[PATCH] perf tools: Fix use before NULL check introduced by map__dso() introduction - CoreSight

18 Apr 2023

James Clark noticed that the recent 63df0e4bc368adbd ("perf map: Add
accessor for dso") patch accessed map->dso before the 'map' variable was
NULL checked, which is a change in logic that leads to segmentation
faults, so comb thru that patch to fix similar cases.
Fixes: 63df0e4bc368adbd ("perf map: Add accessor for dso")
Cc: Adrian Hunter adrian.hunter@intel.com
Cc: Alexander Shishkin alexander.shishkin@linux.intel.com
Cc: Ian Rogers irogers@google.com
Cc: Ingo Molnar mingo@redhat.com
Cc: Jiri Olsa jolsa@kernel.org
Cc: John Garry john.g.garry@oracle.com
Cc: Leo Yan leo.yan@linaro.org
Cc: Mark Rutland mark.rutland@arm.com
Cc: Mathieu Poirier mathieu.poirier@linaro.org
Cc: Mike Leach mike.leach@linaro.org
Cc: Namhyung Kim namhyung@kernel.org
Cc: Peter Zijlstra <peterz@infradead.org
Cc: Suzuki K Poulose suzuki.poulose@arm.com
Cc: Will Deacon will@kernel.org
To: James Clark james.clark@arm.com
Link: https://lore.kernel.org/lkml/
Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com
---
 tools/perf/builtin-script.c    | 7 +++----
 tools/perf/ui/browsers/hists.c | 4 ++--
 tools/perf/util/sort.c         | 2 +-
 3 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 8fba247b798ca307..006f522d0e7f6a18 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -1075,8 +1075,7 @@ static int grab_bb(u8 *buffer, u64 start, u64 end,
    	return 0;
    }
-	dso = map__dso(al.map);
-	if (!thread__find_map(thread, *cpumode, start, &al) || !dso) {
+	if (!thread__find_map(thread, *cpumode, start, &al) || (dso = map__dso(al.map)) == NULL) {
    	pr_debug("\tcannot resolve %" PRIx64 "-%" PRIx64 "\n", start, end);
    	return 0;
    }
@@ -1106,9 +1105,9 @@ static int map__fprintf_srccode(struct map *map, u64 addr, FILE *fp, struct srcc
    unsigned line;
    int len;
    char *srccode;
-	struct dso *dso = map__dso(map);
+	struct dso *dso;
-	if (!map || !dso)
+	if (!map || (dso = map__dso(map)) == NULL)
    	return 0;
    srcfile = get_srcline_split(dso,
    			    map__rip_2objdump(map, addr),
diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index ab70e5f5fad236e5..69c81759a64f938f 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -2499,9 +2499,9 @@ add_annotate_opt(struct hist_browser *browser __maybe_unused,
    	 struct map_symbol *ms,
    	 u64 addr)
 {
-	struct dso *dso = map__dso(ms->map);
+	struct dso *dso;
-	if (!ms->map || !dso || dso->annotate_warned)
+	if (!ms->map || (dso = map__dso(ms->map)) == NULL || dso->annotate_warned)
    	return 0;
if (!ms->sym)
diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c
index f2ffaf90648e469e..31b1cd0935e277ba 100644
--- a/tools/perf/util/sort.c
+++ b/tools/perf/util/sort.c
@@ -1568,7 +1568,7 @@ static int hist_entry__dcacheline_snprintf(struct hist_entry *he, char *bf,
if (he->mem_info) {
    	struct map *map = he->mem_info->daddr.ms.map;
-		struct dso *dso = map__dso(map);
+		struct dso *dso = map ? map__dso(map) : NULL;
addr = cl_address(he->mem_info->daddr.al_addr, chk_double_cl);
    	ms = &he->mem_info->daddr.ms;
-- 
2.39.2


    