From patchwork Fri Feb 2 23:40:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Rogers X-Patchwork-Id: 13543576 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (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 4F27412F361 for ; Fri, 2 Feb 2024 23:41:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706917276; cv=none; b=VUqKWDyXeUHIZZPzzU1INHvUdv4lEbL+5ZEKSRIDm6Qxq2NzkQFyalWy0Q9QqNJ9MluK9+H+KldNzKO8WUU0pAdkW37bIdefCfReZyIr5eRWZPurE8gex0aFHvywrzvzRTWw5s32767sEI50y4UIoKKeQ7L7tYPpZ+4x6i66d7g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706917276; c=relaxed/simple; bh=R7HDLt+WXCKcw0UAraBcZnWD54QthkXyaQu13uOf35M=; h=Date:In-Reply-To:Message-Id:Mime-Version:References:Subject:From: To:Content-Type; b=XKpmu8y8+udJTpwzDBGaVjNKVjon810ETvYveNdP+/AnoOJk2a3mIxJnJzBDWDqK8v4maTvtRkRh8h02fy7R/asCXEGuYtKTosbtF3pz+GDzdujeDAFwK4re7uxs+lhUTAL+C5jvMmxY0AifESMkpuy4pU5yx07MKZ4IqgMA5v4= 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=AyrvHKJj; arc=none smtp.client-ip=209.85.128.202 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="AyrvHKJj" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-60436130450so9478377b3.0 for ; Fri, 02 Feb 2024 15:41:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1706917274; x=1707522074; 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=wOc7/ot5clrlqkd/XVVApb41eylij+dgoGLfSlWPOp0=; b=AyrvHKJjjXcpTnTw4Q1Oh72rOi5vJrbZ3NSKSgFRcmHrdQ9urAxqzaDeeAWfqmw1CL V2OIprdiY9MJ0htwTWHjbjukLdw7GmjOkyqarwZWfqn2/8Nov6Ocp/QbJOAyaHPZqEhv hziwunHjYpud1MfPnxCijqL4At/8TCLcXP3ITG/sHjJf5dLMZBDCWVnSsVuJpt8WizXl wZDeqrqXusMSV10naS2Ovb/WYhlAqQRr2Xtbkc0txIShOu29QlZQm42MK7Ezu4CBW1H2 OxpzDQzCpQwQLEealrpbXlNFI9Pleu4GOdpHUI3AnJSzmnPwCCL/ker674WkFBkQGxwz OW2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706917274; x=1707522074; 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=wOc7/ot5clrlqkd/XVVApb41eylij+dgoGLfSlWPOp0=; b=JTMrIf7nBYwqIW4+FXBYjif7LWc5R0IauQvtLxhjmLU7L8wCFEdUnUw69d//GoydZn Bf8qWi6VB5SVBj8ctKn16NBGxZCPUsRuf5KhfXsk3wXdWQDmmwofkNgHGLJFJDb2DNg4 SKMhi8BLd3vbjnY177MmAFm2NO3bnbIKTuhplk6CbJtN6sD+UXmG37/mfp2iRXW5O7Ga 0WxkeOUVkG7ruz/p46OUnU3lovUV1Z6ENzqj+n9MjMTi8E9m/YEbPXRAQei7TBt+eK2/ AJVTnQuL24Pu8QwwBgSfWO2/H15Po8rhsXRg0xGwPKltAc952lb9Z9j+TqZw2KveXo3C ZjKA== X-Gm-Message-State: AOJu0Ywgw2TSQT0z/tsBVBw0TDo8Y4vMf33m+a3dyJ019Cm0c841USg0 SvHy1gG/jHFtatFK4cybuXVgUpPC4rGyRMfy4RXtzl+TJ3qxbWaBoDxtx5ZXc4hHxho/yOLblnv 4+ywgyw== X-Google-Smtp-Source: AGHT+IHFL6+6WJT+TDjsN0v4AycgXqtEdFuE4PFoyenBnNnNjcCA2pFf3NUeukXxzibAja4cMAtIanSVNF3E X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:7732:d863:503:f53d]) (user=irogers job=sendgmr) by 2002:a05:6902:1b08:b0:dc2:398d:a671 with SMTP id eh8-20020a0569021b0800b00dc2398da671mr1024554ybb.10.1706917274174; Fri, 02 Feb 2024 15:41:14 -0800 (PST) Date: Fri, 2 Feb 2024 15:40:51 -0800 In-Reply-To: <20240202234057.2085863-1-irogers@google.com> Message-Id: <20240202234057.2085863-3-irogers@google.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240202234057.2085863-1-irogers@google.com> X-Mailer: git-send-email 2.43.0.594.gd9cf4e227d-goog Subject: [PATCH v3 2/8] libperf cpumap: Ensure empty cpumap is NULL from alloc From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Suzuki K Poulose , Mike Leach , James Clark , Leo Yan , John Garry , Will Deacon , Thomas Gleixner , Darren Hart , Davidlohr Bueso , " =?utf-8?q?Andr=C3=A9_Almeida?= " , Kan Liang , K Prateek Nayak , Sean Christopherson , Paolo Bonzini , Kajol Jain , Athira Rajeev , Andrew Jones , Alexandre Ghiti , Atish Patra , "Steinar H. Gunderson" , Yang Jihong , Yang Li , Changbin Du , Sandipan Das , Ravi Bangoria , Paran Lee , Nick Desaulniers , Huacai Chen , Yanteng Si , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, bpf@vger.kernel.org Potential corner cases could cause a cpumap to be allocated with size 0, but an empty cpumap should be represented as NULL. Add a path in perf_cpu_map__alloc to ensure this. Suggested-by: James Clark Closes: https://lore.kernel.org/lkml/2cd09e7c-eb88-6726-6169-647dcd0a8101@arm.com/ Signed-off-by: Ian Rogers --- tools/lib/perf/cpumap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c index ba49552952c5..cae799ad44e1 100644 --- a/tools/lib/perf/cpumap.c +++ b/tools/lib/perf/cpumap.c @@ -18,9 +18,13 @@ void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus) struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus) { - RC_STRUCT(perf_cpu_map) *cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus); + RC_STRUCT(perf_cpu_map) *cpus; struct perf_cpu_map *result; + if (nr_cpus == 0) + return NULL; + + cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus); if (ADD_RC_CHK(result, cpus)) { cpus->nr = nr_cpus; refcount_set(&cpus->refcnt, 1);