diff options
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 35 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify.h | 3 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 9 |
3 files changed, 42 insertions, 5 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 812c975df7ec..ff7b8a1cdfe1 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -77,6 +77,13 @@ static int fanotify_merge(struct list_head *list, struct fsnotify_event *event) return 0; } +/* + * Wait for response to permission event. The function also takes care of + * freeing the permission event (or offloads that in case the wait is canceled + * by a signal). The function returns 0 in case access got allowed by userspace, + * -EPERM in case userspace disallowed the access, and -ERESTARTSYS in case + * the wait got interrupted by a signal. + */ static int fanotify_get_response(struct fsnotify_group *group, struct fanotify_perm_event *event, struct fsnotify_iter_info *iter_info) @@ -85,8 +92,29 @@ static int fanotify_get_response(struct fsnotify_group *group, pr_debug("%s: group=%p event=%p\n", __func__, group, event); - wait_event(group->fanotify_data.access_waitq, - event->state == FAN_EVENT_ANSWERED); + ret = wait_event_interruptible(group->fanotify_data.access_waitq, + event->state == FAN_EVENT_ANSWERED); + /* Signal pending? */ + if (ret < 0) { + spin_lock(&group->notification_lock); + /* Event reported to userspace and no answer yet? */ + if (event->state == FAN_EVENT_REPORTED) { + /* Event will get freed once userspace answers to it */ + event->state = FAN_EVENT_CANCELED; + spin_unlock(&group->notification_lock); + return ret; + } + /* Event not yet reported? Just remove it. */ + if (event->state == FAN_EVENT_INIT) + fsnotify_remove_queued_event(group, &event->fae.fse); + /* + * Event may be also answered in case signal delivery raced + * with wakeup. In that case we have nothing to do besides + * freeing the event and reporting error. + */ + spin_unlock(&group->notification_lock); + goto out; + } /* userspace responded, convert to something usable */ switch (event->response & ~FAN_AUDIT) { @@ -104,6 +132,8 @@ static int fanotify_get_response(struct fsnotify_group *group, pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__, group, event, ret); +out: + fsnotify_destroy_event(group, &event->fae.fse); return ret; } @@ -406,7 +436,6 @@ static int fanotify_handle_event(struct fsnotify_group *group, } else if (fanotify_is_perm_event(mask)) { ret = fanotify_get_response(group, FANOTIFY_PE(fsn_event), iter_info); - fsnotify_destroy_event(group, fsn_event); } finish: if (fanotify_is_perm_event(mask)) diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index 480f281996d4..68b30504284c 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -12,7 +12,8 @@ extern struct kmem_cache *fanotify_perm_event_cachep; enum { FAN_EVENT_INIT, FAN_EVENT_REPORTED, - FAN_EVENT_ANSWERED + FAN_EVENT_ANSWERED, + FAN_EVENT_CANCELED, }; /* diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 3c272f61d341..56992b32c6bb 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -147,10 +147,17 @@ static void finish_permission_event(struct fsnotify_group *group, unsigned int response) __releases(&group->notification_lock) { + bool destroy = false; + assert_spin_locked(&group->notification_lock); event->response = response; - event->state = FAN_EVENT_ANSWERED; + if (event->state == FAN_EVENT_CANCELED) + destroy = true; + else + event->state = FAN_EVENT_ANSWERED; spin_unlock(&group->notification_lock); + if (destroy) + fsnotify_destroy_event(group, &event->fae.fse); } static int process_access_response(struct fsnotify_group *group, |