram set up zram: support page writeback mm/process_vm_access: remove redundant initialization of iov_r mm/zsmalloc.c: rework the list_add code in insert_zspage() mm/zswap: move to use crypto_acomp API for hardware acceleration mm/zswap: fix passing zero to 'PTR_ERR' warning mm/zswap: make struct kernel_param_ops definitions const userfaultfd/selftests: hint the test runner on required privilege userfaultfd/selftests: fix retval check for userfaultfd_open() userfaultfd/selftests: always dump something in modes userfaultfd: selftests: make __{s,u}64 format specifiers portable ... 
Merge misc updates from Andrew Morton:

 - a few random little subsystems

 - almost all of the MM patches which are staged ahead of linux-next
   material. I'll trickle to post-linux-next work in as the dependents
   get merged up.

Subsystems affected by this patch series: kthread, kbuild, ide, ntfs,
ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache,
gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation,
kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction,
oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc,
uaccess, zram, and cleanups).

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits)
  mm: cleanup kstrto*() usage
  mm: fix fall-through warnings for Clang
  mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at
  mm: shmem: convert shmem_enabled_show to use sysfs_emit_at
  mm:backing-dev: use sysfs_emit in macro defining functions
  mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening
  mm: use sysfs_emit for struct kobject * uses
  mm: fix kernel-doc markups
  zram: break the strict dependency from lzo
  zram: add stat to gather incompressible pages since zram set up
  zram: support page writeback
  mm/process_vm_access: remove redundant initialization of iov_r
  mm/zsmalloc.c: rework the list_add code in insert_zspage()
  mm/zswap: move to use crypto_acomp API for hardware acceleration
  mm/zswap: fix passing zero to 'PTR_ERR' warning
  mm/zswap: make struct kernel_param_ops definitions const
  userfaultfd/selftests: hint the test runner on required privilege
  userfaultfd/selftests: fix retval check for userfaultfd_open()
  userfaultfd/selftests: always dump something in modes
  userfaultfd: selftests: make __{s,u}64 format specifiers portable
  ...
workqueue: kasan: record workqueue stack 2020-12-15T20:13:42+00:00 Walter Wu walter-zh.wu@mediatek.com 2020-12-15T03:09:09+00:00 e89a85d63fb2e187f5afcbf83c12743132596563 Patch series "kasan: add workqueue stack for generic KASAN", v5. Syzbot reports many UAF issues for workqueue, see [1]. In some of these access/allocation happened in process_one_work(), we see the free stack is useless in KASAN report, it doesn't help programmers to solve UAF for workqueue issue. This patchset improves KASAN reports by making them to have workqueue queueing stack. It is useful for programmers to solve use-after-free or double-free memory issue. Generic KASAN also records the last two workqueue stacks and prints them in KASAN report. It is only suitable for generic KASAN. [1] https://groups.google.com/g/syzkaller-bugs/search?q=%22use-after-free%22+process_one_work [2] https://bugzilla.kernel.org/show_bug.cgi?id=198437 This patch (of 4): When analyzing use-after-free or double-free issue, recording the enqueuing work stacks is helpful to preserve usage history which potentially gives a hint about the affected code. For workqueue it has turned out to be useful to record the enqueuing work call stacks. Because user can see KASAN report to determine whether it is root cause. They don't need to enable debugobjects, but they have a chance to find out the root cause. Link: https://lkml.kernel.org/r/20201203022148.29754-1-walter-zh.wu@mediatek.com Link: https://lkml.kernel.org/r/20201203022442.30006-1-walter-zh.wu@mediatek.com Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com> Suggested-by: Marco Elver <elver@google.com> Acked-by: Marco Elver <elver@google.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Patch series "kasan: add workqueue stack for generic KASAN", v5.

Syzbot reports many UAF issues for workqueue, see [1].

In some of these access/allocation happened in process_one_work(), we
see the free stack is useless in KASAN report, it doesn't help
programmers to solve UAF for workqueue issue.

This patchset improves KASAN reports by making them to have workqueue
queueing stack.  It is useful for programmers to solve use-after-free or
double-free memory issue.

Generic KASAN also records the last two workqueue stacks and prints them
in KASAN report.  It is only suitable for generic KASAN.

[1] https://groups.google.com/g/syzkaller-bugs/search?q=%22use-after-free%22+process_one_work
[2] https://bugzilla.kernel.org/show_bug.cgi?id=198437

This patch (of 4):

When analyzing use-after-free or double-free issue, recording the
enqueuing work stacks is helpful to preserve usage history which
potentially gives a hint about the affected code.

For workqueue it has turned out to be useful to record the enqueuing work
call stacks.  Because user can see KASAN report to determine whether it is
root cause.  They don't need to enable debugobjects, but they have a
chance to find out the root cause.

