diff options
| -rw-r--r-- | mm/mremap.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/mm/mremap.c b/mm/mremap.c index 5f346178f16f..90e422c9f410 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -366,6 +366,17 @@ out: return ret; } +static int vma_expandable(struct vm_area_struct *vma, unsigned long 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) + return 0; + /* we need to do arch-specific checks here */ + return 1; +} + /* * Expand (or shrink) an existing mapping, potentially moving it at the * same time (controlled by the MREMAP_MAYMOVE flag and available VM space) @@ -430,11 +441,8 @@ unsigned long do_mremap(unsigned long addr, /* old_len exactly to the end of the area.. */ if (old_len == vma->vm_end - addr) { - unsigned long max_addr = TASK_SIZE; - if (vma->vm_next) - max_addr = vma->vm_next->vm_start; /* can we just expand the current mapping? */ - if (max_addr - addr >= new_len) { + if (vma_expandable(vma, new_len - old_len)) { int pages = (new_len - old_len) >> PAGE_SHIFT; vma_adjust(vma, vma->vm_start, |