linux-toradex.git/kernel/workqueue.c, branch v5.1-rc1 Linux kernel for Apalis and Colibri modules Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-03-10T20:48:14+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-03-10T20:48:14+00:00 9e55f87c0e3b3db11f52834222f881094eb97205 Pull locking fixes from Thomas Gleixner: "A few fixes for lockdep: - initialize lockdep internal RCU head after initializing RCU - prevent use after free in a alloc_workqueue() error handling path - plug a memory leak in the workqueue core which fails to free a dynamically allocated lock name. - make Clang happy" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: workqueue, lockdep: Fix a memory leak in wq->lock_name workqueue, lockdep: Fix an alloc_workqueue() error path locking/lockdep: Only call init_rcu_head() after RCU has been initialized locking/lockdep: Avoid a Clang warning 
Pull locking fixes from Thomas Gleixner:
 "A few fixes for lockdep:

   - initialize lockdep internal RCU head after initializing RCU

   - prevent use after free in a alloc_workqueue() error handling path

   - plug a memory leak in the workqueue core which fails to free a
     dynamically allocated lock name.

   - make Clang happy"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  workqueue, lockdep: Fix a memory leak in wq->lock_name
  workqueue, lockdep: Fix an alloc_workqueue() error path
  locking/lockdep: Only call init_rcu_head() after RCU has been initialized
  locking/lockdep: Avoid a Clang warning
workqueue, lockdep: Fix a memory leak in wq->lock_name 2019-03-09T13:15:52+00:00 Qian Cai cai@lca.pw 2019-03-07T00:27:31+00:00 69a106c00e8554a7e6b3f4bb2967332670f89337 The following commit: 669de8bda87b ("kernel/workqueue: Use dynamic lockdep keys for workqueues") introduced a memory leak as wq_free_lockdep() calls kfree(wq->lock_name), but wq_init_lockdep() does not point wq->lock_name to the newly allocated slab object. This can be reproduced by running LTP fallocate04 followed by oom01 tests: unreferenced object 0xc0000005876384d8 (size 64): comm "fallocate04", pid 26972, jiffies 4297139141 (age 40370.480s) hex dump (first 32 bytes): 28 77 71 5f 63 6f 6d 70 6c 65 74 69 6f 6e 29 65 (wq_completion)e 78 74 34 2d 72 73 76 2d 63 6f 6e 76 65 72 73 69 xt4-rsv-conversi backtrace: [<00000000cb452883>] kvasprintf+0x6c/0xe0 [<000000004654ddac>] kasprintf+0x34/0x60 [<000000001c68f311>] alloc_workqueue+0x1f8/0x6ac [<0000000003c2ad83>] ext4_fill_super+0x23d4/0x3c80 [ext4] [<0000000006610538>] mount_bdev+0x25c/0x290 [<00000000bcf955ec>] ext4_mount+0x28/0x50 [ext4] [<0000000016e08fd3>] legacy_get_tree+0x4c/0xb0 [<0000000042b6a5fc>] vfs_get_tree+0x6c/0x190 [<00000000268ab022>] do_mount+0xb9c/0x1100 [<00000000698e6898>] ksys_mount+0x158/0x180 [<0000000064e391fd>] sys_mount+0x20/0x30 [<00000000ba378f12>] system_call+0x5c/0x70 Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: catalin.marinas@arm.com Cc: jiangshanlai@gmail.com Cc: tj@kernel.org Fixes: 669de8bda87b ("kernel/workqueue: Use dynamic lockdep keys for workqueues") Link: https://lkml.kernel.org/r/20190307002731.47371-1-cai@lca.pw Signed-off-by: Ingo Molnar <mingo@kernel.org> 
The following commit:

  669de8bda87b ("kernel/workqueue: Use dynamic lockdep keys for workqueues")

introduced a memory leak as wq_free_lockdep() calls kfree(wq->lock_name),
but wq_init_lockdep() does not point wq->lock_name to the newly allocated
slab object.

