Commit b48b2c3e authored by Jonas Bonn's avatar Jonas Bonn Committed by Linus Torvalds
Browse files

openrisc: use generic strnlen_user() function 



The generic version is both easier to support and more correct.

Signed-off-by: default avatarJonas Bonn <jonas@southpole.se>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1629372c

arch/openrisc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ config OPENRISC 
	select GENERIC_ATOMIC64

	select GENERIC_CLOCKEVENTS

	select GENERIC_STRNCPY_FROM_USER

	select GENERIC_STRNLEN_USER



config MMU

	def_bool y

arch/openrisc/include/asm/uaccess.h

+2 −28
Original line number Diff line number Diff line
@@ -318,33 +318,7 @@ clear_user(void *addr, unsigned long size) 


extern long strncpy_from_user(char *dest, const char __user *src, long count);



/*

 * Return the size of a string (including the ending 0)

 *

 * Return 0 for error

 */



extern int __strnlen_user(const char *str, long len, unsigned long top);



/*

 * Returns the length of the string at str (including the null byte),

 * or 0 if we hit a page we can't access,

 * or something > len if we didn't find a null byte.

 *

 * The `top' parameter to __strnlen_user is to make sure that

 * we can never overflow from the user area into kernel space.

 */

static inline long strnlen_user(const char __user *str, long len)

{

	unsigned long top = (unsigned long)get_fs();

	unsigned long res = 0;



	if (__addr_ok(str))

		res = __strnlen_user(str, len, top);



	return res;

}



#define strlen_user(str) strnlen_user(str, TASK_SIZE-1)

extern __must_check long strlen_user(const char __user *str);

extern __must_check long strnlen_user(const char __user *str, long n);



#endif /* __ASM_OPENRISC_UACCESS_H */

arch/openrisc/lib/string.S

+0 −47
Original line number Diff line number Diff line
@@ -103,50 +103,3 @@ __clear_user: 
	.section __ex_table, "a"

		.long 9b, 99b		// write fault

	.previous
 




/*

 * extern int __strnlen_user(const char *str, long len, unsigned long top);

 *

 *

 * RTRN: - length of a string including NUL termination character

 *       - on page fault 0

 */



	.global __strnlen_user

__strnlen_user:

	l.addi  r1,r1,-8

	l.sw    0(r1),r6

	l.sw    4(r1),r3



	l.addi  r11,r0,0

2:  	l.sfeq  r11,r4

	l.bf    1f

	l.addi  r11,r11,1

8:    	l.lbz   r6,0(r3)

	l.sfeq  r6,r0

	l.bf    1f

	l.sfgeu r3,r5                  // are we over the top ?

	l.bf    99f

	l.j     2b

	l.addi  r3,r3,1



1:

	l.lwz   r6,0(r1)

	l.lwz	r3,4(r1)

	l.jr    r9

	l.addi  r1,r1,8



	.section .fixup, "ax"

99:

		l.addi  r11,r0,0



		l.lwz   r6,0(r1)

		l.lwz	r3,4(r1)

		l.jr	r9

		l.addi  r1,r1,8

	.previous



	.section __ex_table, "a"

		.long 8b, 99b		// read fault

	.previous