ipc: use simple_read_from_buffer()
Also this patch kills unneccesary trailing NULL character.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Pierre Peiffer <peifferp@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 3e84b95..1fdc2eb 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -314,15 +314,11 @@
* through std routines)
*/
static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
- size_t count, loff_t * off)
+ size_t count, loff_t *off)
{
struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
char buffer[FILENT_SIZE];
- size_t slen;
- loff_t o;
-
- if (!count)
- return 0;
+ ssize_t ret;
spin_lock(&info->lock);
snprintf(buffer, sizeof(buffer),
@@ -335,21 +331,14 @@
pid_vnr(info->notify_owner));
spin_unlock(&info->lock);
buffer[sizeof(buffer)-1] = '\0';
- slen = strlen(buffer)+1;
- o = *off;
- if (o > slen)
- return 0;
+ ret = simple_read_from_buffer(u_data, count, off, buffer,
+ strlen(buffer));
+ if (ret <= 0)
+ return ret;
- if (o + count > slen)
- count = slen - o;
-
- if (copy_to_user(u_data, buffer + o, count))
- return -EFAULT;
-
- *off = o + count;
filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME;
- return count;
+ return ret;
}
static int mqueue_flush_file(struct file *filp, fl_owner_t id)
