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| author | Al Viro <viro@zeniv.linux.org.uk> | 2009-11-24 08:25:18 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2009-12-11 06:30:23 -0500 |
| commit | f106af4e90eadd76cfc0b5325f659619e08fb762 (patch) | |
| tree | da78db736b9fa92fbfab81ae06bcbd3f92dc72fa /mm/mremap.c | |
| parent | 1a0ef85f84feb13f07b604fcf5b90ef7c2b5c82f (diff) | |
| download | lwn-f106af4e90eadd76cfc0b5325f659619e08fb762.tar.gz lwn-f106af4e90eadd76cfc0b5325f659619e08fb762.zip | |
fix checks for expand-in-place mremap
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'mm/mremap.c')
| -rw-r--r-- | mm/mremap.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/mm/mremap.c b/mm/mremap.c index 90e422c9f410..9d0753983dcb 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; } |