On Thu, Sep 17, 2015 at 05:14:35PM -0500, Chris J Arges wrote:
> Numerous 'call without frame pointer save/setup' warnings are introduced by
> stacktool because of functions using the get_user macro. Bad stack traces could
> occur due to lack of or misplacement of stack frame setup code.
>
> This patch forces a stack frame to be created before the inline asm code if
> CONFIG_FRAME_POINTER is enabled by listing the stack pointer as an output
> operand for the get_user inline assembly statement.
>
> Signed-off-by: Chris J Arges <chris.j.arges@xxxxxxxxxxxxx>
Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
> ---
> arch/x86/include/asm/uaccess.h | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
> index a8df874..55b8db5 100644
> --- a/arch/x86/include/asm/uaccess.h
> +++ b/arch/x86/include/asm/uaccess.h
> @@ -176,10 +176,11 @@ __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
> ({ \
> int __ret_gu; \
> register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \
> + register void *__sp asm(_ASM_SP); \
> __chk_user_ptr(ptr); \
> might_fault(); \
> - asm volatile("call __get_user_%P3" \
> - : "=a" (__ret_gu), "=r" (__val_gu) \
> + asm volatile("call __get_user_%P4" \
> + : "=a" (__ret_gu), "=r" (__val_gu), "+r" (__sp) \
> : "0" (ptr), "i" (sizeof(*(ptr)))); \
> (x) = (__force __typeof__(*(ptr))) __val_gu; \
> __ret_gu; \
> --
> 1.9.1
>
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