4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Borislav Petkov <bp@xxxxxxx> commit 723f2828a98c8ca19842042f418fb30dd8cfc0f7 upstream. Blacklist Broadwell X model 79 for late loading due to an erratum. Signed-off-by: Borislav Petkov <bp@xxxxxxx> Acked-by: Tony Luck <tony.luck@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: http://lkml.kernel.org/r/20171018111225.25635-1-bp@xxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/cpu/microcode/intel.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) --- a/arch/x86/kernel/cpu/microcode/intel.c +++ b/arch/x86/kernel/cpu/microcode/intel.c @@ -990,6 +990,18 @@ static int get_ucode_fw(void *to, const return 0; } +static bool is_blacklisted(unsigned int cpu) +{ + struct cpuinfo_x86 *c = &cpu_data(cpu); + + if (c->x86 == 6 && c->x86_model == 79) { + pr_err_once("late loading on model 79 is disabled.\n"); + return true; + } + + return false; +} + static enum ucode_state request_microcode_fw(int cpu, struct device *device, bool refresh_fw) { @@ -998,6 +1010,9 @@ static enum ucode_state request_microcod const struct firmware *firmware; enum ucode_state ret; + if (is_blacklisted(cpu)) + return UCODE_NFOUND; + sprintf(name, "intel-ucode/%02x-%02x-%02x", c->x86, c->x86_model, c->x86_mask); @@ -1022,6 +1037,9 @@ static int get_ucode_user(void *to, cons static enum ucode_state request_microcode_user(int cpu, const void __user *buf, size_t size) { + if (is_blacklisted(cpu)) + return UCODE_NFOUND; + return generic_load_microcode(cpu, (void *)buf, size, &get_ucode_user); }