This can be reproduced by running LTP fallocate04 followed by oom01 tests:

 unreferenced object 0xc0000005876384d8 (size 64):
  comm "fallocate04", pid 26972, jiffies 4297139141 (age 40370.480s)
  hex dump (first 32 bytes):
    28 77 71 5f 63 6f 6d 70 6c 65 74 69 6f 6e 29 65  (wq_completion)e
    78 74 34 2d 72 73 76 2d 63 6f 6e 76 65 72 73 69  xt4-rsv-conversi
  backtrace:
    [<00000000cb452883>] kvasprintf+0x6c/0xe0
    [<000000004654ddac>] kasprintf+0x34/0x60
    [<000000001c68f311>] alloc_workqueue+0x1f8/0x6ac
    [<0000000003c2ad83>] ext4_fill_super+0x23d4/0x3c80 [ext4]
    [<0000000006610538>] mount_bdev+0x25c/0x290
    [<00000000bcf955ec>] ext4_mount+0x28/0x50 [ext4]
    [<0000000016e08fd3>] legacy_get_tree+0x4c/0xb0
    [<0000000042b6a5fc>] vfs_get_tree+0x6c/0x190
    [<00000000268ab022>] do_mount+0xb9c/0x1100
    [<00000000698e6898>] ksys_mount+0x158/0x180
    [<0000000064e391fd>] sys_mount+0x20/0x30
    [<00000000ba378f12>] system_call+0x5c/0x70

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: catalin.marinas@arm.com
Cc: jiangshanlai@gmail.com
Cc: tj@kernel.org
Fixes: 669de8bda87b ("kernel/workqueue: Use dynamic lockdep keys for workqueues")
Link: https://lkml.kernel.org/r/20190307002731.47371-1-cai@lca.pw
Signed-off-by: Ingo Molnar <mingo@kernel.org>
workqueue, lockdep: Fix an alloc_workqueue() error path 2019-03-09T13:15:52+00:00 Bart Van Assche bvanassche@acm.org 2019-03-03T22:00:46+00:00 009bb421b6ceb7916ce627023d0eb7ced04c8910 This patch fixes a use-after-free and a memory leak in an alloc_workqueue() error path. Repoted by syzkaller and KASAN: BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:197 [inline] BUG: KASAN: use-after-free in lockdep_register_key+0x3b9/0x490 kernel/locking/lockdep.c:1023 Read of size 8 at addr ffff888090fc2698 by task syz-executor134/7858 CPU: 1 PID: 7858 Comm: syz-executor134 Not tainted 5.0.0-rc8-next-20190301 #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 __read_once_size include/linux/compiler.h:197 [inline] lockdep_register_key+0x3b9/0x490 kernel/locking/lockdep.c:1023 wq_init_lockdep kernel/workqueue.c:3444 [inline] alloc_workqueue+0x427/0xe70 kernel/workqueue.c:4263 ucma_open+0x76/0x290 drivers/infiniband/core/ucma.c:1732 misc_open+0x398/0x4c0 drivers/char/misc.c:141 chrdev_open+0x247/0x6b0 fs/char_dev.c:417 do_dentry_open+0x488/0x1160 fs/open.c:771 vfs_open+0xa0/0xd0 fs/open.c:880 do_last fs/namei.c:3416 [inline] path_openat+0x10e9/0x46e0 fs/namei.c:3533 do_filp_open+0x1a1/0x280 fs/namei.c:3563 do_sys_open+0x3fe/0x5d0 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Allocated by task 7789: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_kmalloc mm/kasan/common.c:497 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:511 __do_kmalloc mm/slab.c:3726 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3735 kmalloc include/linux/slab.h:553 [inline] kzalloc include/linux/slab.h:743 [inline] alloc_workqueue+0x13c/0xe70 kernel/workqueue.c:4236 ucma_open+0x76/0x290 drivers/infiniband/core/ucma.c:1732 misc_open+0x398/0x4c0 drivers/char/misc.c:141 chrdev_open+0x247/0x6b0 fs/char_dev.c:417 do_dentry_open+0x488/0x1160 fs/open.c:771 vfs_open+0xa0/0xd0 fs/open.c:880 do_last fs/namei.c:3416 [inline] path_openat+0x10e9/0x46e0 fs/namei.c:3533 do_filp_open+0x1a1/0x280 fs/namei.c:3563 do_sys_open+0x3fe/0x5d0 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 7789: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3821 alloc_workqueue+0xc3e/0xe70 kernel/workqueue.c:4295 ucma_open+0x76/0x290 drivers/infiniband/core/ucma.c:1732 misc_open+0x398/0x4c0 drivers/char/misc.c:141 chrdev_open+0x247/0x6b0 fs/char_dev.c:417 do_dentry_open+0x488/0x1160 fs/open.c:771 vfs_open+0xa0/0xd0 fs/open.c:880 do_last fs/namei.c:3416 [inline] path_openat+0x10e9/0x46e0 fs/namei.c:3533 do_filp_open+0x1a1/0x280 fs/namei.c:3563 do_sys_open+0x3fe/0x5d0 fs/open.c:1063 __do_sys_openat fs/open.c:1090 [inline] __se_sys_openat fs/open.c:1084 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1084 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888090fc2580 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 280 bytes inside of 512-byte region [ffff888090fc2580, ffff888090fc2780) Reported-by: syzbot+17335689e239ce135d8b@syzkaller.appspotmail.com Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Fixes: 669de8bda87b ("kernel/workqueue: Use dynamic lockdep keys for workqueues") Link: https://lkml.kernel.org/r/20190303220046.29448-1-bvanassche@acm.org Signed-off-by: Ingo Molnar <mingo@kernel.org> 
This patch fixes a use-after-free and a memory leak in an alloc_workqueue()
error path.

Repoted by syzkaller and KASAN:

  BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:197 [inline]
  BUG: KASAN: use-after-free in lockdep_register_key+0x3b9/0x490 kernel/locking/lockdep.c:1023
  Read of size 8 at addr ffff888090fc2698 by task syz-executor134/7858

  CPU: 1 PID: 7858 Comm: syz-executor134 Not tainted 5.0.0-rc8-next-20190301 #1
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0x172/0x1f0 lib/dump_stack.c:113
   print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
   kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
   __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132
   __read_once_size include/linux/compiler.h:197 [inline]
   lockdep_register_key+0x3b9/0x490 kernel/locking/lockdep.c:1023
   wq_init_lockdep kernel/workqueue.c:3444 [inline]
   alloc_workqueue+0x427/0xe70 kernel/workqueue.c:4263
   ucma_open+0x76/0x290 drivers/infiniband/core/ucma.c:1732
   misc_open+0x398/0x4c0 drivers/char/misc.c:141
   chrdev_open+0x247/0x6b0 fs/char_dev.c:417
   do_dentry_open+0x488/0x1160 fs/open.c:771
   vfs_open+0xa0/0xd0 fs/open.c:880
   do_last fs/namei.c:3416 [inline]
   path_openat+0x10e9/0x46e0 fs/namei.c:3533
   do_filp_open+0x1a1/0x280 fs/namei.c:3563
   do_sys_open+0x3fe/0x5d0 fs/open.c:1063
   __do_sys_openat fs/open.c:1090 [inline]
   __se_sys_openat fs/open.c:1084 [inline]
   __x64_sys_openat+0x9d/0x100 fs/open.c:1084
   do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

  Allocated by task 7789:
   save_stack+0x45/0xd0 mm/kasan/common.c:75
   set_track mm/kasan/common.c:87 [inline]
   __kasan_kmalloc mm/kasan/common.c:497 [inline]
   __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
   kasan_kmalloc+0x9/0x10 mm/kasan/common.c:511
   __do_kmalloc mm/slab.c:3726 [inline]
   __kmalloc+0x15c/0x740 mm/slab.c:3735
   kmalloc include/linux/slab.h:553 [inline]
   kzalloc include/linux/slab.h:743 [inline]
   alloc_workqueue+0x13c/0xe70 kernel/workqueue.c:4236
   ucma_open+0x76/0x290 drivers/infiniband/core/ucma.c:1732
   misc_open+0x398/0x4c0 drivers/char/misc.c:141
   chrdev_open+0x247/0x6b0 fs/char_dev.c:417
   do_dentry_open+0x488/0x1160 fs/open.c:771
   vfs_open+0xa0/0xd0 fs/open.c:880
   do_last fs/namei.c:3416 [inline]
   path_openat+0x10e9/0x46e0 fs/namei.c:3533
   do_filp_open+0x1a1/0x280 fs/namei.c:3563
   do_sys_open+0x3fe/0x5d0 fs/open.c:1063
   __do_sys_openat fs/open.c:1090 [inline]
   __se_sys_openat fs/open.c:1084 [inline]
   __x64_sys_openat+0x9d/0x100 fs/open.c:1084
   do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

