* vma->vm_start/vm_end cannot change under us because the caller
* is required to hold the mmap_sem in read mode. We need the
* anon_vma lock to serialize against concurrent expand_stacks.
+ * Also guard against wrapping around to address 0.
*/
- address += 4 + PAGE_SIZE - 1;
- address &= PAGE_MASK;
+ if (address < PAGE_ALIGN(address+4))
+ address = PAGE_ALIGN(address+4);
+ else {
+ anon_vma_unlock(vma);
+ return -ENOMEM;
+ }
error = 0;
/* Somebody else might have raced and expanded it already */
/*
* Split a vma into two pieces at address 'addr', a new vma is allocated
- * either for the first part or the the tail.
+ * either for the first part or the tail.
*/
int split_vma(struct mm_struct * mm, struct vm_area_struct * vma,
unsigned long addr, int new_below)