[PATCH] lockdep: annotate do_debug() trap handler

From: Peter Zijlstra
Date: Sat Nov 17 2007 - 18:07:34 EST


Subject: lockdep: annotate do_debug() trap handler

Ensure the hardirq state is consistent before using locks. Use the rare
trace_hardirqs_fixup() because the trap can happen in any context.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
arch/x86/kernel/traps_32.c | 2 ++
arch/x86/kernel/traps_64.c | 2 ++
2 files changed, 4 insertions(+)

Index: linux-2.6/arch/x86/kernel/traps_32.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/traps_32.c
+++ linux-2.6/arch/x86/kernel/traps_32.c
@@ -830,6 +830,8 @@ fastcall void __kprobes do_debug(struct
unsigned int condition;
struct task_struct *tsk = current;

+ trace_hardirqs_fixup();
+
get_debugreg(condition, 6);

if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
Index: linux-2.6/arch/x86/kernel/traps_64.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/traps_64.c
+++ linux-2.6/arch/x86/kernel/traps_64.c
@@ -840,6 +840,8 @@ asmlinkage void __kprobes do_debug(struc
struct task_struct *tsk = current;
siginfo_t info;

+ trace_hardirqs_fixup();
+
get_debugreg(condition, 6);

if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
-
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