From: GuanXuetao <gxt@mprc.pku.edu.cn>
Date: Sat, 15 Jan 2011 10:08:09 +0000 (+0800)
Subject: asm-generic headers: add arch-specific __strnlen_user calling in uaccess.h
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7f509a9ef7af0d6ac852d49eb87ed2b9857821cc;p=linux-beck.git

asm-generic headers: add arch-specific __strnlen_user calling in uaccess.h

This patch changes the implementation of strnlen_user in include/asm-generic/uaccess.h.
Originally, it calls strlen() function directly, which may not correctly handle the access of
user space in most mmu-enabled architectures.
New __strnlen_user is added for using as an architecture specific function.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
---

diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index b218b8513d04..ac68c999b6c2 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -288,14 +288,16 @@ strncpy_from_user(char *dst, const char __user *src, long count)
  *
  * Return 0 on exception, a value greater than N if too long
  */
-#ifndef strnlen_user
+#ifndef __strnlen_user
+#define __strnlen_user strnlen
+#endif
+
 static inline long strnlen_user(const char __user *src, long n)
 {
 	if (!access_ok(VERIFY_READ, src, 1))
 		return 0;
-	return strlen((void * __force)src) + 1;
+	return __strnlen_user(src, n);
 }
-#endif
 
 static inline long strlen_user(const char __user *src)
 {