From nobody Thu Jan 1 08:57:38 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4DF3C25B6B for ; Tue, 24 Oct 2023 22:24:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344467AbjJXWYZ (ORCPT ); Tue, 24 Oct 2023 18:24:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344431AbjJXWYU (ORCPT ); Tue, 24 Oct 2023 18:24:20 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 490E010CB for ; Tue, 24 Oct 2023 15:24:18 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-da040c021aeso1140818276.3 for ; Tue, 24 Oct 2023 15:24:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1698186257; x=1698791057; 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=soqORP6tbK7HSPMdiExWiSFnufIqC4NXz+eAMSjew4k=; b=VAYKbecQNlVTg/B52zPDUaaiURDyjiKy7S+6RIJOxJpJ0eHhouwdTSRRBJ27EJULRu dxqgDSMBuegaaEh2V9wyGFRlyBqDnas82lSaTbvD97QErmN4VbCrwd0kjJRS7TO3x9FG tVNhfEvHEB2Z/CQ6oMCpKUWDBVFqU090UkqLf+jv2vfjskvOUE8FlHbCKTT2mZsnQ+CN kegQ5T4b6AhmuMBRT431gSOe7l5kezCOzc/yHc/ZJmidQMGqyLqsQAIlmn4DT6WXgMhg osWbRexaBrpnCVGgOf22q7eEulXwowZ8Lmy7vwtcI9C+cz0kdMMFoWER/jYCV8iUL5cC 4KLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698186257; x=1698791057; 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=soqORP6tbK7HSPMdiExWiSFnufIqC4NXz+eAMSjew4k=; b=sleI/+GYK6CKPllGJMxQ6AGn6XD0RtnpwbU9MtV8TxctYRR+gYO/0sCv64cjDnbHJG q/DdNpSJxKKrN/Qb9WzLtbnELFZrzPRixKa7VYrgKzn0kTCnYlteQ80SVlkvvd9UT1qu IXUCMmP/sJwUTVN2Tqgrz7GRGWRs3Bhy2kmTWlNRthv4NdVZjSmYym1/ivzbyUvmw+Il rpQYIoL8VgBZ0ZQ3zYUd4loBgSt9D/tVBQ38/Z/tN27E+4JeCy7PzGwplp++6gKHdfBC s68wspFjR7R+RVL5TLlVNCK0m0bUlgVcm22AY3w4U1P+sYLaqBFNILhcIvA0Z7DTFzUP 9Law== X-Gm-Message-State: AOJu0YyFE3VJTigjuMj6UgYGtr41NybZjrb6Xqw/nh5aoT7oNMCafwpS GuKtHNJTv1e4hf7a8Tq5VOgA7dJ8rPZS X-Google-Smtp-Source: AGHT+IEeWCPNZG1JcJgc7vYx5Xq8cYep1D+KXTRDSFxJng+4UHbNRG8N9ZPuO2UyyIN/UZxk0Kv+FVlm1ZMA X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:93d2:18cc:4d63:45ba]) (user=irogers job=sendgmr) by 2002:a25:324b:0:b0:d9b:f88c:ca2b with SMTP id y72-20020a25324b000000b00d9bf88cca2bmr258271yby.11.1698186257401; Tue, 24 Oct 2023 15:24:17 -0700 (PDT) Date: Tue, 24 Oct 2023 15:23:05 -0700 In-Reply-To: <20231024222353.3024098-1-irogers@google.com> Message-Id: <20231024222353.3024098-3-irogers@google.com> Mime-Version: 1.0 References: <20231024222353.3024098-1-irogers@google.com> X-Mailer: git-send-email 2.42.0.758.gaed0368e0e-goog Subject: [PATCH v3 02/50] perf machine: Avoid out of bounds LBR memory read From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Nick Terrell , Kan Liang , Andi Kleen , Leo Yan , Song Liu , Sandipan Das , James Clark , Anshuman Khandual , Miguel Ojeda , Liam Howlett , Yang Jihong , Athira Rajeev , Kajol Jain , K Prateek Nayak , Sean Christopherson , Yanteng Si , Ravi Bangoria , German Gomez , Changbin Du , Paolo Bonzini , Masami Hiramatsu , liuwenyu , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Running perf top with address sanitizer and "--call-graph=3Dlbr" fails due to reading sample 0 when no samples exist. Add a guard to prevent this. Fixes: e2b23483eb1d ("perf machine: Factor out lbr_callchain_add_lbr_ip()") Signed-off-by: Ian Rogers --- tools/perf/util/machine.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index addfae2f63ef..e0e2c4a943e4 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -2622,16 +2622,18 @@ static int lbr_callchain_add_lbr_ip(struct thread *= thread, save_lbr_cursor_node(thread, cursor, i); } =20 - /* Add LBR ip from first entries.to */ - ip =3D entries[0].to; - flags =3D &entries[0].flags; - *branch_from =3D entries[0].from; - err =3D add_callchain_ip(thread, cursor, parent, - root_al, &cpumode, ip, - true, flags, NULL, - *branch_from); - if (err) - return err; + if (lbr_nr > 0) { + /* Add LBR ip from first entries.to */ + ip =3D entries[0].to; + flags =3D &entries[0].flags; + *branch_from =3D entries[0].from; + err =3D add_callchain_ip(thread, cursor, parent, + root_al, &cpumode, ip, + true, flags, NULL, + *branch_from); + if (err) + return err; + } =20 return 0; } --=20 2.42.0.758.gaed0368e0e-goog