[xen stable-4.16] x86/ucode: Fix error paths control_thread_fn()

[patchbot@xxxxxxx]

commit 0f81c5a2c8e0432d5af3d9f4e6398376cd514516
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Fri Mar 31 08:40:56 2023 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Mar 31 08:40:56 2023 +0200

    x86/ucode: Fix error paths control_thread_fn()
    
    These two early exits skipped re-enabling the watchdog, restoring the NMI
    callback, and clearing the nmi_patch global pointer.  Always execute the 
tail
    of the function on the way out.
    
    Fixes: 8dd4dfa92d62 ("x86/microcode: Synchronize late microcode loading")
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Sergey Dyasli <sergey.dyasli@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    master commit: fc2e1f3aad602a66c14b8285a1bd38a82f8fd02d
    master date: 2023-03-28 11:57:56 +0100
---
 xen/arch/x86/cpu/microcode/core.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/xen/arch/x86/cpu/microcode/core.c 
b/xen/arch/x86/cpu/microcode/core.c
index ee7df9a591..ad150e5963 100644
--- a/xen/arch/x86/cpu/microcode/core.c
+++ b/xen/arch/x86/cpu/microcode/core.c
@@ -488,10 +488,7 @@ static int control_thread_fn(const struct microcode_patch 
*patch)
     ret = wait_for_condition(wait_cpu_callin, num_online_cpus(),
                              MICROCODE_CALLIN_TIMEOUT_US);
     if ( ret )
-    {
-        set_state(LOADING_EXIT);
-        return ret;
-    }
+        goto out;
 
     /* Control thread loads ucode first while others are in NMI handler. */
     ret = microcode_ops->apply_microcode(patch);
@@ -503,8 +500,7 @@ static int control_thread_fn(const struct microcode_patch 
*patch)
     {
         printk(XENLOG_ERR
                "Late loading aborted: CPU%u failed to update ucode\n", cpu);
-        set_state(LOADING_EXIT);
-        return ret;
+        goto out;
     }
 
     /* Let primary threads load the given ucode update */
@@ -535,6 +531,7 @@ static int control_thread_fn(const struct microcode_patch 
*patch)
         }
     }
 
+ out:
     /* Mark loading is done to unblock other threads */
     set_state(LOADING_EXIT);
 
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.16