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authorJan Kiszka <jan.kiszka@siemens.com>2008-10-06 13:50:59 -0500
committerJason Wessel <jason.wessel@windriver.com>2008-10-06 13:50:59 -0500
commite85ceae9102f6e3c1d707e7ac88fa48d252e9cfa (patch)
treec0ea708310452d42b35ea3eb422654fc4fd1f778
parentfec6ed1d1f9b78a6acb4a3eb2c46c812ac2e96f0 (diff)
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kgdb, x86: Avoid invoking kgdb_nmicallback twice per NMI
Stress-testing KVM's latest NMI support with kgdbts inside an SMP guest, I came across spurious unhandled NMIs while running the singlestep test. Looking closer at the code path each NMI takes when KGDB is enabled, I noticed that kgdb_nmicallback is called twice per event: One time via DIE_NMI_IPI notification, the second time on DIE_NMI. Removing the first invocation cures the unhandled NMIs here. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
-rw-r--r--arch/x86/kernel/kgdb.c7
1 files changed, 1 insertions, 6 deletions
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 8282a21..10435a1 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -455,12 +455,7 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd)
return NOTIFY_DONE;
case DIE_NMI_IPI:
- if (atomic_read(&kgdb_active) != -1) {
- /* KGDB CPU roundup */
- kgdb_nmicallback(raw_smp_processor_id(), regs);
- was_in_debug_nmi[raw_smp_processor_id()] = 1;
- touch_nmi_watchdog();
- }
+ /* Just ignore, we will handle the roundup on DIE_NMI. */
return NOTIFY_DONE;
case DIE_NMIUNKNOWN:
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