* w: (no) no
* x: (yes) yes
*/
-pgprot_t protection_map[16] = {
+pgprot_t protection_map[16] __ro_after_init = {
__P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111,
__S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
};
gap_addr = TASK_SIZE;
next = vma->vm_next;
- if (next && next->vm_start < gap_addr) {
+ if (next && next->vm_start < gap_addr &&
+ (next->vm_flags & (VM_WRITE|VM_READ|VM_EXEC))) {
if (!(next->vm_flags & VM_GROWSUP))
return -ENOMEM;
/* Check that both stack segments have the same anon_vma? */
{
struct mm_struct *mm = vma->vm_mm;
struct vm_area_struct *prev;
- unsigned long gap_addr;
int error;
address &= PAGE_MASK;
return error;
/* Enforce stack_guard_gap */
- gap_addr = address - stack_guard_gap;
- if (gap_addr > address)
- return -ENOMEM;
prev = vma->vm_prev;
- if (prev && prev->vm_end > gap_addr) {
- if (!(prev->vm_flags & VM_GROWSDOWN))
+ /* Check that both stack segments have the same anon_vma? */
+ if (prev && !(prev->vm_flags & VM_GROWSDOWN) &&
+ (prev->vm_flags & (VM_WRITE|VM_READ|VM_EXEC))) {
+ if (address - prev->vm_end < stack_guard_gap)
return -ENOMEM;
- /* Check that both stack segments have the same anon_vma? */
}
/* We must make sure the anon_vma is allocated. */
{
struct vm_special_mapping *sm = new_vma->vm_private_data;
+ if (WARN_ON_ONCE(current->mm != new_vma->vm_mm))
+ return -EFAULT;
+
if (sm->mremap)
return sm->mremap(sm, new_vma);
+
return 0;
}