> diff --git a/kernel/fork.c b/kernel/fork.c > index cf65139..cb215c0 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -425,6 +425,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) > goto fail_nomem_anon_vma_fork; > tmp->vm_flags &= ~VM_LOCKED; > tmp->vm_next = tmp->vm_prev = NULL; > + tmp->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; This creates an interesting effect when the userfaultfd is used outside of the process which created and activated one. If I try to monitor the memory usage of one task with another, once the first task fork()-s, its child begins to see zero-pages in the places where the monitor task was supposed to insert pages with data. > file = tmp->vm_file; > if (file) { > struct inode *inode = file_inode(file); > . > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>