rt-patches/0262-ptrace-don-t-open-IRQs-in-ptrace_freeze_traced-too-e.patch

   1 From 24a4176c16eb260d7caf5e18bbff4db3c9ba1914 Mon Sep 17 00:00:00 2001
   2 From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
   3 Date: Wed, 13 Jan 2016 14:09:05 +0100
   4 Subject: [PATCH 262/366] ptrace: don't open IRQs in ptrace_freeze_traced() too
   5  early
   6
   7 In the non-RT case the spin_lock_irq() here disables interrupts as well
   8 as raw_spin_lock_irq(). So in the unlock case the interrupts are enabled
   9 too early.
  10
  11 Reported-by: kernel test robot <ying.huang@linux.intel.com>
  12 Cc: stable-rt@vger.kernel.org
  13 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
  14 ---
  15  kernel/ptrace.c | 6 ++++--
  16  1 file changed, 4 insertions(+), 2 deletions(-)
  17
  18 diff --git a/kernel/ptrace.c b/kernel/ptrace.c
  19 index b852051..1004af7 100644
  20 --- a/kernel/ptrace.c
  21 +++ b/kernel/ptrace.c
  22 @@ -129,12 +129,14 @@ static bool ptrace_freeze_traced(struct task_struct *task)
  23
  24         spin_lock_irq(&task->sighand->siglock);
  25         if (task_is_traced(task) && !__fatal_signal_pending(task)) {
  26 -               raw_spin_lock_irq(&task->pi_lock);
  27 +               unsigned long flags;
  28 +
  29 +               raw_spin_lock_irqsave(&task->pi_lock, flags);
  30                 if (task->state & __TASK_TRACED)
  31                         task->state = __TASK_TRACED;
  32                 else
  33                         task->saved_state = __TASK_TRACED;
  34 -               raw_spin_unlock_irq(&task->pi_lock);
  35 +               raw_spin_unlock_irqrestore(&task->pi_lock, flags);
  36                 ret = true;
  37         }
  38         spin_unlock_irq(&task->sighand->siglock);
  39 --
  40 1.9.1
  41