1. 16 9月, 2011 2 次提交
  2. 15 9月, 2011 2 次提交
    • A
      ALSA: pcm - fix race condition in wait_for_avail() · 763437a9
      Arjan van de Ven 提交于
      wait_for_avail() in pcm_lib.c has a race in it (observed in practice by an
      Intel validation group).
      
      The function is supposed to return once space in the buffer has become
      available, or if some timeout happens.  The entity that creates space (irq
      handler of sound driver and some such) will do a wake up on a waitqueue
      that this function registers for.
      
      However there are two races in the existing code
      
      1) If space became available between the caller noticing there was no
         space and this function actually sleeping, the wakeup is missed and the
         timeout condition will happen instead
      
      2) If a wakeup happened but not sufficient space became available, the
         code will loop again and wait for more space.  However, if the second
         wake comes in prior to hitting the schedule_timeout_interruptible(), it
         will be missed, and potentially you'll wait out until the timeout
         happens.
      
      The fix consists of using more careful setting of the current state (so
      that if a wakeup happens in the main loop window, the schedule_timeout()
      falls through) and by checking for available space prior to going into the
      schedule_timeout() loop, but after being on the waitqueue and having the
      state set to interruptible.
      
      [tiwai: the following changes have been added to Arjan's original patch:
       - merged akpm's fix for waitqueue adding order into a single patch
       - reduction of duplicated code of avail check
      ]
      Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Cc: <stable@kernel.org>
      Signed-off-by: NTakashi Iwai <tiwai@suse.de>
      763437a9
    • T
      Merge branch 'fix/asoc' into for-linus · 4038a12e
      Takashi Iwai 提交于
      4038a12e
  3. 14 9月, 2011 6 次提交
  4. 13 9月, 2011 1 次提交
  5. 12 9月, 2011 5 次提交
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  12. 23 8月, 2011 5 次提交