From 36d3e4138e1b6cc9ab179f3f397b5548f8b1eaae Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Tue, 6 Jun 2023 16:11:10 -0300 Subject: [PATCH] perf script: Fix allocation of evsel->priv related to per-event dump files When printing output we may want to generate per event files, where the --per-event-dump option should be used, creating perf.data.EVENT.dump files instead of printing to stdout. The callback thar processes event thus expects that evsel->priv->fp should point to either the per-event FILE descriptor or to stdout. The a3af66f51bd0bca7 ("perf script: Fix crash because of missing evsel->priv") changeset fixed a case where evsel->priv wasn't setup, thus set to NULL, causing a segfault when trying to access evsel->priv->fp. But it did it for the non --per-event-dump case by allocating a 'struct perf_evsel_script' just to set its ->fp to stdout. Since evsel->priv is only freed when --per-event-dump is used, we ended up with a memory leak, detected using ASAN. Fix it by using the same method as perf_script__setup_per_event_dump(), and reuse that static 'struct perf_evsel_script'. Also check if evsel_script__new() failed. Fixes: a3af66f51bd0bca7 ("perf script: Fix crash because of missing evsel->priv") Reported-by: Ian Rogers Tested-by: Ian Rogers Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Ravi Bangoria Link: https://lore.kernel.org/lkml/ZH+F0wGAWV14zvMP@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-script.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c index 70549fc93b125..b02ad386a55ba 100644 --- a/tools/perf/builtin-script.c +++ b/tools/perf/builtin-script.c @@ -2410,6 +2410,9 @@ static int process_sample_event(struct perf_tool *tool, return ret; } +// Used when scr->per_event_dump is not set +static struct evsel_script es_stdout; + static int process_attr(struct perf_tool *tool, union perf_event *event, struct evlist **pevlist) { @@ -2418,7 +2421,6 @@ static int process_attr(struct perf_tool *tool, union perf_event *event, struct evsel *evsel, *pos; u64 sample_type; int err; - static struct evsel_script *es; err = perf_event__process_attr(tool, event, pevlist); if (err) @@ -2428,14 +2430,13 @@ static int process_attr(struct perf_tool *tool, union perf_event *event, evsel = evlist__last(*pevlist); if (!evsel->priv) { - if (scr->per_event_dump) { + if (scr->per_event_dump) { evsel->priv = evsel_script__new(evsel, scr->session->data); - } else { - es = zalloc(sizeof(*es)); - if (!es) + if (!evsel->priv) return -ENOMEM; - es->fp = stdout; - evsel->priv = es; + } else { // Replicate what is done in perf_script__setup_per_event_dump() + es_stdout.fp = stdout; + evsel->priv = &es_stdout; } } @@ -2741,7 +2742,6 @@ static int perf_script__fopen_per_event_dump(struct perf_script *script) static int perf_script__setup_per_event_dump(struct perf_script *script) { struct evsel *evsel; - static struct evsel_script es_stdout; if (script->per_event_dump) return perf_script__fopen_per_event_dump(script);