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SubjectRe: [PATCH 1/2] x86/microcode/intel: Save microcode patch unconditionally
On Fri, Apr 20, 2018 at 12:34:28PM +0200, Borislav Petkov wrote:
> save_mc_for_early() was a no-op on !CONFIG_HOTPLUG_CPU but the
> generic_load_microcode() path saves the microcode patches it has found
> into our cache of patches which is used for late loading too. Regardless
> of whether we do CPU hotplug or not.
>
> So make the saving unconditional so that late loading can find the
> proper patch.
>
> Reported-by: Vitezslav Samel <vitezslav@samel.cz>

Tested-by: Vitezslav Samel <vitezslav@samel.cz>

> Signed-off-by: Borislav Petkov <bp@suse.de>
> Cc: Ashok Raj <ashok.raj@intel.com>
> Cc: <stable@vger.kernel.org> # if it has backported d8c3b52c00a05036e0a6b315b4b17921a7b67997
> Link: http://lkml.kernel.org/r/20180418081140.GA2439@pc11.op.pod.cz
> ---
> arch/x86/kernel/cpu/microcode/intel.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
> index 32b8e5724f96..1c2cfa0644aa 100644
> --- a/arch/x86/kernel/cpu/microcode/intel.c
> +++ b/arch/x86/kernel/cpu/microcode/intel.c
> @@ -485,7 +485,6 @@ static void show_saved_mc(void)
> */
> static void save_mc_for_early(u8 *mc, unsigned int size)
> {
> -#ifdef CONFIG_HOTPLUG_CPU
> /* Synchronization during CPU hotplug. */
> static DEFINE_MUTEX(x86_cpu_microcode_mutex);
>
> @@ -495,7 +494,6 @@ static void save_mc_for_early(u8 *mc, unsigned int size)
> show_saved_mc();
>
> mutex_unlock(&x86_cpu_microcode_mutex);
> -#endif
> }
>
> static bool load_builtin_intel_microcode(struct cpio_data *cp)
> --
> 2.13.0
>
> SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
> --

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