Link: https://lkml.kernel.org/r/20201203022148.29754-1-walter-zh.wu@mediatek.com
Link: https://lkml.kernel.org/r/20201203022442.30006-1-walter-zh.wu@mediatek.com
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Suggested-by: Marco Elver <elver@google.com>
Acked-by: Marco Elver <elver@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
workqueue: Kick a worker based on the actual activation of delayed works 2020-11-25T22:10:28+00:00 Yunfeng Ye yeyunfeng@huawei.com 2020-11-19T06:21:25+00:00 01341fbd0d8d4e717fc1231cdffe00343088ce0b In realtime scenario, We do not want to have interference on the isolated cpu cores. but when invoking alloc_workqueue() for percpu wq on the housekeeping cpu, it kick a kworker on the isolated cpu. alloc_workqueue pwq_adjust_max_active wake_up_worker The comment in pwq_adjust_max_active() said: "Need to kick a worker after thawed or an unbound wq's max_active is bumped" So it is unnecessary to kick a kworker for percpu's wq when invoking alloc_workqueue(). this patch only kick a worker based on the actual activation of delayed works. Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> 
In realtime scenario, We do not want to have interference on the
isolated cpu cores. but when invoking alloc_workqueue() for percpu wq
on the housekeeping cpu, it kick a kworker on the isolated cpu.

  alloc_workqueue
    pwq_adjust_max_active
      wake_up_worker

The comment in pwq_adjust_max_active() said:
  "Need to kick a worker after thawed or an unbound wq's
   max_active is bumped"

So it is unnecessary to kick a kworker for percpu's wq when invoking
alloc_workqueue(). this patch only kick a worker based on the actual
activation of delayed works.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: Manually break affinity on hotplug 2020-11-10T17:38:58+00:00 Peter Zijlstra peterz@infradead.org 2020-09-25T13:45:11+00:00 06249738a41a70f2201a148866899f84cbebc45e Don't rely on the scheduler to force break affinity for us -- it will stop doing that for per-cpu-kthreads. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Link: https://lkml.kernel.org/r/20201023102346.464718669@infradead.org 
Don't rely on the scheduler to force break affinity for us -- it will
stop doing that for per-cpu-kthreads.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Link: https://lkml.kernel.org/r/20201023102346.464718669@infradead.org
workqueue: fix a kernel-doc warning 2020-10-16T05:28:20+00:00 Mauro Carvalho Chehab mchehab+huawei@kernel.org 2020-09-29T11:12:51+00:00 3eb6b31bfb1732f4c48ef5a271dc15158efe8323 As warned by Sphinx: ./Documentation/core-api/workqueue:400: ./kernel/workqueue.c:1218: WARNING: Unexpected indentation. the return code table is currently not recognized, as it lacks markups. Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> 
As warned by Sphinx:

	./Documentation/core-api/workqueue:400: ./kernel/workqueue.c:1218: WARNING: Unexpected indentation.

the return code table is currently not recognized, as it lacks
markups.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
treewide: Make all debug_obj_descriptors const 2020-09-24T19:56:25+00:00 Stephen Boyd swboyd@chromium.org 2020-08-15T00:40:27+00:00 f9e62f318fd706a54b7ce9b28e5c7e49bbde8788 This should make it harder for the kernel to corrupt the debug object descriptor, used to call functions to fixup state and track debug objects, by moving the structure to read-only memory. Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20200815004027.2046113-3-swboyd@chromium.org 
This should make it harder for the kernel to corrupt the debug object
descriptor, used to call functions to fixup state and track debug objects,
by moving the structure to read-only memory.

Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200815004027.2046113-3-swboyd@chromium.org
maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17T17:57:41+00:00 Christoph Hellwig hch@lst.de 2020-06-17T07:37:53+00:00 fe557319aa06c23cffc9346000f119547e0f289a Better describe what these functions do. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Better describe what these functions do.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
workqueue: use BUILD_BUG_ON() for compile time test instead of WARN_ON() 2020-06-01T15:02:42+00:00 Lai Jiangshan laijs@linux.alibaba.com 2020-06-01T08:44:40+00:00 10cdb15759540f03d056e2f73fe26377ed7dcfda Any runtime WARN_ON() has to be fixed, and BUILD_BUG_ON() can help you nitice it earlier. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org> 
Any runtime WARN_ON() has to be fixed, and BUILD_BUG_ON() can
help you nitice it earlier.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: remove useless unlock() and lock() in series 2020-05-29T14:25:23+00:00 Lai Jiangshan laijs@linux.alibaba.com 2020-05-29T06:59:02+00:00 b8f06b0444ec146e3ae98caac8039c77e5308ce2 This is no point to unlock() and then lock() the same mutex back to back. Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org> 
This is no point to unlock() and then lock() the same mutex
back to back.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>