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=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 BCE7BC43463 for ; Sun, 20 Sep 2020 02:57:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7230A20DD4 for ; Sun, 20 Sep 2020 02:57:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726772AbgITC5z (ORCPT ); Sat, 19 Sep 2020 22:57:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726760AbgITC5z (ORCPT ); Sat, 19 Sep 2020 22:57:55 -0400 Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F8DAC061755; Sat, 19 Sep 2020 19:57:55 -0700 (PDT) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJpXt-0026Rb-Iq; Sun, 20 Sep 2020 02:57:45 +0000 Date: Sun, 20 Sep 2020 03:57:45 +0100 From: Al Viro To: Andy Lutomirski Cc: Christoph Hellwig , Andrew Morton , Jens Axboe , Arnd Bergmann , David Howells , linux-arm-kernel , X86 ML , LKML , "open list:MIPS" , Parisc List , linuxppc-dev , linux-s390 , sparclinux , linux-block , Linux SCSI List , Linux FS Devel , linux-aio@kvack.org, io-uring@vger.kernel.org, linux-arch , Linux-MM , Network Development , keyrings@vger.kernel.org, LSM List Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Message-ID: <20200920025745.GL3421308@ZenIV.linux.org.uk> References: <20200919224122.GJ3421308@ZenIV.linux.org.uk> <36CF3DE7-7B4B-41FD-9818-FDF8A5B440FB@amacapital.net> <20200919232411.GK3421308@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On Sat, Sep 19, 2020 at 05:14:41PM -0700, Andy Lutomirski wrote: > > 2) have you counted the syscalls that do and do not need that? > > No. Might be illuminating... > > 3) how many of those realistically *can* be unified with their > > compat counterparts? [hint: ioctl(2) cannot] > > There would be no requirement to unify anything. The idea is that > we'd get rid of all the global state flags. _What_ global state flags? When you have separate SYSCALL_DEFINE3(ioctl...) and COMPAT_SYSCALL_DEFINE3(ioctl...), there's no flags at all, global or local. They only come into the play when you try to share the same function for both, right on the top level. > For ioctl, we'd have a new file_operation: > > long ioctl(struct file *, unsigned int, unsigned long, enum syscall_arch); > > I'm not saying this is easy, but I think it's possible and the result > would be more obviously correct than what we have now. No, it would not. Seriously, from time to time a bit of RTFS before grand proposals turns out to be useful. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Date: Sun, 20 Sep 2020 02:57:45 +0000 Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Message-Id: <20200920025745.GL3421308@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit List-Id: References: <20200919224122.GJ3421308@ZenIV.linux.org.uk> <36CF3DE7-7B4B-41FD-9818-FDF8A5B440FB@amacapital.net> <20200919232411.GK3421308@ZenIV.linux.org.uk> In-Reply-To: To: Andy Lutomirski Cc: Christoph Hellwig , Andrew Morton , Jens Axboe , Arnd Bergmann , David Howells , linux-arm-kernel , X86 ML , LKML , "open list:MIPS" , Parisc List , linuxppc-dev , linux-s390 , sparclinux , linux-block , Linux SCSI List , Linux FS Devel , linux-aio@kvack.org, io-uring@vger.kernel.org, linux-arch , Linux-MM , Network Development , keyrings@vger.kernel.org, LSM List On Sat, Sep 19, 2020 at 05:14:41PM -0700, Andy Lutomirski wrote: > > 2) have you counted the syscalls that do and do not need that? > > No. Might be illuminating... > > 3) how many of those realistically *can* be unified with their > > compat counterparts? [hint: ioctl(2) cannot] > > There would be no requirement to unify anything. The idea is that > we'd get rid of all the global state flags. _What_ global state flags? When you have separate SYSCALL_DEFINE3(ioctl...) and COMPAT_SYSCALL_DEFINE3(ioctl...), there's no flags at all, global or local. They only come into the play when you try to share the same function for both, right on the top level. > For ioctl, we'd have a new file_operation: > > long ioctl(struct file *, unsigned int, unsigned long, enum syscall_arch); > > I'm not saying this is easy, but I think it's possible and the result > would be more obviously correct than what we have now. No, it would not. Seriously, from time to time a bit of RTFS before grand proposals turns out to be useful. 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=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 E1E17C43463 for ; Sun, 20 Sep 2020 03:00:23 +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 B1268208C3 for ; Sun, 20 Sep 2020 03:00:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B1268208C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk 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 4BvC434BN2zDqdn for ; Sun, 20 Sep 2020 13:00:19 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=ftp.linux.org.uk (client-ip=2002:c35c:fd02::1; helo=zeniv.linux.org.uk; envelope-from=viro@ftp.linux.org.uk; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4BvC1W5qcVzDqvW for ; Sun, 20 Sep 2020 12:58:03 +1000 (AEST) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJpXt-0026Rb-Iq; Sun, 20 Sep 2020 02:57:45 +0000 Date: Sun, 20 Sep 2020 03:57:45 +0100 From: Al Viro