[U-Boot] [PATCH v3] arm: bugfix: save_boot_params_default accesses uninitalized stack when -O0

[Tetsuyuki Kobayashi]

save_boot_params_default() in cpu.c accesses uninitialized stack area
when it compiled with -O0 (not optimized).

Signed-off-by: Tetsuyuki Kobayashi <koba at kmckk.co.jp>
---
Changes for v2:
 - include <linux/compiler.h> and use __naked instead of __attribute__((naked))

Changes for v3:
 - move __naked after void
 - reformat comments

 arch/arm/cpu/armv7/cpu.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm/cpu/armv7/cpu.c b/arch/arm/cpu/armv7/cpu.c
index c6fa8ef..9eb484a 100644
--- a/arch/arm/cpu/armv7/cpu.c
+++ b/arch/arm/cpu/armv7/cpu.c
@@ -36,9 +36,15 @@
 #include <asm/system.h>
 #include <asm/cache.h>
 #include <asm/armv7.h>
+#include <linux/compiler.h>
 
-void save_boot_params_default(u32 r0, u32 r1, u32 r2, u32 r3)
+void __naked save_boot_params_default(u32 r0, u32 r1, u32 r2, u32 r3)
 {
+	/*
+	 * Stack pointer is not yet initialized
+	 * Don't save anything to stack even if compiled with -O0
+	 */
+	asm("bx lr");
 }
 
 void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)
-- 1.7.9.5