From nobody Fri Dec 19 15:01:57 2025 Received: from mail-pj1-f74.google.com (mail-pj1-f74.google.com [209.85.216.74]) (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 4A1B5204689 for ; Wed, 4 Jun 2025 17:46:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749059167; cv=none; b=Ho7UEGkUhGP+s8MSrff5MsGHjQMk7n0Te76LtL54sbBMWngOmiyTMjqTASp9Nzf6ozXYDSV7NJFCLTtgVd2fWWiD7Am0btEAWUK/OfkSBwBF/56Kb4rlJQfLLD/CIM86M+BPcWbZg0R6H4POanY4BUnCaYiY/jvlGifgpvdvfbE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749059167; c=relaxed/simple; bh=Pr6uyNOCYDQtOIdkrEEBjYxHbHN2ZcnxheLKgXvILHI=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Content-Type; b=Tn026U5aFNucWl+930qT4K6pbm2mIBPldQPhfgpOZjQblqfw/UPjsCYtsiy4tF5C17wk3F3gxcMb3ZS/TvBjrr+lsvh41cRyhVJj574afwa64mcLZISY0edF5ABSsjuc9aMLnqGDQRgzNOazIo0xryGU6KPmFfQ5iE0BQX8lCEA= 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=iVDLVAwc; arc=none smtp.client-ip=209.85.216.74 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="iVDLVAwc" Received: by mail-pj1-f74.google.com with SMTP id 98e67ed59e1d1-31171a736b2so154186a91.1 for ; Wed, 04 Jun 2025 10:46:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1749059165; x=1749663965; darn=vger.kernel.org; h=to:from:subject:message-id:references:mime-version:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=osXo3AqwK/4YO7kimxxv/q9KVIECdD745Jh5D5390RI=; b=iVDLVAwcmEppPf5aDxsk390schat4c0OKRO4W7rz3Q4L+lGVbABoIdDY/9w9GAYAgd 3ia8cUEYUGPkUIufU9js5BeUNk2AxgIZiss2/aTIWVZZUissYrFYf8zM7idiErSFMEAt V/o3Btn9oOeu2gI9FJ+VInIoZTwNdTR3uBPetaWaqSGZTQ4WuWeCJojQRVLIGJkr5DXv LpxnGo6xUbO+3FxhtO/Od2awlfS6GCDoJANSU1/gZI/idJdWPGiEUHt7YyXF9nxLAyPe RduuV6C5g8edbIMKfl5I6nNycHwyDf6wSRay4TcfLgT7QG0nKXM9bXWUmf50Sea4F2SJ 1v4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749059165; x=1749663965; h=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; bh=osXo3AqwK/4YO7kimxxv/q9KVIECdD745Jh5D5390RI=; b=UUiN294uzXDqE8HHEUEOmR5FP/WbKDO4Fib9i+PNz6VOz/arXlNGkS8aSY9O1Ztohf GyiAmKHU/gd+XcIKWxXkZ3m1EffVDdhW1Ge9gB0QjrhYBQ4jLFl0XYkXE5ZxVdA1nTjH bgEPF25gwidRP3vdNCgLEyYDexRYpcIs3MlCPohDfS7esnzZG7zLmRPQk6yAdkeA5d0W l+UrDo22f7LbFIuwDtc4fT9vMSnfZoISTkY84ZSiwbLf6BFZNwH/O0L7nWYrBGbfdgmQ 5TToXcU3U4tP9e26/+TKbr9XXWLIAO9wFZf6NHEks0hXLqbCF72rOnXvwRL+d4V7Z9MI J75g== X-Forwarded-Encrypted: i=1; AJvYcCUv0+zWr9jx0yUqm5WnuTVg/qnpn4KwgbWYGtBbWm8ua6G2FeCkgCQpz3LnCigROIob6ruYKDWrFq2qjAs=@vger.kernel.org X-Gm-Message-State: AOJu0YwtdsyKbxu6Ffysex5veRhnH0BBKFQVb9eWOnjxaqOCUGxPNRoc yhZ++r4m7FyKJ+xnKPiR/Tr2khsJfGdbw2CPZH4fxujsH+XIKrItpvtDV3NBNkhrwtaoBAzRJk7 b9Y1sxiKogg== X-Google-Smtp-Source: AGHT+IGaJvKbsygH4nlibrH4C9ybgV0Y+hG1/QFJLM/QlJRX7V3i3wxQTU1yhbDG2f0xCgPzM5E/1IiYFrh1 X-Received: from pjg14.prod.google.com ([2002:a17:90b:3f4e:b0:311:a879:981f]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90a:c0f:b0:313:1769:eb49 with SMTP id 98e67ed59e1d1-3131769eb8cmr2917651a91.8.1749059165471; Wed, 04 Jun 2025 