From: Tom Zanussi Date: Mon, 25 Apr 2016 19:01:27 +0000 (-0500) Subject: tracing: Add check for NULL event field when creating hist field X-Git-Tag: v4.7-rc1~125^2~12 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=432480c58219eff32904b879eb3fcc1d268a3b06;p=karo-tx-linux.git tracing: Add check for NULL event field when creating hist field Smatch flagged create_hist_field() as possibly being able to dereference a NULL pointer, although the current code exits in all cases where the event field could be NULL, so it's not actually a problem. Still, to prevent future changes to the code from overlooking new cases, make the NULL pointer check explicit and warn once in that case. Link: http://lkml.kernel.org/r/cfbc003f534a3e441b4313272fd412310aba6336.1461610073.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index f98b6b3a2804..0c05b8a99806 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -371,6 +371,9 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, goto out; } + if (WARN_ON_ONCE(!field)) + goto out; + if (is_string_field(field)) { flags |= HIST_FIELD_FL_STRING;