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

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Tuesday, March 29, 2011, Xiaotian Feng wrote:
> 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@redhat.com>
> Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> 
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>

Acked-by: Rafael J. Wysocki <rjw@sisk.pl>

> ---
>  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);
>