10:46:05 -0700 (PDT) Date: Wed, 4 Jun 2025 10:45:38 -0700 In-Reply-To: <20250604174545.2853620-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250604174545.2853620-1-irogers@google.com> X-Mailer: git-send-email 2.50.0.rc0.604.gd4ff7b7c86-goog Message-ID: <20250604174545.2853620-5-irogers@google.com> Subject: [PATCH v4 04/10] perf record: Switch user option to use BPF filter From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , Kan Liang , James Clark , Dapeng Mi , Thomas Richter , Veronika Molnarova , Chun-Tse Shao , Leo Yan , Hao Ge , Howard Chu , Weilin Wang , Levi Yun , "Dr. David Alan Gilbert" , Gautam Menghani , Tengda Wu , 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 user processes by scanning /proc is inherently racy and results in perf_event_open failures. Use a BPF filter to drop samples where the uid doesn't match. Ensure adding the BPF filter forces system-wide. Signed-off-by: Ian Rogers --- tools/perf/builtin-record.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 8059bce85a51..0b566f300569 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -175,6 +175,7 @@ struct record { bool timestamp_boundary; bool off_cpu; const char *filter_action; + const char *uid_str; struct switch_output switch_output; unsigned long long samples; unsigned long output_max_size; /* =3D 0: unlimited */ @@ -3513,8 +3514,7 @@ static struct option __record_options[] =3D { "or ranges of time to enable events e.g. '-D 10-20,30-40'", record__parse_event_enable_time), OPT_BOOLEAN(0, "kcore", &record.opts.kcore, "copy /proc/kcore"), - OPT_STRING('u', "uid", &record.opts.target.uid_str, "user", - "user to profile"), + OPT_STRING('u', "uid", &record.uid_str, "user", "user to profile"), =20 OPT_CALLBACK_NOOPT('b', "branch-any", &record.opts.branch_stack, "branch any", "sample any taken branches", @@ -4256,19 +4256,24 @@ int cmd_record(int argc, const char **argv) ui__warning("%s\n", errbuf); } =20 - err =3D target__parse_uid(&rec->opts.target); - if (err) { - int saved_errno =3D errno; + if (rec->uid_str) { + uid_t uid =3D parse_uid(rec->uid_str); =20 - target__strerror(&rec->opts.target, err, errbuf, BUFSIZ); - ui__error("%s", errbuf); + if (uid =3D=3D UINT_MAX) { + ui__error("Invalid User: %s", rec->uid_str); + err =3D -EINVAL; + goto out; + } + err =3D parse_uid_filter(rec->evlist, uid); + if (err) + goto out; =20 - err =3D -saved_errno; - goto out; + /* User ID filtering implies system wide. */ + rec->opts.target.system_wide =3D true; } =20 - /* Enable ignoring missing threads when -u/-p option is defined. */ - rec->opts.ignore_missing_thread =3D rec->opts.target.uid !=3D UINT_MAX ||= rec->opts.target.pid; + /* Enable ignoring missing threads when -p option is defined. */ + rec->opts.ignore_missing_thread =3D rec->opts.target.pid; =20 evlist__warn_user_requested_cpus(rec->evlist, rec->opts.target.cpu_list); =20 --=20 2.50.0.rc0.604.gd4ff7b7c86-goog