platform/x86: toshiba_acpi: use memdup_user_nul

Use memdup_user_nul() helper instead of open-coding to simplify the
code.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
index d0daf75..88f9f79 100644 (file)
--- a/drivers/platform/x86/toshiba_acpi.c
+++ b/drivers/platform/x86/toshiba_acpi.c
@@ -1502,14 +1502,9 @@ static ssize_t video_proc_write(struct file *file, const char __user *buf,
        int ret;
        u32 video_out;
 
-       cmd = kmalloc(count + 1, GFP_KERNEL);
-       if (!cmd)
-               return -ENOMEM;
-       if (copy_from_user(cmd, buf, count)) {
-               kfree(cmd);
-               return -EFAULT;
-       }
-       cmd[count] = '\0';
+       cmd = memdup_user_nul(buf, count);
+       if (IS_ERR(cmd))
+               return PTR_ERR(cmd);
 
        buffer = cmd;