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 8053EC4346A for ; Sun, 20 Sep 2020 18:12:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52B8C21D7A for ; Sun, 20 Sep 2020 18:12:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726314AbgITSMR (ORCPT ); Sun, 20 Sep 2020 14:12:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726305AbgITSMP (ORCPT ); Sun, 20 Sep 2020 14:12:15 -0400 Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [IPv6:2002:c35c:fd02::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C43F1C061755; Sun, 20 Sep 2020 11:12:14 -0700 (PDT) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kK3om-002bUn-Fx; Sun, 20 Sep 2020 18:12:08 +0000 Date: Sun, 20 Sep 2020 19:12:08 +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 , 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: <20200920181208.GO3421308@ZenIV.linux.org.uk> References: <20200919224122.GJ3421308@ZenIV.linux.org.uk> <36CF3DE7-7B4B-41FD-9818-FDF8A5B440FB@amacapital.net> <20200919232411.GK3421308@ZenIV.linux.org.uk> <20200920025745.GL3421308@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 Sun, Sep 20, 2020 at 09:59:36AM -0700, Andy Lutomirski wrote: > As one example, look at __sys_setsockopt(). It's called for the > native and compat versions, and it contains an in_compat_syscall() > check. (This particularly check looks dubious to me, but that's > another story.) If this were to be done with equivalent semantics > without a separate COMPAT_DEFINE_SYSCALL and without > in_compat_syscall(), there would need to be some indication as to > whether this is compat or native setsockopt. There are other > setsockopt implementations in the net stack with more > legitimate-seeming uses of in_compat_syscall() that would need some > other mechanism if in_compat_syscall() were to go away. > > setsockopt is (I hope!) out of scope for io_uring, but the situation > isn't fundamentally different from read and write. Except that setsockopt() had that crap very widespread; for read() and write() those are very rare exceptions. Andy, please RTFS. Or dig through archives. The situation with setsockopt() is *NOT* a good thing - it's (probably) the least of the evils. The last thing we need is making that the norm. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Date: Sun, 20 Sep 2020 18:12:08 +0000 Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Message-Id: <20200920181208.GO3421308@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> <20200920025745.GL3421308@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 , io-uring@vger.kernel.org, linux-arch , Linux-MM , Network Development , keyrings@vger.kernel.org, LSM List On Sun, Sep 20, 2020 at 09:59:36AM -0700, Andy Lutomirski wrote: > As one example, look at __sys_setsockopt(). It's called for the > native and compat versions, and it contains an in_compat_syscall() > check. (This particularly check looks dubious to me, but that's > another story.) If this were to be done with equivalent semantics > without a separate COMPAT_DEFINE_SYSCALL and without > in_compat_syscall(), there would need to be some indication as to > whether this is compat or native setsockopt. There are other > setsockopt implementations in the net stack with more > legitimate-seeming uses of in_compat_syscall() that would need some > other mechanism if in_compat_syscall() were to go away. > > setsockopt is (I hope!) out of scope for io_uring, but the situation > isn't fundamentally different from read and write. Except that setsockopt() had that crap very widespread; for read() and write() those are very rare exceptions. Andy, please RTFS. Or dig through archives. The situation with setsockopt() is *NOT* a good thing - it's (probably) the least of the evils. The last thing we need is making that the norm. 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 DA11DC43463 for ; Sun, 20 Sep 2020 18:15:10 +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 E7229207EA for ; Sun, 20 Sep 2020 18:15:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E7229207EA 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 4BvbMb5B7fzDqhF for ; Mon, 21 Sep 2020 04:15:07 +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 4BvbJL2Zq1zDqXv for ; Mon, 21 Sep 2020 04:12:18 +1000 (AEST) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kK3om-002bUn-Fx; Sun, 20 Sep 2020 18:12:08 +0000 Date: Sun, 20 Sep 2020 19:12:08 +0100 From: Al Viro To: Andy