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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 E224BC433C1 for ; Tue, 23 Mar 2021 10:38:31 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 866DA6023B for ; Tue, 23 Mar 2021 10:38:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 866DA6023B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=DCkwZ2YK1P9e7N0jSh2/sJXNPyj/0PIL9FkuN1GJeTs=; b=jQ3ThdIXaCjifDnoc/2q9aQIJ Go1BWaZn+PFlV++jtev3QLUIrTiTZ9pdXrvs/IdSCJgAOodyL3kVgcAFLpyvYdW4+yHUPcaoU2e6T oeoeY3t8/q/WClXn+/ZDTfqd/NM+P2KofW7V9nrP6kveOnWaZ7AvEkf8xb6JuO6F+k2BFY4PWXTgI lftV/MoBGyzEnJNrv9B2bEHsvA8tRe4C8AfSlXxjUVPQhOeKwjYdQZJk8oZ9tXvuKVXPFvK1CtnM1 MBqSnRg7nbRHZuWMqdttZSXJpahTQEdM7b1ZtBF4qy4ajx21jihe+8eFJaTnDRmRw63CNoCkizrEL mgznB5PQg==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lOePA-00EdUx-3v; Tue, 23 Mar 2021 10:36:57 +0000 Received: from foss.arm.com ([217.140.110.172]) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lOeP5-00EdTp-Pd for linux-arm-kernel@lists.infradead.org; Tue, 23 Mar 2021 10:36:54 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E25D81042; Tue, 23 Mar 2021 03:36:49 -0700 (PDT) Received: from C02TD0UTHF1T.local (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B8EE63F719; Tue, 23 Mar 2021 03:36:47 -0700 (PDT) Date: Tue, 23 Mar 2021 10:36:44 +0000 From: Mark Rutland To: "Madhavan T. Venkataraman" Cc: Mark Brown , jpoimboe@redhat.com, jthierry@redhat.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v2 3/8] arm64: Terminate the stack trace at TASK_FRAME and EL0_FRAME Message-ID: <20210323103644.GC95840@C02TD0UTHF1T.local> References: <5997dfe8d261a3a543667b83c902883c1e4bd270> <20210315165800.5948-1-madvenka@linux.microsoft.com> <20210315165800.5948-4-madvenka@linux.microsoft.com> <20210318182607.GO5469@sirena.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210323_103652_059196_3F3C508F X-CRM114-Status: GOOD ( 21.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Mar 18, 2021 at 03:29:19PM -0500, Madhavan T. Venkataraman wrote: > > > On 3/18/21 1:26 PM, Mark Brown wrote: > > On Mon, Mar 15, 2021 at 11:57:55AM -0500, madvenka@linux.microsoft.com wrote: > > > >> + /* Terminal record, nothing to unwind */ > >> + if (fp == (unsigned long) regs->stackframe) { > >> + if (regs->frame_type == TASK_FRAME || > >> + regs->frame_type == EL0_FRAME) > >> + return -ENOENT; > >> return -EINVAL; > >> + } > > > > This is conflating the reliable stacktrace checks (which your series > > will later flag up with frame->reliable) with verifying that we found > > the bottom of the stack by looking for this terminal stack frame record. > > For the purposes of determining if the unwinder got to the bottom of the > > stack we don't care what stack type we're looking at, we just care if it > > managed to walk to this defined final record. > > > > At the minute nothing except reliable stack trace has any intention of > > checking the specific return code but it's clearer to be consistent. > > > > So, you are saying that the type check is redundant. OK. I will remove it > and just return -ENOENT on reaching the final record. Yes please; and please fold that into the same patch that adds the final records. Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel