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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 17397C28CF8 for ; Mon, 15 Oct 2018 04:46:02 +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 A777B205C9 for ; Mon, 15 Oct 2018 04:46:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A777B205C9 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 lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 42YQqq2yshzF3Cb for ; Mon, 15 Oct 2018 15:45:59 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 42YPrB5tbVzF2Dx for ; Mon, 15 Oct 2018 15:01:14 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Received: by ozlabs.org (Postfix) id 42YPrB3G7gzB2xk; Mon, 15 Oct 2018 15:01:14 +1100 (AEDT) Received: by ozlabs.org (Postfix, from userid 1034) id 42YPrB1H6nz9sj2; Mon, 15 Oct 2018 15:01:13 +1100 (AEDT) X-powerpc-patch-notification: thanks X-powerpc-patch-commit: 002af9391bfbe84f8e491bb10bd9c6001a6becee In-Reply-To: <20181013105646.5147-1-mpe@ellerman.id.au> To: Michael Ellerman , linuxppc-dev@ozlabs.org From: Michael Ellerman Subject: Re: [1/3] powerpc: Split user/kernel definitions of struct pt_regs Message-Id: <42YPrB1H6nz9sj2@ozlabs.org> Date: Mon, 15 Oct 2018 15:01:13 +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: , Cc: npiggin@gmail.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Sat, 2018-10-13 at 10:56:44 UTC, Michael Ellerman wrote: > We use a shared definition for struct pt_regs in uapi/asm/ptrace.h. > That means the layout of the structure is ABI, ie. we can't change it. > > That would be fine if it was only used to describe the user-visible > register state of a process, but it's also the struct we use in the > kernel to describe the registers saved in an interrupt frame. > > We'd like more flexibility in the content (and possibly layout) of the > kernel version of the struct, but currently that's not possible. > > So split the definition into a user-visible definition which remains > unchanged, and a kernel internal one. > > At the moment they're still identical, and we check that at build > time. That's because we have code (in ptrace etc.) that assumes that > they are the same. We will fix that code in future patches, and then > we can break the strict symmetry between the two structs. > > Signed-off-by: Michael Ellerman > Reviewed-by: Nicholas Piggin Series applied to powerpc next. https://git.kernel.org/powerpc/c/002af9391bfbe84f8e491bb10bd9c6 cheers