Merge drm/drm-next into drm-misc-next

Backmerging to get drm-misc-next up to v7.3-rc2. Requested for
commit 3a2c4d55e32a ("treewide: refresh kmalloc_obj() conversions").

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

1 files changed, 12 insertions, 13 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index a6c8e38a3110..33210aff3ee6 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7029,7 +7029,6 @@ static void perf_mmap_close(struct vm_area_struct *vma)
 	mapped_f unmapped = get_mapped(event, event_unmapped);
 	struct perf_buffer *rb = ring_buffer_get(event);
 	struct user_struct *mmap_user = rb->mmap_user;
-	bool detach_rest = false;
 
 	/* FIXIES vs perf_pmu_unregister() */
 	if (unmapped)
@@ -7060,17 +7059,18 @@ static void perf_mmap_close(struct vm_area_struct *vma)
 		mutex_unlock(&rb->aux_mutex);
 	}
 
-	if (refcount_dec_and_test(&rb->mmap_count))
-		detach_rest = true;
-
-	if (!refcount_dec_and_mutex_lock(&event->mmap_count, &event->mmap_mutex))
-		goto out_put;
-
-	ring_buffer_attach(event, NULL);
-	mutex_unlock(&event->mmap_mutex);
+	/*
+	 * Drop references in reverse order of perf_mmap() to prevent
+	 * rb revival after rb->mmap_count reaches zero.
+	 */
+	if (refcount_dec_and_mutex_lock(&event->mmap_count,
+					&event->mmap_mutex)) {
+		ring_buffer_attach(event, NULL);
+		mutex_unlock(&event->mmap_mutex);
+	}
 
 	/* If there's still other mmap()s of this buffer, we're done. */
-	if (!detach_rest)
+	if (!refcount_dec_and_test(&rb->mmap_count))
 		goto out_put;
 
 	/*
@@ -13558,9 +13558,8 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
 		return ERR_PTR(err);
 
 	if (has_addr_filter(event)) {
-		event->addr_filter_ranges = kcalloc(pmu->nr_addr_filters,
-						    sizeof(struct perf_addr_filter_range),
-						    GFP_KERNEL);
+		event->addr_filter_ranges = kzalloc_objs(struct perf_addr_filter_range,
+							 pmu->nr_addr_filters);
 		if (!event->addr_filter_ranges)
 			return ERR_PTR(-ENOMEM);