diff options
| -rw-r--r-- | fs/userfaultfd.c | 70 |
1 files changed, 9 insertions, 61 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index a9d0ddc12ace..87a13a7c8270 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -988,24 +988,14 @@ static int resolve_userfault_fork(struct userfaultfd_ctx *ctx, struct uffd_msg *msg) { int fd; - struct file *file; - unsigned int flags = new->flags & UFFD_SHARED_FCNTL_FLAGS; - fd = get_unused_fd_flags(flags); + fd = anon_inode_getfd("[userfaultfd]", &userfaultfd_fops, new, + O_RDWR | (new->flags & UFFD_SHARED_FCNTL_FLAGS)); if (fd < 0) return fd; - file = anon_inode_getfile("[userfaultfd]", &userfaultfd_fops, new, - O_RDWR | flags); - if (IS_ERR(file)) { - put_unused_fd(fd); - return PTR_ERR(file); - } - - fd_install(fd, file); msg->arg.reserved.reserved1 = 0; msg->arg.fork.ufd = fd; - return 0; } @@ -1887,24 +1877,10 @@ static void init_once_userfaultfd_ctx(void *mem) seqcount_init(&ctx->refile_seq); } -/** - * userfaultfd_file_create - Creates a userfaultfd file pointer. - * @flags: Flags for the userfaultfd file. - * - * This function creates a userfaultfd file pointer, w/out installing - * it into the fd table. This is useful when the userfaultfd file is - * used during the initialization of data structures that require - * extra setup after the userfaultfd creation. So the userfaultfd - * creation is split into the file pointer creation phase, and the - * file descriptor installation phase. In this way races with - * userspace closing the newly installed file descriptor can be - * avoided. Returns a userfaultfd file pointer, or a proper error - * pointer. - */ -static struct file *userfaultfd_file_create(int flags) +SYSCALL_DEFINE1(userfaultfd, int, flags) { - struct file *file; struct userfaultfd_ctx *ctx; + int fd; BUG_ON(!current->mm); @@ -1912,14 +1888,12 @@ static struct file *userfaultfd_file_create(int flags) BUILD_BUG_ON(UFFD_CLOEXEC != O_CLOEXEC); BUILD_BUG_ON(UFFD_NONBLOCK != O_NONBLOCK); - file = ERR_PTR(-EINVAL); if (flags & ~UFFD_SHARED_FCNTL_FLAGS) - goto out; + return -EINVAL; - file = ERR_PTR(-ENOMEM); ctx = kmem_cache_alloc(userfaultfd_ctx_cachep, GFP_KERNEL); if (!ctx) - goto out; + return -ENOMEM; atomic_set(&ctx->refcount, 1); ctx->flags = flags; @@ -1930,39 +1904,13 @@ static struct file *userfaultfd_file_create(int flags) /* prevent the mm struct to be freed */ mmgrab(ctx->mm); - file = anon_inode_getfile("[userfaultfd]", &userfaultfd_fops, ctx, - O_RDWR | (flags & UFFD_SHARED_FCNTL_FLAGS)); - if (IS_ERR(file)) { + fd = anon_inode_getfd("[userfaultfd]", &userfaultfd_fops, ctx, + O_RDWR | (flags & UFFD_SHARED_FCNTL_FLAGS)); + if (fd < 0) { mmdrop(ctx->mm); kmem_cache_free(userfaultfd_ctx_cachep, ctx); } -out: - return file; -} - -SYSCALL_DEFINE1(userfaultfd, int, flags) -{ - int fd, error; - struct file *file; - - error = get_unused_fd_flags(flags & UFFD_SHARED_FCNTL_FLAGS); - if (error < 0) - return error; - fd = error; - - file = userfaultfd_file_create(flags); - if (IS_ERR(file)) { - error = PTR_ERR(file); - goto err_put_unused_fd; - } - fd_install(fd, file); - return fd; - -err_put_unused_fd: - put_unused_fd(fd); - - return error; } static int __init userfaultfd_init(void) |