From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl1-f71.google.com (mail-dl1-f71.google.com [74.125.82.71]) (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 E083B58B6C7 for ; Fri, 16 Oct 2026 17:32:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792171923; cv=none; b=cL4ateDr4dDfNf+Hw5I7I/HwDQjuJYeG3LBpsr5slvt0hCwzY84aOUXJTO3YadZsq3mgkw6sdp9CSTOITa+a/ZOhVHiiQ4eVimk5OVMw5PzbPb1SR/O++oqY+MmOaa5Ikh/3Q5qIdpCrZeQPBJPO8sgMvlMlLRxAtjNZR3gS6Rw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792171923; c=relaxed/simple; bh=CCjXTNqHT89zyONIcSR+OwfqIxnWIP+Ljxt3b+OKT+A=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=JsZNIDCrGGpPgvbnO0ji38/qRxkDKwKr+saRi5gAiLmBr1Vv4GDLLCNKqSwvMX7ADdqNhEA0kCU5o3nGVOocdJAxBn5hfeq8OZly9B68gI1JViZ6gjrWQcyZSlr5C2UCZxOZLqLcf6ps4QN8NEusLrChKIfQv91NhHp0Ky6K+7w= 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=Jy23NXNB; arc=none smtp.client-ip=74.125.82.71 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="Jy23NXNB" Received: by mail-dl1-f71.google.com with SMTP id a92af1059eb24-1383723dfddso232140c88.0 for ; Fri, 16 Oct 2026 10:32:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1792171921; x=1792776721; darn=lists.linux.dev; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=SUulpA5j+azs4E3npojsUIbJgcVsNwHBau6Ow0JhWuo=; b=Jy23NXNB2aoeORWdC7XHKH+nH1gY/kIHSlQXryme152p2bj0/zHSp4gPB+DybcaTe+ gICdrz3J7SVRGICnhFkLlDHqG/p1bdRWrH1/s4O5xAm2xHp9fBX2RanxFqEkYQnUySGx wB4KJBF93DfTnws4cyhHEOTk72Fs2ZnWkz1YRRuAzsoL+AwKejehuZ+vFtgC947nKwQR qfaVKlRYdJdbeBaWFdZw0q4ERXwoGuV4TDhcB9mwGiMHMjLhrsn82uU3mES3AF1WdflT ay/hlU6tJaOcJaXCJRhxOs/7OAktqF1zbV/99z8vagpUy9qhde2Ht4yPDK5x14BiSvG8 MjNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792171921; x=1792776721; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=SUulpA5j+azs4E3npojsUIbJgcVsNwHBau6Ow0JhWuo=; b=rwah1yKoll44jiq8ZgnUueeZyGHaFijroRmrbpfJvQG+pr8cNImc61kU20WROAPIoP SE2eOXSN8mLDUYcz/9vsCswBg3xLtZt2kQKUxsniKbmKCmhlXq138z/H4GPqzQVSEkNr FeETXMfMoxcBPFSDuikdbEQ+YcyAzqA8m7Igm+tUHa4V3FougVySjyxlPx6tv7hkzeXW /scrbGvmE8Il+9uempAhxCUg03b6BCwRWyXMz2ImSoH8/OdetrOPvNGTeSvxvPs/2mNW 1GTkQSQbYaZl3dnSFKvaUsDiE3uhqEc7SsF+X16rQUM8KiACcH/DIicBkHiPEJmZ3Cpy LbiA== X-Forwarded-Encrypted: i=1; AKwUvBxm56PHJ0OOVuiWV5ErAxvP98cusoy+BaLj23/NbZjXxv7hT8iFxk5awKm8nZTdafOM/+P2@lists.linux.dev X-Gm-Message-State: AFq9FYIyYwgKdJI8ul/ND2A+xxqSjrpGXXkxs3wgLtPS3gHv+FYqbwwO fP+9NUqKBm5elZfIE6MkOK2LgRWWAFecqCN9WV4cWICSy83Dys5o2oI1GRWnmb/THc917fI6j53 OZDzr+AftnQ== X-Received: from dlee25.prod.google.com ([2002:a05:7022:6299:b0:144:c124:514e]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:7f01:b0:178:d38c:eafa with SMTP id a92af1059eb24-18512579328mr608006c88.21.1792171920582; Fri, 16 Oct 2026 10:32:00 -0700 (PDT) Date: Fri, 16 Oct 2026 10:31:05 -0700 In-Reply-To: <20261016173106.679725-1-irogers@google.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20261013222622.1822619-1-irogers@google.com> <20261016173106.679725-1-irogers@google.com> X-Mailer: git-send-email 2.56.0.212.g129ede20d9-goog Message-ID: <20261016173106.679725-17-irogers@google.com> Subject: [PATCH v3 16/17] perf maps: Fix lock inversion in maps__load_first() and bounds check in __maps__remove() From: Ian Rogers To: irogers@google.com, acme@kernel.org, elver@google.com, namhyung@kernel.org Cc: adrian.hunter@intel.com, james.clark@linaro.org, jolsa@kernel.org, justinstitt@google.com, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, ljs@kernel.org, llvm@lists.linux.dev, mingo@redhat.com, morbo@google.com, nathan@kernel.org, ndesaulniers@google.com, peterz@infradead.org Content-Type: text/plain; charset="UTF-8" In maps__load_first(), take a reference to the first map and drop maps__lock(maps) before calling map__load() to avoid a read-to-write self-deadlock when loading kernel maps inserts extra trampoline maps. In __maps__remove(), check that the index returned by maps__by_address_index() and maps__by_name_index() is within nr_maps before indexing and removing the entry, in case a concurrent thread already removed the map. Signed-off-by: Ian Rogers --- tools/perf/util/maps.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c index f808df2fe77b..c0fccb776bed 100644 --- a/tools/perf/util/maps.c +++ b/tools/perf/util/maps.c @@ -548,6 +548,8 @@ static void __maps__remove(struct maps *maps, struct map *map) /* Slide later mappings over the one to remove */ address_idx = maps__by_address_index(maps, map); + if (address_idx >= nr_maps) + return; map__put(maps_by_address[address_idx]); memmove(&maps_by_address[address_idx], &maps_by_address[address_idx + 1], @@ -556,10 +558,14 @@ static void __maps__remove(struct maps *maps, struct map *map) if (maps_by_name) { unsigned int name_idx = maps__by_name_index(maps, map); - map__put(maps_by_name[name_idx]); - memmove(&maps_by_name[name_idx], - &maps_by_name[name_idx + 1], - (nr_maps - name_idx - 1) * sizeof(*maps_by_name)); + if (name_idx < nr_maps) { + map__put(maps_by_name[name_idx]); + memmove(&maps_by_name[name_idx], + &maps_by_name[name_idx + 1], + (nr_maps - name_idx - 1) * sizeof(*maps_by_name)); + } else { + __maps__free_maps_by_name(maps); + } } --RC_CHK_ACCESS(maps)->nr_maps; @@ -1459,10 +1465,15 @@ int maps__merge_in(struct maps *kmaps, struct map *new_map) void maps__load_first(struct maps *maps) { - down_read(maps__lock(maps)); + struct map *first = NULL; + down_read(maps__lock(maps)); if (maps__nr_maps(maps) > 0) - map__load(maps__maps_by_address(maps)[0]); - + first = map__get(maps__maps_by_address(maps)[0]); up_read(maps__lock(maps)); + + if (first) { + map__load(first); + map__put(first); + } } -- 2.56.0.212.g129ede20d9-goog