uml: use simple_write_to_buffer()
Simplify write file operation for mmapper by using
simple_write_to_buffer().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/drivers/mmapper_kern.c b/arch/um/drivers/mmapper_kern.c
index 6bc73f0..7e0619c 100644
--- a/arch/um/drivers/mmapper_kern.c
+++ b/arch/um/drivers/mmapper_kern.c
@@ -37,13 +37,7 @@
if (*ppos > mmapper_size)
return -EINVAL;
- if (count > mmapper_size - *ppos)
- count = mmapper_size - *ppos;
-
- if (copy_from_user(&v_buf[*ppos], buf, count))
- return -EFAULT;
-
- return count;
+ return simple_write_to_buffer(v_buf, mmapper_size, ppos, buf, count);
}
static long mmapper_ioctl(struct file *file, unsigned int cmd, unsigned long arg)