[PATCH 3.12 004/181] powerpc: Fix Oops in rtas_stop_self()

[Jiri Slaby]

From: Li Zhong <zhong@xxxxxxxxxxxxxxxxxx>

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

===============

commit 4fb8d027dca0236c811272d342cf185569d91311 upstream.

commit 41dd03a9 may cause Oops in rtas_stop_self().

The reason is that the rtas_args was moved into stack space. For a box
with more that 4GB RAM, the stack could easily be outside 32bit range,
but RTAS is 32bit.

So the patch moves rtas_args away from stack by adding static before
it.

Signed-off-by: Li Zhong <zhong@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 3.14+
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 arch/powerpc/platforms/pseries/hotplug-cpu.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 0ea99e3d4815..2d6fe89ff89d 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -88,13 +88,14 @@ void set_default_offline_state(int cpu)
 
 static void rtas_stop_self(void)
 {
-	struct rtas_args args = {
-		.token = cpu_to_be32(rtas_stop_self_token),
+	static struct rtas_args args = {
 		.nargs = 0,
 		.nret = 1,
 		.rets = &args.args[0],
 	};
 
+	args.token = cpu_to_be32(rtas_stop_self_token);
+
 	local_irq_disable();
 
 	BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE);
-- 
2.0.0

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