From patchwork Wed Apr 5 02:21:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 79433 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b0ea:0:b0:3b6:4342:cba0 with SMTP id b10csp13208vqo; Tue, 4 Apr 2023 19:29:35 -0700 (PDT) X-Google-Smtp-Source: AKy350YmjF2+iNGSn1W6lFpey8MhEA1krgSyCg9w8ZEcEAiWTu95j3BTUzC4urxp6VgL+jvuyVbY X-Received: by 2002:a17:906:6d6:b0:8f6:5a70:cccc with SMTP id v22-20020a17090606d600b008f65a70ccccmr1501662ejb.66.1680661775419; Tue, 04 Apr 2023 19:29:35 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1680661775; cv=none; d=google.com; s=arc-20160816; b=x8ymGhFJ/n2QNaU/yfIURoSDd86xbhzTIRcowdhBiAF85FYeyvnJHwDs9LxN+FTiuM jDc+QvCLU8Ll92nTXh6XTssa6A3D3U9pb1BFwZ6wXrpXGFoPHqBBNwKHoIkDfL3m1Epy 90tkT6zO9tP3DdFOWbaBU8N6TlB7d3Hrq4PxkuZCiTjE3VUGPCZtjpUNX0vgwUox8/HJ VNLEZzpohw0mE38qUZZ3pdaaPVnAlZCgkceK7IKTwK4MRE8gFZsXugAm/Y3qTx5rgBvH dK8mx94KQHDZTR3cVaAPUOQECycrylidaSQSrp7G2CMYgx4cAdo+pH6+B2v9GVrnYuGi tyaQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:references:subject:cc:to:from:date :user-agent:message-id; bh=fwRbmplwV6PzqCn5hv6PV93bWVrYQQVpzsuhmxJrKSg=; b=THqisPapPvnXHdRKqHLwD1IEk6uQeOGM5DQNpXRU7sZFy3pAGIOXEpMASdBOlZkLKx J6uAvKFNl+O5iVZMEqlQk4AkUfhLhmlCgX0lKEs0d42WQdeGh03LaY/ZijskwcCJj7dT Mz5XNMho9WoVbzw45EI15auR/l/0xECnk+n9VisfFI30nFdEaQP8ge81FI06sMiMG9Uk eDPojyIk7m8oXmriCns8thZfriOq8ruxJFww8JfkFYcGlc7F6KrFDpyXWTTBAfiOkFns hCCDukJxkGqgT+HrSUlVY98fmXf6Ff0JMKvVTs65/m2lqNXXyfgccL8OVCnEwssXK3pf djlQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id x2-20020a170906804200b0093e5bd9064esi1804204ejw.482.2023.04.04.19.29.11; Tue, 04 Apr 2023 19:29:35 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236532AbjDECXw (ORCPT + 99 others); Tue, 4 Apr 2023 22:23:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42320 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236548AbjDECXp (ORCPT ); Tue, 4 Apr 2023 22:23:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39B282106; Tue, 4 Apr 2023 19:23:44 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C022B60DD5; Wed, 5 Apr 2023 02:23:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A30CC4339E; Wed, 5 Apr 2023 02:23:43 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.96) (envelope-from ) id 1pjsoI-000hVn-0E; Tue, 04 Apr 2023 22:23:42 -0400 Message-ID: <20230405022341.895334039@goodmis.org> User-Agent: quilt/0.66 Date: Tue, 04 Apr 2023 22:21:15 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Andrew Morton , Ross Zwisler , stable@vger.kernel.org Subject: [PATCH 2/2 v2] tracing: Fix ftrace_boot_snapshot command line logic References: <20230405022113.860447811@goodmis.org> MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1762301602127116328?= X-GMAIL-MSGID: =?utf-8?q?1762301602127116328?= From: "Steven Rostedt (Google)" The kernel command line ftrace_boot_snapshot by itself is supposed to trigger a snapshot at the end of boot up of the main top level trace buffer. A ftrace_boot_snapshot=foo will do the same for an instance called foo that was created by trace_instance=foo,... The logic was broken where if ftrace_boot_snapshot was by itself, it would trigger a snapshot for all instances that had tracing enabled, regardless if it asked for a snapshot or not. When a snapshot is requested for a buffer, the buffer's tr->allocated_snapshot is set to true. Use that to know if a trace buffer wants a snapshot at boot up or not. Since the top level buffer is part of the ftrace_trace_arrays list, there's no reason to treat it differently than the other buffers. Just iterate the list if ftrace_boot_snapshot was specified. Cc: stable@vger.kernel.org Fixes: 9c1c251d670bc ("tracing: Allow boot instances to have snapshot buffers") Signed-off-by: Steven Rostedt (Google) --- Changes since v1: https://lkml.kernel.org/r/20230404230308.501833715@goodmis.org - Protect use of tr->allocated_snapshot around #ifdef TRACER_MAX_TRACE kernel/trace/trace.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 93740a9370c6..36a6037823cd 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -10394,19 +10394,20 @@ __init static int tracer_alloc_buffers(void) void __init ftrace_boot_snapshot(void) { +#ifdef CONFIG_TRACER_MAX_TRACE struct trace_array *tr; - if (snapshot_at_boot) { - tracing_snapshot(); - internal_trace_puts("** Boot snapshot taken **\n"); - } + if (!snapshot_at_boot) + return; list_for_each_entry(tr, &ftrace_trace_arrays, list) { - if (tr == &global_trace) + if (!tr->allocated_snapshot) continue; - trace_array_puts(tr, "** Boot snapshot taken **\n"); + tracing_snapshot_instance(tr); + trace_array_puts(tr, "** Boot snapshot taken **\n"); } +#endif } void __init early_trace_init(void)