Commit 84749d83 authored Apr 21, 2018 by Borislav Petkov Committed by Thomas Gleixner Apr 24, 2018

x86/microcode/intel: Save microcode patch unconditionally



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
the cache of patches which is used for late loading too. Regardless of
whether CPU hotplug is used or not.

Make the saving unconditional so that late loading can find the proper
patch.

Reported-by: Vitezslav Samel <vitezslav@samel.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vitezslav Samel <vitezslav@samel.cz>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180418081140.GA2439@pc11.op.pod.cz
Link: https://lkml.kernel.org/r/20180421081930.15741-1-bp@alien8.de

parent 7010adcd

arch/x86/kernel/cpu/microcode/intel.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -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)