sh: switch to generic strncpy_from_user().

This kills off the special sh32/64 versions and adopts the generic
version. It should be possible to optimize this for SH-4A unaligned
loads, but this is a corner case that can be supported incrementally.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/Kconfig

@@ -32,6 +32,7 @@ config SUPERH
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_CMOS_UPDATE if SH_SH03 || SH_DREAMCAST
+	select GENERIC_STRNCPY_FROM_USER
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast

arch/sh/include/asm/uaccess.h

@@ -25,6 +25,8 @@
 	(__chk_user_ptr(addr),		\
 	 __access_ok((unsigned long __force)(addr), (size)))
 
+#define user_addr_max()	(current_thread_info()->addr_limit.seg)
+
 /*
  * Uh, these should become the main single-value transfer routines ...
  * They automatically use the right size if we just have the right
@@ -100,6 +102,8 @@ struct __large_struct { unsigned long buf[100]; };
 # include "uaccess_64.h"
 #endif
 
+extern long strncpy_from_user(char *dest, const char __user *src, long count);
+
 /* Generic arbitrary sized copy.  */
 /* Return the number of bytes NOT copied */
 __kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
@@ -137,37 +141,6 @@ __kernel_size_t __clear_user(void *addr, __kernel_size_t size);
 	__cl_size;							\
 })
 
-/**
- * strncpy_from_user: - Copy a NUL terminated string from userspace.
- * @dst:   Destination address, in kernel space.  This buffer must be at
- *         least @count bytes long.
- * @src:   Source address, in user space.
- * @count: Maximum number of bytes to copy, including the trailing NUL.
- *
- * Copies a NUL-terminated string from userspace to kernel space.
- *
- * On success, returns the length of the string (not including the trailing
- * NUL).
- *
- * If access to userspace fails, returns -EFAULT (some data may have been
- * copied).
- *
- * If @count is smaller than the length of the string, copies @count bytes
- * and returns @count.
- */
-#define strncpy_from_user(dest,src,count)				\
-({									\
-	unsigned long __sfu_src = (unsigned long)(src);			\
-	int __sfu_count = (int)(count);					\
-	long __sfu_res = -EFAULT;					\
-									\
-	if (__access_ok(__sfu_src, __sfu_count))			\
-		__sfu_res = __strncpy_from_user((unsigned long)(dest),	\
-				__sfu_src, __sfu_count);		\
-									\
-	__sfu_res;							\
-})
-
 static inline unsigned long
 copy_from_user(void *to, const void __user *from, unsigned long n)
 {

arch/sh/include/asm/uaccess_32.h

@@ -170,45 +170,6 @@ __asm__ __volatile__( \
 
 extern void __put_user_unknown(void);
 
-static inline int
-__strncpy_from_user(unsigned long __dest, unsigned long __user __src, int __count)
-{
-	__kernel_size_t res;
-	unsigned long __dummy, _d, _s, _c;
-
-	__asm__ __volatile__(
-		"9:\n"
-		"mov.b	@%2+, %1\n\t"
-		"cmp/eq	#0, %1\n\t"
-		"bt/s	2f\n"
-		"1:\n"
-		"mov.b	%1, @%3\n\t"
-		"dt	%4\n\t"
-		"bf/s	9b\n\t"
-		" add	#1, %3\n\t"
-		"2:\n\t"
-		"sub	%4, %0\n"
-		"3:\n"
-		".section .fixup,\"ax\"\n"
-		"4:\n\t"
-		"mov.l	5f, %1\n\t"
-		"jmp	@%1\n\t"
-		" mov	%9, %0\n\t"
-		".balign 4\n"
-		"5:	.long 3b\n"
-		".previous\n"
-		".section __ex_table,\"a\"\n"
-		"	.balign 4\n"
-		"	.long 9b,4b\n"
-		".previous"
-		: "=r" (res), "=&z" (__dummy), "=r" (_s), "=r" (_d), "=r"(_c)
-		: "0" (__count), "2" (__src), "3" (__dest), "4" (__count),
-		  "i" (-EFAULT)
-		: "memory", "t");
-
-	return res;
-}
-
 /*
  * Return the size of a string (including the ending 0 even when we have
  * exceeded the maximum string length).

arch/sh/include/asm/uaccess_64.h

@@ -85,7 +85,5 @@ extern long __put_user_asm_q(void *, long);
 extern void __put_user_unknown(void);
 
 extern long __strnlen_user(const char *__s, long __n);
-extern int __strncpy_from_user(unsigned long __dest,
-	       unsigned long __user __src, int __count);
 
 #endif /* __ASM_SH_UACCESS_64_H */

arch/sh/kernel/cpu/sh5/entry.S

@@ -1568,46 +1568,6 @@ ___clear_user_exit:
 
 #endif /* CONFIG_MMU */
 
-/*
- * int __strncpy_from_user(unsigned long __dest, unsigned long __src,
- *			   int __count)
- *
- * Inputs:
- * (r2)  target address
- * (r3)  source address
- * (r4)  maximum size in bytes
- *
- * Ouputs:
- * (*r2) copied data
- * (r2)  -EFAULT (in case of faulting)
- *       copied data (otherwise)
- */
-	.global	__strncpy_from_user
-__strncpy_from_user:
-	pta	___strncpy_from_user1, tr0
-	pta	___strncpy_from_user_done, tr1
-	or	r4, ZERO, r5		/* r5 = original count */
-	beq/u	r4, r63, tr1		/* early exit if r4==0 */
-	movi	-(EFAULT), r6		/* r6 = reply, no real fixup */
-	or	ZERO, ZERO, r7		/* r7 = data, clear top byte of data */
-
-___strncpy_from_user1:
-	ld.b	r3, 0, r7		/* Fault address: only in reading */
-	st.b	r2, 0, r7
-	addi	r2, 1, r2
-	addi	r3, 1, r3
-	beq/u	ZERO, r7, tr1
-	addi	r4, -1, r4		/* return real number of copied bytes */
-	bne/l	ZERO, r4, tr0
-
-___strncpy_from_user_done:
-	sub	r5, r4, r6		/* If done, return copied */
-
-___strncpy_from_user_exit:
-	or	r6, ZERO, r2
-	ptabs	LINK, tr0
-	blink	tr0, ZERO
-
 /*
  * extern long __strnlen_user(const char *__s, long __n)
  *
@@ -1982,7 +1942,6 @@ asm_uaccess_start:
 	.long	___copy_user2, ___copy_user_exit
 	.long	___clear_user1, ___clear_user_exit
 #endif
-	.long	___strncpy_from_user1, ___strncpy_from_user_exit
 	.long	___strnlen_user1, ___strnlen_user_exit
 	.long	___get_user_asm_b1, ___get_user_asm_b_exit
 	.long	___get_user_asm_w1, ___get_user_asm_w_exit

arch/sh/kernel/sh_ksyms_64.c

@@ -33,7 +33,6 @@ EXPORT_SYMBOL(__get_user_asm_w);
 EXPORT_SYMBOL(__get_user_asm_l);
 EXPORT_SYMBOL(__get_user_asm_q);
 EXPORT_SYMBOL(__strnlen_user);
-EXPORT_SYMBOL(__strncpy_from_user);
 EXPORT_SYMBOL(__clear_user);
 EXPORT_SYMBOL(copy_page);
 EXPORT_SYMBOL(__copy_user);