[xen master] arinc653: move next_switch_time access under lock

[patchbot@xxxxxxx]

commit 28fa31d6bb7835be530c2855dd6cf4e77438ae12
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Tue Mar 25 09:23:48 2025 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Mar 25 09:23:48 2025 +0100

    arinc653: move next_switch_time access under lock
    
    Even before its recent movement to the scheduler's private data
    structure it looks to have been wrong to update the field under lock,
    but then read it with the lock no longer held.
    
    Coverity-ID: 1644500
    Fixes: 9f0c658baedc ("arinc: add cpu-pool support to scheduler")
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Nathan Studer <nathan.studer@xxxxxxxxxxxxxxx>
---
 xen/common/sched/arinc653.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/xen/common/sched/arinc653.c b/xen/common/sched/arinc653.c
index 930361fa5c..432ccfe662 100644
--- a/xen/common/sched/arinc653.c
+++ b/xen/common/sched/arinc653.c
@@ -580,6 +580,9 @@ a653sched_do_schedule(
      */
     BUG_ON(now >= sched_priv->next_major_frame);
 
+    /* Return the amount of time the next domain has to run. */
+    prev->next_time = sched_priv->next_switch_time - now;
+
     spin_unlock_irqrestore(&sched_priv->lock, flags);
 
     /* Tasklet work (which runs in idle UNIT context) overrides all else. */
@@ -591,11 +594,7 @@ a653sched_do_schedule(
          && (sched_unit_master(new_task) != cpu) )
         new_task = IDLETASK(cpu);
 
-    /*
-     * Return the amount of time the next domain has to run and the address
-     * of the selected task's UNIT structure.
-     */
-    prev->next_time = sched_priv->next_switch_time - now;
+    /* Also return the address of the selected task's UNIT structure. */
     prev->next_task = new_task;
     new_task->migrated = false;
 
--
generated by git-patchbot for /home/xen/git/xen.git#master