Patchwork [U-Boot,v2] arm: bugfix: save_boot_params_default accesses uninitalized stack when -O0

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Submitter Tetsuyuki Kobayashi
Date June 28, 2012, 11:17 a.m.
Message ID <4FEC3D36.1050901@kmckk.co.jp>
Download mbox | patch
Permalink /patch/167856/
State Superseded
Headers show

Comments

Tetsuyuki Kobayashi - June 28, 2012, 11:17 a.m.
save_boot_params_default() in cpu.c accesses uninitialized stack area
when it compiled with -O0 (not optimized).

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


 arch/arm/cpu/armv7/cpu.c |    4 ++++
 1 file changed, 4 insertions(+)
Tetsuyuki Kobayashi - June 28, 2012, 11:39 a.m.
I'm sorry. This post is missing In-Reply-To. I sent again. Discard this.

(2012/06/28 20:17), Tetsuyuki Kobayashi wrote:
> save_boot_params_default() in cpu.c accesses uninitialized stack area
> when it compiled with -O0 (not optimized).
>
> Signed-off-by: Tetsuyuki Kobayashi<koba@kmckk.co.jp>
> ---
> Changes for v2:
>   - include<linux/compiler.h>  and use __naked instead of __attribute__((naked))
>
>
>   arch/arm/cpu/armv7/cpu.c |    4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/arch/arm/cpu/armv7/cpu.c b/arch/arm/cpu/armv7/cpu.c
> index c6fa8ef..3e2a75c 100644
> --- a/arch/arm/cpu/armv7/cpu.c
> +++ b/arch/arm/cpu/armv7/cpu.c
> @@ -36,9 +36,13 @@
>   #include<asm/system.h>
>   #include<asm/cache.h>
>   #include<asm/armv7.h>
> +#include<linux/compiler.h>
>
> +__naked /* don't save anything to stack even if compiled with -O0 */
>   void save_boot_params_default(u32 r0, u32 r1, u32 r2, u32 r3)
>   {
> +	/* stack is not yet initialized */
> +	asm("bx lr");
>   }
>
>   void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)

Patch

diff --git a/arch/arm/cpu/armv7/cpu.c b/arch/arm/cpu/armv7/cpu.c
index c6fa8ef..3e2a75c 100644
--- a/arch/arm/cpu/armv7/cpu.c
+++ b/arch/arm/cpu/armv7/cpu.c
@@ -36,9 +36,13 @@ 
 #include <asm/system.h>
 #include <asm/cache.h>
 #include <asm/armv7.h>
+#include <linux/compiler.h>
 
+__naked /* don't save anything to stack even if compiled with -O0 */
 void save_boot_params_default(u32 r0, u32 r1, u32 r2, u32 r3)
 {
+	/* stack is not yet initialized */
+	asm("bx lr");
 }
 
 void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)