From: Don Zickus Date: Fri, 12 Aug 2011 17:54:51 +0000 (-0700) Subject: pstore: change mutex locking to spin_locks X-Git-Tag: v3.2-rc1~103^2~1 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=abd4d5587be911f63592537284dad78766d97d62;p=pandora-kernel.git pstore: change mutex locking to spin_locks pstore was using mutex locking to protect read/write access to the backend plug-ins. This causes problems when pstore is executed in an NMI context through panic() -> kmsg_dump(). This patch changes the mutex to a spin_lock_irqsave then also checks to see if we are in an NMI context. If we are in an NMI and can't get the lock, just print a message stating that and blow by the locking. All this is probably a hack around the bigger locking problem but it solves my current situation of trying to sleep in an NMI context. Tested by loading the lkdtm module and executing a HARDLOCKUP which will cause the machine to panic inside the nmi handler. Signed-off-by: Don Zickus Acked-by: Matthew Garrett Signed-off-by: Tony Luck --- Reading git-diff-tree failed