[S390] s390/vmcp: use simple_read_from_buffer()
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/vmcp.c b/drivers/s390/char/vmcp.c
index 2f419b0..af616ae 100644
--- a/drivers/s390/char/vmcp.c
+++ b/drivers/s390/char/vmcp.c
@@ -61,30 +61,24 @@
static ssize_t
vmcp_read(struct file *file, char __user *buff, size_t count, loff_t *ppos)
{
- size_t tocopy;
+ ssize_t ret;
+ size_t size;
struct vmcp_session *session;
- session = (struct vmcp_session *)file->private_data;
+ session = file->private_data;
if (mutex_lock_interruptible(&session->mutex))
return -ERESTARTSYS;
if (!session->response) {
mutex_unlock(&session->mutex);
return 0;
}
- if (*ppos > session->resp_size) {
- mutex_unlock(&session->mutex);
- return 0;
- }
- tocopy = min(session->resp_size - (size_t) (*ppos), count);
- tocopy = min(tocopy, session->bufsize - (size_t) (*ppos));
+ size = min_t(size_t, session->resp_size, session->bufsize);
+ ret = simple_read_from_buffer(buff, count, ppos,
+ session->response, size);
- if (copy_to_user(buff, session->response + (*ppos), tocopy)) {
- mutex_unlock(&session->mutex);
- return -EFAULT;
- }
mutex_unlock(&session->mutex);
- *ppos += tocopy;
- return tocopy;
+
+ return ret;
}
static ssize_t