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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT 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 19677C48BD5 for ; Tue, 25 Jun 2019 22:29:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA74F2085A for ; Tue, 25 Jun 2019 22:29:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726524AbfFYW3y (ORCPT ); Tue, 25 Jun 2019 18:29:54 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:40222 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726077AbfFYW3y (ORCPT ); Tue, 25 Jun 2019 18:29:54 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92 #3 (Red Hat Linux)) id 1hftwb-0001ZR-4N; Tue, 25 Jun 2019 22:29:41 +0000 Date: Tue, 25 Jun 2019 23:29:41 +0100 From: Al Viro To: Christoph Hellwig Cc: Greg Ungerer , Michal Simek , linux-arm-kernel@lists.infradead.org, linux-c6x-dev@linux-c6x.org, uclinux-h8-devel@lists.sourceforge.jp, linux-m68k@lists.linux-m68k.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 08/17] binfmt_flat: consolidate two version of flat_v2_reloc_t Message-ID: <20190625222941.GA1343@ZenIV.linux.org.uk> References: <20190613070903.17214-1-hch@lst.de> <20190613070903.17214-9-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190613070903.17214-9-hch@lst.de> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 13, 2019 at 09:08:54AM +0200, Christoph Hellwig wrote: > Two branches of the ifdef maze actually have the same content, so merge > them. > > Signed-off-by: Christoph Hellwig > --- > include/linux/flat.h | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/include/linux/flat.h b/include/linux/flat.h > index 2b7cda6e9c1b..19c586b74b99 100644 > --- a/include/linux/flat.h > +++ b/include/linux/flat.h > @@ -69,15 +69,13 @@ struct flat_hdr { > typedef union { > unsigned long value; > struct { > -# if defined(mc68000) && !defined(CONFIG_COLDFIRE) > +#if defined(__LITTLE_ENDIAN_BITFIELD) || \ > + (defined(mc68000) && !defined(CONFIG_COLDFIRE)) > signed long offset : 30; > unsigned long type : 2; > # elif defined(__BIG_ENDIAN_BITFIELD) > unsigned long type : 2; > signed long offset : 30; > -# elif defined(__LITTLE_ENDIAN_BITFIELD) > - signed long offset : 30; > - unsigned long type : 2; > # else > # error "Unknown bitfield order for flat files." > # endif > -- > 2.20.1 > FWIW, I wonder if keeping that type is worth bothering. Something like old_reloc(__be32 reloc) { u32 v = be32_to_cpu(reloc); int offset, type; #if (defined(mc68000) && !defined(CONFIG_COLDFIRE)) /* old m68k uses unusual format - type is in lower bits of octet 3 */ type = v % 4; offset = (int)v / 4; #else /* everything else (including coldfire) has it in upper bits of octet 0 */ type = v >> 30; offset = (int)(v << 2) >> 2; /* or (v & 0x1fffffff) - (v & 0x20000000) * 4 */ #endif ... and to hell with bitfields, aliasing unions, etc. Unless I'm misreading the whole thing, that is... Greg?