diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 15549578d559..26a30c3566f0 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -256,6 +256,16 @@ struct vm_region { * this region */ }; +#ifdef CONFIG_USERFAULTFD +#define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, }) +struct vm_userfaultfd_ctx { + struct userfaultfd_ctx *ctx; +}; +#else /* CONFIG_USERFAULTFD */ +#define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {}) +struct vm_userfaultfd_ctx {}; +#endif /* CONFIG_USERFAULTFD */ + /* * This struct defines a memory VMM memory area. There is one of these * per VM-area/task. A VM area is any part of the process virtual memory @@ -322,6 +332,7 @@ struct vm_area_struct { #ifdef CONFIG_NUMA struct mempolicy *vm_policy; /* NUMA policy for the VMA */ #endif + struct vm_userfaultfd_ctx vm_userfaultfd_ctx; }; struct core_thread { diff --git a/kernel/fork.c b/kernel/fork.c index 03aa2e6de7a4..ceb4eb4abb9d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -456,6 +456,7 @@ 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; file = tmp->vm_file; if (file) { struct inode *inode = file_inode(file);