4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Borislav Petkov <bp@xxxxxxx> commit 84749d83758af6576552046b215b9b7f37f9556b upstream. 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@xxxxxxxx> Signed-off-by: Borislav Petkov <bp@xxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Tested-by: Vitezslav Samel <vitezslav@xxxxxxxx> Tested-by: Ashok Raj <ashok.raj@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/20180418081140.GA2439@xxxxxxxxxxxxxx Link: https://lkml.kernel.org/r/20180421081930.15741-1-bp@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/cpu/microcode/intel.c | 2 -- 1 file changed, 2 deletions(-) --- 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, un show_saved_mc(); mutex_unlock(&x86_cpu_microcode_mutex); -#endif } static bool load_builtin_intel_microcode(struct cpio_data *cp)
