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| author | Jan Kiszka <jan.kiszka@siemens.com> | 2008-10-06 20:50:59 +0200 |
|---|---|---|
| committer | Jason Wessel <jason.wessel@windriver.com> | 2008-10-06 20:50:59 +0200 |
| commit | e85ceae9102f6e3c1d707e7ac88fa48d252e9cfa (patch) | |
| tree | c0ea708310452d42b35ea3eb422654fc4fd1f778 | |
| parent | Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/k... (diff) | |
| download | linux-e85ceae9102f6e3c1d707e7ac88fa48d252e9cfa.tar.xz linux-e85ceae9102f6e3c1d707e7ac88fa48d252e9cfa.zip | |
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.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index 8282a2139681..10435a120d22 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: |