[ 36/53] powerpc/kexec: Disable hard IRQ before kexec

From: Greg Kroah-Hartman
Date: Tue Feb 26 2013 - 19:03:31 EST


3.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: Phileas Fogg <phileas-fogg@xxxxxxx>

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@xxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/powerpc/kernel/machine_kexec_64.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -163,6 +163,8 @@ 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)
@@ -245,6 +247,8 @@ 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;

@@ -282,6 +286,7 @@ 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 */


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/