From 5d30d9525ad3f184e2bf3790ab5de573dc82e558 Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@redhat.com>
Date: Tue, 27 Mar 2012 09:02:02 -0400
Subject: [PATCH] Apply patch to fix MCE rcu splat (rhbz 789644)

---
 kernel.spec            | 11 ++++++++++-
 mcelog-rcu-splat.patch | 15 +++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 mcelog-rcu-splat.patch

diff --git a/kernel.spec b/kernel.spec
index 8284e1838..b3e584d51 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -54,7 +54,7 @@ Summary: The Linux kernel
 # For non-released -rc kernels, this will be appended after the rcX and
 # gitX tags, so a 3 here would become part of release "0.rcX.gitX.3"
 #
-%global baserelease 5
+%global baserelease 6
 %global fedora_build %{baserelease}
 
 # base_sublevel is the kernel version we're starting with and patching
@@ -756,6 +756,9 @@ Patch21233: jbd2-clear-BH_Delay-and-BH_Unwritten-in-journal_unmap_buf.patch
 #rhbz 754518
 #Patch21235: scsi-sd_revalidate_disk-prevent-NULL-ptr-deref.patch
 
+#rhbz 789644
+Patch21237: mcelog-rcu-splat.patch
+
 #rhbz 727865 730007
 Patch21240: ACPICA-Fix-regression-in-FADT-revision-checks.patch
 
@@ -1419,6 +1422,9 @@ ApplyPatch jbd2-clear-BH_Delay-and-BH_Unwritten-in-journal_unmap_buf.patch
 #rhbz 754518
 #ApplyPatch scsi-sd_revalidate_disk-prevent-NULL-ptr-deref.patch
 
+#rhbz 789644
+ApplyPatch mcelog-rcu-splat.patch
+
 #rhbz 727865 730007
 ApplyPatch ACPICA-Fix-regression-in-FADT-revision-checks.patch
 
@@ -2178,6 +2184,9 @@ fi
 # and build.
 
 %changelog
+* Tue Mar 27 2012 Josh Boyer <jwboyer@redhat.com>
+- Apply patch to fix MCE rcu splat (rhbz 789644)
+
 * Fri Mar 23 2012 Dave Jones <davej@redhat.com>
 - Apply patches that should solve the bluetooth use-after-free oopses. (rhbz 806033)
 
diff --git a/mcelog-rcu-splat.patch b/mcelog-rcu-splat.patch
new file mode 100644
index 000000000..12c1fe3ea
--- /dev/null
+++ b/mcelog-rcu-splat.patch
@@ -0,0 +1,15 @@
+diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
+index f22a9f7..f525f99 100644
+--- a/arch/x86/kernel/cpu/mcheck/mce.c
++++ b/arch/x86/kernel/cpu/mcheck/mce.c
+@@ -191,7 +191,7 @@ static void drain_mcelog_buffer(void)
+ {
+ 	unsigned int next, i, prev = 0;
+ 
+-	next = rcu_dereference_check_mce(mcelog.next);
++	next = ACCESS_ONCE(mcelog.next);
+ 
+ 	do {
+ 		struct mce *m;
+
+  
\ No newline at end of file