[PATCH v1] x86/mtrr: Convert to use strncpy_from_user() helper

[Andy Shevchenko]

Replace the open coded string fetch from the user.

Signed-off-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
---
 arch/x86/kernel/cpu/mtrr/if.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c
index e4adad68b5e5..3cbae60663fa 100644
--- a/arch/x86/kernel/cpu/mtrr/if.c
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -105,17 +105,9 @@ mtrr_write(struct file *file, const char __user *buf, 
size_t len, loff_t * ppos)
 
        memset(line, 0, LINE_SIZE);
 
-       length = len;
-       length--;
-
-       if (length > LINE_SIZE - 1)
-               length = LINE_SIZE - 1;
-
+       length = strncpy_from_user(line, buf, LINE_SIZE - 1);
        if (length < 0)
-               return -EINVAL;
-
-       if (copy_from_user(line, buf, length))
-               return -EFAULT;
+               return length;
 
        strim(line);
 
-- 
2.17.0