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Commit 7f509a9e authored by GuanXuetao's avatar GuanXuetao
Browse files

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: default avatarGuan Xuetao <gxt@mprc.pku.edu.cn>
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 38f5bf84

include/asm-generic/uaccess.h

+5 −3
Original line number Diff line number Diff line
@@ -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)

{