Merge tag 'metag-for-v4.11-rc6' of git://git.kernel.org/pub/scm/linux…

…/kernel/git/jhogan/metag

Pull metag usercopy fixes from James Hogan:
 "Metag usercopy fault handling fixes

  These patches fix a bunch of longstanding (some over a decade old)
  metag user copy fault handling bugs. Thanks go to Al Viro for spotting
  some of the questionable code in the first place"

* tag 'metag-for-v4.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag:
  metag/usercopy: Add missing fixups
  metag/usercopy: Fix src fixup in from user rapf loops
  metag/usercopy: Set flags before ADDZ
  metag/usercopy: Zero rest of buffer from copy_from_user
  metag/usercopy: Add early abort to copy_to_user
  metag/usercopy: Fix alignment error checking
  metag/usercopy: Drop unused macros

arch/metag/include/asm/uaccess.h

@@ -197,20 +197,21 @@ extern long __must_check strnlen_user(const char __user *src, long count);
 
 #define strlen_user(str) strnlen_user(str, 32767)
 
-extern unsigned long __must_check __copy_user_zeroing(void *to,
-						      const void __user *from,
-						      unsigned long n);
+extern unsigned long raw_copy_from_user(void *to, const void __user *from,
+					unsigned long n);
 
 static inline unsigned long
 copy_from_user(void *to, const void __user *from, unsigned long n)
 {
+	unsigned long res = n;
 	if (likely(access_ok(VERIFY_READ, from, n)))
-		return __copy_user_zeroing(to, from, n);
-	memset(to, 0, n);
-	return n;
+		res = raw_copy_from_user(to, from, n);
+	if (unlikely(res))
+		memset(to + (n - res), 0, res);
+	return res;
 }
 
-#define __copy_from_user(to, from, n) __copy_user_zeroing(to, from, n)
+#define __copy_from_user(to, from, n) raw_copy_from_user(to, from, n)
 #define __copy_from_user_inatomic __copy_from_user
 
 extern unsigned long __must_check __copy_user(void __user *to,