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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0EA5C4332F for ; Mon, 28 Feb 2022 06:40:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233349AbiB1Gkx convert rfc822-to-8bit (ORCPT ); Mon, 28 Feb 2022 01:40:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233317AbiB1Gks (ORCPT ); Mon, 28 Feb 2022 01:40:48 -0500 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 149F83D1CF for ; Sun, 27 Feb 2022 22:40:09 -0800 (PST) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-127-ln2z8qc2NY6O0etIBpyffg-1; Mon, 28 Feb 2022 06:40:07 +0000 X-MC-Unique: ln2z8qc2NY6O0etIBpyffg-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.28; Mon, 28 Feb 2022 06:40:04 +0000 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.028; Mon, 28 Feb 2022 06:40:04 +0000 From: David Laight To: "'guoren@kernel.org'" , "palmer@dabbelt.com" , "arnd@arndb.de" , "anup@brainfault.org" , "gregkh@linuxfoundation.org" , "liush@allwinnertech.com" , "wefu@redhat.com" , "drew@beagleboard.org" , "wangjunqiang@iscas.ac.cn" , "hch@lst.de" CC: "linux-arch@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-riscv@lists.infradead.org" , "linux-csky@vger.kernel.org" , "linux-s390@vger.kernel.org" , "sparclinux@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-parisc@vger.kernel.org" , "linux-mips@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "x86@kernel.org" Subject: RE: [PATCH V7 03/20] compat: consolidate the compat_flock{,64} definition Thread-Topic: [PATCH V7 03/20] compat: consolidate the compat_flock{,64} definition Thread-Index: AQHYK/ctkLOBFN5NzkqkonsQCyvC26yogbZg Date: Mon, 28 Feb 2022 06:40:04 +0000 Message-ID: References: <20220227162831.674483-1-guoren@kernel.org> <20220227162831.674483-4-guoren@kernel.org> In-Reply-To: <20220227162831.674483-4-guoren@kernel.org> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: guoren@kernel.org > Sent: 27 February 2022 16:28 > > From: Christoph Hellwig > > Provide a single common definition for the compat_flock and > compat_flock64 structures using the same tricks as for the native > variants. Another extra define is added for the packing required on > x86. ... > diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h ... > /* > - * IA32 uses 4 byte alignment for 64 bit quantities, > - * so we need to pack this structure. > + * IA32 uses 4 byte alignment for 64 bit quantities, so we need to pack the > + * compat flock64 structure. > */ ... > +#define __ARCH_NEED_COMPAT_FLOCK64_PACKED > > struct compat_statfs { > int f_type; > diff --git a/include/linux/compat.h b/include/linux/compat.h > index 1c758b0e0359..a0481fe6c5d5 100644 > --- a/include/linux/compat.h > +++ b/include/linux/compat.h > @@ -258,6 +258,37 @@ struct compat_rlimit { > compat_ulong_t rlim_max; > }; > > +#ifdef __ARCH_NEED_COMPAT_FLOCK64_PACKED > +#define __ARCH_COMPAT_FLOCK64_PACK __attribute__((packed)) > +#else > +#define __ARCH_COMPAT_FLOCK64_PACK > +#endif ... > +struct compat_flock64 { > + short l_type; > + short l_whence; > + compat_loff_t l_start; > + compat_loff_t l_len; > + compat_pid_t l_pid; > +#ifdef __ARCH_COMPAT_FLOCK64_PAD > + __ARCH_COMPAT_FLOCK64_PAD > +#endif > +} __ARCH_COMPAT_FLOCK64_PACK; > + Provided compat_loff_t are correctly defined with __aligned__(4) marking the structure packed isn't needed. I believe compat_u64 and compat_s64 both have aligned(4). It is also wrong, consider: struct foo { char x; struct compat_flock64 fl64; }; There should be 3 bytes of padding after 'x'. But you've removed it. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)