From patchwork Tue Feb 6 03:33:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Rogers X-Patchwork-Id: 13546599 Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 329CD74E0A for ; Tue, 6 Feb 2024 03:33:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707190414; cv=none; b=cOWTZUdnC5oJoj35IjKZ5GHyPYSLH/jVIBQtb+42bXuTMwJHNmjOza63mCMpnc327Jvq35Gb2VpP5rE+c9ZAoULQMomBrTemNlFBKFsTITvj7E8uTqNaSkZ6ym5znXtSjiVARugJvh9mhRWVwaC2M/sA+odGr89C56Sya+ZXHhw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707190414; c=relaxed/simple; bh=TNL0GOyieHu9AqHO4Zi22Cz7C0gAfBXx8CvzAmJoOYo=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Content-Type; b=vBdUzohJIzrNu1Z9YBJmlX+FIckqX/qsu1fwXFwDv1/IYbElE1Bvov9HMR0pH959SMwLJTjiVTGWRYh5TFuleC/e295hP5dVm7RA27soIybqpRrsawg+ucp0ysuIXt+pXqXGhsk1s1quxw/NFbcK63JNfsohk8a2NVRR/eQcTqs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=jg0zMoc3; arc=none smtp.client-ip=209.85.219.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="jg0zMoc3" Received: by mail-yb1-f202.google.com with SMTP id 3f1490d57ef6-dc6ba5fdf1aso6934465276.1 for ; Mon, 05 Feb 2024 19:33:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1707190411; x=1707795211; darn=vger.kernel.org; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=DWu8c5dtrh0uqi6zk1zlORUMaHx/FkkbOqGaT9PZG5U=; b=jg0zMoc3iXuKLN1LrNcpLm1P3O4Mo7KCJrqBCLipSxTgWfi2C6iH1Dv1SriHXh/mxq CgWmUa8nbBj10xFdM7ZKczjs0zzLPOPbnSo2iVsuctclJGUfFWGBaPvExe2ArcqKp6WK 8Msud07NetMRXVKkRix75vdXVqHyP1/MOb3qQesxSh9OjEB4mxBZ2BTaMHmeZvEekMQW TnRpHmH7rYCRU2bwulJoHc1uaTyOi6K2lzkmGt8bCnfllf7PjTPIFnQtxerf+O4gs43O wHoWVDPc5YiahEPKn2Vc9ysQUIB0wH+6XNckLZMUq/krKWkNhI3WDKl26Q/xipBXuHrn DWkg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1707190411; x=1707795211; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=DWu8c5dtrh0uqi6zk1zlORUMaHx/FkkbOqGaT9PZG5U=; b=lIwtACz4oIsnVkZAcXstZWdAJhiTQuvv3SP838HD+WiJtn+iqTO0uvNR33lPMDLbU2 /NrXRRFJzMsklXbhmitfuNQhZjL2hQInz+wvbTf/hqBe0K9bM5S7OgGHzfEeRTzGztHr arFP+ilHRthLeSTGumjNHCUBIMJ33Da8YgyeykUS33aMZJ8nsiatOTIHJZgV/EEMOJ3k JF8s02oQ5ZucfqXrCkJ+TQQb5870EA90bi+YCIXEYY6gjqWcwO5etSceTaWna4cL4Bbh wuRGXquFWqyaNcGD8peJ6+PeN/6m9EtHbqniwyaiLxdvIAVs0t+v3owQitVspKqZfaXY bRRQ== X-Gm-Message-State: AOJu0YzBqI40998pjNWIxIyKxqbg3yAr5ywouwY6sm6qdQ46TI0KdLUg 9Jz8VKcNwP7hp8oi1ggLsoMmf1czGPRZT9G1jwSfOtOSrp3JCl1u0I2WyBnWZmG5bPaXQqHETgW bU8U6zA== X-Google-Smtp-Source: AGHT+IHWhdCTORLqjMG3/cupDyLTJZz99O34XglzQXDalnE6/G79+H/eYyZPVuf3yj2snNU4HqVopu4hoGfl X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:326b:71bb:e465:6f39]) (user=irogers job=sendgmr) by 2002:a05:6902:1b89:b0:dc6:d9eb:6422 with SMTP id ei9-20020a0569021b8900b00dc6d9eb6422mr16445ybb.10.1707190411197; Mon, 05 Feb 2024 19:33:31 -0800 (PST) Date: Mon, 5 Feb 2024 19:33:17 -0800 In-Reply-To: <20240206033320.2657716-1-irogers@google.com> Message-Id: <20240206033320.2657716-4-irogers@google.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240206033320.2657716-1-irogers@google.com> X-Mailer: git-send-email 2.43.0.594.gd9cf4e227d-goog Subject: [PATCH v1 3/6] perf maps: Get map before returning in maps__find_by_name 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 , Miguel Ojeda , Liam Howlett , Colin Ian King , K Prateek Nayak , Artem Savkov , Changbin Du , Masami Hiramatsu , Athira Rajeev , Yang Jihong , Tiezhu Yang , James Clark , liuwenyu , Leo Yan , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org 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. Also fix some reference counted pointer comparisons. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim --- tools/perf/tests/vmlinux-kallsyms.c | 5 +++-- tools/perf/util/machine.c | 6 ++++-- tools/perf/util/maps.c | 6 +++--- tools/perf/util/probe-event.c | 1 + tools/perf/util/symbol-elf.c | 4 +++- tools/perf/util/symbol.c | 18 +++++++++++------- 6 files changed, 25 insertions(+), 15 deletions(-) diff --git a/tools/perf/tests/vmlinux-kallsyms.c b/tools/perf/tests/vmlinux-kallsyms.c index e808e6fc8f76..fecbf851bb2e 100644 --- a/tools/perf/tests/vmlinux-kallsyms.c +++ b/tools/perf/tests/vmlinux-kallsyms.c @@ -131,9 +131,10 @@ static int test__vmlinux_matches_kallsyms_cb1(struct map *map, void *data) struct map *pair = maps__find_by_name(args->kallsyms.kmaps, (dso->kernel ? dso->short_name : dso->name)); - if (pair) + if (pair) { map__set_priv(pair, 1); - else { + map__put(pair); + } else { if (!args->header_printed) { pr_info("WARN: Maps only in vmlinux:\n"); args->header_printed = true; diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index e8eb9f0b073f..7031f6fddcae 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1537,8 +1537,10 @@ static int maps__set_module_path(struct maps *maps, const char *path, struct kmo return 0; long_name = strdup(path); - if (long_name == NULL) + if (long_name == NULL) { + map__put(map); return -ENOMEM; + } dso = map__dso(map); dso__set_long_name(dso, long_name, true); @@ -1552,7 +1554,7 @@ static int maps__set_module_path(struct maps *maps, const char *path, struct kmo dso->symtab_type++; dso->comp = m->comp; } - + map__put(map); return 0; } diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c index 3336d540c577..f4855e2bfd6e 100644 --- a/tools/perf/util/maps.c +++ b/tools/perf/util/maps.c @@ -899,7 +899,7 @@ struct map *maps__find_by_name(struct maps *maps, const char *name) struct dso *dso = map__dso(maps__maps_by_name(maps)[i]); if (dso && strcmp(dso->short_name, name) == 0) { - result = maps__maps_by_name(maps)[i]; // TODO: map__get + result = map__get(maps__maps_by_name(maps)[i]); done = true; } } @@ -911,7 +911,7 @@ struct map *maps__find_by_name(struct maps *maps, const char *name) sizeof(*mapp), map__strcmp_name); if (mapp) { - result = *mapp; // TODO: map__get + result = map__get(*mapp); i = mapp - maps__maps_by_name(maps); RC_CHK_ACCESS(maps)->last_search_by_name_idx = i; } @@ -936,7 +936,7 @@ struct map *maps__find_by_name(struct maps *maps, const char *name) struct dso *dso = map__dso(pos); if (dso && strcmp(dso->short_name, name) == 0) { - result = pos; // TODO: map__get + result = map__get(pos); break; } } diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index a1a796043691..be71abe8b9b0 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -358,6 +358,7 @@ static int kernel_get_module_dso(const char *module, struct dso **pdso) map = maps__find_by_name(machine__kernel_maps(host_machine), module_name); if (map) { dso = map__dso(map); + map__put(map); goto found; } pr_debug("Failed to find module %s.\n", module); diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 4b934ed3bfd1..5990e3fabdb5 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1470,8 +1470,10 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map, dso__set_loaded(curr_dso); *curr_mapp = curr_map; *curr_dsop = curr_dso; - } else + } else { *curr_dsop = map__dso(curr_map); + map__put(curr_map); + } return 0; } diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 1710b89e207c..0785a54e832e 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -814,7 +814,7 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta, struct map *initial_map) { struct machine *machine; - struct map *curr_map = initial_map; + struct map *curr_map = map__get(initial_map); struct symbol *pos; int count = 0, moved = 0; struct rb_root_cached *root = &dso->symbols; @@ -858,13 +858,14 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta, dso__set_loaded(curr_map_dso); } + map__zput(curr_map); curr_map = maps__find_by_name(kmaps, module); if (curr_map == NULL) { pr_debug("%s/proc/{kallsyms,modules} " "inconsistency while looking " "for \"%s\" module!\n", machine->root_dir, module); - curr_map = initial_map; + curr_map = map__get(initial_map); goto discard_symbol; } curr_map_dso = map__dso(curr_map); @@ -888,7 +889,7 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta, * symbols at this point. */ goto discard_symbol; - } else if (curr_map != initial_map) { + } else if (!RC_CHK_EQUAL(curr_map, initial_map)) { char dso_name[PATH_MAX]; struct dso *ndso; @@ -899,7 +900,8 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta, } if (count == 0) { - curr_map = initial_map; + map__zput(curr_map); + curr_map = map__get(initial_map); goto add_symbol; } @@ -913,6 +915,7 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta, kernel_range++); ndso = dso__new(dso_name); + map__zput(curr_map); if (ndso == NULL) return -1; @@ -926,6 +929,7 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta, map__set_mapping_type(curr_map, MAPPING_TYPE__IDENTITY); if (maps__insert(kmaps, curr_map)) { + map__zput(curr_map); dso__put(ndso); return -1; } @@ -936,7 +940,7 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta, pos->end -= delta; } add_symbol: - if (curr_map != initial_map) { + if (!RC_CHK_EQUAL(curr_map, initial_map)) { struct dso *curr_map_dso = map__dso(curr_map); rb_erase_cached(&pos->rb_node, root); @@ -951,12 +955,12 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta, symbol__delete(pos); } - if (curr_map != initial_map && + if (!RC_CHK_EQUAL(curr_map, initial_map) && dso->kernel == DSO_SPACE__KERNEL_GUEST && machine__is_default_guest(maps__machine(kmaps))) { dso__set_loaded(map__dso(curr_map)); } - + map__put(curr_map); return count + moved; }