1 files changed, 14 insertions, 0 deletions

diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 232f00f273cb..725c416085e3 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -493,6 +493,20 @@ int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
                         rb->aux_pages[rb->aux_nr_pages] = page_address(page++);
         }
 
+        /*
+         * In overwrite mode, PMUs that don't support SG may not handle more
+         * than one contiguous allocation, since they rely on PMI to do double
+         * buffering. In this case, the entire buffer has to be one contiguous
+         * chunk.
+         */
+        if ((event->pmu->capabilities & PERF_PMU_CAP_AUX_NO_SG) &&
+            overwrite) {
+                struct page *page = virt_to_page(rb->aux_pages[0]);
+
+                if (page_private(page) != max_order)
+                        goto out;
+        }
+
         rb->aux_priv = event->pmu->setup_aux(event->cpu, rb->aux_pages, nr_pages,
                                              overwrite);
         if (!rb->aux_priv)