1. 25 9月, 2009 1 次提交
    • M
      clocksource: Resume clocksource without taking the clocksource mutex · 89133f93
      Martin Schwidefsky 提交于
      git commit 75c5158f converted the clocksource spinlock to a
      mutex. This causes the following BUG:
      
      BUG: sleeping function called from invalid context at
      kernel/mutex.c:280 in_atomic(): 0, irqs_disabled(): 1, pid: 2473,
      name: pm-suspend 2 locks held by pm-suspend/2473:
       #0:  (&buffer->mutex){......}, at: [<ffffffff8115ab13>]
      sysfs_write_file+0x3c/0x137
       #1:  (pm_mutex){......}, at: [<ffffffff810865b5>]
      enter_state+0x39/0x130 Pid: 2473, comm: pm-suspend Not tainted 2.6.31
      #1 Call Trace:
       [<ffffffff810792f0>] ? __debug_show_held_locks+0x22/0x24
       [<ffffffff8104a2ef>] __might_sleep+0x107/0x10b
       [<ffffffff8141fca9>] mutex_lock_nested+0x25/0x43
       [<ffffffff81073537>] clocksource_resume+0x1c/0x60
       [<ffffffff81072902>] timekeeping_resume+0x1e/0x1c8
       [<ffffffff812aee62>] __sysdev_resume+0x25/0xcf
       [<ffffffff812aef79>] sysdev_resume+0x6d/0xae
       [<ffffffff810864f8>] suspend_devices_and_enter+0x12b/0x1af
       [<ffffffff8108665b>] enter_state+0xdf/0x130
       [<ffffffff81085dc3>] state_store+0xb6/0xd3
       [<ffffffff81204c73>] kobj_attr_store+0x17/0x19
       [<ffffffff8115abd2>] sysfs_write_file+0xfb/0x137
       [<ffffffff811057d2>] vfs_write+0xae/0x10b
       [<ffffffff81208392>] ? __up_read+0x1a/0x7f
       [<ffffffff811058ef>] sys_write+0x4a/0x6e
       [<ffffffff81011b82>] system_call_fastpath+0x16/0x1b
      
      clocksource_resume is called early in the resume process, there is
      only one cpu, no processes are running and the interrupts are
      disabled. It is therefore possible to resume the clocksources
      without taking the clocksource mutex.
      Reported-by: NXiaotian Feng <xtfeng@gmail.com>
      Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      Tested-by: NMichal Schmidt <mschmidt@redhat.com>
      Cc: Xiaotian Feng <xtfeng@gmail.com>
      Cc: John Stultz <johnstul@us.ibm.com>
      LKML-Reference: <20090924172952.49697825@mschwide.boeblingen.de.ibm.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      89133f93
  2. 24 9月, 2009 39 次提交