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) --- 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