To: Andy Lutomirski Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Message-ID: <20200920025745.GL3421308@ZenIV.linux.org.uk> References: <20200919224122.GJ3421308@ZenIV.linux.org.uk> <36CF3DE7-7B4B-41FD-9818-FDF8A5B440FB@amacapital.net> <20200919232411.GK3421308@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: linux-aio@kvack.org, "open list:MIPS" , David Howells , Linux-MM , keyrings@vger.kernel.org, sparclinux , Christoph Hellwig , linux-arch , linux-s390 , Linux SCSI List , X86 ML , Arnd Bergmann , linux-block , io-uring@vger.kernel.org, linux-arm-kernel , Jens Axboe , Parisc List , Network Development , LKML , LSM List , Linux FS Devel , Andrew Morton , linuxppc-dev Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Sat, Sep 19, 2020 at 05:14:41PM -0700, Andy Lutomirski wrote: > > 2) have you counted the syscalls that do and do not need that? > > No. Might be illuminating... > > 3) how many of those realistically *can* be unified with their > > compat counterparts? [hint: ioctl(2) cannot] > > There would be no requirement to unify anything. The idea is that > we'd get rid of all the global state flags. _What_ global state flags? When you have separate SYSCALL_DEFINE3(ioctl...) and COMPAT_SYSCALL_DEFINE3(ioctl...), there's no flags at all, global or local. They only come into the play when you try to share the same function for both, right on the top level. > For ioctl, we'd have a new file_operation: > > long ioctl(struct file *, unsigned int, unsigned long, enum syscall_arch); > > I'm not saying this is easy, but I think it's possible and the result > would be more obviously correct than what we have now. No, it would not. Seriously, from time to time a bit of RTFS before grand proposals turns out to be useful. 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=-6.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D799DC43464 for ; Sun, 20 Sep 2020 03:01:05 +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 31C33208C3 for ; Sun, 20 Sep 2020 03:01:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ex8GS0i0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 31C33208C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk 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-Transfer-Encoding: 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-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=U6EnzAExvJt91eAqvShQ1bA8d6aDKqEPOAch2pcmZzY=; b=ex8GS0i0cMcfkFCIp+saDASwN KdH3GKNcNJSeyzWxYWmuAohYAdNo7Swt4OLIeRLkqO+luLJvkQOxtGiJ3zrRsq/GKpWIrHVFZNIPP RK8EHbMC/Gk80pc5OGjQoR2NJxp7Y8hVCYWW1ESNBNjmkwhHFl+pG4c4yO/5NioG83xMu+ZRPHIDr pgwqKZ8NL2KyXCzIvTu8MlUma2LiGhiHeg2aw/y6bNei/ZQILzYZX1plDM6FJxYIMeOlZK6193AgH hrd29iinSet8j9veu36FUO05K/ZpKZ9K4a5ucHYXIV+MYSgfFI22Z9m8GePYxRnU+wb6R2BCsh1XX zANX1izpA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJpY3-00082Z-Cy; Sun, 20 Sep 2020 02:57:55 +0000 Received: from [2002:c35c:fd02::1] (helo=ZenIV.linux.org.uk) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJpY0-00082C-UQ for linux-arm-kernel@lists.infradead.org; Sun, 20 Sep 2020 02:57:53 +0000 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJpXt-0026Rb-Iq; Sun, 20 Sep 2020 02:57:45 +0000 Date: Sun, 20 Sep 2020 03:57:45 +0100 From: Al Viro To: Andy Lutomirski Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Message-ID: <20200920025745.GL3421308@ZenIV.linux.org.uk> References: <20200919224122.GJ3421308@ZenIV.linux.org.uk> <36CF3DE7-7B4B-41FD-9818-FDF8A5B440FB@amacapital.net> <20200919232411.GK3421308@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200919_225752_995321_16F0E0AA X-CRM114-Status: GOOD ( 17.61 ) 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: linux-aio@kvack.org, "open list:MIPS" , David Howells , Linux-MM , keyrings@vger.kernel.org, sparclinux , Christoph Hellwig , linux-arch , linux-s390 , Linux SCSI List , X86 ML , Arnd Bergmann , linux-block , io-uring@vger.kernel.org, linux-arm-kernel , Jens Axboe , Parisc List , Network Development , LKML , LSM List , Linux FS Devel , Andrew Morton , linuxppc-dev Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, Sep 19, 2020 at 05:14:41PM -0700, Andy Lutomirski wrote: > > 2) have you counted the syscalls that do and do not need that? > > No. Might be illuminating... > > 3) how many of those realistically *can* be unified with their > > compat counterparts? [hint: ioctl(2) cannot] > > There would be no requirement to unify anything. The idea is that > we'd get rid of all the global state flags. _What_ global state flags? When you have separate SYSCALL_DEFINE3(ioctl...) and COMPAT_SYSCALL_DEFINE3(ioctl...), there's no flags at all, global or local. They only come into the play when you try to share the same function for both, right on the top level. > For ioctl, we'd have a new file_operation: > > long ioctl(struct file *, unsigned int, unsigned long, enum syscall_arch); > > I'm not saying this is easy, but I think it's possible and the result > would be more obviously correct than what we have now. No, it would not. Seriously, from time to time a bit of RTFS before grand proposals turns out to be useful. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel