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authorOlof Johansson <olof@lixom.net>2012-02-10 12:40:34 -0800
committerOlof Johansson <olof@lixom.net>2012-02-10 12:40:34 -0800
commit082f53c2f573c75a8f1610c587a43b6817e20f90 (patch)
treec3ad3a58967e7f7f61ff12ff59284dba1e76d093 /kernel/exit.c
parente69128b947da0a2474447868f73c76311e2baedb (diff)
parentb024e33682c8e56cc8e869245dabd1b91ffe00ea (diff)
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 ...
Diffstat (limited to 'kernel/exit.c')
-rw-r--r--kernel/exit.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 294b1709170..4b4042f9bc6 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 */