[PATCH 2/3] x86/microcode: Fix the ancient deprecated microcode loading method

From: Borislav Petkov
Date: Fri Apr 05 2019 - 09:30:26 EST


From: Borislav Petkov <bp@xxxxxxx>

The commit in Fixes: added the new define UCODE_NEW to denote that an
update should happen only when newer microcode (than installed on the
system) has been found.

But it missed adjusting that for the old /dev/cpu/microcode loading
interface. Fix it.

Fixes: 2613f36ed965 ("x86/microcode: Attempt late loading only when new microcode is present")
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
---
arch/x86/kernel/cpu/microcode/core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index 5260185cbf7b..8a4a7823451a 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -418,8 +418,9 @@ static int do_microcode_update(const void __user *buf, size_t size)
if (ustate == UCODE_ERROR) {
error = -1;
break;
- } else if (ustate == UCODE_OK)
+ } else if (ustate == UCODE_NEW) {
apply_microcode_on_target(cpu);
+ }
}

return error;
--
2.21.0