1. 13 Oct, 2009 1 commit
    • Thomas Gleixner's avatar
      futex: Handle spurious wake up · d58e6576
      Thomas Gleixner authored
      The futex code does not handle spurious wake up in futex_wait and
      futex_wait_requeue_pi.
      
      The code assumes that any wake up which was not caused by futex_wake /
      requeue or by a timeout was caused by a signal wake up and returns one
      of the syscall restart error codes.
      
      In case of a spurious wake up the signal delivery code which deals
      with the restart error codes is not invoked and we return that error
      code to user space. That causes applications which actually check the
      return codes to fail. Blaise reported that on preempt-rt a python test
      program run into a exception trap. -rt exposed that due to a built in
      spurious wake up accelerator :)
      
      Solve this by checking signal_pending(current) in the wake up path and
      handle the spurious wake up case w/o returning to user space.
      Reported-by: default avatarBlaise Gassend <blaise@willowgarage.com>
      Debugged-by: default avatarDarren Hart <dvhltc@us.ibm.com>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: stable@kernel.org
      LKML-Reference: <new-submission>
      d58e6576
  2. 12 Oct, 2009 1 commit
  3. 09 Oct, 2009 3 commits
  4. 08 Oct, 2009 35 commits