summaryrefslogtreecommitdiff
path: root/kernel/trace/ring_buffer.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index ec01803e0a55..4cb5e5147165 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -3783,12 +3783,17 @@ void
ring_buffer_read_finish(struct ring_buffer_iter *iter)
{
struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
+ unsigned long flags;
/*
* Ring buffer is disabled from recording, here's a good place
- * to check the integrity of the ring buffer.
+ * to check the integrity of the ring buffer.
+ * Must prevent readers from trying to read, as the check
+ * clears the HEAD page and readers require it.
*/
+ raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
rb_check_pages(cpu_buffer);
+ raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
atomic_dec(&cpu_buffer->record_disabled);
atomic_dec(&cpu_buffer->buffer->resize_disabled);