sysfs: use memdup_user()

Remove open-coded memdup_user().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index 93e0c02..9345806 100644 (file)
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -157,14 +157,9 @@ static ssize_t write(struct file *file, const char __user *userbuf,
                        count = size - offs;
        }
 
-       temp = kmalloc(count, GFP_KERNEL);
-       if (!temp)
-               return -ENOMEM;
-
-       if (copy_from_user(temp, userbuf, count)) {
-               count = -EFAULT;
-               goto out_free;
-       }
+       temp = memdup_user(userbuf, count);
+       if (IS_ERR(temp))
+               return PTR_ERR(temp);
 
        mutex_lock(&bb->mutex);
 
@@ -176,8 +171,6 @@ static ssize_t write(struct file *file, const char __user *userbuf,
        if (count > 0)
                *off = offs + count;
 
-out_free:
-       kfree(temp);
        return count;
 }