tools lib traceevent: Make sure that arg->op.right is set properly

When process_op failed, @arg will be freed on a caller with type of
PRINT_OP.  Thus free_arg() will try to free ->op.right field which can
have stale value if something bad happens in the middle.

Signed-off-by: Namhyung Kim <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 6270ee2e98308cf0f8e786bd75d8beb842445dc4..27088c55af1bbc03ed1b6ebaac1d0fd3ef7dc21b 100644 (file)
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -1719,6 +1719,7 @@ process_op(struct event_format *event, struct print_arg *arg, char **tok)
                arg->op.left = left;
                arg->op.prio = 0;
 
+               /* it will set arg->op.right */
                type = process_cond(event, arg, tok);
 
        } else if (strcmp(token, ">>") == 0 ||
@@ -1745,6 +1746,7 @@ process_op(struct event_format *event, struct print_arg *arg, char **tok)
                arg->type = PRINT_OP;
                arg->op.op = token;
                arg->op.left = left;
+               arg->op.right = NULL;
 
                if (set_op_prio(arg) == -1) {
                        event->flags |= EVENT_FL_FAILED;
@@ -1792,6 +1794,7 @@ process_op(struct event_format *event, struct print_arg *arg, char **tok)
 
                arg->op.prio = 0;
 
+               /* it will set arg->op.right */
                type = process_array(event, arg, tok);
 
        } else {