Lutomirski Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Message-ID: <20200920181208.GO3421308@ZenIV.linux.org.uk> References: <20200919224122.GJ3421308@ZenIV.linux.org.uk> <36CF3DE7-7B4B-41FD-9818-FDF8A5B440FB@amacapital.net> <20200919232411.GK3421308@ZenIV.linux.org.uk> <20200920025745.GL3421308@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 , "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 Sun, Sep 20, 2020 at 09:59:36AM -0700, Andy Lutomirski wrote: > As one example, look at __sys_setsockopt(). It's called for the > native and compat versions, and it contains an in_compat_syscall() > check. (This particularly check looks dubious to me, but that's > another story.) If this were to be done with equivalent semantics > without a separate COMPAT_DEFINE_SYSCALL and without > in_compat_syscall(), there would need to be some indication as to > whether this is compat or native setsockopt. There are other > setsockopt implementations in the net stack with more > legitimate-seeming uses of in_compat_syscall() that would need some > other mechanism if in_compat_syscall() were to go away. > > setsockopt is (I hope!) out of scope for io_uring, but the situation > isn't fundamentally different from read and write. Except that setsockopt() had that crap very widespread; for read() and write() those are very rare exceptions. Andy, please RTFS. Or dig through archives. The situation with setsockopt() is *NOT* a good thing - it's (probably) the least of the evils. The last thing we need is making that the norm. 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=-5.3 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 D9A3CC43465 for ; Sun, 20 Sep 2020 18:14:47 +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 87E50207EA for ; Sun, 20 Sep 2020 18:14:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Kj5Z8pUm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 87E50207EA 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=+v0Y1K+9KETrwJ6EblZO8zJoAyCTWy50v0kYkhs5Hjw=; b=Kj5Z8pUmZrjAvOGlaKvXsFzhz gQNxVGxOgYiy5GbZFEZbXGRHtL8nJu7CKSBdMpUeMU2cILBkIR3pQoHDw3yxPt2wyKH40x1RA/lL2 KPRzoBTfvx9ah5kgzWjY9bsh9Bv5s3uEeTy9s2zmJAAKd8TX/g9Nr/SuLewICiK4hsLCxtnkpcQN0 4bUxjPnnbfhCXwoINDbJAxYDGnzBUj7w/zpcj7Vf0h3HwxP/CHm27eCEQfKh4uArcj62TT57v5de1 JGYhGMLDB8Av7A5d7MVe15w/mkWpOcCcarfPrNFXoZho41PwyTopvajkHSmsBgm0KaRpYLTLTUoLs lqHHEkYsA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kK3pK-0003FN-Pm; Sun, 20 Sep 2020 18:12:43 +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 1kK3or-0002w0-IL for linux-arm-kernel@lists.infradead.org; Sun, 20 Sep 2020 18:12:14 +0000 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kK3om-002bUn-Fx; Sun, 20 Sep 2020 18:12:08 +0000 Date: Sun, 20 Sep 2020 19:12:08 +0100 From: Al Viro To: Andy Lutomirski Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Message-ID: <20200920181208.GO3421308@ZenIV.linux.org.uk> References: <20200919224122.GJ3421308@ZenIV.linux.org.uk> <36CF3DE7-7B4B-41FD-9818-FDF8A5B440FB@amacapital.net> <20200919232411.GK3421308@ZenIV.linux.org.uk> <20200920025745.GL3421308@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-20200920_141213_688471_B4FB947B X-CRM114-Status: GOOD ( 15.86 ) 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 , "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 Sun, Sep 20, 2020 at 09:59:36AM -0700, Andy Lutomirski wrote: > As one example, look at __sys_setsockopt(). It's called for the > native and compat versions, and it contains an in_compat_syscall() > check. (This particularly check looks dubious to me, but that's > another story.) If this were to be done with equivalent semantics > without a separate COMPAT_DEFINE_SYSCALL and without > in_compat_syscall(), there would need to be some indication as to > whether this is compat or native setsockopt. There are other > setsockopt implementations in the net stack with more > legitimate-seeming uses of in_compat_syscall() that would need some > other mechanism if in_compat_syscall() were to go away. > > setsockopt is (I hope!) out of scope for io_uring, but the situation > isn't fundamentally different from read and write. Except that setsockopt() had that crap very widespread; for read() and write() those are very rare exceptions. Andy, please RTFS. Or dig through archives. The situation with setsockopt() is *NOT* a good thing - it's (probably) the least of the evils. The last thing we need is making that the norm. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel