From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751855AbeCTVce (ORCPT ); Tue, 20 Mar 2018 17:32:34 -0400 Received: from out30-132.freemail.mail.aliyun.com ([115.124.30.132]:55303 "EHLO out30-132.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751498AbeCTVcb (ORCPT ); Tue, 20 Mar 2018 17:32:31 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01429;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0SzoMu-x_1521581495; From: Yang Shi To: akpm@linux-foundation.org Cc: yang.shi@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH 5/8] ipc: shm: pass atomic parameter to do_munmap() Date: Wed, 21 Mar 2018 05:31:23 +0800 Message-Id: <1521581486-99134-6-git-send-email-yang.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1521581486-99134-1-git-send-email-yang.shi@linux.alibaba.com> References: <1521581486-99134-1-git-send-email-yang.shi@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It looks safe to do unlock/relock mmap_sem in the middle of shmat(), so passing "false" here. Signed-off-by: Yang Shi --- ipc/shm.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/ipc/shm.c b/ipc/shm.c index 4643865..1617523 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -1537,7 +1537,8 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, */ file = vma->vm_file; size = i_size_read(file_inode(vma->vm_file)); - do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL); + do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, + NULL, false); /* * We discovered the size of the shm segment, so * break out of here and fall through to the next @@ -1564,7 +1565,8 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, if ((vma->vm_ops == &shm_vm_ops) && ((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) && (vma->vm_file == file)) - do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL); + do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, + NULL, false); vma = next; } @@ -1573,7 +1575,8 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, * given */ if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) { - do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL); + do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, + NULL, false); retval = 0; } -- 1.8.3.1