[S390] qdio: Use kstrtoul_from_user

This patch replaces the code for getting an unsigned long from a
userspace buffer by a simple call to kstroul_from_user.
This makes it easier to read and less error prone.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Acked-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 3 insertions, 9 deletions

diff --git a/drivers/s390/cio/qdio_debug.c b/drivers/s390/cio/qdio_debug.c
index f8b03a636e49..0e615cb912d0 100644
--- a/drivers/s390/cio/qdio_debug.c
+++ b/drivers/s390/cio/qdio_debug.c
@@ -188,19 +188,13 @@ static ssize_t qperf_seq_write(struct file *file, const char __user *ubuf,
         struct qdio_irq *irq_ptr = seq->private;
         struct qdio_q *q;
         unsigned long val;
-        char buf[8];
         int ret, i;
 
         if (!irq_ptr)
                 return 0;
-        if (count >= sizeof(buf))
-                return -EINVAL;
-        if (copy_from_user(&buf, ubuf, count))
-                return -EFAULT;
-        buf[count] = 0;
-
-        ret = strict_strtoul(buf, 10, &val);
-        if (ret < 0)
+
+        ret = kstrtoul_from_user(ubuf, count, 10, &val);
+        if (ret)
                 return ret;
 
         switch (val) {