convert a bunch of open-coded instances of memdup_user_nul()

A _lot_ of ->write() instances were open-coding it; some are
converted to memdup_user_nul(), a lot more remain...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 3 insertions, 10 deletions

diff --git a/drivers/sbus/char/openprom.c b/drivers/sbus/char/openprom.c
index 5843288f64bc..e077ebd89319 100644
--- a/drivers/sbus/char/openprom.c
+++ b/drivers/sbus/char/openprom.c
@@ -390,16 +390,9 @@ static int copyin_string(char __user *user, size_t len, char **ptr)
         if ((ssize_t)len < 0 || (ssize_t)(len + 1) < 0)
                 return -EINVAL;
 
-        tmp = kmalloc(len + 1, GFP_KERNEL);
-        if (!tmp)
-                return -ENOMEM;
-
-        if (copy_from_user(tmp, user, len)) {
-                kfree(tmp);
-                return -EFAULT;
-        }
-
-        tmp[len] = '\0';
+        tmp = memdup_user_nul(user, len);
+        if (IS_ERR(tmp))
+                return PTR_ERR(tmp);
 
         *ptr = tmp;