Merge tag 'xfs-5.2-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

[linux-2.6-block.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index bd7b9f293b391f22b85810e48bc7c0679b217f05..7e8c3e8ae75f123e7782444127aa91264b83417e 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * mm/mmap.c
  *
@@ -2735,9 +2736,17 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
                return -EINVAL;
 
        len = PAGE_ALIGN(len);
+       end = start + len;
        if (len == 0)
                return -EINVAL;
 
+       /*
+        * arch_unmap() might do unmaps itself.  It must be called
+        * and finish any rbtree manipulation before this code
+        * runs and also starts to manipulate the rbtree.
+        */
+       arch_unmap(mm, start, end);
+
        /* Find the first overlapping VMA */
        vma = find_vma(mm, start);
        if (!vma)
@@ -2746,7 +2755,6 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
        /* we have  start < vma->vm_end  */
 
        /* if it doesn't overlap, we have nothing.. */
-       end = start + len;
        if (vma->vm_start >= end)
                return 0;
 
@@ -2816,12 +2824,6 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len,
        /* Detach vmas from rbtree */
        detach_vmas_to_be_unmapped(mm, vma, prev, end);
 
-       /*
-        * mpx unmap needs to be called with mmap_sem held for write.
-        * It is safe to call it before unmap_region().
-        */
-       arch_unmap(mm, vma, start, end);
-
        if (downgrade)
                downgrade_write(&mm->mmap_sem);