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

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Submitter Tetsuyuki Kobayashi
Date June 25, 2012, 12:42 p.m.
Message ID <4FE85CB5.6070505@kmckk.co.jp>
Download mbox | patch
Permalink /patch/167098/
State Superseded
Headers show

Comments

Tetsuyuki Kobayashi - June 25, 2012, 12:42 p.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>
---
 arch/arm/cpu/armv7/cpu.c |    3 +++
 1 file changed, 3 insertions(+)
Tom Rini - June 27, 2012, 5:40 p.m.
On Mon, Jun 25, 2012 at 09:42:29PM +0900, 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>
> ---
>  arch/arm/cpu/armv7/cpu.c |    3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/arm/cpu/armv7/cpu.c b/arch/arm/cpu/armv7/cpu.c
> index c6fa8ef..6104cb2 100644
> --- a/arch/arm/cpu/armv7/cpu.c
> +++ b/arch/arm/cpu/armv7/cpu.c
> @@ -37,8 +37,11 @@
>  #include <asm/cache.h>
>  #include <asm/armv7.h>
>  
> +__attribute__((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");
>  }

Please add <linux/compiler.h> and use __naked instead.  Thanks!
Tetsuyuki Kobayashi - June 28, 2012, 1:14 a.m.
Hi Tom, thank you for reviewing.

(2012/06/28 2:40), Tom Rini wrote:
> On Mon, Jun 25, 2012 at 09:42:29PM +0900, 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>
>> ---
>>   arch/arm/cpu/armv7/cpu.c |    3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/arch/arm/cpu/armv7/cpu.c b/arch/arm/cpu/armv7/cpu.c
>> index c6fa8ef..6104cb2 100644
>> --- a/arch/arm/cpu/armv7/cpu.c
>> +++ b/arch/arm/cpu/armv7/cpu.c
>> @@ -37,8 +37,11 @@
>>   #include<asm/cache.h>
>>   #include<asm/armv7.h>
>>
>> +__attribute__((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");
>>   }
>
> Please add<linux/compiler.h>  and use __naked instead.  Thanks!
>
OK. I will post V2 patch.

Patch

diff --git a/arch/arm/cpu/armv7/cpu.c b/arch/arm/cpu/armv7/cpu.c
index c6fa8ef..6104cb2 100644
--- a/arch/arm/cpu/armv7/cpu.c
+++ b/arch/arm/cpu/armv7/cpu.c
@@ -37,8 +37,11 @@ 
 #include <asm/cache.h>
 #include <asm/armv7.h>
 
+__attribute__((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)