Em Fri, Feb 10, 2017 at 02:14:08PM -0500, Steven Rostedt escreveu: > On Fri, 10 Feb 2017 14:03:17 -0300 > Arnaldo Carvalho de Melo <[email protected]> wrote: > > + case OLD_RINGBUF_TYPE_TIME_EXTEND: > > + extend = read_4(kbuf, ptr); > > + extend <<= TS_SHIFT; > > + extend += delta; > > + delta = extend; > > + ptr += 4; > > + /* Fall through */ > No, actually, the length should be zeroed here. > length = 0; > As the ptr is placed passed the metadata. At the end of this case > statement, the ptr will be after the metadata. The length is > to represent the length of the data that is part of the event. The > index is the ptr - start_data + length. As there's no data to this type > of event, it should be zero. > When I add length = 0, I get more events from my old 2.6.30 trace.dat > file :-/ I'll have to update my tests. > Care to send another patch?
I have this now in my tree, and since the patch is basically yours, I just made myself the reporter and you the author, please ack. commit 1fb82b6cba967afde11957099a9ef440cf8c2248 Author: Steven Rostedt <[email protected]> Date: Mon Feb 13 13:18:29 2017 -0300 tools lib traceevent: Initialize lenght on OLD_RING_BUFFER_TYPE_TIME_STAMP A undefined value was being used for the OLD_RING_BUFFER_TYPE_TIME_STAMP case entry, as the 'lenght' variable was not being initialized, fix it. Caught by the reporter when building tools/perf/ using clang, which emmitted this warning: kbuffer-parse.c:312:7: warning: variable 'length' is used uninitialized whenever switch case is taken [-Wsometimes-uninitialized] case OLD_RINGBUF_TYPE_TIME_EXTEND: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ kbuffer-parse.c:339:29: note: uninitialized use occurs here kbuf->next = kbuf->index + length; ^~~~~~ kbuffer-parse.c:297:21: note: initialize the variable 'length' to silence this warning unsigned int length; ^ = 0 Reported-by: Arnaldo Carvalho de Melo <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Steven Rostedt <[email protected]> diff --git a/tools/lib/traceevent/kbuffer-parse.c b/tools/lib/traceevent/kbuffer-parse.c index 65984f1c2974..2009cb7d9675 100644 --- a/tools/lib/traceevent/kbuffer-parse.c +++ b/tools/lib/traceevent/kbuffer-parse.c @@ -315,6 +315,7 @@ static unsigned int old_update_pointers(struct kbuffer *kbuf) extend += delta; delta = extend; ptr += 4; + lenght = 0; break; case OLD_RINGBUF_TYPE_TIME_STAMP:
