[PATCH] x86, microcode: unregister syscore_ops after microcode unloaded

From: Xiaotian Feng
Date: Tue Mar 29 2011 - 04:35:41 EST


Currently, microcode doesn't unregister syscore_ops after it's unloaded.
So if we modprobe then rmmod microcode, the stale microcode syscore_ops info
will stay on syscore_ops_list. Later when we're trying to reboot/halt/shutdown
the machine, kernel will panic on syscore_shutdown(). With the patch
applied, I can reboot/halt/shutdown my machine successfully.

Signed-off-by: Xiaotian Feng <dfeng@xxxxxxxxxx>
Cc: Tigran Aivazian <tigran@xxxxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxx>
---
arch/x86/kernel/microcode_core.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c
index 5ed0ab5..f924280 100644
--- a/arch/x86/kernel/microcode_core.c
+++ b/arch/x86/kernel/microcode_core.c
@@ -550,6 +550,7 @@ static void __exit microcode_exit(void)
microcode_dev_exit();

unregister_hotcpu_notifier(&mc_cpu_notifier);
+ unregister_syscore_ops(&mc_syscore_ops);

get_online_cpus();
mutex_lock(&microcode_mutex);
--
1.7.1

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