alistair23-linux/kernel/power
Rafael J. Wysocki 6a0c7cd330 PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps()
I have received a report about the BUG_ON() in free_basic_memory_bitmaps()
triggering mysteriously during an aborted s2disk hibernation attempt.
The only way I can explain that is that /dev/snapshot was first
opened for writing (resume mode), then closed and then opened again
for reading and closed again without freezing tasks.  In that case
the first invocation of snapshot_open() would set the free_bitmaps
flag in snapshot_state, which is a static variable.  That flag
wouldn't be cleared later and the second invocation of snapshot_open()
would just leave it like that, so the subsequent snapshot_release()
would see data->frozen set and free_basic_memory_bitmaps() would be
called unnecessarily.

To prevent that from happening clear data->free_bitmaps in
snapshot_open() when the file is being opened for reading (hibernate
mode).

In addition to that, replace the BUG_ON() in free_basic_memory_bitmaps()
with a WARN_ON() as the kernel can continue just fine if the condition
checked by that macro occurs.

Fixes: aab1728915 (PM / hibernate: Fix user space driven resume regression)
Reported-by: Oliver Lorenz <olli@olorenz.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 3.12+ <stable@vger.kernel.org> # 3.12+
2013-11-14 23:26:58 +01:00
..
autosleep.c PM / Sleep: avoid 'autosleep' in shutdown progress 2013-07-15 01:31:37 +02:00
block_io.c
console.c PM: make VT switching to the suspend console optional v3 2013-02-20 01:33:41 +01:00
hibernate.c PM / hibernate: Move software_resume to late_initcall_sync 2013-10-25 01:58:49 +02:00
Kconfig Merge branch 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2013-07-02 19:53:30 -07:00
main.c PM / Sleep: Warn about system time after resume with pm_trace 2013-06-27 22:14:46 +02:00
Makefile
power.h
poweroff.c power/sysrq: fix inconstistent help message of sysrq key 2013-04-30 17:04:10 -07:00
process.c freezer: set PF_SUSPEND_TASK flag on tasks that call freeze_processes 2013-07-30 14:05:06 +02:00
qos.c PM / QoS: Fix workqueue deadlock when using pm_qos_update_request_timeout() 2013-08-14 00:42:05 +02:00
snapshot.c PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps() 2013-11-14 23:26:58 +01:00
suspend.c PM / Sleep: increase ftrace coverage in suspend/resume 2013-07-26 00:49:07 +02:00
suspend_test.c driver-core: constify data for class_find_device() 2013-02-06 12:18:56 -08:00
swap.c
user.c PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps() 2013-11-14 23:26:58 +01:00
wakelock.c