[tip:perf/urgent] perf trace: Handle perf.data files with no tracepoints

tip-bot for Arnaldo Carvalho de Melo
2013-09-12T11:11:24Z

Commit-ID: ccf53eac2097fb47bc40875ffb22c2d10fa8c46c
Gitweb: http://git.kernel.org/tip/ccf53eac2097fb47bc40875ffb22c2d10fa8c46c
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Fri, 6 Sep 2013 15:19:01 -0300
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 9 Sep 2013 15:50:44 -0300

perf trace: Handle perf.data files with no tracepoints

Before:

perf trace -i perf.data
Segmentation fault (core dumped)
#

After:

# perf trace -i perf.data
Data file does not have raw_syscalls:sys_enter events
#

When there are no tracepoints in a perf.data file the struct pevent
that contains the list of tracepoints that will be used to lookup the
tracepoint id by name will not be populated, causing a NULL deref.

And we don't need to do all that dance to look at pevents for an entry
with a slighly different name to then lookup the tracepoint by its id on
the evlist, just use the perf_evlist__find_tracepoint_by_name() routine,
that will find the tracepoint, if present.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-egcm21k1e6gcyxpcgjxtmsq3@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/session.c | 40 +++++++---------------------------------
1 file changed, 7 insertions(+), 33 deletions(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 476caa1..0308d9e 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1620,52 +1620,26 @@ int __perf_session__set_tracepoints_handlers(struct perf_session *session,
const struct perf_evsel_str_handler *assocs,
size_t nr_assocs)
{
- struct perf_evlist *evlist = session->evlist;
- struct event_format *format;
struct perf_evsel *evsel;
- char *tracepoint, *name;
size_t i;
int err;

for (i = 0; i < nr_assocs; i++) {
- err = -ENOMEM;
- tracepoint = strdup(assocs[i].name);
- if (tracepoint == NULL)
- goto out;
-
- err = -ENOENT;
- name = strchr(tracepoint, ':');
- if (name == NULL)
- goto out_free;
-
- *name++ = '\0';
- format = pevent_find_event_by_name(session->pevent,
- tracepoint, name);
- if (format == NULL) {
- /*
- * Adding a handler for an event not in the session,
- * just ignore it.
- */
- goto next;
- }
-
- evsel = perf_evlist__find_tracepoint_by_id(evlist, format->id);
+ /*
+ * Adding a handler for an event not in the session,
+ * just ignore it.
+ */
+ evsel = perf_evlist__find_tracepoint_by_name(session->evlist, assocs[i].name);
if (evsel == NULL)
- goto next;
+ continue;

err = -EEXIST;
if (evsel->handler.func != NULL)
- goto out_free;
+ goto out;
evsel->handler.func = assocs[i].handler;
-next:
- free(tracepoint);
}

err = 0;
out:
return err;
-
-out_free:
- free(tracepoint);
- goto out;
}