From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754622AbbDGMzm (ORCPT ); Tue, 7 Apr 2015 08:55:42 -0400 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:54448 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754205AbbDGMw1 (ORCPT ); Tue, 7 Apr 2015 08:52:27 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Dave Hansen , Manfred Spraul , Davidlohr Bueso , Andrew Morton , Linus Torvalds , Jiri Slaby Subject: [PATCH 3.12 078/155] shmdt: use i_size_read() instead of ->i_size Date: Tue, 7 Apr 2015 14:50:47 +0200 Message-Id: <12b72b792acd6b6412357aab022ca7f27264562c.1428411004.git.jslaby@suse.cz> X-Mailer: git-send-email 2.3.4 In-Reply-To: <9a548862b8a26cbccc14f2c6c9c3688813d8d14b.1428411003.git.jslaby@suse.cz> References: <9a548862b8a26cbccc14f2c6c9c3688813d8d14b.1428411003.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Hansen 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 07a46ed27dc6344de831a450df82336270a157a9 upstream. Andrew Morton noted http://lkml.kernel.org/r/20141104142027.a7a0d010772d84560b445f59@linux-foundation.org that the shmdt uses inode->i_size outside of i_mutex being held. There is one more case in shm.c in shm_destroy(). This converts both users over to use i_size_read(). Signed-off-by: Dave Hansen Cc: Manfred Spraul Cc: Davidlohr Bueso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby --- ipc/shm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/ipc/shm.c b/ipc/shm.c index b039a85e2b8d..623bc3877118 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -218,7 +218,8 @@ static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp) if (!is_file_hugepages(shm_file)) shmem_lock(shm_file, 0, shp->mlock_user); else if (shp->mlock_user) - user_shm_unlock(file_inode(shm_file)->i_size, shp->mlock_user); + user_shm_unlock(i_size_read(file_inode(shm_file)), + shp->mlock_user); fput(shm_file); ipc_rcu_putref(shp, shm_rcu_free); } @@ -1278,7 +1279,7 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) * in the range we are unmapping. */ file = vma->vm_file; - size = file_inode(file)->i_size; + size = i_size_read(file_inode(vma->vm_file)); do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start); /* * We discovered the size of the shm segment, so -- 2.3.4