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authorPaolo Bonzini <pbonzini@redhat.com>2019-08-09 16:53:39 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2019-08-09 16:53:39 +0200
commit0e1c438c44dd9cde56effb44c5f1cfeda72e108d (patch)
treefa3492d4d7d8b7444e5d8ebe6c78210826333e4b /kernel/padata.c
parentc096397c78f766db972f923433031f2dec01cae0 (diff)
parentcdb2d3ee0436d74fa9092f2df46aaa6f9e03c969 (diff)
Merge tag 'kvmarm-fixes-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm fixes for 5.3 - A bunch of switch/case fall-through annotation, fixing one actual bug - Fix PMU reset bug - Add missing exception class debug strings
Diffstat (limited to 'kernel/padata.c')
-rw-r--r--kernel/padata.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/kernel/padata.c b/kernel/padata.c
index 2d2fddbb7a4ce..15a8ad63f4ffe 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -267,7 +267,12 @@ static void padata_reorder(struct parallel_data *pd)
* The next object that needs serialization might have arrived to
* the reorder queues in the meantime, we will be called again
* from the timer function if no one else cares for it.
+ *
+ * Ensure reorder_objects is read after pd->lock is dropped so we see
+ * an increment from another task in padata_do_serial. Pairs with
+ * smp_mb__after_atomic in padata_do_serial.
*/
+ smp_mb();
if (atomic_read(&pd->reorder_objects)
&& !(pinst->flags & PADATA_RESET))
mod_timer(&pd->timer, jiffies + HZ);
@@ -387,6 +392,13 @@ void padata_do_serial(struct padata_priv *padata)
list_add_tail(&padata->list, &pqueue->reorder.list);
spin_unlock(&pqueue->reorder.lock);
+ /*
+ * Ensure the atomic_inc of reorder_objects above is ordered correctly
+ * with the trylock of pd->lock in padata_reorder. Pairs with smp_mb
+ * in padata_reorder.
+ */
+ smp_mb__after_atomic();
+
put_cpu();
/* If we're running on the wrong CPU, call padata_reorder() via a