[ 3.5.y.z extended stable ] Patch "powerpc/kexec: Disable hard IRQ before kexec" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    powerpc/kexec: Disable hard IRQ before kexec

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 1628a5d1b64608aecaec006d6a82cc1c9df7ac00 Mon Sep 17 00:00:00 2001
From: Phileas Fogg <phileas-fogg at mail.ru>
Date: Sat, 23 Feb 2013 00:32:19 +0100
Subject: [PATCH] powerpc/kexec: Disable hard IRQ before kexec

commit 8520e443aa56cc157b015205ea53e7b9fc831291 upstream.

Disable hard IRQ before kexec a new kernel image.
Not doing it can result in corrupted data in the memory segments
reserved for the new kernel.

Signed-off-by: Phileas Fogg <phileas-fogg at mail.ru>
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/powerpc/kernel/machine_kexec_64.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index d7f6090..39833e0 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -162,6 +162,8 @@ static int kexec_all_irq_disabled = 0;
 static void kexec_smp_down(void *arg)
 {
 	local_irq_disable();
+	hard_irq_disable();
+
 	mb(); /* make sure our irqs are disabled before we say they are */
 	get_paca()->kexec_state = KEXEC_STATE_IRQS_OFF;
 	while(kexec_all_irq_disabled == 0)
@@ -244,6 +246,8 @@ static void kexec_prepare_cpus(void)
 	wake_offline_cpus();
 	smp_call_function(kexec_smp_down, NULL, /* wait */0);
 	local_irq_disable();
+	hard_irq_disable();
+
 	mb(); /* make sure IRQs are disabled before we say they are */
 	get_paca()->kexec_state = KEXEC_STATE_IRQS_OFF;

@@ -281,6 +285,7 @@ static void kexec_prepare_cpus(void)
 	if (ppc_md.kexec_cpu_down)
 		ppc_md.kexec_cpu_down(0, 0);
 	local_irq_disable();
+	hard_irq_disable();
 }

 #endif /* SMP */
--
1.8.1.2