4.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> commit 5b0bc9ac2ce4881ee318a21f31140584ce4dbdad upstream. During early boot, load_ucode_intel_ap() uses __load_ucode_intel() to obtain a pointer to the relevant microcode patch (embedded in the initrd), and stores this value in 'intel_ucode_patch' to speed up the microcode patch application for subsequent CPUs. On resuming from suspend-to-RAM, however, load_ucode_ap() calls load_ucode_intel_ap() for each non-boot-CPU. By then the initramfs is long gone so the pointer stored in 'intel_ucode_patch' no longer points to a valid microcode patch. Clear that pointer so that we effectively fall back to the CPU hotplug notifier callbacks to update the microcode. Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> [ Edit and massage commit message. ] Signed-off-by: Borislav Petkov <bp@xxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20170607095819.9754-1-bp@xxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/cpu/microcode/intel.c | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -619,6 +619,9 @@ int __init save_microcode_in_initrd_inte show_saved_mc(); + /* initrd is going away, clear patch ptr. */ + intel_ucode_patch = NULL; + return 0; }