From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f194.google.com ([209.85.215.194]:44795 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2411072AbgJZX4P (ORCPT ); Mon, 26 Oct 2020 19:56:15 -0400 Received: by mail-pg1-f194.google.com with SMTP id o3so6963383pgr.11 for ; Mon, 26 Oct 2020 16:56:15 -0700 (PDT) Subject: Re: [REGRESSION] mm: process_vm_readv testcase no longer works after compat_prcoess_vm_readv removed References: From: Jens Axboe Message-ID: <70d5569e-4ad6-988a-e047-5d12d298684c@kernel.dk> Date: Mon, 26 Oct 2020 17:56:11 -0600 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit List-ID: To: Kyle Huey , open list , Christoph Hellwig Cc: Robert O'Callahan , Alexander Viro , Andrew Morton , Arnd Bergmann , David Howells , "moderated list:ARM PORT" , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, "open list:FILESYSTEMS (VFS and infrastructure)" , linux-aio@kvack.org, io-uring@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, Linus Torvalds On 10/26/20 4:55 PM, Kyle Huey wrote: > A test program from the rr[0] test suite, vm_readv_writev[1], no > longer works on 5.10-rc1 when compiled as a 32 bit binary and executed > on a 64 bit kernel. The first process_vm_readv call (on line 35) now > fails with EFAULT. I have bisected this to > c3973b401ef2b0b8005f8074a10e96e3ea093823. > > It should be fairly straightforward to extract the test case from our > repository into a standalone program. Can you check with this applied? diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index fd12da80b6f2..05676722d9cd 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -273,7 +273,8 @@ static ssize_t process_vm_rw(pid_t pid, return rc; if (!iov_iter_count(&iter)) goto free_iov_l; - iov_r = iovec_from_user(rvec, riovcnt, UIO_FASTIOV, iovstack_r, false); + iov_r = iovec_from_user(rvec, riovcnt, UIO_FASTIOV, iovstack_r, + in_compat_syscall()); if (IS_ERR(iov_r)) { rc = PTR_ERR(iov_r); goto free_iov_l; -- Jens Axboe