From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751786AbeCTVcD (ORCPT ); Tue, 20 Mar 2018 17:32:03 -0400 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:46123 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751701AbeCTVb6 (ORCPT ); Tue, 20 Mar 2018 17:31:58 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R301e4;CH=green;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01422;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 2/8] mm: mmap: pass atomic parameter to do_munmap() call sites Date: Wed, 21 Mar 2018 05:31:20 +0800 Message-Id: <1521581486-99134-3-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 release mmap_sem in the middle for vm_munmap and brk, so passing "false" to do_munmap() call. However it sounds not safe to mmap_region() which is called by SyS_mmap(). Signed-off-by: Yang Shi --- mm/mmap.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index ad6ae7a..374e4ec 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -225,7 +225,7 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma) /* Always allow shrinking brk. */ if (brk <= mm->brk) { - if (!do_munmap(mm, newbrk, oldbrk-newbrk, &uf)) + if (!do_munmap(mm, newbrk, oldbrk-newbrk, &uf, false)) goto set_brk; goto out; } @@ -1643,7 +1643,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr, /* Clear old maps */ while (find_vma_links(mm, addr, addr + len, &prev, &rb_link, &rb_parent)) { - if (do_munmap(mm, addr, len, uf)) + if (do_munmap(mm, addr, len, uf, true)) return -ENOMEM; } @@ -2778,7 +2778,7 @@ int vm_munmap(unsigned long start, size_t len) if (down_write_killable(&mm->mmap_sem)) return -EINTR; - ret = do_munmap(mm, start, len, &uf); + ret = do_munmap(mm, start, len, &uf, false); up_write(&mm->mmap_sem); userfaultfd_unmap_complete(mm, &uf); return ret; @@ -2945,7 +2945,7 @@ static int do_brk_flags(unsigned long addr, unsigned long request, unsigned long */ while (find_vma_links(mm, addr, addr + len, &prev, &rb_link, &rb_parent)) { - if (do_munmap(mm, addr, len, uf)) + if (do_munmap(mm, addr, len, uf, false)) return -ENOMEM; } -- 1.8.3.1