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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 93C59C433DB for ; Mon, 1 Feb 2021 16:24:18 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 1989064DAF for ; Mon, 1 Feb 2021 16:24:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1989064DAF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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=merlin.20170209; h=Sender:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=DGx9ULD35HKQQgtZLOIdjw5Tx7ADt+ZEQJls8BODue0=; b=iny74HmKJ7dLQDKabSE+Trm4i zhQ4ZsSCVmciR2PjPW5v4i0WX9Wne7xaKO95b7S8s1uSm1DDDntrvVoFHODuo0yzVU47B3MjuRC6V XLD4uQJHE/3qpKXce+U0SXQlSKDxvI2aidLsnf4DH8Itnd522S36/mI+ANx2hl6KRXOLa6fobm7Bl dtoRgUAZQfE6+cbniGQSGaHOhKVWazpngcKCF9yYqhDz7jcQY1/shrGSfO4Y11UfToQFuQ3W3FYN+ rMkHPL817mS92TbpvGPieJ1viwWxVMACs4EMZbCG6z67Zj3D9j9yHrukfOteWv8gkPzsfgW4cHnyd QB6fvb5SA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6byn-0000Xk-Ua; Mon, 01 Feb 2021 16:23:10 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6byl-0000XI-N8 for linux-arm-kernel@lists.infradead.org; Mon, 01 Feb 2021 16:23:08 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 78E0F64DAF; Mon, 1 Feb 2021 16:23:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612196585; bh=4n3XADKWPG6NkNu3t6c2lyyzUFPW5KMJwFCVpzynrMo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=gjlcn5e1ExVIETU/4WfP5x0UCqLDe8Tt6d5Gw6/mHFTPJqh/O45+6XQTWOmLzPdY6 zfsH77AbLf22MEKLb94hBKh41RLZ/pwr/ytk2bqsg3VwwRzeFOHrm4tBfolqQ+7epJ zqnxxqIBJxkALHtVI3XsTpvqwMlSuXkBIKJ/+tHblYbuGIR2WaYmvTmw3CuvBhOXgk fHBlHIXrOHLvWNqQ2LLaRERQ7V0TplPtJqqrG4005BYcuGzuUlodzJh2ZJvciHutuN nrJOhJ5snN5UNrCfvk+D7kU31rb95V7ezWnfSttzAaWZCIcWbRX5R6t8MICdOT356D wnrHIAGrS1Zww== Date: Mon, 1 Feb 2021 16:22:18 +0000 From: Mark Brown To: Mark Rutland Subject: Re: [RFC PATCH 0/3] arm64: Implement reliable stack trace Message-ID: <20210201162218.GD5960@sirena.org.uk> References: <20201012172605.10715-1-broonie@kernel.org> <13095563-ff6d-b806-1bf3-efde4383456e@linux.microsoft.com> <20210128142250.GC4537@sirena.org.uk> <20210128152649.6zin3hzim3etbv2p@treble> <20210201160225.GD66060@C02TD0UTHF1T.local> MIME-Version: 1.0 In-Reply-To: <20210201160225.GD66060@C02TD0UTHF1T.local> X-Cookie: Place stamp here. User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210201_112307_866145_0A28E0BB X-CRM114-Status: GOOD ( 12.98 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Julien Thierry , Catalin Marinas , "Madhavan T. Venkataraman" , Josh Poimboeuf , Miroslav Benes , Will Deacon , linux-arm-kernel@lists.infradead.org Content-Type: multipart/mixed; boundary="===============8539494682477860462==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============8539494682477860462== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="iVCmgExH7+hIHJ1A" Content-Disposition: inline --iVCmgExH7+hIHJ1A Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Feb 01, 2021 at 04:02:25PM +0000, Mark Rutland wrote: > On Mon, Feb 01, 2021 at 09:21:43AM -0600, Madhavan T. Venkataraman wrote: > > OK. Before this whole discussion, I did not know that the compiler cannot be trusted. > I think "the compiler cannot be trusted" is overly strong. We want to > *verify* that the compiler is doing what we expect, which might be more > than what it guarantees to do (and those expectations can change over > time), but it doesn't mean we should try to avoid the compiler wherever > possible. Right, part of what objtool offers here is that it is a static checker which has an independent implementation of the assumptions we have about the generated code to that in the compiler - the fact that we've got two implementations means we're more likely to notice any implementation drift or unintended changes that affect those assumptions. Moving code generation into objtool would mean we were again relying on a single implementation. --iVCmgExH7+hIHJ1A Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmAYKroACgkQJNaLcl1U h9DdrQf9G4g8Dr6xSCqtFsWWkpfXWl7iF6jxOImjcm9kICuptsJh4tczas/eEqEi CPnckpAeOucZmxICi0nd4RJUY8vy25UYSM1DUC42S3i2ghp8yMq2MbfCIgt8U/tx LEToH2n4OlEOPfuJYQKXppO/gp/5hB1MorbI6mIFHhn23H3txhbCCJ194c+j2a0C ObMFTHNZ+HRQ/gnTotmOFrUfngyPChpCGh4Ak12RKHusk5HA6dsfqChIGe7YPpZn Td/wkYPEP2hc2VJop4Cin9SFJyjBntuYu1hwVlkK2e7+DJSXFE29YuOXAyslp4ac oqqTmo/6A31QE5IjAjA5KJ5mpHyzQA== =9fG6 -----END PGP SIGNATURE----- --iVCmgExH7+hIHJ1A-- --===============8539494682477860462== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============8539494682477860462==--