On Fri 22-11-13 00:36:57, Jan Kara wrote:
> Rounding of name length when passing it to userspace was done in several
> places. Provide a function to do it and use it in all places.
>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
Ping? Any opinion on this patchset?
Honza
> ---
> fs/notify/inotify/inotify_user.c | 41 ++++++++++++++++++++--------------------
> 1 file changed, 21 insertions(+), 20 deletions(-)
>
> diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
> index 60f954a891ab..1bb6dc8eaf1c 100644
> --- a/fs/notify/inotify/inotify_user.c
> +++ b/fs/notify/inotify/inotify_user.c
> @@ -124,6 +124,13 @@ static unsigned int inotify_poll(struct file *file, poll_table *wait)
> return ret;
> }
>
> +static int round_event_name_len(struct fsnotify_event *event)
> +{
> + if (!event->name_len)
> + return 0;
> + return roundup(event->name_len + 1, sizeof(struct inotify_event));
> +}
> +
> /*
> * Get an inotify_kernel_event if one exists and is small
> * enough to fit in "count". Return an error pointer if
> @@ -144,9 +151,7 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
>
> pr_debug("%s: group=%p event=%p\n", __func__, group, event);
>
> - if (event->name_len)
> - event_size += roundup(event->name_len + 1, event_size);
> -
> + event_size += round_event_name_len(event);
> if (event_size > count)
> return ERR_PTR(-EINVAL);
>
> @@ -171,7 +176,8 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
> struct fsnotify_event_private_data *fsn_priv;
> struct inotify_event_private_data *priv;
> size_t event_size = sizeof(struct inotify_event);
> - size_t name_len = 0;
> + size_t name_len;
> + size_t pad_name_len;
>
> pr_debug("%s: group=%p event=%p\n", __func__, group, event);
>
> @@ -189,14 +195,13 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
> inotify_free_event_priv(fsn_priv);
> }
>
> + name_len = event->name_len;
> /*
> - * round up event->name_len so it is a multiple of event_size
> + * round up name length so it is a multiple of event_size
> * plus an extra byte for the terminating '\0'.
> */
> - if (event->name_len)
> - name_len = roundup(event->name_len + 1, event_size);
> - inotify_event.len = name_len;
> -
> + pad_name_len = round_event_name_len(event);
> + inotify_event.len = pad_name_len;
> inotify_event.mask = inotify_mask_to_arg(event->mask);
> inotify_event.cookie = event->sync_cookie;
>
> @@ -209,20 +214,18 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
> /*
> * fsnotify only stores the pathname, so here we have to send the pathname
> * and then pad that pathname out to a multiple of sizeof(inotify_event)
> - * with zeros. I get my zeros from the nul_inotify_event.
> + * with zeros.
> */
> - if (name_len) {
> - unsigned int len_to_zero = name_len - event->name_len;
> + if (pad_name_len) {
> /* copy the path name */
> - if (copy_to_user(buf, event->file_name, event->name_len))
> + if (copy_to_user(buf, event->file_name, name_len))
> return -EFAULT;
> - buf += event->name_len;
> + buf += name_len;
>
> /* fill userspace with 0's */
> - if (clear_user(buf, len_to_zero))
> + if (clear_user(buf, pad_name_len - name_len))
> return -EFAULT;
> - buf += len_to_zero;
> - event_size += name_len;
> + event_size += pad_name_len;
> }
>
> return event_size;
> @@ -314,9 +317,7 @@ static long inotify_ioctl(struct file *file, unsigned int cmd,
> list_for_each_entry(holder, &group->notification_list, event_list) {
> event = holder->event;
> send_len += sizeof(struct inotify_event);
> - if (event->name_len)
> - send_len += roundup(event->name_len + 1,
> - sizeof(struct inotify_event));
> + send_len += round_event_name_len(event);
> }
> mutex_unlock(&group->notification_mutex);
> ret = put_user(send_len, (int __user *) p);
> --
> 1.8.1.4
>
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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