Commit b26b1816 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

microblaze: use generic strncpy/strnlen from_user 



Remove the microblaze implemenation of strncpy/strnlen and instead use
the generic versions.  The microblaze version is fairly slow because it
always does byte accesses even for aligned data, and it lacks a checks
for user_addr_max().

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 0cd11518

arch/microblaze/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -21,6 +21,8 @@ config MICROBLAZE 
	select GENERIC_IRQ_SHOW

	select GENERIC_PCI_IOMAP

	select GENERIC_SCHED_CLOCK

	select GENERIC_STRNCPY_FROM_USER

	select GENERIC_STRNLEN_USER

	select HAVE_ARCH_HASH

	select HAVE_ARCH_KGDB

	select HAVE_ARCH_SECCOMP

arch/microblaze/include/asm/uaccess.h

+4 −17
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 


# define get_fs()	(current_thread_info()->addr_limit)

# define set_fs(val)	(current_thread_info()->addr_limit = (val))

# define user_addr_max() get_fs().seg



# define uaccess_kernel()	(get_fs().seg == KERNEL_DS.seg)
@@ -296,28 +297,14 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n) 
/*

 * Copy a null terminated string from userspace.

 */

extern int __strncpy_user(char *to, const char __user *from, int len);



static inline long

strncpy_from_user(char *dst, const char __user *src, long count)

{

	if (!access_ok(src, 1))

		return -EFAULT;

	return __strncpy_user(dst, src, count);

}

__must_check long strncpy_from_user(char *dst, const char __user *src,

				    long count);



/*

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

 *

 * Return 0 on exception, a value greater than N if too long

 */

extern int __strnlen_user(const char __user *sstr, int len);



static inline long strnlen_user(const char __user *src, long n)

{

	if (!access_ok(src, 1))

		return 0;

	return __strnlen_user(src, n);

}

__must_check long strnlen_user(const char __user *sstr, long len);



#endif /* _ASM_MICROBLAZE_UACCESS_H */

arch/microblaze/kernel/microblaze_ksyms.c

+0 −1
Original line number Diff line number Diff line
@@ -26,7 +26,6 @@ EXPORT_SYMBOL(_mcount); 
 * Assembly functions that may be used (directly or indirectly) by modules

 */

EXPORT_SYMBOL(__copy_tofrom_user);

EXPORT_SYMBOL(__strncpy_user);



#ifdef CONFIG_OPT_LIB_ASM

EXPORT_SYMBOL(memcpy);

arch/microblaze/lib/uaccess_old.S

+0 −90
Original line number Diff line number Diff line
@@ -12,96 +12,6 @@ 
#include <linux/linkage.h>

#include <asm/page.h>



/*

 * int __strncpy_user(char *to, char *from, int len);

 *

 * Returns:

 *  -EFAULT  for an exception

 *  len      if we hit the buffer limit

 *  bytes copied

 */



	.text

.globl __strncpy_user;

.type  __strncpy_user, @function

.align 4;

__strncpy_user:



	/*

	 * r5 - to

	 * r6 - from

	 * r7 - len

	 * r3 - temp count

	 * r4 - temp val

	 */

	beqid	r7,3f

	addik	r3,r7,0		/* temp_count = len */

1:

	lbu	r4,r6,r0

	beqid	r4,2f

	sb	r4,r5,r0



	addik	r5,r5,1

	addik	r6,r6,1		/* delay slot */



	addik	r3,r3,-1

	bnei	r3,1b		/* break on len */

2:

	rsubk	r3,r3,r7	/* temp_count = len - temp_count */

3:

	rtsd	r15,8

	nop

	.size   __strncpy_user, . - __strncpy_user



	.section	.fixup, "ax"

	.align	2

4:

	brid	3b

	addik	r3,r0, -EFAULT



	.section	__ex_table, "a"

	.word	1b,4b



/*

 * int __strnlen_user(char __user *str, int maxlen);

 *

 * Returns:

 *  0 on error

 *  maxlen + 1  if no NUL byte found within maxlen bytes

 *  size of the string (including NUL byte)

 */



	.text

.globl __strnlen_user;

.type  __strnlen_user, @function

.align 4;

__strnlen_user:

	beqid	r6,3f

	addik	r3,r6,0

1:

	lbu	r4,r5,r0

	beqid	r4,2f		/* break on NUL */

	addik	r3,r3,-1	/* delay slot */



	bneid	r3,1b

	addik	r5,r5,1		/* delay slot */



	addik	r3,r3,-1	/* for break on len */

2:

	rsubk	r3,r3,r6

3:

	rtsd	r15,8

	nop

	.size   __strnlen_user, . - __strnlen_user



	.section	.fixup,"ax"

4:

	brid	3b

	addk	r3,r0,r0



	.section	__ex_table,"a"

	.word	1b,4b



/* Loop unrolling for __copy_tofrom_user */

#define COPY(offset)	\

1:	lwi	r4 , r6, 0x0000 + offset;	\