From 84ab14893054751a2b3adba725834183b872a17f Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy@c-s.fr>
Date: Thu, 20 Feb 2020 22:51:39 +1100
Subject: [PATCH] powerpc/irq: Use current_stack_pointer in
 check_stack_overflow()

References: bsc#1156395
Patch-mainline: v5.7-rc1
Git-commit: 84ab14893054751a2b3adba725834183b872a17f

The purpose of check_stack_overflow() is to verify that the stack has
not overflowed.

To really know whether the stack pointer is still within boundaries,
the check must be done directly on the value of r1.

So use current_stack_pointer, which returns the current value of r1,
rather than current_stack_frame() which causes a frame to be created
and then returns that value.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200220115141.2707-3-mpe@ellerman.id.au
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 arch/powerpc/kernel/irq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 02118c18434d..c7d6f5cdffdb 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -602,7 +602,7 @@ static inline void check_stack_overflow(void)
 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 	long sp;
 
-	sp = current_stack_frame() & (THREAD_SIZE-1);
+	sp = current_stack_pointer & (THREAD_SIZE - 1);
 
 	/* check for stack overflow: is there less than 2KB free? */
 	if (unlikely(sp < 2048)) {
-- 
2.23.0