[tip:perf/urgent] perf inject: The tool->read() call may pass a NULL evsel, handle it

[tip-bot for Arnaldo Carvalho de Melo <tipbot@zytor.com>]

Commit-ID:  40978e9bf2137223993e70921de2731201788049
Gitweb:     https://git.kernel.org/tip/40978e9bf2137223993e70921de2731201788049
Author:     Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Wed, 3 Jul 2019 16:02:09 -0300
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 9 Jul 2019 09:33:55 -0300

perf inject: The tool->read() call may pass a NULL evsel, handle it

Check first, as machines__deliver_event() may have
perf_evlist__id2evsel() returning NULL.

This was found while checking a report from Leo Yan that used the smatch
tool to find places where a pointer is checked before use and then,
later in the same function gets used without checking.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-muvb8xqyh0gysgfjfq35w642@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-inject.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 8e0e06d3edfc..f4591a1438b4 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -224,7 +224,7 @@ static int perf_event__repipe_sample(struct perf_tool *tool,
 				     struct perf_evsel *evsel,
 				     struct machine *machine)
 {
-	if (evsel->handler) {
+	if (evsel && evsel->handler) {
 		inject_handler f = evsel->handler;
 		return f(tool, event, sample, evsel, machine);
 	}