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=-7.9 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=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 EDED2C47078 for ; Fri, 21 May 2021 16:11:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA4C161164 for ; Fri, 21 May 2021 16:11:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236820AbhEUQMq (ORCPT ); Fri, 21 May 2021 12:12:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:33266 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229586AbhEUQMn (ORCPT ); Fri, 21 May 2021 12:12:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6BC12613DB; Fri, 21 May 2021 16:11:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621613480; bh=FNm3jXDRWoCbHZUTEZ8FokhLVtkukv3XsTG0pBzmCNU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pzjPEFKSOYGIVYk5X+06MjnSj+zbF9uPA3+xtNQf31RQJJqJ8JVI5nwbY4d+SYK9u nv/8OayJ21Sztmy0ci0rAku1MnBOHXrgzRHFn1v0yhUjLNSL5AU679ECBfG8VaqwlG l4/zpYHHvBW+CpXy/02qwPlf9EGtdftKNAaAEzxkPU8vQDpFW/m/i57FU3aXo2v2I5 79ErOLvQQD7beWhlcZkMGbINB7Lx7W7B2NhG/iUXGJzZz6tOD0K/ZK+28PXppHqhls fNONnG/6uDG61qsBMapKZjVYjmrKh1jwavLZZ4Iim8rRPda8fyx8vVyyRLArwAmtuW aP7sf32GFf+cA== Date: Fri, 21 May 2021 17:11:17 +0100 From: Mark Brown To: madvenka@linux.microsoft.com Cc: mark.rutland@arm.com, jpoimboe@redhat.com, ardb@kernel.org, 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 v4 1/2] arm64: Introduce stack trace reliability checks in the unwinder Message-ID: <20210521161117.GB5825@sirena.org.uk> References: <68eeda61b3e9579d65698a884b26c8632025e503> <20210516040018.128105-1-madvenka@linux.microsoft.com> <20210516040018.128105-2-madvenka@linux.microsoft.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="rJwd6BRFiFCcLxzm" Content-Disposition: inline In-Reply-To: <20210516040018.128105-2-madvenka@linux.microsoft.com> X-Cookie: Do not write below this line. User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --rJwd6BRFiFCcLxzm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sat, May 15, 2021 at 11:00:17PM -0500, madvenka@linux.microsoft.com wrote: > Other reliability checks will be added in the future. ... > + frame->reliable = true; > + All these checks are good checks but as you say there's more stuff that we need to add (like your patch 2 here) so I'm slightly nervous about actually setting the reliable flag here without even a comment. Equally well there's no actual use of this until arch_stack_walk_reliable() gets implemented so it's not like it's causing any problems and it gives us the structure to start building up the rest of the checks. The other thing I guess is the question of if we want to bother flagging frames as unrelaible when we return an error; I don't see an issue with it and it may turn out to make it easier to do something in the future so I'm fine with that. --rJwd6BRFiFCcLxzm Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmCn26QACgkQJNaLcl1U h9BRjwf+NUkllMR4DUBzihQYZz8gFCBdrphJycb1capE54XA922TiNiSHdNs6Un2 og9xrHSmjkris4pNB4/EoZ8drNtDgp3x8Rwgg7RbRhA0xujYmOoWGJuhdEuUEjID jlkGNpt3oRJgBtEl3evUCSmXW0GK5a3emGmYA1yzUtuCFNIU4IfwO6r0d9R4Vc0U koUUak44PssXvqETo+iCX8BFh1dCVB8hTrPQJRpTjxHUcljYUxRK5/7aT1pj2L/R viAnHaZVX5h7RHy4oc/kKUG5jEY4WWdZembkRUhVjbYy+tNc5SLGNi9Gd3G8BxJw YGsb0HGPBSkXuoM3WVDdcHpNRe3/Hw== =FYp0 -----END PGP SIGNATURE----- --rJwd6BRFiFCcLxzm--