  Freed by task 7789:
   save_stack+0x45/0xd0 mm/kasan/common.c:75
   set_track mm/kasan/common.c:87 [inline]
   __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459
   kasan_slab_free+0xe/0x10 mm/kasan/common.c:467
   __cache_free mm/slab.c:3498 [inline]
   kfree+0xcf/0x230 mm/slab.c:3821
   alloc_workqueue+0xc3e/0xe70 kernel/workqueue.c:4295
   ucma_open+0x76/0x290 drivers/infiniband/core/ucma.c:1732
   misc_open+0x398/0x4c0 drivers/char/misc.c:141
   chrdev_open+0x247/0x6b0 fs/char_dev.c:417
   do_dentry_open+0x488/0x1160 fs/open.c:771
   vfs_open+0xa0/0xd0 fs/open.c:880
   do_last fs/namei.c:3416 [inline]
   path_openat+0x10e9/0x46e0 fs/namei.c:3533
   do_filp_open+0x1a1/0x280 fs/namei.c:3563
   do_sys_open+0x3fe/0x5d0 fs/open.c:1063
   __do_sys_openat fs/open.c:1090 [inline]
   __se_sys_openat fs/open.c:1084 [inline]
   __x64_sys_openat+0x9d/0x100 fs/open.c:1084
   do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

  The buggy address belongs to the object at ffff888090fc2580
   which belongs to the cache kmalloc-512 of size 512
  The buggy address is located 280 bytes inside of
   512-byte region [ffff888090fc2580, ffff888090fc2780)

Reported-by: syzbot+17335689e239ce135d8b@syzkaller.appspotmail.com
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Fixes: 669de8bda87b ("kernel/workqueue: Use dynamic lockdep keys for workqueues")
Link: https://lkml.kernel.org/r/20190303220046.29448-1-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge branch 'akpm' (patches from Andrew) 2019-03-08T03:25:37+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-03-08T03:25:37+00:00 b5dd0c658c31b469ccff1b637e5124851e7a4a1c Merge more updates from Andrew Morton: - some of the rest of MM - various misc things - dynamic-debug updates - checkpatch - some epoll speedups - autofs - rapidio - lib/, lib/lzo/ updates * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (83 commits) samples/mic/mpssd/mpssd.h: remove duplicate header kernel/fork.c: remove duplicated include include/linux/relay.h: fix percpu annotation in struct rchan arch/nios2/mm/fault.c: remove duplicate include unicore32: stop printing the virtual memory layout MAINTAINERS: fix GTA02 entry and mark as orphan mm: create the new vm_fault_t type arm, s390, unicore32: remove oneliner wrappers for memblock_alloc() arch: simplify several early memory allocations openrisc: simplify pte_alloc_one_kernel() sh: prefer memblock APIs returning virtual address microblaze: prefer memblock API returning virtual address powerpc: prefer memblock APIs returning virtual address lib/lzo: separate lzo-rle from lzo lib/lzo: implement run-length encoding lib/lzo: fast 8-byte copy on arm64 lib/lzo: 64-bit CTZ on arm64 lib/lzo: tidy-up ifdefs ipc/sem.c: replace kvmalloc/memset with kvzalloc and use struct_size ipc: annotate implicit fall through ... 
Merge more updates from Andrew Morton:

 - some of the rest of MM

 - various misc things

 - dynamic-debug updates

 - checkpatch

 - some epoll speedups

 - autofs

 - rapidio

 - lib/, lib/lzo/ updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (83 commits)
  samples/mic/mpssd/mpssd.h: remove duplicate header
  kernel/fork.c: remove duplicated include
  include/linux/relay.h: fix percpu annotation in struct rchan
  arch/nios2/mm/fault.c: remove duplicate include
  unicore32: stop printing the virtual memory layout
  MAINTAINERS: fix GTA02 entry and mark as orphan
  mm: create the new vm_fault_t type
  arm, s390, unicore32: remove oneliner wrappers for memblock_alloc()
  arch: simplify several early memory allocations
  openrisc: simplify pte_alloc_one_kernel()
  sh: prefer memblock APIs returning virtual address
  microblaze: prefer memblock API returning virtual address
  powerpc: prefer memblock APIs returning virtual address
  lib/lzo: separate lzo-rle from lzo
  lib/lzo: implement run-length encoding
  lib/lzo: fast 8-byte copy on arm64
  lib/lzo: 64-bit CTZ on arm64
  lib/lzo: tidy-up ifdefs
  ipc/sem.c: replace kvmalloc/memset with kvzalloc and use struct_size
  ipc: annotate implicit fall through
  ...
kernel: workqueue: clarify wq_worker_last_func() caller requirements 2019-03-08T02:32:01+00:00 Johannes Weiner hannes@cmpxchg.org 2019-03-08T00:29:30+00:00 4b0470027528ba98f9617f4ceba328de71d2fe49 This function can only be called safely from very specific scheduler contexts. Document those. Link: http://lkml.kernel.org/r/20190206150528.31198-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
This function can only be called safely from very specific scheduler
contexts.  Document those.

Link: http://lkml.kernel.org/r/20190206150528.31198-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2019-03-07T18:09:52+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-03-07T18:09:52+00:00 abf7c3d8ddea3b43fe758590791878e1fd88ac47 Pull workqueue updates from Tejun Heo: "All trivial. Two comment updates and one more initialization sanity check in flush_work()" * 'for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Fix spelling in source code comments workqueue: fix typo in comment workqueue: Try to catch flush_work() without INIT_WORK(). 
Pull workqueue updates from Tejun Heo:
 "All trivial. Two comment updates and one more initialization sanity
  check in flush_work()"

* 'for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Fix spelling in source code comments
  workqueue: fix typo in comment
  workqueue: Try to catch flush_work() without INIT_WORK().
Merge tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core 2019-03-06T22:52:48+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-03-06T22:52:48+00:00 e431f2d74e1b91e00e71e97cadcadffc4cda8a9b Pull driver core updates from Greg KH: "Here is the big driver core patchset for 5.1-rc1 More patches than "normal" here this merge window, due to some work in the driver core by Alexander Duyck to rework the async probe functionality to work better for a number of devices, and independant work from Rafael for the device link functionality to make it work "correctly". Also in here is: - lots of BUS_ATTR() removals, the macro is about to go away - firmware test fixups - ihex fixups and simplification - component additions (also includes i915 patches) - lots of minor coding style fixups and cleanups. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (65 commits) driver core: platform: remove misleading err_alloc label platform: set of_node in platform_device_register_full() firmware: hardcode the debug message for -ENOENT driver core: Add missing description of new struct device_link field driver core: Fix PM-runtime for links added during consumer probe drivers/component: kerneldoc polish async: Add cmdline option to specify drivers to be async probed driver core: Fix possible supplier PM-usage counter imbalance PM-runtime: Fix __pm_runtime_set_status() race with runtime resume driver: platform: Support parsing GpioInt 0 in platform_get_irq() selftests: firmware: fix verify_reqs() return value Revert "selftests: firmware: remove use of non-standard diff -Z option" Revert "selftests: firmware: add CONFIG_FW_LOADER_USER_HELPER_FALLBACK to config" device: Fix comment for driver_data in struct device kernfs: Allocating memory for kernfs_iattrs with kmem_cache. sysfs: remove unused include of kernfs-internal.h driver core: Postpone DMA tear-down until after devres release driver core: Document limitation related to DL_FLAG_RPM_ACTIVE PM-runtime: Take suppliers into account in __pm_runtime_set_status() device.h: Add __cold to dev_<level> logging functions ... 
Pull driver core updates from Greg KH:
 "Here is the big driver core patchset for 5.1-rc1

  More patches than "normal" here this merge window, due to some work in
  the driver core by Alexander Duyck to rework the async probe
  functionality to work better for a number of devices, and independant
  work from Rafael for the device link functionality to make it work
  "correctly".

  Also in here is:

   - lots of BUS_ATTR() removals, the macro is about to go away

   - firmware test fixups

   - ihex fixups and simplification

   - component additions (also includes i915 patches)

   - lots of minor coding style fixups and cleanups.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (65 commits)
  driver core: platform: remove misleading err_alloc label
  platform: set of_node in platform_device_register_full()
  firmware: hardcode the debug message for -ENOENT
  driver core: Add missing description of new struct device_link field
  driver core: Fix PM-runtime for links added during consumer probe
  drivers/component: kerneldoc polish
  async: Add cmdline option to specify drivers to be async probed
  driver core: Fix possible supplier PM-usage counter imbalance
  PM-runtime: Fix __pm_runtime_set_status() race with runtime resume
  driver: platform: Support parsing GpioInt 0 in platform_get_irq()
  selftests: firmware: fix verify_reqs() return value
  Revert "selftests: firmware: remove use of non-standard diff -Z option"
  Revert "selftests: firmware: add CONFIG_FW_LOADER_USER_HELPER_FALLBACK to config"
  device: Fix comment for driver_data in struct device
  kernfs: Allocating memory for kernfs_iattrs with kmem_cache.
  sysfs: remove unused include of kernfs-internal.h
  driver core: Postpone DMA tear-down until after devres release
  driver core: Document limitation related to DL_FLAG_RPM_ACTIVE
  PM-runtime: Take suppliers into account in __pm_runtime_set_status()
  device.h: Add __cold to dev_<level> logging functions
  ...
workqueue: Fix spelling in source code comments 2019-03-05T15:52:39+00:00 Bart Van Assche bvanassche@acm.org 2019-03-01T21:57:25+00:00 bf393fd4a3c888e6d407968f461900481bd0c041 Change "execuing" into "executing" and "guarnateed" into "guaranteed". Cc: Lai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Tejun Heo <tj@kernel.org> 
Change "execuing" into "executing" and "guarnateed" into "guaranteed".

Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
kernel/workqueue: Use dynamic lockdep keys for workqueues 2019-02-28T06:55:47+00:00 Bart Van Assche bvanassche@acm.org 2019-02-14T23:00:54+00:00 669de8bda87b92ab9a2fc663b3f5743c2ad1ae9f The following commit: 87915adc3f0a ("workqueue: re-add lockdep dependencies for flushing") improved deadlock checking in the workqueue implementation. Unfortunately that patch also introduced a few false positive lockdep complaints. This patch suppresses these false positives by allocating the workqueue mutex lockdep key dynamically. An example of a false positive lockdep complaint suppressed by this patch can be found below. The root cause of the lockdep complaint shown below is that the direct I/O code can call alloc_workqueue() from inside a work item created by another alloc_workqueue() call and that both workqueues share the same lockdep key. This patch avoids that that lockdep complaint is triggered by allocating the work queue lockdep keys dynamically. In other words, this patch guarantees that a unique lockdep key is associated with each work queue mutex. ====================================================== WARNING: possible circular locking dependency detected 4.19.0-dbg+ #1 Not tainted fio/4129 is trying to acquire lock: 00000000a01cfe1a ((wq_completion)"dio/%s"sb->s_id){+.+.}, at: flush_workqueue+0xd0/0x970 but task is already holding lock: 00000000a0acecf9 (&sb->s_type->i_mutex_key#14){+.+.}, at: ext4_file_write_iter+0x154/0x710 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&sb->s_type->i_mutex_key#14){+.+.}: down_write+0x3d/0x80 __generic_file_fsync+0x77/0xf0 ext4_sync_file+0x3c9/0x780 vfs_fsync_range+0x66/0x100 dio_complete+0x2f5/0x360 dio_aio_complete_work+0x1c/0x20 process_one_work+0x481/0x9f0 worker_thread+0x63/0x5a0 kthread+0x1cf/0x1f0 ret_from_fork+0x24/0x30 -> #1 ((work_completion)(&dio->complete_work)){+.+.}: process_one_work+0x447/0x9f0 worker_thread+0x63/0x5a0 kthread+0x1cf/0x1f0 ret_from_fork+0x24/0x30 -> #0 ((wq_completion)"dio/%s"sb->s_id){+.+.}: lock_acquire+0xc5/0x200 flush_workqueue+0xf3/0x970 drain_workqueue+0xec/0x220 destroy_workqueue+0x23/0x350 sb_init_dio_done_wq+0x6a/0x80 do_blockdev_direct_IO+0x1f33/0x4be0 __blockdev_direct_IO+0x79/0x86 ext4_direct_IO+0x5df/0xbb0 generic_file_direct_write+0x119/0x220 __generic_file_write_iter+0x131/0x2d0 ext4_file_write_iter+0x3fa/0x710 aio_write+0x235/0x330 io_submit_one+0x510/0xeb0 __x64_sys_io_submit+0x122/0x340 do_syscall_64+0x71/0x220 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: (wq_completion)"dio/%s"sb->s_id --> (work_completion)(&dio->complete_work) --> &sb->s_type->i_mutex_key#14 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#14); lock((work_completion)(&dio->complete_work)); lock(&sb->s_type->i_mutex_key#14); lock((wq_completion)"dio/%s"sb->s_id); *** DEADLOCK *** 1 lock held by fio/4129: #0: 00000000a0acecf9 (&sb->s_type->i_mutex_key#14){+.+.}, at: ext4_file_write_iter+0x154/0x710 stack backtrace: CPU: 3 PID: 4129 Comm: fio Not tainted 4.19.0-dbg+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Call Trace: dump_stack+0x86/0xc5 print_circular_bug.isra.32+0x20a/0x218 __lock_acquire+0x1c68/0x1cf0 lock_acquire+0xc5/0x200 flush_workqueue+0xf3/0x970 drain_workqueue+0xec/0x220 destroy_workqueue+0x23/0x350 sb_init_dio_done_wq+0x6a/0x80 do_blockdev_direct_IO+0x1f33/0x4be0 __blockdev_direct_IO+0x79/0x86 ext4_direct_IO+0x5df/0xbb0 generic_file_direct_write+0x119/0x220 __generic_file_write_iter+0x131/0x2d0 ext4_file_write_iter+0x3fa/0x710 aio_write+0x235/0x330 io_submit_one+0x510/0xeb0 __x64_sys_io_submit+0x122/0x340 do_syscall_64+0x71/0x220 entry_SYSCALL_64_after_hwframe+0x49/0xbe Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Berg <johannes.berg@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Link: https://lkml.kernel.org/r/20190214230058.196511-20-bvanassche@acm.org [ Reworked the changelog a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> 
The following commit:

  87915adc3f0a ("workqueue: re-add lockdep dependencies for flushing")

improved deadlock checking in the workqueue implementation. Unfortunately
that patch also introduced a few false positive lockdep complaints.

This patch suppresses these false positives by allocating the workqueue mutex
lockdep key dynamically.

An example of a false positive lockdep complaint suppressed by this patch
can be found below. The root cause of the lockdep complaint shown below
is that the direct I/O code can call alloc_workqueue() from inside a work
item created by another alloc_workqueue() call and that both workqueues
share the same lockdep key. This patch avoids that that lockdep complaint
is triggered by allocating the work queue lockdep keys dynamically.

In other words, this patch guarantees that a unique lockdep key is
associated with each work queue mutex.

