From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 067B4C433FF for ; Fri, 2 Aug 2019 08:32:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D6249218BA for ; Fri, 2 Aug 2019 08:32:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404234AbfHBIcW (ORCPT ); Fri, 2 Aug 2019 04:32:22 -0400 Received: from mail5.windriver.com ([192.103.53.11]:50568 "EHLO mail5.wrs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729866AbfHBIcW (ORCPT ); Fri, 2 Aug 2019 04:32:22 -0400 Received: from ALA-HCB.corp.ad.wrs.com (ala-hcb.corp.ad.wrs.com [147.11.189.41]) by mail5.wrs.com (8.15.2/8.15.2) with ESMTPS id x728Twtg028074 (version=TLSv1 cipher=AES128-SHA bits=128 verify=FAIL); Fri, 2 Aug 2019 01:30:19 -0700 Received: from pek-lpg-core2.corp.ad.wrs.com (128.224.153.41) by ALA-HCB.corp.ad.wrs.com (147.11.189.41) with Microsoft SMTP Server id 14.3.468.0; Fri, 2 Aug 2019 01:29:55 -0700 From: To: , , , , , , , , , , Subject: [PATCH 1/2] perf: Fix failure to set cpumask when only one cpu Date: Fri, 2 Aug 2019 16:29:51 +0800 Message-ID: <1564734592-15624-1-git-send-email-zhe.he@windriver.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: He Zhe The buffer containing string used to set cpumask is overwritten by end of string later in cpu_map__snprint_mask due to not enough memory space, when there is only one cpu. And thus causes the following failure. $ perf ftrace ls failed to reset ftrace This patch fixes the calculation of cpumask string size. Signed-off-by: He Zhe --- tools/perf/builtin-ftrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 66d5a66..0193128 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -173,7 +173,7 @@ static int set_tracing_cpumask(struct cpu_map *cpumap) int last_cpu; last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1); - mask_size = (last_cpu + 3) / 4 + 1; + mask_size = last_cpu / 4 + 2; /* one more byte for EOS */ mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */ cpumask = malloc(mask_size); -- 2.7.4