Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932815AbdFLPmu (ORCPT ); Mon, 12 Jun 2017 11:42:50 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:45486 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932378AbdFLPmr (ORCPT ); Mon, 12 Jun 2017 11:42:47 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "John L. Hammond" , Andreas Dilger , Li Wei , Oleg Drokin Subject: [PATCH 3.18 22/45] staging/lustre/lov: remove set_fs() call from lov_getstripe() Date: Mon, 12 Jun 2017 17:26:32 +0200 Message-Id: <20170612152554.540287712@linuxfoundation.org> X-Mailer: git-send-email 2.13.1 In-Reply-To: <20170612152553.118037974@linuxfoundation.org> References: <20170612152553.118037974@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 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: 1901 Lines: 58 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Drokin commit 0a33252e060e97ed3fbdcec9517672f1e91aaef3 upstream. lov_getstripe() calls set_fs(KERNEL_DS) so that it can handle a struct lov_user_md pointer from user- or kernel-space. This changes the behavior of copy_from_user() on SPARC and may result in a misaligned access exception which in turn oopses the kernel. In fact the relevant argument to lov_getstripe() is never called with a kernel-space pointer and so changing the address limits is unnecessary and so we remove the calls to save, set, and restore the address limits. Signed-off-by: John L. Hammond Reviewed-on: http://review.whamcloud.com/6150 Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3221 Reviewed-by: Andreas Dilger Reviewed-by: Li Wei Signed-off-by: Oleg Drokin Signed-off-by: Greg Kroah-Hartman --- drivers/staging/lustre/lustre/lov/lov_pack.c | 9 --------- 1 file changed, 9 deletions(-) --- a/drivers/staging/lustre/lustre/lov/lov_pack.c +++ b/drivers/staging/lustre/lustre/lov/lov_pack.c @@ -420,18 +420,10 @@ int lov_getstripe(struct obd_export *exp struct lov_mds_md *lmmk = NULL; int rc, lmm_size; int lum_size; - mm_segment_t seg; if (!lsm) return -ENODATA; - /* - * "Switch to kernel segment" to allow copying from kernel space by - * copy_{to,from}_user(). - */ - seg = get_fs(); - set_fs(KERNEL_DS); - /* we only need the header part from user space to get lmm_magic and * lmm_stripe_count, (the header part is common to v1 and v3) */ lum_size = sizeof(struct lov_user_md_v1); @@ -507,6 +499,5 @@ int lov_getstripe(struct obd_export *exp obd_free_diskmd(exp, &lmmk); out_set: - set_fs(seg); return rc; }