From 7bc0153c53bc1ef96e5d1ffb039d9070a944966b Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 4 Aug 2023 13:18:38 -0300 Subject: [PATCH] perf probe: Free string returned by synthesize_perf_probe_point() on failure to add a probe Building perf with EXTRA_CFLAGS="-fsanitize=address" a leak is detect when trying to add a probe to a non-existent function: # perf probe -x ~/bin/perf dso__neW Probe point 'dso__neW' not found. Error: Failed to add events. ================================================================= ==296634==ERROR: LeakSanitizer: detected memory leaks Direct leak of 128 byte(s) in 1 object(s) allocated from: #0 0x7f67642ba097 in calloc (/lib64/libasan.so.8+0xba097) #1 0x7f67641a76f1 in allocate_cfi (/lib64/libdw.so.1+0x3f6f1) Direct leak of 65 byte(s) in 1 object(s) allocated from: #0 0x7f67642b95b5 in __interceptor_realloc.part.0 (/lib64/libasan.so.8+0xb95b5) #1 0x6cac75 in strbuf_grow util/strbuf.c:64 #2 0x6ca934 in strbuf_init util/strbuf.c:25 #3 0x9337d2 in synthesize_perf_probe_point util/probe-event.c:2018 #4 0x92be51 in try_to_find_probe_trace_events util/probe-event.c:964 #5 0x93d5c6 in convert_to_probe_trace_events util/probe-event.c:3512 #6 0x93d6d5 in convert_perf_probe_events util/probe-event.c:3529 #7 0x56f37f in perf_add_probe_events /var/home/acme/git/perf-tools-next/tools/perf/builtin-probe.c:354 #8 0x572fbc in __cmd_probe /var/home/acme/git/perf-tools-next/tools/perf/builtin-probe.c:738 #9 0x5730f2 in cmd_probe /var/home/acme/git/perf-tools-next/tools/perf/builtin-probe.c:766 #10 0x635d81 in run_builtin /var/home/acme/git/perf-tools-next/tools/perf/perf.c:323 #11 0x6362c1 in handle_internal_command /var/home/acme/git/perf-tools-next/tools/perf/perf.c:377 #12 0x63667a in run_argv /var/home/acme/git/perf-tools-next/tools/perf/perf.c:421 #13 0x636b8d in main /var/home/acme/git/perf-tools-next/tools/perf/perf.c:537 #14 0x7f676302950f in __libc_start_call_main (/lib64/libc.so.6+0x2950f) SUMMARY: AddressSanitizer: 193 byte(s) leaked in 2 allocation(s). # synthesize_perf_probe_point() returns a "detachec" strbuf, i.e. a malloc'ed string that needs to be free'd. An audit will be performed to find other such cases. Acked-by: Masami Hiramatsu Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lore.kernel.org/lkml/ZM0l1Oxamr4SVjfY@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 2d056f02ae40..c7bfeab610a3 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -961,8 +961,9 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, debuginfo__delete(dinfo); if (ntevs == 0) { /* No error but failed to find probe point. */ - pr_warning("Probe point '%s' not found.\n", - synthesize_perf_probe_point(&pev->point)); + char *probe_point = synthesize_perf_probe_point(&pev->point); + pr_warning("Probe point '%s' not found.\n", probe_point); + free(probe_point); return -ENODEV; } else if (ntevs < 0) { /* Error path : ntevs < 0 */