Received: by 2002:a25:868d:0:0:0:0:0 with SMTP id z13csp498118ybk; Fri, 15 May 2020 06:17:22 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxbmWdj5qND+2UeoSYa5kxyxnwdXf9P8XDX3S6eD6PLvcbwM/q8HE12F5dxyVbhpu9mWfh2 X-Received: by 2002:a17:906:27d1:: with SMTP id k17mr2633536ejc.134.1589548642782; Fri, 15 May 2020 06:17:22 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1589548642; cv=none; d=google.com; s=arc-20160816; b=KF/8J62tnSnaKQNWiAUSvNjHg/b+rcPBkFzwHe5E7Vq+L5+e6B0SU0i3b97vqhmv/q HA4A4x+aSVuwhXYcwJKNSMAn9vCBbbhyDPKaX0MKVUuxgSf0sU+jxQEFK2S4RExLRfXS L2bvtQInjrcxXuKzTcRdmJHHQXppdjYG1yXVJSV4kgNXMT/H4F3jPNgxsiRWEG9NOOZn 8kfu/KLfDB3ADnx+DlInuE66wrfL8XgUhlyDk1w5T6F8gb2XfiaZvQHLDrQ2Kbxz0lZk fDLBPABcgVrFSgT+aKK7og6bTNsY2A7UGHgAx5ixgrZWzidolI/HoA/7e3YP82fgG5Jd NM6w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:subject:cc:to:from:date; bh=VrOvHfRPZDm4fvzo+a5aXq248cgCV0I3AwHGwgQyBjE=; b=0eyeAA+psJoPXb7j+HBRl0NDuACH+w7gOh7ZA3kNJQlR6OArYLdHHGTqOLH/h36lfg hFiJHFkmeKKXGMyqZwROvLhJJI02NES56yoMOeHk9p+vwF6xGlOpr3tph+Q/dcumyMp4 nENJg2PY9hoW1+2VwXRr/XGeaQCqeOfUmAVIqkWEImXRqRN5v2FcjM9X0od+895fvRzK DeY+5dl53o3FZqdUyUsCfvxfYJt4s0K0JEjJDRmszUR7Oz3GYx6HzShn0KODAPJJMDUI 1Gg3YzWV+9gbx0yQrRrJ6P1t0XXWY8a88B7lszocnoQFLQ6pxIXqJ+wQQkRG8ka9FaqI 7qig== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id e18si1185098ejh.211.2020.05.15.06.16.59; Fri, 15 May 2020 06:17:22 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726297AbgEONPQ (ORCPT + 99 others); Fri, 15 May 2020 09:15:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:56340 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726140AbgEONPQ (ORCPT ); Fri, 15 May 2020 09:15:16 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 053BF206D4; Fri, 15 May 2020 13:15:14 +0000 (UTC) Date: Fri, 15 May 2020 09:15:13 -0400 From: Steven Rostedt To: Cheng Jian Cc: , , , , , Subject: Re: [PATCH] ftrace: show debugging information when panic_on_warn set Message-ID: <20200515091513.4947ff02@gandalf.local.home> In-Reply-To: <20200515100828.7091-1-cj.chengjian@huawei.com> References: <20200515100828.7091-1-cj.chengjian@huawei.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 15 May 2020 10:08:28 +0000 Cheng Jian wrote: > When an anomaly is detected in the function call modification > code, ftrace_bug() is called to disable function tracing as well > as give some warn and information that may help debug the problem. > > But currently, we call FTRACE_WARN_ON_ONCE() first in ftrace_bug(), > so when panic_on_warn is set, we can't see the debugging information > here. Call FTRACE_WARN_ON_ONCE() at the end of ftrace_bug() to ensure > that the debugging information is displayed first. > > after this patch, the dmesg looks like: > Thanks, I'll add this to my queue. -- Steve