tools lib traceevent: Do not link broken field arg for an old ftrace event

Defer linking a newly allocated arg to print_fmt.args until all of its
field is setup so that later access to ->field.name cannot be NULL.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1345618831-9148-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index b7c2c491f61e..33fcd943f096 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -4754,20 +4754,20 @@ int pevent_parse_event(struct pevent *pevent,
                 struct print_arg *arg, **list;
 
                 /* old ftrace had no args */
-
                 list = &event->print_fmt.args;
                 for (field = event->format.fields; field; field = field->next) {
                         arg = alloc_arg();
-                        *list = arg;
-                        list = &arg->next;
                         arg->type = PRINT_FIELD;
                         arg->field.name = strdup(field->name);
                         if (!arg->field.name) {
                                 do_warning("failed to allocate field name");
                                 event->flags |= EVENT_FL_FAILED;
+                                free_arg(arg);
                                 return -1;
                         }
                         arg->field.field = field;
+                        *list = arg;
+                        list = &arg->next;
                 }
                 return 0;
         }