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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 4F7C5C433DF for ; Mon, 15 Jun 2020 14:20:22 +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 055952067B for ; Mon, 15 Jun 2020 14:20:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 055952067B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de 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 49ltlR6pLbzDqc3 for ; Tue, 16 Jun 2020 00:20:19 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=lst.de Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (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 49ltZk5sb2zDqB3 for ; Tue, 16 Jun 2020 00:12:45 +1000 (AEST) Received: by verein.lst.de (Postfix, from userid 2407) id 1873468AFE; Mon, 15 Jun 2020 16:12:40 +0200 (CEST) Date: Mon, 15 Jun 2020 16:12:39 +0200 From: Christoph Hellwig To: Arnd Bergmann Subject: Re: [PATCH 2/6] exec: simplify the compat syscall handling Message-ID: <20200615141239.GA12951@lst.de> References: <20200615130032.931285-1-hch@lst.de> <20200615130032.931285-3-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) 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-arch , linux-s390 , Parisc List , the arch/x86 maintainers , "open list:BROADCOM NVRAM DRIVER" , "linux-kernel@vger.kernel.org" , Linux FS-devel Mailing List , Luis Chamberlain , Al Viro , sparclinux , linuxppc-dev , Christoph Hellwig , Linux ARM Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Jun 15, 2020 at 03:31:35PM +0200, Arnd Bergmann wrote: > > #ifdef CONFIG_COMPAT > > - if (unlikely(argv.is_compat)) { > > + if (in_compat_syscall()) { > > + const compat_uptr_t __user *compat_argv = > > + compat_ptr((unsigned long)argv); > > compat_uptr_t compat; > > > > - if (get_user(compat, argv.ptr.compat + nr)) > > + if (get_user(compat, compat_argv + nr)) > > return ERR_PTR(-EFAULT); > > > > return compat_ptr(compat); > > } > > #endif > > I would expect that the "#ifdef CONFIG_COMPAT" can be removed > now, since compat_ptr() and in_compat_syscall() are now defined > unconditionally. I have not tried that though. True, I'll give it a spin. > > +/* > > + * x32 syscalls are listed in the same table as x86_64 ones, so we need to > > + * define compat syscalls that are exactly the same as the native version for > > + * the syscall table machinery to work. Sigh.. > > + */ > > +#ifdef CONFIG_X86_X32 > > COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename, > > - const compat_uptr_t __user *, argv, > > - const compat_uptr_t __user *, envp) > > + const char __user *const __user *, argv, > > + const char __user *const __user *, envp) > > { > > - return do_compat_execve(AT_FDCWD, getname(filename), argv, envp, 0); > > + return do_execveat(AT_FDCWD, getname(filename), argv, envp, 0, NULL); > > } > > Maybe move it to arch/x86/kernel/process_64.c or arch/x86/entry/syscall_x32.c > to keep it out of the common code if this is needed. I'd rather keep it in common code as that allows all the low-level exec stuff to be marked static, and avoid us growing new pointless compat variants through copy and paste. smart compiler to d > I don't really understand > the comment, why can't this just use this? That errors out with: ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1040): undefined reference to `__x32_sys_execve' ld: arch/x86/entry/syscall_x32.o:(.rodata+0x1108): undefined reference to `__x32_sys_execveat' make: *** [Makefile:1139: vmlinux] Error 1