This is a note to let you know that I've just added the patch titled
x86/microcode/intel: Disable late loading on model 79
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-microcode-intel-disable-late-loading-on-model-79.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 723f2828a98c8ca19842042f418fb30dd8cfc0f7 Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@xxxxxxx>
Date: Wed, 18 Oct 2017 13:12:25 +0200
Subject: x86/microcode/intel: Disable late loading on model 79
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);
}
Patches currently in stable-queue which might be from bp@xxxxxxx are
queue-4.4/x86-microcode-intel-disable-late-loading-on-model-79.patch