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authorJan Kara <jack@suse.cz>2014-01-21 15:48:13 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-21 16:19:41 -0800
commite9fe69045bd648d75d8d8099b8658a4ee005a8e5 (patch)
tree9c3e81c861c50df65e3337cbb85af6420a2df47d /fs/notify
parent0abdd7a81b7e3fd781d7fabcca49501852bba17e (diff)
downloadlinux-linaro-stable-e9fe69045bd648d75d8d8099b8658a4ee005a8e5.tar.gz
inotify: provide function for name length rounding
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@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Eric Paris <eparis@parisplace.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/notify')
-rw-r--r--fs/notify/inotify/inotify_user.c41
1 files 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);