Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751822AbdGAFOG (ORCPT ); Sat, 1 Jul 2017 01:14:06 -0400 Received: from mail-pg0-f53.google.com ([74.125.83.53]:34505 "EHLO mail-pg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751254AbdGAFOF (ORCPT ); Sat, 1 Jul 2017 01:14:05 -0400 MIME-Version: 1.0 In-Reply-To: References: From: "David F." Date: Fri, 30 Jun 2017 22:14:04 -0700 Message-ID: Subject: Re: did vfs_read or something related to it get broken? To: linux-kernel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1264 Lines: 51 Answer: No nothing got broken except the driver itself. On Fri, Jun 30, 2017 at 4:10 PM, David F. wrote: > Hi, > > I have a driver that reads data from a file that has worked from > kernel 3.x up to 4.9.13. I haven't tried all the other 4.9's or 4.10, > or 4.11.6 or earlier, but in 4.11.7 it's now broken and an error is > returned. It's based on > http://krishnamohanlinux.blogspot.com/2013/12/how-to-write-to-file-from-kernel-module.html > > Is there a new requirement of some sort or did it get broken? > > int driver_file_read(struct file *file, unsigned char *data, unsigned int size) > { > int ret; > mm_segment_t oldfs; > > // get file pointer > loff_t pos = file->f_pos; > > oldfs = get_fs(); > set_fs(get_ds()); > > ret=vfs_read(file, data, size, &pos); > > set_fs(oldfs); > > // update file pointer > file->f_pos=pos; > > return (ret); > } > > > struct file *driver_file_open(const char *path, int flags, int mode, int *err) > { > int ec=0; > struct file *filp = NULL; > filp=filp_open(path, flags, mode); > if (IS_ERR(filp)) { > ec=PTR_ERR(filp); > filp=NULL; > } > // update callers error code > if (err) { > *err=ec; > } > // return pointer to file > return (filp); > }