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=-15.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,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 9F909C432C2 for ; Thu, 26 Sep 2019 00:33:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 734C9222C2 for ; Thu, 26 Sep 2019 00:33:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569457999; bh=RgsAanqTifp71PLJSM6G+W1ujaztqtJpBUszycOkJS4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=f49mgyhYRPirbfGO6lUpkz3b42moBqK6jGWvAvm7u/O9NOBzE2IRr+gWChWytSQxF nXv5YJF3HvDpy3FA5+JMX53TJKgY2P7vvH2ygjWdOd9NM/h8cZt3g7saLqM9TI/r// 8ms4CllMltMs71m3udhay3BrdABtok5psOgMsJ5I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729146AbfIZAdF (ORCPT ); Wed, 25 Sep 2019 20:33:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:35640 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726984AbfIZAdF (ORCPT ); Wed, 25 Sep 2019 20:33:05 -0400 Received: from quaco.localdomain (unknown [179.97.35.50]) (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 6EC3D21D7B; Thu, 26 Sep 2019 00:33:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569457984; bh=RgsAanqTifp71PLJSM6G+W1ujaztqtJpBUszycOkJS4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JZoDjmkVz/+hDt/OY7il9w1vGPwia3yekvCrkD0hPXXwk5Se67JoqpYwEGv7N8oU0 dfMTNsD1SLoL0tPVExLs6B4sA2NvjG0mq0tI+CtoFNzYwXlE/XXGHw/Z3d3YN+h42o rTbejam7cBhenHyjdzpvGrUR/x/aopZ0GhCK+hgU= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , Adrian Hunter , Stephane Eranian Subject: [PATCH 02/66] perf record: Move restricted maps check to after a possible fallback to not collect kernel samples Date: Wed, 25 Sep 2019 21:31:40 -0300 Message-Id: <20190926003244.13962-3-acme@kernel.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190926003244.13962-1-acme@kernel.org> References: <20190926003244.13962-1-acme@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnaldo Carvalho de Melo Before: [acme@quaco ~]$ perf record -b -e cycles date WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted, check /proc/sys/kernel/kptr_restrict and /proc/sys/kernel/perf_event_paranoid. Samples in kernel functions may not be resolved if a suitable vmlinux file is not found in the buildid cache or in the vmlinux path. Samples in kernel modules won't be resolved at all. If some relocation was applied (e.g. kexec) symbols may be misresolved even with a suitable vmlinux or kallsyms file. Mon 23 Sep 2019 11:00:59 AM -03 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.005 MB perf.data (14 samples) ] [acme@quaco ~]$ But we did a fallback and exclude_kernel was set, so no need for resolving kernel symbols: $ perf evlist -v cycles:u: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD|BRANCH_STACK, read_format: ID, disabled: 1, inherit: 1, exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, branch_sample_type: ANY $ After: [acme@quaco ~]$ perf record -b -e cycles date Mon 23 Sep 2019 11:07:18 AM -03 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.007 MB perf.data (16 samples) ] [acme@quaco ~]$ perf evlist -v cycles:u: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD|BRANCH_STACK, read_format: ID, disabled: 1, inherit: 1, exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, branch_sample_type: ANY [acme@quaco ~]$ No needless warning is emitted. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian Link: https://lkml.kernel.org/n/tip-5yqnr8xcqwhr15xktj2097ac@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-record.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 3f66a49a997f..1e1f97139f16 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -788,6 +788,17 @@ static int record__open(struct record *rec) pos->supported = true; } + if (symbol_conf.kptr_restrict && !perf_evlist__exclude_kernel(evlist)) { + pr_warning( +"WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted,\n" +"check /proc/sys/kernel/kptr_restrict and /proc/sys/kernel/perf_event_paranoid.\n\n" +"Samples in kernel functions may not be resolved if a suitable vmlinux\n" +"file is not found in the buildid cache or in the vmlinux path.\n\n" +"Samples in kernel modules won't be resolved at all.\n\n" +"If some relocation was applied (e.g. kexec) symbols may be misresolved\n" +"even with a suitable vmlinux or kallsyms file.\n\n"); + } + if (perf_evlist__apply_filters(evlist, &pos)) { pr_err("failed to set filter \"%s\" on event %s with %d (%s)\n", pos->filter, perf_evsel__name(pos), errno, @@ -2364,16 +2375,6 @@ int cmd_record(int argc, const char **argv) err = -ENOMEM; - if (symbol_conf.kptr_restrict && !perf_evlist__exclude_kernel(rec->evlist)) - pr_warning( -"WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted,\n" -"check /proc/sys/kernel/kptr_restrict and /proc/sys/kernel/perf_event_paranoid.\n\n" -"Samples in kernel functions may not be resolved if a suitable vmlinux\n" -"file is not found in the buildid cache or in the vmlinux path.\n\n" -"Samples in kernel modules won't be resolved at all.\n\n" -"If some relocation was applied (e.g. kexec) symbols may be misresolved\n" -"even with a suitable vmlinux or kallsyms file.\n\n"); - if (rec->no_buildid_cache || rec->no_buildid) { disable_buildid_cache(); } else if (rec->switch_output.enabled) { -- 2.21.0