tree c0be993507d8fd7276a853a2eac524809f87afeb
parent 287683d027a3ff83feb6c7044430c79881664ecf
author Borislav Petkov <bp@suse.de> 1509554874 +0100
committer Thomas Gleixner <tglx@linutronix.de> 1509567876 +0100

x86/mcelog: Get rid of RCU remnants

Jeremy reported a suspicious RCU usage warning in mcelog.

/dev/mcelog is called in process context now as part of the notifier
chain and doesn't need any of the fancy RCU and lockless accesses which
it did in atomic context.

Axe it all in favor of a simple mutex synchronization which cures the
problem reported.

Fixes: 5de97c9f6d85 ("x86/mce: Factor out and deprecate the /dev/mcelog driver")
Reported-by: Jeremy Cline <jcline@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-and-tested-by: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: linux-edac@vger.kernel.org
Cc: Laura Abbott <labbott@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20171101164754.xzzmskl4ngrqc5br@pd.tnic
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1498969