diff options
| -rw-r--r-- | fs/notify/fanotify/fanotify.h | 5 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 82 | ||||
| -rw-r--r-- | include/uapi/linux/fanotify.h | 20 |
3 files changed, 102 insertions, 5 deletions
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index 271482fb9611..4aafc7144c3d 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -95,6 +95,11 @@ static inline bool fanotify_event_has_ext_fh(struct fanotify_event *event) event->fh_len > FANOTIFY_INLINE_FH_LEN; } +static inline void *fanotify_event_fh(struct fanotify_event *event) +{ + return fanotify_fid_fh(&event->fid, event->fh_len); +} + /* * Structure for permission fanotify events. It gets allocated and freed in * fanotify_handle_event() since we wait there for user response. When the diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index c965fcf4979e..cd82dd713c91 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -47,6 +47,18 @@ struct kmem_cache *fanotify_mark_cache __read_mostly; struct kmem_cache *fanotify_event_cachep __read_mostly; struct kmem_cache *fanotify_perm_event_cachep __read_mostly; +#define FANOTIFY_EVENT_ALIGN 4 + +static int fanotify_event_info_len(struct fanotify_event *event) +{ + if (!fanotify_event_has_fid(event)) + return 0; + + return roundup(sizeof(struct fanotify_event_info_fid) + + sizeof(struct file_handle) + event->fh_len, + FANOTIFY_EVENT_ALIGN); +} + /* * Get an fsnotify notification event if one exists and is small * enough to fit in "count". Return an error pointer if the count @@ -57,6 +69,9 @@ struct kmem_cache *fanotify_perm_event_cachep __read_mostly; static struct fsnotify_event *get_one_event(struct fsnotify_group *group, size_t count) { + size_t event_size = FAN_EVENT_METADATA_LEN; + struct fanotify_event *event; + assert_spin_locked(&group->notification_lock); pr_debug("%s: group=%p count=%zd\n", __func__, group, count); @@ -64,11 +79,18 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group, if (fsnotify_notify_queue_is_empty(group)) return NULL; - if (FAN_EVENT_METADATA_LEN > count) + if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { + event = FANOTIFY_E(fsnotify_peek_first_event(group)); + event_size += fanotify_event_info_len(event); + } + + if (event_size > count) return ERR_PTR(-EINVAL); - /* held the notification_lock the whole time, so this is the - * same event we peeked above */ + /* + * Held the notification_lock the whole time, so this is the + * same event we peeked above + */ return fsnotify_remove_first_event(group); } @@ -174,6 +196,48 @@ static int process_access_response(struct fsnotify_group *group, return 0; } +static int copy_fid_to_user(struct fanotify_event *event, char __user *buf) +{ + struct fanotify_event_info_fid info = { }; + struct file_handle handle = { }; + size_t fh_len = event->fh_len; + size_t len = fanotify_event_info_len(event); + + if (!len) + return 0; + + if (WARN_ON_ONCE(len < sizeof(info) + sizeof(handle) + fh_len)) + return -EFAULT; + + /* Copy event info fid header followed by vaiable sized file handle */ + info.hdr.info_type = FAN_EVENT_INFO_TYPE_FID; + info.hdr.len = len; + info.fsid = event->fid.fsid; + if (copy_to_user(buf, &info, sizeof(info))) + return -EFAULT; + + buf += sizeof(info); + len -= sizeof(info); + handle.handle_type = event->fh_type; + handle.handle_bytes = fh_len; + if (copy_to_user(buf, &handle, sizeof(handle))) + return -EFAULT; + + buf += sizeof(handle); + len -= sizeof(handle); + if (copy_to_user(buf, fanotify_event_fh(event), fh_len)) + return -EFAULT; + + /* Pad with 0's */ + buf += fh_len; + len -= fh_len; + WARN_ON_ONCE(len < 0 || len >= FANOTIFY_EVENT_ALIGN); + if (len > 0 && clear_user(buf, len)) + return -EFAULT; + + return 0; +} + static ssize_t copy_event_to_user(struct fsnotify_group *group, struct fsnotify_event *fsn_event, char __user *buf, size_t count) @@ -197,6 +261,8 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, fd = create_fd(group, event, &f); if (fd < 0) return fd; + } else if (fanotify_event_has_fid(event)) { + metadata.event_len += fanotify_event_info_len(event); } metadata.fd = fd; @@ -208,14 +274,20 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, if (WARN_ON_ONCE(metadata.event_len > count)) goto out_close_fd; - if (copy_to_user(buf, &metadata, metadata.event_len)) + if (copy_to_user(buf, &metadata, FAN_EVENT_METADATA_LEN)) goto out_close_fd; if (fanotify_is_perm_event(event->mask)) FANOTIFY_PE(fsn_event)->fd = fd; - if (fd != FAN_NOFD) + if (fanotify_event_has_path(event)) { fd_install(fd, f); + } else if (fanotify_event_has_fid(event)) { + ret = copy_fid_to_user(event, buf + FAN_EVENT_METADATA_LEN); + if (ret < 0) + return ret; + } + return metadata.event_len; out_close_fd: diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h index d07f3cbc2786..959ae2bdc7ca 100644 --- a/include/uapi/linux/fanotify.h +++ b/include/uapi/linux/fanotify.h @@ -107,6 +107,26 @@ struct fanotify_event_metadata { __s32 pid; }; +#define FAN_EVENT_INFO_TYPE_FID 1 + +/* Variable length info record following event metadata */ +struct fanotify_event_info_header { + __u8 info_type; + __u8 pad; + __u16 len; +}; + +/* Unique file identifier info record */ +struct fanotify_event_info_fid { + struct fanotify_event_info_header hdr; + __kernel_fsid_t fsid; + /* + * Following is an opaque struct file_handle that can be passed as + * an argument to open_by_handle_at(2). + */ + unsigned char handle[0]; +}; + struct fanotify_response { __s32 fd; __u32 response; |