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@chello.nl>
---
 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,
-

[ message continues ]