Re: [PATCH] event: fix TP_printk() argument in sched_switch

[Steven Rostedt <rostedt@goodmis.org>]

On Wed, 2011-11-02 at 19:07 -0400, Steven Rostedt wrote:
> On Thu, 2011-11-03 at 01:40 +0300, Andrew Vagin wrote:
> > process_arg(...) can't parse "__entry->prev_state & (TASK_STATE_MAX-1)",
> > because a complicated argument should be within brackets.
> 
> No it is fine, the userspace tool is broken.
> 
> > 
> > Without this patch "perf report" prints following errors:
> > $ ./perf record -ag -e sched:sched_switch
> > ...
> > $ ./perf report
> >   Warning: Error: expected type 5 but read 4
> >   Warning: Error: expected type 4 but read 0
> >   Fatal: bad op token {
> > 
> > Signed-off-by: Andrew Vagin <avagin@openvz.org>
> 
> NACK!
> 
> This is a perf userspace bug, not a kernel one. Please fix the userspace
> tool instead.
> 
> Note, the new version of libparsevent handles this case without issue.
> Perf just needs to be updated.
> 

Can you try this patch on perf. It's untested (not even compiled tested)

-- Steve

diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 0a7ed5b..6c164dc 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -1537,6 +1537,8 @@ process_flags(struct event *event, struct print_arg *arg, char **tok)
 	field = malloc_or_die(sizeof(*field));
 
 	type = process_arg(event, field, &token);
+	while (type == EVENT_OP)
+		type = process_op(event, field, &token);
 	if (test_type_token(type, token, EVENT_DELIM, ","))
 		goto out_free;