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=-7.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 71A95C433DB for ; Sun, 20 Sep 2020 00:14:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40C0020E65 for ; Sun, 20 Sep 2020 00:14:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600560899; bh=hFlNFuPTeOm0L/kdCL4zZ1r5D8O6dPLmjujTGrKOlYM=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=Am8irQxnuKCrYm3r+avEQp16JfPFywnB04i96wgjY5tJPFdjfKrkjqIKBYQrLAt/w ZbnuWww4U2KkBUlIGB/7OdTZQ4svvVdaTtmkHMTe2NTKSKFRRgGxfdRJoLaPQTn5IK 4bzwgXKaHShYu+G4DZ4VI5GJ2B+ePdAZi1xjiH6Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726843AbgITAO4 (ORCPT ); Sat, 19 Sep 2020 20:14:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:60860 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726806AbgITAO4 (ORCPT ); Sat, 19 Sep 2020 20:14:56 -0400 Received: from mail-wr1-f52.google.com (mail-wr1-f52.google.com [209.85.221.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id ED49D23718 for ; Sun, 20 Sep 2020 00:14:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600560895; bh=hFlNFuPTeOm0L/kdCL4zZ1r5D8O6dPLmjujTGrKOlYM=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=puNMNVSIh3nOcXZR2bsSX89mx7JsoFWoBEe7Ak/z+DHmLOhb+Kh9sSU8Baw2xkYcL D2jd4AOn8hF0K/zn41LjhaaVl7xocGLJmOT8gdJrwj7qZg0ejYTZECwuJzlzHWv+kO OFRT3p90VCBE1oiQrCZZUJZydIgvG/SANufNNLCU= Received: by mail-wr1-f52.google.com with SMTP id m6so9190711wrn.0 for ; Sat, 19 Sep 2020 17:14:54 -0700 (PDT) X-Gm-Message-State: AOAM5303td4JhW/VDgFu1mb2p096GdRDsEcSEIh2jusxobET0nmxwHj6 ucGeLME1KFRLIEgNcl3SCBopIPLPE9ElGJmHo6/2Qw== X-Google-Smtp-Source: ABdhPJwNa+g9tI1uon0gRHcB2mOJvq7bEiosz+i+17dS26MXBg9h+I1xFom2CJCFuIf/wJaqwzsOPjK0guk9bG2/Zms= X-Received: by 2002:adf:a3c3:: with SMTP id m3mr251480wrb.70.1600560893353; Sat, 19 Sep 2020 17:14:53 -0700 (PDT) MIME-Version: 1.0 References: <20200919224122.GJ3421308@ZenIV.linux.org.uk> <36CF3DE7-7B4B-41FD-9818-FDF8A5B440FB@amacapital.net> <20200919232411.GK3421308@ZenIV.linux.org.uk> In-Reply-To: <20200919232411.GK3421308@ZenIV.linux.org.uk> From: Andy Lutomirski Date: Sat, 19 Sep 2020 17:14:41 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag To: Al Viro 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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Sat, Sep 19, 2020 at 4:24 PM Al Viro wrote: > > On Sat, Sep 19, 2020 at 03:53:40PM -0700, Andy Lutomirski wrote: > > > > It would not be a win - most of the syscalls don't give a damn > > > about 32bit vs. 64bit... > > > > Any reasonable implementation would optimize it out for syscalls that d= on=E2=80=99t care. Or it could be explicit: > > > > DEFINE_MULTIARCH_SYSCALL(...) > > 1) what would that look like? In effect, it would work like this: /* Arch-specific, but there's a generic case for sane architectures. */ enum syscall_arch { SYSCALL_NATIVE, SYSCALL_COMPAT, SYSCALL_X32, }; DEFINE_MULTIARCH_SYSCALLn(args, arch) { args are the args here, and arch is the arch. } > 2) have you counted the syscalls that do and do not need that? No. > 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. 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. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Lutomirski Date: Sun, 20 Sep 2020 00:14:41 +0000 Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Message-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="windows-1250" Content-Transfer-Encoding: base64 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: <20200919232411.GK3421308@ZenIV.linux.org.uk> To: Al Viro 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 T24gU2F0LCBTZXAgMTksIDIwMjAgYXQgNDoyNCBQTSBBbCBWaXJvIDx2aXJvQHplbml2LmxpbnV4 Lm9yZy51az4gd3JvdGU6Cj4KPiBPbiBTYXQsIFNlcCAxOSwgMjAyMCBhdCAwMzo1Mzo0MFBNIC0w NzAwLCBBbmR5IEx1dG9taXJza2kgd3JvdGU6Cj4KPiA+ID4gSXQgd291bGQgbm90IGJlIGEgd2lu IC0gbW9zdCBvZiB0aGUgc3lzY2FsbHMgZG9uJ3QgZ2l2ZSBhIGRhbW4KPiA+ID4gYWJvdXQgMzJi aXQgdnMuIDY0Yml0Li4uCj4gPgo+ID4gQW55IHJlYXNvbmFibGUgaW1wbGVtZW50YXRpb24gd291 bGQgb3B0aW1pemUgaXQgb3V0IGZvciBzeXNjYWxscyB0aGF0IGRvbuKAmXQgY2FyZS4gIE9yIGl0 IGNvdWxkIGJlIGV4cGxpY2l0Ogo+ID4KPiA+IERFRklORV9NVUxUSUFSQ0hfU1lTQ0FMTCguLi4p Cj4KPiAxKSB3aGF0IHdvdWxkIHRoYXQgbG9vayBsaWtlPwoKSW4gZWZmZWN0LCBpdCB3b3VsZCB3 b3JrIGxpa2UgdGhpczoKCi8qIEFyY2gtc3BlY2lmaWMsIGJ1dCB0aGVyZSdzIGEgZ2VuZXJpYyBj YXNlIGZvciBzYW5lIGFyY2hpdGVjdHVyZXMuICovCmVudW0gc3lzY2FsbF9hcmNoIHsKICBTWVND QUxMX05BVElWRSwKICBTWVNDQUxMX0NPTVBBVCwKICBTWVNDQUxMX1gzMiwKfTsKCkRFRklORV9N VUxUSUFSQ0hfU1lTQ0FMTG4oYXJncywgYXJjaCkKewogIGFyZ3MgYXJlIHRoZSBhcmdzIGhlcmUs IGFuZCBhcmNoIGlzIHRoZSBhcmNoLgp9Cgo+IDIpIGhhdmUgeW91IGNvdW50ZWQgdGhlIHN5c2Nh bGxzIHRoYXQgZG8gYW5kIGRvIG5vdCBuZWVkIHRoYXQ/CgpOby4KCj4gMykgaG93IG1hbnkgb2Yg dGhvc2UgcmVhbGlzdGljYWxseSAqY2FuKiBiZSB1bmlmaWVkIHdpdGggdGhlaXIKPiBjb21wYXQg Y291bnRlcnBhcnRzPyAgW2hpbnQ6IGlvY3RsKDIpIGNhbm5vdF0KClRoZXJlIHdvdWxkIGJlIG5v IHJlcXVpcmVtZW50IHRvIHVuaWZ5IGFueXRoaW5nLiAgVGhlIGlkZWEgaXMgdGhhdAp3ZSdkIGdl dCByaWQgb2YgYWxsIHRoZSBnbG9iYWwgc3RhdGUgZmxhZ3MuCgpGb3IgaW9jdGwsIHdlJ2QgaGF2 ZSBhIG5ldyBmaWxlX29wZXJhdGlvbjoKCmxvbmcgaW9jdGwoc3RydWN0IGZpbGUgKiwgdW5zaWdu ZWQgaW50LCB1bnNpZ25lZCBsb25nLCBlbnVtIHN5c2NhbGxfYXJjaCk7CgpJJ20gbm90IHNheWlu ZyB0aGlzIGlzIGVhc3ksIGJ1dCBJIHRoaW5rIGl0J3MgcG9zc2libGUgYW5kIHRoZSByZXN1bHQK d291bGQgYmUgbW9yZSBvYnZpb3VzbHkgY29ycmVjdCB0aGFuIHdoYXQgd2UgaGF2ZSBub3cu 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=-7.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 07539C43463 for ; 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d=kernel.org; s=default; t=1600560895; bh=hFlNFuPTeOm0L/kdCL4zZ1r5D8O6dPLmjujTGrKOlYM=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=puNMNVSIh3nOcXZR2bsSX89mx7JsoFWoBEe7Ak/z+DHmLOhb+Kh9sSU8Baw2xkYcL D2jd4AOn8hF0K/zn41LjhaaVl7xocGLJmOT8gdJrwj7qZg0ejYTZECwuJzlzHWv+kO OFRT3p90VCBE1oiQrCZZUJZydIgvG/SANufNNLCU= Received: by mail-ej1-f48.google.com with SMTP id i26so12875712ejb.12 for ; Sat, 19 Sep 2020 17:14:55 -0700 (PDT) X-Gm-Message-State: AOAM532DeV89wucKOm361NGRvEia7fH9R26FvGG+ew0GWtsHoP1e4+Ng rjBhp36YGhsbZi4Ylhzg72zZ+/fztRJDiBC25/yUbw== X-Google-Smtp-Source: ABdhPJwNa+g9tI1uon0gRHcB2mOJvq7bEiosz+i+17dS26MXBg9h+I1xFom2CJCFuIf/wJaqwzsOPjK0guk9bG2/Zms= X-Received: by 2002:adf:a3c3:: with SMTP id m3mr251480wrb.70.1600560893353; Sat, 19 Sep 2020 17:14:53 -0700 (PDT) MIME-Version: 1.0 References: <20200919224122.GJ3421308@ZenIV.linux.org.uk> <36CF3DE7-7B4B-41FD-9818-FDF8A5B440FB@amacapital.net> <20200919232411.GK3421308@ZenIV.linux.org.uk> In-Reply-To: <20200919232411.GK3421308@ZenIV.linux.org.uk> From: Andy Lutomirski Date: Sat, 19 Sep 2020 17:14:41 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag To: Al Viro 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 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat, Sep 19, 2020 at 4:24 PM Al Viro wrote: > > On Sat, Sep 19, 2020 at 03:53:40PM -0700, Andy Lutomirski wrote: > > > > It would not be a win - most of the syscalls don't give a damn > > > about 32bit vs. 64bit... > > > > Any reasonable implementation would optimize it out for syscalls that d= on=E2=80=99t care. Or it could be explicit: > > > > DEFINE_MULTIARCH_SYSCALL(...) > > 1) what would that look like? In effect, it would work like this: /* Arch-specific, but there's a generic case for sane architectures. */ enum syscall_arch { SYSCALL_NATIVE, SYSCALL_COMPAT, SYSCALL_X32, }; DEFINE_MULTIARCH_SYSCALLn(args, arch) { args are the args here, and arch is the arch. } > 2) have you counted the syscalls that do and do not need that? No. > 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. 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. 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,DKIM_INVALID, DKIM_SIGNED,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 ACA81C43463 for ; Sun, 20 Sep 2020 00:16:50 +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 94F6B20DD4 for ; Sun, 20 Sep 2020 00:16:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="puNMNVSI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 94F6B20DD4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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 4Bv7RM20fqzDqxX for ; Sun, 20 Sep 2020 10:16:47 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=luto@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=puNMNVSI; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4Bv7PG3bfmzDqtK for ; Sun, 20 Sep 2020 10:14:58 +1000 (AEST) Received: from mail-wr1-f51.google.com (mail-wr1-f51.google.com [209.85.221.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BD40820DD4 for ; Sun, 20 Sep 2020 00:14:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600560895; bh=hFlNFuPTeOm0L/kdCL4zZ1r5D8O6dPLmjujTGrKOlYM=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=puNMNVSIh3nOcXZR2bsSX89mx7JsoFWoBEe7Ak/z+DHmLOhb+Kh9sSU8Baw2xkYcL D2jd4AOn8hF0K/zn41LjhaaVl7xocGLJmOT8gdJrwj7qZg0ejYTZECwuJzlzHWv+kO OFRT3p90VCBE1oiQrCZZUJZydIgvG/SANufNNLCU= Received: by mail-wr1-f51.google.com with SMTP id m6so9190710wrn.0 for ; Sat, 19 Sep 2020 17:14:54 -0700 (PDT) X-Gm-Message-State: AOAM533RbvL0uPGfyBUT6v6Tg9X3LK1Wi/rupNhCxR+57zgMLWwLMc4T RZP0QXfsGlmKE/k9tfiThIs18jF2rpzty5l+Lp6M0Q== X-Google-Smtp-Source: ABdhPJwNa+g9tI1uon0gRHcB2mOJvq7bEiosz+i+17dS26MXBg9h+I1xFom2CJCFuIf/wJaqwzsOPjK0guk9bG2/Zms= X-Received: by 2002:adf:a3c3:: with SMTP id m3mr251480wrb.70.1600560893353; Sat, 19 Sep 2020 17:14:53 -0700 (PDT) MIME-Version: 1.0 References: <20200919224122.GJ3421308@ZenIV.linux.org.uk> <36CF3DE7-7B4B-41FD-9818-FDF8A5B440FB@amacapital.net> <20200919232411.GK3421308@ZenIV.linux.org.uk> In-Reply-To: <20200919232411.GK3421308@ZenIV.linux.org.uk> From: Andy Lutomirski Date: Sat, 19 Sep 2020 17:14:41 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag To: Al Viro Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable 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 4:24 PM Al Viro wrote: > > On Sat, Sep 19, 2020 at 03:53:40PM -0700, Andy Lutomirski wrote: > > > > It would not be a win - most of the syscalls don't give a damn > > > about 32bit vs. 64bit... > > > > Any reasonable implementation would optimize it out for syscalls that d= on=E2=80=99t care. Or it could be explicit: > > > > DEFINE_MULTIARCH_SYSCALL(...) > > 1) what would that look like? In effect, it would work like this: /* Arch-specific, but there's a generic case for sane architectures. */ enum syscall_arch { SYSCALL_NATIVE, SYSCALL_COMPAT, SYSCALL_X32, }; DEFINE_MULTIARCH_SYSCALLn(args, arch) { args are the args here, and arch is the arch. } > 2) have you counted the syscalls that do and do not need that? No. > 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. 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. 