Commit c52801a7 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

arc: use generic strncpy/strnlen from_user 



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

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 2820cfdc

arch/arc/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -27,6 +27,8 @@ config ARC 
	select GENERIC_PENDING_IRQ if SMP

	select GENERIC_SCHED_CLOCK

	select GENERIC_SMP_IDLE_THREAD

	select GENERIC_STRNCPY_FROM_USER

	select GENERIC_STRNLEN_USER

	select HAVE_ARCH_KGDB

	select HAVE_ARCH_TRACEHOOK

	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARC_MMU_V4

arch/arc/include/asm/uaccess.h

+5 −78
Original line number Diff line number Diff line
@@ -655,96 +655,23 @@ static inline unsigned long __arc_clear_user(void __user *to, unsigned long n) 
	return res;

}



static inline long

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

{

	long res = 0;

	char val;



	if (!access_ok(src, 1))

		return -EFAULT;



	if (count == 0)

		return 0;



	__asm__ __volatile__(

	"	mov	lp_count, %5		\n"

	"	lp	3f			\n"

	"1:	ldb.ab  %3, [%2, 1]		\n"

	"	breq.d	%3, 0, 3f               \n"

	"	stb.ab  %3, [%1, 1]		\n"

	"	add	%0, %0, 1	# Num of NON NULL bytes copied	\n"

	"3:								\n"

	"	.section .fixup, \"ax\"		\n"

	"	.align 4			\n"

	"4:	mov %0, %4		# sets @res as -EFAULT	\n"

	"	j   3b				\n"

	"	.previous			\n"

	"	.section __ex_table, \"a\"	\n"

	"	.align 4			\n"

	"	.word   1b, 4b			\n"

	"	.previous			\n"

	: "+r"(res), "+r"(dst), "+r"(src), "=r"(val)

	: "g"(-EFAULT), "r"(count)

	: "lp_count", "memory");



	return res;

}



static inline long __arc_strnlen_user(const char __user *s, long n)

{

	long res, tmp1, cnt;

	char val;



	if (!access_ok(s, 1))

		return 0;



	__asm__ __volatile__(

	"	mov %2, %1			\n"

	"1:	ldb.ab  %3, [%0, 1]		\n"

	"	breq.d  %3, 0, 2f		\n"

	"	sub.f   %2, %2, 1		\n"

	"	bnz 1b				\n"

	"	sub %2, %2, 1			\n"

	"2:	sub %0, %1, %2			\n"

	"3:	;nop				\n"

	"	.section .fixup, \"ax\"		\n"

	"	.align 4			\n"

	"4:	mov %0, 0			\n"

	"	j   3b				\n"

	"	.previous			\n"

	"	.section __ex_table, \"a\"	\n"

	"	.align 4			\n"

	"	.word 1b, 4b			\n"

	"	.previous			\n"

	: "=r"(res), "=r"(tmp1), "=r"(cnt), "=r"(val)

	: "0"(s), "1"(n)

	: "memory");



	return res;

}



#ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE



#define INLINE_COPY_TO_USER

#define INLINE_COPY_FROM_USER



#define __clear_user(d, n)		__arc_clear_user(d, n)

#define strncpy_from_user(d, s, n)	__arc_strncpy_from_user(d, s, n)

#define strnlen_user(s, n)		__arc_strnlen_user(s, n)

#else

extern unsigned long arc_clear_user_noinline(void __user *to,

		unsigned long n);

extern long arc_strncpy_from_user_noinline (char *dst, const char __user *src,

		long count);

extern long arc_strnlen_user_noinline(const char __user *src, long n);



#define __clear_user(d, n)		arc_clear_user_noinline(d, n)

#define strncpy_from_user(d, s, n)	arc_strncpy_from_user_noinline(d, s, n)

#define strnlen_user(s, n)		arc_strnlen_user_noinline(s, n)



#endif



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

#define strncpy_from_user(d, s, n)	strncpy_from_user(d, s, n)

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

#define strnlen_user(s, n)		strnlen_user(s, n)



#include <asm/segment.h>

#include <asm-generic/uaccess.h>

arch/arc/mm/extable.c

+0 −12
Original line number Diff line number Diff line
@@ -32,16 +32,4 @@ unsigned long arc_clear_user_noinline(void __user *to, 
}

EXPORT_SYMBOL(arc_clear_user_noinline);



long arc_strncpy_from_user_noinline(char *dst, const char __user *src,

		long count)

{

	return __arc_strncpy_from_user(dst, src, count);

}

EXPORT_SYMBOL(arc_strncpy_from_user_noinline);



long arc_strnlen_user_noinline(const char __user *src, long n)

{

	return __arc_strnlen_user(src, n);

}

EXPORT_SYMBOL(arc_strnlen_user_noinline);

#endif