On Sun 06-08-17 10:04:25, Rik van Riel wrote:
[...]
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 17921b0390b4..db1fb2802ecc 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -659,6 +659,13 @@ static __latent_entropy int dup_mmap(struct mm_struct
> *mm,
> tmp->vm_flags &= ~(VM_LOCKED | VM_LOCKONFAULT);
> tmp->vm_next = tmp->vm_prev = NULL;
> file = tmp->vm_file;
> +
> + /* With VM_WIPEONFORK, the child gets an empty VMA. */
> + if (tmp->vm_flags & VM_WIPEONFORK) {
> + tmp->vm_file = file = NULL;
> + tmp->vm_ops = NULL;
> + }
What about VM_SHARED/|VM)MAYSHARE flags. Is it OK to keep the around? At
least do_anonymous_page SIGBUS on !vm_ops && VM_SHARED. Or do I miss
where those flags are cleared?
> +
> if (file) {
> struct inode *inode = file_inode(file);
> struct address_space *mapping = file->f_mapping;
--
Michal Hocko
SUSE Labs
