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* [PATCH 1/4] x86, putuser: add ASM_CALL_CONSTRAINT
@ 2019-03-16 21:01 Alexey Dobriyan
  2019-03-24 21:32 ` Borislav Petkov
  0 siblings, 1 reply; 2+ messages in thread
From: Alexey Dobriyan @ 2019-03-16 21:01 UTC (permalink / raw)
  To: tglx, mingo, bp, hpa; +Cc: x86, linux-kernel

Clobber stack pointer given that assembly does CALL.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

 arch/x86/include/asm/uaccess.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -176,7 +176,8 @@ __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
 })
 
 #define __put_user_x(size, x, ptr, __ret_pu)			\
-	asm volatile("call __put_user_" #size : "=a" (__ret_pu)	\
+	asm volatile("call __put_user_" #size			\
+		     : "=a" (__ret_pu), ASM_CALL_CONSTRAINT	\
 		     : "0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
 
 

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH 1/4] x86, putuser: add ASM_CALL_CONSTRAINT
  2019-03-16 21:01 [PATCH 1/4] x86, putuser: add ASM_CALL_CONSTRAINT Alexey Dobriyan
@ 2019-03-24 21:32 ` Borislav Petkov
  0 siblings, 0 replies; 2+ messages in thread
From: Borislav Petkov @ 2019-03-24 21:32 UTC (permalink / raw)
  To: Alexey Dobriyan; +Cc: tglx, mingo, hpa, x86, linux-kernel

On Sun, Mar 17, 2019 at 12:01:27AM +0300, Alexey Dobriyan wrote:
> Clobber stack pointer given that assembly does CALL.

Clobber?

Comment over ASM_CALL_CONSTRAINT talks about something else.

Also, pls change all your subject prefixes to

"x86/uaccess: ..."

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2019-03-16 21:01 [PATCH 1/4] x86, putuser: add ASM_CALL_CONSTRAINT Alexey Dobriyan
2019-03-24 21:32 ` Borislav Petkov

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