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=-5.2 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 98820C3A59B for ; Mon, 2 Sep 2019 09:42:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7BF4A21881 for ; Mon, 2 Sep 2019 09:42:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731345AbfIBJmp (ORCPT ); Mon, 2 Sep 2019 05:42:45 -0400 Received: from mx2.suse.de ([195.135.220.15]:48178 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730680AbfIBJmp (ORCPT ); Mon, 2 Sep 2019 05:42:45 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 3AA39ABBE; Mon, 2 Sep 2019 09:42:43 +0000 (UTC) Date: Mon, 2 Sep 2019 11:42:39 +0200 From: Michal =?UTF-8?B?U3VjaMOhbmVr?= To: Michael Ellerman Cc: linuxppc-dev@lists.ozlabs.org, Madhavan Srinivasan , David Hildenbrand , Heiko Carstens , Paul Mackerras , Breno Leitao , Michael Neuling , Diana Craciun , Firoz Khan , Hari Bathini , Joel Stanley , Arnd Bergmann , Nicholas Piggin , Alexander Viro , Thomas Gleixner , Allison Randal , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, "Eric W. Biederman" , Andrew Donnellan , Andrew Morton Subject: Re: [PATCH v7 5/6] powerpc/64: Make COMPAT user-selectable disabled on littleendian by default. Message-ID: <20190902114239.32bd81f4@naga> In-Reply-To: <87ftlftpy7.fsf@mpe.ellerman.id.au> References: <87ftlftpy7.fsf@mpe.ellerman.id.au> Followup-To: linux-fsdevel@vger.kernel.org X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 02 Sep 2019 12:03:12 +1000 Michael Ellerman wrote: > Michal Suchanek writes: > > On bigendian ppc64 it is common to have 32bit legacy binaries but much > > less so on littleendian. > > I think the toolchain people will tell you that there is no 32-bit > little endian ABI defined at all, if anything works it's by accident. I have seen a piece of software that workarounds code issues on 64bit by always compiling 32bit code. So it does work in some way. Also it has been pointed out that you can still switch to BE even with the 'fast-switch' removed. > > So I think we should not make this selectable, unless someone puts their > hand up to say they want it and are willing to test it and keep it > working. I don't really care either way. Thanks Michal > > cheers > > > v3: make configurable > > --- > > arch/powerpc/Kconfig | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > > index 5bab0bb6b833..b0339e892329 100644 > > --- a/arch/powerpc/Kconfig > > +++ b/arch/powerpc/Kconfig > > @@ -264,8 +264,9 @@ config PANIC_TIMEOUT > > default 180 > > > > config COMPAT > > - bool > > - default y if PPC64 > > + bool "Enable support for 32bit binaries" > > + depends on PPC64 > > + default y if !CPU_LITTLE_ENDIAN > > select COMPAT_BINFMT_ELF > > select ARCH_WANT_OLD_COMPAT_IPC > > select COMPAT_OLD_SIGACTION > > -- > > 2.22.0