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authorIngo Molnar <mingo@elte.hu>2007-12-21 03:27:19 +0300
committerIngo Molnar <mingo@elte.hu>2007-12-21 03:27:19 +0300
commitc0a698b7443a9fce76b0a849f06c45ac78f3b0a0 (patch)
treece528f832d075920f1030206a1fd016d7bf215eb
parentfaa4877f023bafa35239d411b160955dc0629fe9 (diff)
downloadlinux-c0a698b7443a9fce76b0a849f06c45ac78f3b0a0.tar.xz
x86: fix die() to not be preemptible
Andrew "Eagle Eye" Morton noticed that we use raw_local_save_flags() instead of raw_local_irq_save(flags) in die(). This allows the preemption of oopsing contexts - which is highly undesirable. It also causes CONFIG_DEBUG_PREEMPT to complain, as reported by Miles Lane. this bug was introduced via: commit 39743c9ef717fd4f2b5583f010115c5f2482b8ae Author: Andi Kleen <ak@suse.de> Date: Fri Oct 19 20:35:03 2007 +0200 x86: use raw locks during oopses - spin_lock_irqsave(&die.lock, flags); + __raw_spin_lock(&die.lock); + raw_local_save_flags(flags); that is not a correct open-coding of spin_lock_irqsave(): both the ordering is wrong (irqs should be disabled _first_), and the wrong flags-saving API was used. Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/traps_32.c7
1 files changed, 3 insertions, 4 deletions
diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
index ef6010262597..c88bbffcaa03 100644
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps_32.c
@@ -373,14 +373,13 @@ void die(const char * str, struct pt_regs * regs, long err)
if (die.lock_owner != raw_smp_processor_id()) {
console_verbose();
+ raw_local_irq_save(flags);
__raw_spin_lock(&die.lock);
- raw_local_save_flags(flags);
die.lock_owner = smp_processor_id();
die.lock_owner_depth = 0;
bust_spinlocks(1);
- }
- else
- raw_local_save_flags(flags);
+ } else
+ raw_local_irq_save(flags);
if (++die.lock_owner_depth < 3) {
unsigned long esp;