  ======================================================
  WARNING: possible circular locking dependency detected
  4.19.0-dbg+ #1 Not tainted
  fio/4129 is trying to acquire lock:
  00000000a01cfe1a ((wq_completion)"dio/%s"sb->s_id){+.+.}, at: flush_workqueue+0xd0/0x970

  but task is already holding lock:
  00000000a0acecf9 (&sb->s_type->i_mutex_key#14){+.+.}, at: ext4_file_write_iter+0x154/0x710

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (&sb->s_type->i_mutex_key#14){+.+.}:
         down_write+0x3d/0x80
         __generic_file_fsync+0x77/0xf0
         ext4_sync_file+0x3c9/0x780
         vfs_fsync_range+0x66/0x100
         dio_complete+0x2f5/0x360
         dio_aio_complete_work+0x1c/0x20
         process_one_work+0x481/0x9f0
         worker_thread+0x63/0x5a0
         kthread+0x1cf/0x1f0
         ret_from_fork+0x24/0x30

  -> #1 ((work_completion)(&dio->complete_work)){+.+.}:
         process_one_work+0x447/0x9f0
         worker_thread+0x63/0x5a0
         kthread+0x1cf/0x1f0
         ret_from_fork+0x24/0x30

  -> #0 ((wq_completion)"dio/%s"sb->s_id){+.+.}:
         lock_acquire+0xc5/0x200
         flush_workqueue+0xf3/0x970
         drain_workqueue+0xec/0x220
         destroy_workqueue+0x23/0x350
         sb_init_dio_done_wq+0x6a/0x80
         do_blockdev_direct_IO+0x1f33/0x4be0
         __blockdev_direct_IO+0x79/0x86
         ext4_direct_IO+0x5df/0xbb0
         generic_file_direct_write+0x119/0x220
         __generic_file_write_iter+0x131/0x2d0
         ext4_file_write_iter+0x3fa/0x710
         aio_write+0x235/0x330
         io_submit_one+0x510/0xeb0
         __x64_sys_io_submit+0x122/0x340
         do_syscall_64+0x71/0x220
         entry_SYSCALL_64_after_hwframe+0x49/0xbe

  other info that might help us debug this:

  Chain exists of:
    (wq_completion)"dio/%s"sb->s_id --> (work_completion)(&dio->complete_work) --> &sb->s_type->i_mutex_key#14

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(&sb->s_type->i_mutex_key#14);
                                 lock((work_completion)(&dio->complete_work));
                                 lock(&sb->s_type->i_mutex_key#14);
    lock((wq_completion)"dio/%s"sb->s_id);

   *** DEADLOCK ***

  1 lock held by fio/4129:
   #0: 00000000a0acecf9 (&sb->s_type->i_mutex_key#14){+.+.}, at: ext4_file_write_iter+0x154/0x710

  stack backtrace:
  CPU: 3 PID: 4129 Comm: fio Not tainted 4.19.0-dbg+ #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
  Call Trace:
   dump_stack+0x86/0xc5
   print_circular_bug.isra.32+0x20a/0x218
   __lock_acquire+0x1c68/0x1cf0
   lock_acquire+0xc5/0x200
   flush_workqueue+0xf3/0x970
   drain_workqueue+0xec/0x220
   destroy_workqueue+0x23/0x350
   sb_init_dio_done_wq+0x6a/0x80
   do_blockdev_direct_IO+0x1f33/0x4be0
   __blockdev_direct_IO+0x79/0x86
   ext4_direct_IO+0x5df/0xbb0
   generic_file_direct_write+0x119/0x220
   __generic_file_write_iter+0x131/0x2d0
   ext4_file_write_iter+0x3fa/0x710
   aio_write+0x235/0x330
   io_submit_one+0x510/0xeb0
   __x64_sys_io_submit+0x122/0x340
   do_syscall_64+0x71/0x220
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/20190214230058.196511-20-bvanassche@acm.org
[ Reworked the changelog a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
workqueue: fix typo in comment 2019-02-21T16:03:38+00:00 Liu Song fishland@aliyun.com 2019-02-19T15:53:27+00:00 8bdc6201785d0b5231bfd77bf2b62726395092d7 qeueue/queue Signed-off-by: Liu Song <liu.song11@zte.com.cn> Signed-off-by: Tejun Heo <tj@kernel.org> 
qeueue/queue

Signed-off-by: Liu Song <liu.song11@zte.com.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>