[PATCH] x86: fix debug handler for kmemcheck

[Vegard Nossum <vegard.nossum@gmail.com>]

Hi Ingo,

Patch description says everything :-)

This actually comes from my kmemcheck git repository at
git://git.kernel.org/pub/scm/linux/kernel/git/vegard/kmemcheck.git

but it's not in x86.git. CCing LKML in case anybody cares :-)


Vegard


>From 68400903a6348769152f9a2ed102bad0a4774912 Mon Sep 17 00:00:00 2001
From: Vegard Nossum <vegard.nossum@gmail.com>
Date: Thu, 1 May 2008 19:10:07 +0200
Subject: [PATCH] x86: fix debug handler for kmemcheck

This changes the 64-bit debug exception handler to match the 32-bit version
(which is also correct).

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
---
 arch/x86/kernel/traps_64.c |    7 +------
 1 files changed, 1 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
index 8069073..72923ba 100644
--- a/arch/x86/kernel/traps_64.c
+++ b/arch/x86/kernel/traps_64.c
@@ -915,18 +915,13 @@ asmlinkage void __kprobes do_debug(struct pt_regs * regs,
 
 	get_debugreg(condition, 6);
 
-#ifdef CONFIG_KMEMCHECK
 	/* Catch kmemcheck conditions first of all! */
 	if (condition & DR_STEP) {
-		if (!(regs->flags & X86_VM_MASK) && !user_mode(regs) &&
-			((void *)regs->ip != system_call) &&
-			((void *)regs->ip != x86_debug) &&
-			((void *)regs->ip != ia32_sysenter_target)) {
+		if (kmemcheck_active(regs)) {
 			kmemcheck_hide(regs);
 			return;
 		}
 	}
-#endif
 
 	/*
 	 * The processor cleared BTF, so don't mark that we need it set.
-- 
1.5.4.1