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authorChuck Ebbert <76306.1226@compuserve.com>2006-09-26 10:52:32 +0200
committerAndi Kleen <andi@basil.nowhere.org>2006-09-26 10:52:32 +0200
commita752d7194c4fb5a3e767c95542d04fc5decb1d52 (patch)
treeb63d56f85c10f5f26c67dc3e8cf4ac6366f4824b /arch/x86_64/kernel
parent8578bdf835d6d6ece6718858d351456367b8a5cf (diff)
[PATCH] fix is_at_popf() for compat tasks
When testing for the REX instruction prefix, first check for 32-bit mode because in compat mode the REX prefix is an increment instruction. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch/x86_64/kernel')
-rw-r--r--arch/x86_64/kernel/ptrace.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c
index d35ec1bc696..3a52c7bcfd1 100644
--- a/arch/x86_64/kernel/ptrace.c
+++ b/arch/x86_64/kernel/ptrace.c
@@ -141,8 +141,11 @@ static int is_at_popf(struct task_struct *child, struct pt_regs *regs)
case 0xf0: case 0xf2: case 0xf3:
continue;
- /* REX prefixes */
case 0x40 ... 0x4f:
+ if (regs->cs != __USER_CS)
+ /* 32-bit mode: register increment */
+ return 0;
+ /* 64-bit mode: REX prefix */
continue;
/* CHECKME: f0, f2, f3 */