From nobody Wed Apr 8 21:36:06 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 A0BE3C38A02 for ; Fri, 28 Oct 2022 18:01:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229993AbiJ1SBx (ORCPT ); Fri, 28 Oct 2022 14:01:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230018AbiJ1SBg (ORCPT ); Fri, 28 Oct 2022 14:01:36 -0400 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE1DD20FB1D; Fri, 28 Oct 2022 11:01:35 -0700 (PDT) Received: by mail-pj1-x102a.google.com with SMTP id 3-20020a17090a0f8300b00212d5cd4e5eso10527919pjz.4; Fri, 28 Oct 2022 11:01:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:from:to:cc:subject:date :message-id:reply-to; bh=RRaWyTNG36H59bEp88dgewnNjHxw44C35a4VhyGtZjQ=; b=MWTjbjOl5lZi7Xu1Znd5gj0cW3FkMbJFkKKN/mVYofTaIK7sVXhT07pR31GWyqOnl/ 9SR9oSl2m4vw2H4zyeFubiK4coIylPo2pQNNzjHz0tDkBNkP+6C/qnBqSof6VUXLPaM1 D12+rnxDSHhTSMvXTWP4wOoBjBM1Q4c0zz2zas65ePGiwPNVyeN9UfUGHLOD9IdlHKt0 mWWr0YMIXY+25RgHy0noTUbYAnCaqxJ1qDtctIxR3qCOtT7kS1SIZTRedRAHPkpUIgDa AkSKwuY3lm2Rd54tzk9rXY18qB2SzAQf0s+zdI8gEGd1SfjBhN9LNtaNocTvUlJUdDoX NbjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:sender:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=RRaWyTNG36H59bEp88dgewnNjHxw44C35a4VhyGtZjQ=; b=J/8IIb9V+wdyZMtqP6JaMxgUX1oP/ppuCu2p8B3u+7ygbKRhRbSKhPQ/W2wqq9dCFP 2bFWkuvjN7yPGYFDRsC/lxtSupdd4bpq2yG1DqgPwNrIsNxJ/Dd1bueuDL61akX2v+A3 hu4kx/Rkjxwznbh80BTEwlX54XYUcv83jziwSPqvkpDN1kCOA6AjznF5Bv+kAsyKa+Ix Up42Mtaqv6XgdRX/l7wOf2drt9ce0Pkcn8aYdPVVrgonPTKuWCqR6xalI7amXNvSK0k+ UjYFSZ9NdCPS0F4+1ZwCtqEKhajWJf0Cw9JgpR/NsdiohAgl4WwGPC5KQC46MjRn+Zwq IDRQ== X-Gm-Message-State: ACrzQf3jN1uCD2Rx8dBRG83/q3Yb5HkQ8YVwZ/4oazp6HkQBbAcEGFks niavH8x0MSP4o6AVTD8bCZ8= X-Google-Smtp-Source: AMsMyM6r0qYzt6JLtN3tJ9YK3WpjzmR5jceTXdkdKOG21sqTVszZBLHMDbSR/AFDINwyJMNx4Xy8+g== X-Received: by 2002:a17:902:f710:b0:184:7a4c:fdc1 with SMTP id h16-20020a170902f71000b001847a4cfdc1mr186767plo.27.1666980095311; Fri, 28 Oct 2022 11:01:35 -0700 (PDT) Received: from youngsil.svl.corp.google.com ([2620:15c:2d4:203:976f:f075:7c14:87a2]) by smtp.gmail.com with ESMTPSA id n3-20020a170903110300b00186b86ed450sm3400236plh.156.2022.10.28.11.01.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 28 Oct 2022 11:01:34 -0700 (PDT) Sender: Namhyung Kim From: Namhyung Kim To: Arnaldo Carvalho de Melo , Jiri Olsa Cc: Ingo Molnar , Peter Zijlstra , LKML , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org Subject: [PATCH 2/4] perf lock contention: Check --max-stack option Date: Fri, 28 Oct 2022 11:01:26 -0700 Message-Id: <20221028180128.3311491-3-namhyung@kernel.org> X-Mailer: git-send-email 2.38.1.273.g43a17bfeac-goog In-Reply-To: <20221028180128.3311491-1-namhyung@kernel.org> References: <20221028180128.3311491-1-namhyung@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The --max-stack option is used to allocate the BPF stack map and stack trace array in the userspace. Check the value properly before using. Practically it cannot be greater than the sysctl_perf_event_max_stack. Signed-off-by: Namhyung Kim --- tools/perf/builtin-lock.c | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-) diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c index 9722d4ab2e55..f67db60f1de6 100644 --- a/tools/perf/builtin-lock.c +++ b/tools/perf/builtin-lock.c @@ -24,6 +24,7 @@ #include "util/data.h" #include "util/string2.h" #include "util/map.h" +#include "util/util.h" =20 #include #include @@ -1858,6 +1859,29 @@ static int parse_map_entry(const struct option *opt,= const char *str, return 0; } =20 +static int parse_max_stack(const struct option *opt, const char *str, + int unset __maybe_unused) +{ + unsigned long *len =3D (unsigned long *)opt->value; + long val; + char *endptr; + + errno =3D 0; + val =3D strtol(str, &endptr, 0); + if (*endptr !=3D '\0' || errno !=3D 0) { + pr_err("invalid max stack depth: %s\n", str); + return -1; + } + + if (val < 0 || val > sysctl__max_stack()) { + pr_err("invalid max stack depth: %ld\n", val); + return -1; + } + + *len =3D val; + return 0; +} + int cmd_lock(int argc, const char **argv) { const struct option lock_options[] =3D { @@ -1913,9 +1937,9 @@ int cmd_lock(int argc, const char **argv) "Trace on existing thread id (exclusive to --pid)"), OPT_CALLBACK(0, "map-nr-entries", &bpf_map_entries, "num", "Max number of BPF map entries", parse_map_entry), - OPT_INTEGER(0, "max-stack", &max_stack_depth, - "Set the maximum stack depth when collecting lock contention, " - "Default: " __stringify(CONTENTION_STACK_DEPTH)), + OPT_CALLBACK(0, "max-stack", &max_stack_depth, "num", + "Set the maximum stack depth when collecting lopck contention, " + "Default: " __stringify(CONTENTION_STACK_DEPTH), parse_max_stack), OPT_INTEGER(0, "stack-skip", &stack_skip, "Set the number of stack depth to skip when finding a lock caller, " "Default: " __stringify(CONTENTION_STACK_SKIP)), --=20 2.38.1.273.g43a17bfeac-goog