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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 9E84BC5DF61 for ; Thu, 7 Nov 2019 08:21:46 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (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 55C0E20673 for ; Thu, 7 Nov 2019 08:21:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 55C0E20673 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 477xFh3MfgzF5qF for ; Thu, 7 Nov 2019 19:21:44 +1100 (AEDT) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 477q734Ly5zF5wZ for ; Thu, 7 Nov 2019 14:45:35 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: by ozlabs.org (Postfix) id 477q730FcSz9sRD; Thu, 7 Nov 2019 14:45:35 +1100 (AEDT) Received: by ozlabs.org (Postfix, from userid 1034) id 477q725sMzz9sR4; Thu, 7 Nov 2019 14:45:34 +1100 (AEDT) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: b9e0805abf2e92fc275ac5fbd8c1c9a92b00413d In-Reply-To: <20191030111231.22720-1-mpe@ellerman.id.au> To: Michael Ellerman , linuxppc-dev@ozlabs.org From: Michael Ellerman Subject: Re: [PATCH] powerpc: Add build-time check of ptrace PT_xx defines Message-Id: <477q725sMzz9sR4@ozlabs.org> Date: Thu, 7 Nov 2019 14:45:34 +1100 (AEDT) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, 2019-10-30 at 11:12:31 UTC, Michael Ellerman wrote: > As part of the uapi we export a lot of PT_xx defines for each register > in struct pt_regs. These are expressed as an index from gpr[0], in > units of unsigned long. > > Currently there's nothing tying the values of those defines to the > actual layout of the struct. > > But we *don't* want to change the uapi defines to derive the PT_xx > values based on the layout of the struct, those values are ABI and > must never change. > > Instead we want to do the reverse, make sure that the layout of the > struct never changes vs the PT_xx defines. So add build time checks of > that. > > This probably seems paranoid, but at least once in the past someone > has sent a patch that would have broken the ABI if it hadn't been > spotted. Although it probably would have been detected via testing, > it's preferable to just quash any issues at the source. > > Signed-off-by: Michael Ellerman Applied to powerpc next. https://git.kernel.org/powerpc/c/b9e0805abf2e92fc275ac5fbd8c1c9a92b00413d cheers