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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 03327C43461 for ; Tue, 8 Sep 2020 17:07:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA18621D40 for ; Tue, 8 Sep 2020 17:07:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599584825; bh=5lqjgR8g9+OBvNFISo9CIMaYPERA98kvgU95UhpC3E4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=u/Sz97tvyBe8qAtB4WUEOXplRi5SizDXDmejdkOvdEnQDdpYUzBDk93gbpffudpx6 2irZSFPffpQLkmuPz2e+BJTQW5hjeO4PFtUdGBRThtCOobc26JN8kCY0Qw9v4dyrl6 40w/3Pg0rkktDTOLZk1Ni+stMp+XcRsfr+sti19o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731788AbgIHRHB (ORCPT ); Tue, 8 Sep 2020 13:07:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:57568 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731811AbgIHQTU (ORCPT ); Tue, 8 Sep 2020 12:19:20 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 95A1323C43; Tue, 8 Sep 2020 15:36:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599579377; bh=5lqjgR8g9+OBvNFISo9CIMaYPERA98kvgU95UhpC3E4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=v7vXP07hk5zBazan5uzyjz822JVO3M2usN7+82Ml9DcOeDNka2ZeQzrVLl+vWY7n5 JkB0aWObAq2VSWu6+kzjr5ry8q6ylexUiU2zTrfmAo56cN1at0JdDg5iQYMu8sroYw ymJ36H31f0NK9d9ivzBxvoeJC1RAfIWUPHJIuaKE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tiezhu Yang , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Mark Rutland , Namhyung Kim , Peter Zijlstra , Xuefeng Li , Sasha Levin Subject: [PATCH 5.8 053/186] perf top: Skip side-band event setup if HAVE_LIBBPF_SUPPORT is not set Date: Tue, 8 Sep 2020 17:23:15 +0200 Message-Id: <20200908152244.243347192@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200908152241.646390211@linuxfoundation.org> References: <20200908152241.646390211@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tiezhu Yang [ Upstream commit 0c5f1acc2a14416bf30023f373558d369afdbfc8 ] When I execute 'perf top' without HAVE_LIBBPF_SUPPORT, there exists the following segmentation fault, skip the side-band event setup to fix it, this is similar with commit 1101c872c8c7 ("perf record: Skip side-band event setup if HAVE_LIBBPF_SUPPORT is not set"). [yangtiezhu@linux perf]$ ./perf top perf: Segmentation fault Obtained 6 stack frames. ./perf(sighandler_dump_stack+0x5c) [0x12011b604] [0xffffffc010] ./perf(perf_mmap__read_init+0x3e) [0x1201feeae] ./perf() [0x1200d715c] /lib64/libpthread.so.0(+0xab9c) [0xffee10ab9c] /lib64/libc.so.6(+0x128f4c) [0xffedc08f4c] Segmentation fault [yangtiezhu@linux perf]$ I use git bisect to find commit b38d85ef49cf ("perf bpf: Decouple creating the evlist from adding the SB event") is the first bad commit, so also add the Fixes tag. Committer testing: First build perf explicitely disabling libbpf: $ make NO_LIBBPF=1 O=/tmp/build/perf -C tools/perf install-bin && perf test python Now make sure it isn't linked: $ perf -vv | grep -w bpf bpf: [ OFF ] # HAVE_LIBBPF_SUPPORT $ $ nm ~/bin/perf | grep libbpf $ And now try to run 'perf top': # perf top perf: Segmentation fault -------- backtrace -------- perf[0x5bcd6d] /lib64/libc.so.6(+0x3ca6f)[0x7fd0f5a66a6f] perf(perf_mmap__read_init+0x1e)[0x5e1afe] perf[0x4cc468] /lib64/libpthread.so.0(+0x9431)[0x7fd0f645a431] /lib64/libc.so.6(clone+0x42)[0x7fd0f5b2b912] # Applying this patch fixes the issue. Fixes: b38d85ef49cf ("perf bpf: Decouple creating the evlist from adding the SB event") Signed-off-by: Tiezhu Yang Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Xuefeng Li Link: http://lore.kernel.org/lkml/1597753837-16222-1-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/builtin-top.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 13889d73f8dd5..c665d69c0651d 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -1746,6 +1746,7 @@ int cmd_top(int argc, const char **argv) goto out_delete_evlist; } +#ifdef HAVE_LIBBPF_SUPPORT if (!top.record_opts.no_bpf_event) { top.sb_evlist = evlist__new(); @@ -1759,6 +1760,7 @@ int cmd_top(int argc, const char **argv) goto out_delete_evlist; } } +#endif if (perf_evlist__start_sb_thread(top.sb_evlist, target)) { pr_debug("Couldn't start the BPF side band thread:\nBPF programs starting from now on won't be annotatable\n"); -- 2.25.1