From mboxrd@z Thu Jan 1 00:00:00 1970 From: Al Viro Subject: [RFC][PATCH 4/18] fix checks for expand-in-place mremap Date: Sat, 05 Dec 2009 19:08:50 +0000 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from zeniv.linux.org.uk ([195.92.253.2]:41332 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754039AbZLEUQs (ORCPT ); Sat, 5 Dec 2009 15:16:48 -0500 Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-arch@vger.kernel.org Cc: torvalds@linux-foundation.org, linux-kernel@vger.kernel.org Signed-off-by: Al Viro --- mm/mremap.c | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-) diff --git a/mm/mremap.c b/mm/mremap.c index 90e422c..9d07539 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -27,6 +27,10 @@ #include "internal.h" +#ifndef arch_mmap_check +#define arch_mmap_check(addr, len, flags) (0) +#endif + static pmd_t *get_old_pmd(struct mm_struct *mm, unsigned long addr) { pgd_t *pgd; @@ -368,12 +372,17 @@ out: static int vma_expandable(struct vm_area_struct *vma, unsigned long delta) { + unsigned long end = vma->vm_end + delta; unsigned long max_addr = TASK_SIZE; if (vma->vm_next) max_addr = vma->vm_next->vm_start; - if (max_addr - vma->vm_end < delta) + if (max_addr < end || end < vma->vm_end) + return 0; + if (arch_mmap_check(vma->vm_start, end - vma->vm_start, MAP_FIXED)) + return 0; + if (get_unmapped_area(NULL, vma->vm_start, end - vma->vm_start, + 0, MAP_FIXED) & ~PAGE_MASK) return 0; - /* we need to do arch-specific checks here */ return 1; } -- 1.5.6.5