Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6f7f4185 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'perf-fixes-for-linus' of... 

Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ring_buffer: Off-by-one and duplicate events in ring_buffer_read_page
parents 82cd19cd e1e35927

kernel/trace/ring_buffer.c

+8 −1
Original line number Original line Diff line number Diff line
@@ -3853,6 +3853,13 @@ int ring_buffer_read_page(struct ring_buffer *buffer, 




		/* Need to copy one event at a time */

		/* Need to copy one event at a time */

		do {

		do {

			/* We need the size of one event, because

			 * rb_advance_reader only advances by one event,

			 * whereas rb_event_ts_length may include the size of

			 * one or two events.

			 * We have already ensured there's enough space if this

			 * is a time extend. */

			size = rb_event_length(event);

			memcpy(bpage->data + pos, rpage->data + rpos, size);

			memcpy(bpage->data + pos, rpage->data + rpos, size);





			len -= size;

			len -= size;
@@ -3867,7 +3874,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer, 
			event = rb_reader_event(cpu_buffer);

			event = rb_reader_event(cpu_buffer);

			/* Always keep the time extend and data together */

			/* Always keep the time extend and data together */

			size = rb_event_ts_length(event);

			size = rb_event_ts_length(event);

		} while (len > size);

		} while (len >= size);





		/* update bpage */

		/* update bpage */

		local_set(&bpage->commit, pos);

		local_set(&bpage->commit, pos);