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=-8.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 24527C433B4 for ; Thu, 6 May 2021 14:44:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE5BF6103E for ; Thu, 6 May 2021 14:44:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234914AbhEFOp2 (ORCPT ); Thu, 6 May 2021 10:45:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:40660 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234836AbhEFOp1 (ORCPT ); Thu, 6 May 2021 10:45:27 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3F86B6103E; Thu, 6 May 2021 14:44:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620312268; bh=BOhOb6YgchE5ciMqLJmE7uRp8FW6NeGqAmUnITHfSVU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hvDyxTYYz+7gnw5cNYYNCDXxdLfrZECQ3xI/3yWIQ3URVZNyowehM36n2Juet/7AB WuY+G79hTYxn6YL45OCZuVoieyqD60yM46C4qcTJJR2r1l58pHhr++zBIPq5DhbudN zeLG3Uaeqhe3qtTcmfIuuITVrZFPG93O9TdvDjevkth3BBpUyX18VciivkyJXSyl/7 5aQ5GI+V+6A4WmJfdJzFRtFjqDPx32uZoCJlaNxkdgFnJd2PuicV8miLFmyl4tqbVm bd1p4T8uEMXTRa/EpHhTcz6wx4WYyC2mDLOQHRFBYifvpM027W7e7NYZAIg4aPt0Az aBHviYEG6l7qQ== Date: Thu, 6 May 2021 15:43:52 +0100 From: Mark Brown To: madvenka@linux.microsoft.com Cc: jpoimboe@redhat.com, mark.rutland@arm.com, jthierry@redhat.com, catalin.marinas@arm.com, will@kernel.org, jmorris@namei.org, pasha.tatashin@soleen.com, linux-arm-kernel@lists.infradead.org, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v3 4/4] arm64: Handle funtion graph tracer better in the unwinder Message-ID: <20210506144352.GF4642@sirena.org.uk> References: <65cf4dfbc439b010b50a0c46ec500432acde86d6> <20210503173615.21576-1-madvenka@linux.microsoft.com> <20210503173615.21576-5-madvenka@linux.microsoft.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="A9z/3b/E4MkkD+7G" Content-Disposition: inline In-Reply-To: <20210503173615.21576-5-madvenka@linux.microsoft.com> X-Cookie: If it ain't baroque, don't phiques it. User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --A9z/3b/E4MkkD+7G Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, May 03, 2021 at 12:36:15PM -0500, madvenka@linux.microsoft.com wrot= e: > From: "Madhavan T. Venkataraman" >=20 > The Function Graph Tracer modifies the return address of a traced function > to a return trampoline (return_to_handler()) to gather tracing data on > function return. When the unwinder encounters return_to_handler(), it cal= ls > ftrace_graph_get_ret_stack() to lookup the original return address in the > return address stack. This makes sense to me, I'll need to re-review properly with the changes earlier on in the series but should be fine. --A9z/3b/E4MkkD+7G Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmCUAKcACgkQJNaLcl1U h9AW0gf/UurypPhoAeS5tOMAkEizbXPWkIR/0u9nPaBTkZHxtXZw07LAQrvIQ/wC Q2UqJ3qIzHtM1KGaSWU+VOS2GYMY7WGmlhr6JNCmIk3LUuSoFxtlUYjwDoYWdKB+ UL7DhFiXJHHj6UfEquGtXpQ8WE9rl5s7c0MIxhbRmvXQVi12PLHobB0ksvZpGIkG tcceN55GrlF6fTByLeQQwstNiD35/5dByUW0Swg3zXeYalbqd3GIlCv63K69IvFG vCw4PoDBO6KCkped6KVPH9Mu7Ddf/8v8ZSOYVVTAVlRC+YNqpVDk942WbQsa7rBC p8/D0psgllhFHPKxnwfUli1sECzxVw== =zBTy -----END PGP SIGNATURE----- --A9z/3b/E4MkkD+7G--