x86/microcode: Don't return error if microcode update is not needed

Commit 347b54683 ("x86/microcode: Synchronize late microcode loading")
incorrectly returns -EINVAL error on all request_microcode_fw() failures
in reload_store(). In fact, when update is not needed or if there is no
microcode to load we don't need to treat this as an error.

Orabug: 29759756

Fixes: 347b54683 ("x86/microcode: Synchronize late microcode loading")
Reported-by: Jamie Iles <jamie.iles@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Reviewed-by: Jamie Iles <jamie.iles@oracle.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Bhavesh Davda <bhavesh.davda@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: John Haxby <john.haxby@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index a60cb1ada21d3422450b1d17a0409318040afbc2..5ed127679798a4f90319333fe40701421c711a8c 100644 (file)
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -475,7 +475,7 @@ static ssize_t reload_store(struct device *dev,
 
        for_each_online_cpu(cpu) {
                ret = microcode_ops->request_microcode_fw(cpu, &microcode_pdev->dev, true);
-               if (ret != UCODE_OK) {
+               if (ret == UCODE_ERROR) {
                        ret = -EINVAL;
                        goto out;
                }