Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
+8
-1
+8
-1
kernel/trace/ring_buffer.c
+8
-1
kernel/trace/ring_buffer.c
···
3853
3853
3854
3854
/* Need to copy one event at a time */
3855
3855
do {
3856
+
/* We need the size of one event, because
3857
+
* rb_advance_reader only advances by one event,
3858
+
* whereas rb_event_ts_length may include the size of
3859
+
* one or two events.
3860
+
* We have already ensured there's enough space if this
3861
+
* is a time extend. */
3862
+
size = rb_event_length(event);
3856
3863
memcpy(bpage->data + pos, rpage->data + rpos, size);
3857
3864
3858
3865
len -= size;
···
3874
3867
event = rb_reader_event(cpu_buffer);
3875
3868
/* Always keep the time extend and data together */
3876
3869
size = rb_event_ts_length(event);
3877
-
} while (len > size);
3870
+
} while (len >= size);
3878
3871
3879
3872
/* update bpage */
3880
3873
local_set(&bpage->commit, pos);