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| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2015-11-23 17:35:24 -0500 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2015-11-24 09:27:25 -0500 |
| commit | bd1b7cd360f529394936f28746eb4aaa12d6770a (patch) | |
| tree | 7ff2c87020172dee449997bda223f1900b43a5f3 /kernel | |
| parent | b81f472a208d3e2b4392faa6d17037a89442f4ce (diff) | |
| download | linux-bd1b7cd360f529394936f28746eb4aaa12d6770a.tar.bz2 | |
ring-buffer: Put back the length if crossed page with add_timestamp
Commit fcc742eaad7c "ring-buffer: Add event descriptor to simplify passing
data" added a descriptor that holds various data instead of passing around
several variables through parameters. The problem was that one of the
parameters was modified in a function and the code was designed not to have
an effect on that modified parameter. Now that the parameter is a
descriptor and any modifications to it are non-volatile, the size of the
data could be unnecessarily expanded.
Remove the extra space added if a timestamp was added and the event went
across the page.
Cc: stable@vger.kernel.org # 4.3+
Fixes: fcc742eaad7c "ring-buffer: Add event descriptor to simplify passing data"
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 4dd6d5bc4e11..9c6045a27ba3 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2797,8 +2797,11 @@ rb_reserve_next_event(struct ring_buffer *buffer, event = __rb_reserve_next(cpu_buffer, &info); - if (unlikely(PTR_ERR(event) == -EAGAIN)) + if (unlikely(PTR_ERR(event) == -EAGAIN)) { + if (info.add_timestamp) + info.length -= RB_LEN_TIME_EXTEND; goto again; + } if (!event) goto out_fail; |