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AJvYcCXPad2SJlDbcvXUJcReid9D+jPqdr/aoOV7nhmSTwrEhV/Y/Irq91LmYikUBaUwOxwKlcs5fQSMvHEwv5iwUqauB3eIIptpkdj/VvBV X-Gm-Message-State: AOJu0YxgUaSEy8Tz9oyK/lpQb/GAnhBRZCPfbNKh4lfEgpCzM88NhvWM LlekIkGnCipncC5lKgdXO8EGrUDux50Sx1LWl0kXh6c62akNLsvxbf+bi0XbhTW2SAaa9WKaNfS UWxdUBg== X-Google-Smtp-Source: AGHT+IE+Fj4pzKGvpjOG4c0i+qY8ApmS6WRhnUjNga2NlY4vxZvK+caBXOIKF5xvEAVx8bP8oFyl7nh+BLe1 X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:877:241d:8c35:1c5b]) (user=irogers job=sendgmr) by 2002:a25:ce05:0:b0:dc7:31f3:9f98 with SMTP id x5-20020a25ce05000000b00dc731f39f98mr241172ybe.9.1707535085769; Fri, 09 Feb 2024 19:18:05 -0800 (PST) Date: Fri, 9 Feb 2024 19:17:44 -0800 In-Reply-To: <20240210031746.4057262-1-irogers@google.com> Message-Id: <20240210031746.4057262-5-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240210031746.4057262-1-irogers@google.com> X-Mailer: git-send-email 2.43.0.687.g38aa6559b0-goog Subject: [PATCH v3 4/6] perf maps: Get map before returning in maps__find_next_entry From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Song Liu , Colin Ian King , Liam Howlett , K Prateek Nayak , Artem Savkov , Changbin Du , Masami Hiramatsu , Athira Rajeev , Alexey Dobriyan , James Clark , Vincent Whitchurch , Leo Yan , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Finding a map is done under a lock, returning the map without a reference count means it can be removed without notice and causing uses after free. Grab a reference count to the map within the lock region and return this. Fix up locations that need a map__put following this. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim --- tools/perf/util/machine.c | 4 +++- tools/perf/util/maps.c | 2 +- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 7031f6fddcae..4911734411b5 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1761,8 +1761,10 @@ int machine__create_kernel_maps(struct machine *mach= ine) struct map *next =3D maps__find_next_entry(machine__kernel_maps(machine), machine__kernel_map(machine)); =20 - if (next) + if (next) { machine__set_kernel_mmap(machine, start, map__start(next)); + map__put(next); + } } =20 out_put: diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c index ea8fa684e8c6..df0c8041899e 100644 --- a/tools/perf/util/maps.c +++ b/tools/perf/util/maps.c @@ -962,7 +962,7 @@ struct map *maps__find_next_entry(struct maps *maps, st= ruct map *map) down_read(maps__lock(maps)); i =3D maps__by_address_index(maps, map); if (i < maps__nr_maps(maps)) - result =3D maps__maps_by_address(maps)[i]; // TODO: map__get + result =3D map__get(maps__maps_by_address(maps)[i]); =20 up_read(maps__lock(maps)); return result; --=20 2.43.0.687.g38aa6559b0-goog