This is a note to let you know that I've just added the patch titled
x86/microcode: Print previous version of microcode after reload
to the 5.15-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-print-previous-version-of-microcode-af.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b460baf3fca096323297ebf1a36ad2e91923260d
Author: Ashok Raj <ashok.raj@xxxxxxxxx>
Date: Mon Aug 29 18:10:30 2022 +0000
x86/microcode: Print previous version of microcode after reload
[ Upstream commit 7fce8d6eccbc31a561d07c79f359ad09f0424347 ]
Print both old and new versions of microcode after a reload is complete
because knowing the previous microcode version is sometimes important
from a debugging perspective.
[ bp: Massage commit message. ]
Signed-off-by: Ashok Raj <ashok.raj@xxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Acked-by: Tony Luck <tony.luck@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220829181030.722891-1-ashok.raj@xxxxxxxxx
Stable-dep-of: c0dd9245aa9e ("x86/microcode: Check CPU capabilities after late microcode update correctly")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index dc346bbb06777..a7fc2d47a4ace 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -508,7 +508,7 @@ static int __reload_late(void *info)
*/
static int microcode_reload_late(void)
{
- int ret;
+ int old = boot_cpu_data.microcode, ret;
atomic_set(&late_cpus_in, 0);
atomic_set(&late_cpus_out, 0);
@@ -517,7 +517,8 @@ static int microcode_reload_late(void)
if (ret == 0)
microcode_check();
- pr_info("Reload completed, microcode revision: 0x%x\n", boot_cpu_data.microcode);
+ pr_info("Reload completed, microcode revision: 0x%x -> 0x%x\n",
+ old, boot_cpu_data.microcode);
return ret;
}
