Merge branch 'for-arm-soc' of git://sources.calxeda.com/kernel/linux into next/soc

* 'for-arm-soc' of git://sources.calxeda.com/kernel/linux: (247 commits)
  ARM: highbank: remove unused memory.h
  ARM: highbank: enable sp804 based sched_clock
  ARM: timer-sp: add sched_clock support
  Linux 3.3-rc3
  pcmcia: fix socket refcount decrementing on each resume
  mm: fix UP THP spin_is_locked BUGs
  drivers/leds/leds-lm3530.c: fix setting pltfm->als_vmax
  mm: compaction: check for overlapping nodes during isolation for migration
  nilfs2: avoid overflowing segment numbers in nilfs_ioctl_clean_segments()
  ASoC: wm8994: Disable line output discharge prior to ramping VMID
  ASoC: wm8994: Fix typo in VMID ramp setting
  ALSA: oxygen, virtuoso: fix exchanged L/R volumes of aux and CD inputs
  ALSA: usb-audio: add Edirol UM-3G support
  checkpatch: Warn on code with 6+ tab indentation
  ACPI: remove duplicated lines of merging problems with acpi_processor_add
  ALSA: hda - add support for Uniwill ECS M31EI notebook
  HID: wiimote: fix invalid power_supply_powers call
  ALSA: hda - Fix error handling in patch_ca0132.c
  target: Fix unsupported WRITE_SAME sense payload
  iscsi: use IP_FREEBIND socket option
  ...

1 files changed, 16 insertions, 0 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 294b1709170d..4b4042f9bc6a 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1038,6 +1038,22 @@ void do_exit(long code)
         if (tsk->nr_dirtied)
                 __this_cpu_add(dirty_throttle_leaks, tsk->nr_dirtied);
         exit_rcu();
+
+        /*
+         * The setting of TASK_RUNNING by try_to_wake_up() may be delayed
+         * when the following two conditions become true.
+         *   - There is race condition of mmap_sem (It is acquired by
+         *     exit_mm()), and
+         *   - SMI occurs before setting TASK_RUNINNG.
+         *     (or hypervisor of virtual machine switches to other guest)
+         *  As a result, we may become TASK_RUNNING after becoming TASK_DEAD
+         *
+         * To avoid it, we have to wait for releasing tsk->pi_lock which
+         * is held by try_to_wake_up()
+         */
+        smp_mb();
+        raw_spin_unlock_wait(&tsk->pi_lock);
+
         /* causes final put_task_struct in finish_task_switch(). */
         tsk->state = TASK_DEAD;
         tsk->flags |= PF_NOFREEZE;      /* tell freezer to ignore us */