2006-08-01 11:09:54

by Chuck Ebbert

Subject: [patch] x86_64: remove lock prefix from is_at_popf() tests

The lock prefix will cause an exception when used with the
popf instruction, so no need to continue searching after it's
found.

Signed-off-by: Chuck Ebbert <[email protected]>

--- 2.6.18-rc3-64.orig/arch/x86_64/kernel/ptrace.c
+++ 2.6.18-rc3-64/arch/x86_64/kernel/ptrace.c
@@ -138,7 +138,7 @@ static int is_at_popf(struct task_struct
case 0x26: case 0x2e:
case 0x36: case 0x3e:
case 0x64: case 0x65:
- case 0xf0: case 0xf2: case 0xf3:
+ case 0xf2: case 0xf3:
continue;

case 0x40 ... 0x4f:
@@ -148,7 +148,7 @@ static int is_at_popf(struct task_struct
/* 64-bit mode: REX prefix */
continue;

- /* CHECKME: f0, f2, f3 */
+ /* CHECKME: f2, f3 */

/*
* pushf: NOTE! We should probably not let
--
Chuck

2006-08-01 17:26:05

by Andi Kleen

Subject: Re: [patch] x86_64: remove lock prefix from is_at_popf() tests

On Tuesday 01 August 2006 13:00, Chuck Ebbert wrote:
> The lock prefix will cause an exception when used with the
> popf instruction, so no need to continue searching after it's
> found.

Applied thanks.
-Andi