Fixes the following lockdep error: [ BUG: ktpacpi_nvramd/446 still has locks held! ]
hotkey_kthread() calls set_freezable() after acquiring the hotkey_kthread_mutex(). set_freezable() calls try_to_freeze(). This could block suspend if we were to freeze at this point and another task were to block on the mutex, potentially via writing to one of the sysfs attrs. This race is unlikely but can be easily fixed by moving the set_freezable() call. Reported-by: Maciej Rutecki <[email protected]> Signed-off-by: Mandeep Singh Baines <[email protected]> CC: Aaron Lu <[email protected]> CC: Henrique de Moraes Holschuh <[email protected]> CC: Tejun Heo <[email protected]> CC: Oleg Nesterov <[email protected]> CC: Andrew Morton <[email protected]> --- drivers/platform/x86/thinkpad_acpi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index 9a90756..69870a841 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -2462,13 +2462,13 @@ static int hotkey_kthread(void *data) unsigned int poll_freq; bool was_frozen; + set_freezable(); + mutex_lock(&hotkey_thread_mutex); if (tpacpi_lifecycle == TPACPI_LIFE_EXITING) goto exit; - set_freezable(); - so = 0; si = 1; t = 0; -- 1.7.12.4 ------------------------------------------------------------------------------ Symantec Endpoint Protection 12 positioned as A LEADER in The Forrester Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in the endpoint security space. For insight on selecting the right partner to tackle endpoint security challenges, access the full report. http://p.sf.net/sfu/symantec-dev2dev _______________________________________________ ibm-acpi-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ibm-acpi-devel