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Sat, 19 Sep 2020 17:14:54 -0700 (PDT) X-Gm-Message-State: AOAM5312dKIwT443i/1DWl0nwecwxu4PIHtJiwJNhxNuKjjheytQEkgs ls21PxCTq55c1ux9x352b0Osn/mlaCRi9pxf2kGJlg== X-Google-Smtp-Source: ABdhPJwNa+g9tI1uon0gRHcB2mOJvq7bEiosz+i+17dS26MXBg9h+I1xFom2CJCFuIf/wJaqwzsOPjK0guk9bG2/Zms= X-Received: by 2002:adf:a3c3:: with SMTP id m3mr251480wrb.70.1600560893353; Sat, 19 Sep 2020 17:14:53 -0700 (PDT) MIME-Version: 1.0 References: <20200919224122.GJ3421308@ZenIV.linux.org.uk> <36CF3DE7-7B4B-41FD-9818-FDF8A5B440FB@amacapital.net> <20200919232411.GK3421308@ZenIV.linux.org.uk> In-Reply-To: <20200919232411.GK3421308@ZenIV.linux.org.uk> From: Andy Lutomirski Date: Sat, 19 Sep 2020 17:14:41 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag To: Al Viro X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200919_201456_969422_1BC594C3 X-CRM114-Status: GOOD ( 18.99 ) 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="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gU2F0LCBTZXAgMTksIDIwMjAgYXQgNDoyNCBQTSBBbCBWaXJvIDx2aXJvQHplbml2LmxpbnV4 Lm9yZy51az4gd3JvdGU6Cj4KPiBPbiBTYXQsIFNlcCAxOSwgMjAyMCBhdCAwMzo1Mzo0MFBNIC0w NzAwLCBBbmR5IEx1dG9taXJza2kgd3JvdGU6Cj4KPiA+ID4gSXQgd291bGQgbm90IGJlIGEgd2lu IC0gbW9zdCBvZiB0aGUgc3lzY2FsbHMgZG9uJ3QgZ2l2ZSBhIGRhbW4KPiA+ID4gYWJvdXQgMzJi aXQgdnMuIDY0Yml0Li4uCj4gPgo+ID4gQW55IHJlYXNvbmFibGUgaW1wbGVtZW50YXRpb24gd291 bGQgb3B0aW1pemUgaXQgb3V0IGZvciBzeXNjYWxscyB0aGF0IGRvbuKAmXQgY2FyZS4gIE9yIGl0 IGNvdWxkIGJlIGV4cGxpY2l0Ogo+ID4KPiA+IERFRklORV9NVUxUSUFSQ0hfU1lTQ0FMTCguLi4p Cj4KPiAxKSB3aGF0IHdvdWxkIHRoYXQgbG9vayBsaWtlPwoKSW4gZWZmZWN0LCBpdCB3b3VsZCB3 b3JrIGxpa2UgdGhpczoKCi8qIEFyY2gtc3BlY2lmaWMsIGJ1dCB0aGVyZSdzIGEgZ2VuZXJpYyBj YXNlIGZvciBzYW5lIGFyY2hpdGVjdHVyZXMuICovCmVudW0gc3lzY2FsbF9hcmNoIHsKICBTWVND QUxMX05BVElWRSwKICBTWVNDQUxMX0NPTVBBVCwKICBTWVNDQUxMX1gzMiwKfTsKCkRFRklORV9N VUxUSUFSQ0hfU1lTQ0FMTG4oYXJncywgYXJjaCkKewogIGFyZ3MgYXJlIHRoZSBhcmdzIGhlcmUs IGFuZCBhcmNoIGlzIHRoZSBhcmNoLgp9Cgo+IDIpIGhhdmUgeW91IGNvdW50ZWQgdGhlIHN5c2Nh bGxzIHRoYXQgZG8gYW5kIGRvIG5vdCBuZWVkIHRoYXQ/CgpOby4KCj4gMykgaG93IG1hbnkgb2Yg dGhvc2UgcmVhbGlzdGljYWxseSAqY2FuKiBiZSB1bmlmaWVkIHdpdGggdGhlaXIKPiBjb21wYXQg Y291bnRlcnBhcnRzPyAgW2hpbnQ6IGlvY3RsKDIpIGNhbm5vdF0KClRoZXJlIHdvdWxkIGJlIG5v IHJlcXVpcmVtZW50IHRvIHVuaWZ5IGFueXRoaW5nLiAgVGhlIGlkZWEgaXMgdGhhdAp3ZSdkIGdl dCByaWQgb2YgYWxsIHRoZSBnbG9iYWwgc3RhdGUgZmxhZ3MuCgpGb3IgaW9jdGwsIHdlJ2QgaGF2 ZSBhIG5ldyBmaWxlX29wZXJhdGlvbjoKCmxvbmcgaW9jdGwoc3RydWN0IGZpbGUgKiwgdW5zaWdu ZWQgaW50LCB1bnNpZ25lZCBsb25nLCBlbnVtIHN5c2NhbGxfYXJjaCk7CgpJJ20gbm90IHNheWlu ZyB0aGlzIGlzIGVhc3ksIGJ1dCBJIHRoaW5rIGl0J3MgcG9zc2libGUgYW5kIHRoZSByZXN1bHQK d291bGQgYmUgbW9yZSBvYnZpb3VzbHkgY29ycmVjdCB0aGFuIHdoYXQgd2UgaGF2ZSBub3cuCgpf X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpsaW51eC1hcm0t a2VybmVsIG1haWxpbmcgbGlzdApsaW51eC1hcm0ta2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcK aHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1hcm0ta2Vy bmVsCg==