diff options
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 63 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify.h | 34 | ||||
| -rw-r--r-- | fs/notify/fanotify/fanotify_user.c | 123 |
3 files changed, 116 insertions, 104 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index dc638f786d5c..ee9cb3795c2b 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -60,8 +60,8 @@ static int fanotify_merge(struct list_head *list, struct fsnotify_event *event) } #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS -static int fanotify_get_response_from_access(struct fsnotify_group *group, - struct fanotify_event_info *event) +static int fanotify_get_response(struct fsnotify_group *group, + struct fanotify_perm_event_info *event) { int ret; @@ -142,6 +142,40 @@ static bool fanotify_should_send_event(struct fsnotify_mark *inode_mark, return false; } +struct fanotify_event_info *fanotify_alloc_event(struct inode *inode, u32 mask, + struct path *path) +{ + struct fanotify_event_info *event; + +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + if (mask & FAN_ALL_PERM_EVENTS) { + struct fanotify_perm_event_info *pevent; + + pevent = kmem_cache_alloc(fanotify_perm_event_cachep, + GFP_KERNEL); + if (!pevent) + return NULL; + event = &pevent->fae; + pevent->response = 0; + goto init; + } +#endif + event = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL); + if (!event) + return NULL; +init: __maybe_unused + fsnotify_init_event(&event->fse, inode, mask); + event->tgid = get_pid(task_tgid(current)); + if (path) { + event->path = *path; + path_get(&event->path); + } else { + event->path.mnt = NULL; + event->path.dentry = NULL; + } + return event; +} + static int fanotify_handle_event(struct fsnotify_group *group, struct inode *inode, struct fsnotify_mark *inode_mark, @@ -171,25 +205,11 @@ static int fanotify_handle_event(struct fsnotify_group *group, pr_debug("%s: group=%p inode=%p mask=%x\n", __func__, group, inode, mask); - event = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL); + event = fanotify_alloc_event(inode, mask, data); if (unlikely(!event)) return -ENOMEM; fsn_event = &event->fse; - fsnotify_init_event(fsn_event, inode, mask); - event->tgid = get_pid(task_tgid(current)); - if (data_type == FSNOTIFY_EVENT_PATH) { - struct path *path = data; - event->path = *path; - path_get(&event->path); - } else { - event->path.mnt = NULL; - event->path.dentry = NULL; - } -#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - event->response = 0; -#endif - ret = fsnotify_add_notify_event(group, fsn_event, fanotify_merge); if (ret) { /* Permission events shouldn't be merged */ @@ -202,7 +222,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS if (mask & FAN_ALL_PERM_EVENTS) { - ret = fanotify_get_response_from_access(group, event); + ret = fanotify_get_response(group, FANOTIFY_PE(fsn_event)); fsnotify_destroy_event(group, fsn_event); } #endif @@ -225,6 +245,13 @@ static void fanotify_free_event(struct fsnotify_event *fsn_event) event = FANOTIFY_E(fsn_event); path_put(&event->path); put_pid(event->tgid); +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + if (fsn_event->mask & FAN_ALL_PERM_EVENTS) { + kmem_cache_free(fanotify_perm_event_cachep, + FANOTIFY_PE(fsn_event)); + return; + } +#endif kmem_cache_free(fanotify_event_cachep, event); } diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h index 32a2f034fb94..2a5fb14115df 100644 --- a/fs/notify/fanotify/fanotify.h +++ b/fs/notify/fanotify/fanotify.h @@ -3,13 +3,12 @@ #include <linux/slab.h> extern struct kmem_cache *fanotify_event_cachep; +extern struct kmem_cache *fanotify_perm_event_cachep; /* - * Lifetime of the structure differs for normal and permission events. In both - * cases the structure is allocated in fanotify_handle_event(). For normal - * events the structure is freed immediately after reporting it to userspace. - * For permission events we free it only after we receive response from - * userspace. + * Structure for normal fanotify events. It gets allocated in + * fanotify_handle_event() and