From patchwork Wed Apr 5 13:58:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 79704 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b0ea:0:b0:3b6:4342:cba0 with SMTP id b10csp358896vqo; Wed, 5 Apr 2023 07:41:10 -0700 (PDT) X-Google-Smtp-Source: AKy350Z2ve6T1QqTB8fhloZbDEjoI5LwErQ7oFFsH7w+DNrIgcTMrkqYHc314lv9rA5cxuKyL1pP X-Received: by 2002:a17:906:ce41:b0:944:394:93f7 with SMTP id se1-20020a170906ce4100b00944039493f7mr2852402ejb.61.1680705670099; Wed, 05 Apr 2023 07:41:10 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1680705670; cv=none; d=google.com; s=arc-20160816; b=gtTbA0rqc1MkUPjjenGCKMuHjiyq+1CUGX61hK+E65mDC2kzjADutSCVRhUwKrZIht rXggVldivQm7cw3grd4gvkUj9iQezCHd760aF6mYZtWKmlZCYb4wYGLkvlSIBvsnscdM Sl6ZCXahLK79R5RdhVukiWeF17/OkIOgJp4Yz0A3N2mjCHtVRz4rULMe0W7JL1J4Z+aS xAb5r+ZwZGfwYoFW4V9qCt/6R5F797mlfIWdvjomcpy3fuJVYmHUAaN81zeP8RZpgpVG HjbMqsXiy+dL22Jre3f6sPdAbDZM/9ho7RBPDon5IvXkGzEZ347SsT5PLoJPMIpJRgew sfZA== 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=7q3TZ+m0F0wuqhxwF0ZY6Oq0IFcp/vTigJAui8KXEfc=; b=pA3Ix7tace2ErFEgAHaiX0KSC1wIEYp2C8ge4qlVjrEWuVj+lk9WGNFdQrjsi+KoFb hFpzDK0JYfGMmS7cE0YdbE6snbk/lr64y/NRtvtef1oAN6um1Y5lba1xZbIrcLCRPkRt Va+jy0O4rR5rf65ucUWQpoyClM4AIIL1yFyQ1Kg2dEJQD59LKRVOIyENhgoyqV9aICPI 46/UX7xnMlBYZMQrkR59W5ECbTSVQg3BR7ajbCNpMhZV0sqau8ZSd1XiLkS7GP/JO0AY F62ZW2kWcqMqdZ+iAhosy9dSWCYh4X+/GdYHVHDkSs0h/9iXlUZKyx+BkTg8t+A65/bp NTcA== 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 bm11-20020a170906c04b00b0092043425e1bsi881886ejb.714.2023.04.05.07.40.45; Wed, 05 Apr 2023 07:41:10 -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 S238545AbjDEO1R (ORCPT + 99 others); Wed, 5 Apr 2023 10:27:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238496AbjDEO1J (ORCPT ); Wed, 5 Apr 2023 10:27:09 -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 16A84E7B; Wed, 5 Apr 2023 07:26:57 -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 95592625AC; Wed, 5 Apr 2023 14:26:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D56DC433A0; Wed, 5 Apr 2023 14:26:56 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.96) (envelope-from ) id 1pk46A-000qk7-3D; Wed, 05 Apr 2023 10:26:55 -0400 Message-ID: <20230405142654.813714541@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 05 Apr 2023 09:58:15 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Andrew Morton , stable@vger.kernel.org, Ross Zwisler Subject: [for-linus][PATCH 2/3] tracing: Fix ftrace_boot_snapshot command line logic References: <20230405135813.735507007@goodmis.org> MIME-Version: 1.0 X-Spam-Status: No, score=-2.0 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?1762347628578993140?= X-GMAIL-MSGID: =?utf-8?q?1762347628578993140?= 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. Link: https://lkml.kernel.org/r/20230405022341.895334039@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Andrew Morton Cc: Ross Zwisler Fixes: 9c1c251d670bc ("tracing: Allow boot instances to have snapshot buffers") Signed-off-by: Steven Rostedt (Google) --- 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 ed1d1093f5e9..4686473b8497 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -10393,19 +10393,20 @@ __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)