[PATCH AUTOSEL 5.1 098/141] perf top: Fix potential NULL pointer dereference detected by the smatch tool

Sasha Levin
2019-07-19T04:05:59Z

From: Leo Yan <leo.yan@linaro.org>

[ Upstream commit 111442cfc8abdeaa7ec1407f07ef7b3e5f76654e ]

Based on the following report from Smatch, fix the potential NULL
pointer dereference check.

tools/perf/builtin-top.c:109
perf_top__parse_source() warn: variable dereferenced before check 'he'
(see line 103)

tools/perf/builtin-top.c:233
perf_top__show_details() warn: variable dereferenced before check 'he'
(see line 228)

tools/perf/builtin-top.c
101 static int perf_top__parse_source(struct perf_top *top, struct hist_entry *he)
102 {
103 struct perf_evsel *evsel = hists_to_evsel(he->hists);
^^^^
104 struct symbol *sym;
105 struct annotation *notes;
106 struct map *map;
107 int err = -1;
108
109 if (!he || !he->ms.sym)
110 return -1;

This patch moves the values assignment after validating pointer 'he'.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Changbin Du <changbin.du@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Eric Saint-Etienne <eric.saint.etienne@oracle.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Song Liu <songliubraving@fb.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190702103420.27540-4-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/builtin-top.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index fbbb0da43abb..42e3a4d07b18 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -101,7 +101,7 @@ static void perf_top__resize(struct perf_top *top)

static int perf_top__parse_source(struct perf_top *top, struct hist_entry *he)
{
- struct perf_evsel *evsel = hists_to_evsel(he->hists);
+ struct perf_evsel *evsel;
struct symbol *sym;
struct annotation *notes;
struct map *map;
@@ -110,6 +110,8 @@ static int perf_top__parse_source(struct perf_top *top, struct hist_entry *he)
if (!he || !he->ms.sym)
return -1;

+ evsel = hists_to_evsel(he->hists);
+
sym = he->ms.sym;
map = he->ms.map;

@@ -226,7 +228,7 @@ static void perf_top__record_precise_ip(struct perf_top *top,
static void perf_top__show_details(struct perf_top *top)
{
struct hist_entry *he = top->sym_filter_entry;
- struct perf_evsel *evsel = hists_to_evsel(he->hists);
+ struct perf_evsel *evsel;
struct annotation *notes;
struct symbol *symbol;
int more;
@@ -234,6 +236,8 @@ static void perf_top__show_details(struct perf_top *top)
if (!he)
return;

+ evsel = hists_to_evsel(he->hists);
+
symbol = he->ms.sym;
notes = symbol__annotation(symbol);

--
2.20.1