freed when the information is retrieved by + * userspace */ struct fanotify_event_info { struct fsnotify_event fse; @@ -19,12 +18,33 @@ struct fanotify_event_info { */ struct path path; struct pid *tgid; +}; + #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - u32 response; /* userspace answer to question */ -#endif +/* + * Structure for permission fanotify events. It gets allocated and freed in + * fanotify_handle_event() since we wait there for user response. When the + * information is retrieved by userspace the structure is moved from + * group->notification_list to group->fanotify_data.access_list to wait for + * user response. + */ +struct fanotify_perm_event_info { + struct fanotify_event_info fae; + int response; /* userspace answer to question */ + int fd; /* fd we passed to userspace for this event */ }; +static inline struct fanotify_perm_event_info * +FANOTIFY_PE(struct fsnotify_event *fse) +{ + return container_of(fse, struct fanotify_perm_event_info, fae.fse); +} +#endif + static inline struct fanotify_event_info *FANOTIFY_E(struct fsnotify_event *fse) { return container_of(fse, struct fanotify_event_info, fse); } + +struct fanotify_event_info *fanotify_alloc_event(struct inode *inode, u32 mask, + struct path *path); diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 70fe65437d21..8f5e85269110 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -28,14 +28,8 @@ extern const struct fsnotify_ops fanotify_fsnotify_ops; static struct kmem_cache *fanotify_mark_cache __read_mostly; -static struct kmem_cache *fanotify_response_event_cache __read_mostly; struct kmem_cache *fanotify_event_cachep __read_mostly; - -struct fanotify_response_event { - struct list_head list; - __s32 fd; - struct fanotify_event_info *event; -}; +struct kmem_cache *fanotify_perm_event_cachep __read_mostly; /* * Get an fsnotify notification event if one exists and is small @@ -135,33 +129,34 @@ static int fill_event_metadata(struct fsnotify_group *group, } #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS -static struct fanotify_response_event *dequeue_re(struct fsnotify_group *group, - __s32 fd) +static struct fanotify_perm_event_info *dequeue_event( + struct fsnotify_group *group, int fd) { - struct fanotify_response_event *re, *return_re = NULL; + struct fanotify_perm_event_info *event, *return_e = NULL; mutex_lock(&group->fanotify_data.access_mutex); - list_for_each_entry(re, &group->fanotify_data.access_list, list) { - if (re->fd != fd) + list_for_each_entry(event, &group->fanotify_data.access_list, + fae.fse.list) { + if (event->fd != fd) continue; - list_del_init(&re->list); - return_re = re; + list_del_init(&event->fae.fse.list); + return_e = event; break; } mutex_unlock(&group->fanotify_data.access_mutex); - pr_debug("%s: found return_re=%p\n", __func__, return_re); + pr_debug("%s: found return_re=%p\n", __func__, return_e); - return return_re; + return return_e; } static int process_access_response(struct fsnotify_group *group, struct fanotify_response *response_struct) { - struct fanotify_response_event *re; - __s32 fd = response_struct->fd; - __u32 response = response_struct->response; + struct fanotify_perm_event_info *event; + int fd = response_struct->fd; + int response = response_struct->response; pr_debug("%s: group=%p fd=%d response=%d\n", __func__, group, fd, response); @@ -181,50 +176,15 @@ static int process_access_response(struct fsnotify_group *group, if (fd < 0) return -EINVAL; - re = dequeue_re(group, fd); - if (!re) + event = dequeue_event(group, fd); + if (!event) return -ENOENT; - re->event->response = response; - + event->response = response; wake_up(&group->fanotify_data.access_waitq); - kmem_cache_free(fanotify_response_event_cache, re); - - return 0; -} - -static int prepare_for_access_response(struct fsnotify_group *group, - struct fsnotify_event *event, - __s32 fd) -{ - struct fanotify_response_event *re; - - if (!(event->mask & FAN_ALL_PERM_EVENTS)) - return 0; - - re = kmem_cache_alloc(fanotify_response_event_cache, GFP_KERNEL); - if (!re) - return -ENOMEM; - - re->event = FANOTIFY_E(event); - re->fd = fd; - - mutex_lock(&group->fanotify_data.access_mutex); - list_add_tail(&re->list, &group->fanotify_data.access_list); - mutex_unlock(&group->fanotify_data.access_mutex); - - return 0; -} - -#else -static int prepare_for_access_response(struct fsnotify_group *group, - struct fsnotify_event *event, - __s32 fd) -{ return 0; } - #endif static ssize_t copy_event_to_user(struct fsnotify_group *group, @@ -247,9 +207,18 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, fanotify_event_metadata.event_len)) goto out_close_fd; - ret = prepare_for_access_response(group, event, fd); - if (ret) - goto out_close_fd; +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + if (event->mask & FAN_ALL_PERM_EVENTS) { + struct fanotify_perm_event_info *pevent; + + pevent = FANOTIFY_PE(event); + pevent->fd = fd; + mutex_lock(&group->fanotify_data.access_mutex); + list_add_tail(&pevent->fae.fse.list, + &group->fanotify_data.access_list); + mutex_unlock(&group->fanotify_data.access_mutex); + } +#endif if (fd != FAN_NOFD) fd_install(fd, f); @@ -263,7 +232,7 @@ out_close_fd: out: #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS if (event->mask & FAN_ALL_PERM_EVENTS) { - FANOTIFY_E(event)->response = FAN_DENY; + FANOTIFY_PE(event)->response = FAN_DENY; wake_up(&group->fanotify_data.access_waitq); } #endif @@ -312,8 +281,8 @@ static ssize_t fanotify_read(struct file *file, char __user *buf, break; ret = copy_event_to_user(group, kevent, buf); /* - * Permission events get destroyed after we - * receive response + * Permission events get queued to wait for response. + * Other events can be destroyed now. */ if (!(kevent->mask & FAN_ALL_PERM_EVENTS)) fsnotify_destroy_event(group, kevent); @@ -375,20 +344,19 @@ static int fanotify_release(struct inode *ignored, struct file *file) struct fsnotify_group *group = file->private_data; #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - struct fanotify_response_event *re, *lre; + struct fanotify_perm_event_info *event, *next; mutex_lock(&group->fanotify_data.access_mutex); atomic_inc(&group->fanotify_data.bypass_perm); - list_for_each_entry_safe(re, lre, &group->fanotify_data.access_list, list) { - pr_debug("%s: found group=%p re=%p event=%p\n", __func__, group, - re, re->event); - - list_del_init(&re->list); - re->event->response = FAN_ALLOW; + list_for_each_entry_safe(event, next, &group->fanotify_data.access_list, + fae.fse.list) { + pr_debug("%s: found group=%p event=%p\n", __func__, group, + event); - kmem_cache_free(fanotify_response_event_cache, re); + list_del_init(&event->fae.fse.list); + event->response = FAN_ALLOW; } mutex_unlock(&group->fanotify_data.access_mutex); @@ -723,20 +691,15 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags) group->fanotify_data.user = user; atomic_inc(&user->fanotify_listeners); - oevent = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL); + oevent = fanotify_alloc_event(NULL, FS_Q_OVERFLOW, NULL); if (unlikely(!oevent)) { fd = -ENOMEM; goto out_destroy_group; } group->overflow_event = &oevent->fse; - fsnotify_init_event(group->overflow_event, NULL, FS_Q_OVERFLOW); - oevent->tgid = get_pid(task_tgid(current)); - oevent->path.mnt = NULL; - oevent->path.dentry = NULL; group->fanotify_data.f_flags = event_f_flags; #ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS - oevent->response = 0; mutex_init(&group->fanotify_data.access_mutex); init_waitqueue_head(&group->fanotify_data.access_waitq); INIT_LIST_HEAD(&group->fanotify_data.access_list); @@ -912,9 +875,11 @@ COMPAT_SYSCALL_DEFINE6(fanotify_mark, static int __init fanotify_user_setup(void) { fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC); - fanotify_response_event_cache = KMEM_CACHE(fanotify_response_event, - SLAB_PANIC); fanotify_event_cachep = KMEM_CACHE(fanotify_event_info, SLAB_PANIC); +#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS + fanotify_perm_event_cachep = KMEM_CACHE(fanotify_perm_event_info, + SLAB_PANIC); +#endif return 0; } |