1 files changed, 8 insertions, 6 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index e43c928356ee..db223fe8887f 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -486,7 +486,7 @@ struct ring_buffer_iter {
 /* Up this if you want to test the TIME_EXTENTS and normalization */
 #define DEBUG_SHIFT 0
 
-static inline u64 rb_time_stamp(struct ring_buffer *buffer, int cpu)
+static inline u64 rb_time_stamp(struct ring_buffer *buffer)
 {
         /* shift to debug/test normalization and TIME_EXTENTS */
         return buffer->clock() << DEBUG_SHIFT;
@@ -497,7 +497,7 @@ u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu)
         u64 time;
 
         preempt_disable_notrace();
-        time = rb_time_stamp(buffer, cpu);
+        time = rb_time_stamp(buffer);
         preempt_enable_no_resched_notrace();
 
         return time;
@@ -602,7 +602,7 @@ static struct list_head *rb_list_head(struct list_head *list)
 }
 
 /*
- * rb_is_head_page - test if the give page is the head page
+ * rb_is_head_page - test if the given page is the head page
  *
  * Because the reader may move the head_page pointer, we can
  * not trust what the head page is (it may be pointing to
@@ -1196,6 +1196,7 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
         atomic_inc(&cpu_buffer->record_disabled);
         synchronize_sched();
 
+        spin_lock_irq(&cpu_buffer->reader_lock);
         rb_head_page_deactivate(cpu_buffer);
 
         for (i = 0; i < nr_pages; i++) {
@@ -1210,6 +1211,7 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
                 return;
 
         rb_reset_cpu(cpu_buffer);
+        spin_unlock_irq(&cpu_buffer->reader_lock);
 
         rb_check_pages(cpu_buffer);
 
@@ -1871,7 +1873,7 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
                  * Nested commits always have zero deltas, so
                  * just reread the time stamp
                  */
-                *ts = rb_time_stamp(buffer, cpu_buffer->cpu);
+                *ts = rb_time_stamp(buffer);
                 next_page->page->time_stamp = *ts;
         }
 
@@ -2114,7 +2116,7 @@ rb_reserve_next_event(struct ring_buffer *buffer,
         if (RB_WARN_ON(cpu_buffer, ++nr_loops > 1000))
                 goto out_fail;
 
-        ts = rb_time_stamp(cpu_buffer->buffer, cpu_buffer->cpu);
+        ts = rb_time_stamp(cpu_buffer->buffer);
 
         /*
          * Only the first commit can update the timestamp.
@@ -2684,7 +2686,7 @@ unsigned long ring_buffer_entries(struct ring_buffer *buffer)
 EXPORT_SYMBOL_GPL(ring_buffer_entries);
 
 /**
- * ring_buffer_overrun_cpu - get the number of overruns in buffer
+ * ring_buffer_overruns - get the number of overruns in buffer
  * @buffer: The ring buffer
  *
  * Returns the total number of overruns in the ring buffer