It makes no sense to ever prod at special mappings with any of these
syscalls.
XXX should we include munmap() ?
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
---
mm/madvise.c | 3 +++
mm/mlock.c | 3 ++-
mm/mprotect.c | 3 +++
3 files changed, 8 insertions(+), 1 deletion(-)
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -678,6 +678,9 @@ static long
madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
unsigned long start, unsigned long end, int behavior)
{
+ if (vma_is_special_mapping(vma))
+ return -EINVAL;
+
switch (behavior) {
case MADV_REMOVE:
return madvise_remove(vma, prev, start, end);
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -521,7 +521,8 @@ static int mlock_fixup(struct vm_area_st
vm_flags_t old_flags = vma->vm_flags;
if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) ||
- is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm))
+ is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm) ||
+ vma_is_special_mapping(vma))
/* don't set VM_LOCKED or VM_LOCKONFAULT and don't count */
goto out;
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -307,6 +307,9 @@ mprotect_fixup(struct vm_area_struct *vm
return 0;
}
+ if (vma_is_special_mapping(vma))
+ return -ENOMEM;
+
/*
* If we make a private mapping writable we increase our commit;
* but (without finer accounting) cannot reduce our commit if we
