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.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 72f4a11d
......@@ -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;
}
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment