[linux-2.6-block.git] / arch / nds32 / include / asm / uaccess.h

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation

#ifndef _ASMANDES_UACCESS_H
#define _ASMANDES_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/sched.h>
#include <asm/errno.h>
#include <asm/memory.h>
#include <asm/types.h>
#include <linux/mm.h>

#define __asmeq(x, y)  ".ifnc " x "," y " ; .err ; .endif\n\t"

/*
 * The exception table consists of pairs of addresses: the first is the
 * address of an instruction that is allowed to fault, and the second is
 * the address at which the program should continue.  No registers are
 * modified, so it is entirely up to the continuation code to figure out
 * what to do.
 *
 * All the routines below use bits of fixup code that are out of line
 * with the main instruction path.  This means when everything is well,
 * we don't even have to jump over them.  Further, they do not intrude
 * on our cache or tlb entries.
 */

struct exception_table_entry {
	unsigned long insn, fixup;
};

extern int fixup_exception(struct pt_regs *regs);

#define KERNEL_DS 	((mm_segment_t) { ~0UL })
#define USER_DS		((mm_segment_t) {TASK_SIZE - 1})

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

static inline void set_fs(mm_segment_t fs)
{
	current_thread_info()->addr_limit = fs;
}

#define segment_eq(a, b)	((a) == (b))

#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs() -size))

#define access_ok(addr, size)	\
	__range_ok((unsigned long)addr, (unsigned long)size)
/*
 * Single-value transfer routines.  They automatically use the right
 * size if we just have the right pointer type.  Note that the functions
 * which read from user space (*get_*) need to take care not to leak
 * kernel data even if the calling code is buggy and fails to check
 * the return value.  This means zeroing out the destination variable
 * or buffer on error.  Normally this is done out of line by the
 * fixup code, but there are a few places where it intrudes on the
 * main code path.  When we only write to user space, there is no
 * problem.
 *
 * The "__xxx" versions of the user access functions do not verify the
 * address space - it must have been done previously with a separate
 * "access_ok()" call.
 *
 * The "xxx_error" versions set the third argument to EFAULT if an
 * error occurs, and leave it unchanged on success.  Note that these
 * versions are void (ie, don't return a value as such).
 */

#define get_user	__get_user					\

#define __get_user(x, ptr)						\
({									\
	long __gu_err = 0;						\
	__get_user_check((x), (ptr), __gu_err);				\
	__gu_err;							\
})

#define __get_user_error(x, ptr, err)					\
({									\
	__get_user_check((x), (ptr), (err));				\
	(void)0;							\
})

#define __get_user_check(x, ptr, err)					\
({									\
	const __typeof__(*(ptr)) __user *__p = (ptr);			\
	might_fault();							\
	if (access_ok(__p, sizeof(*__p))) {		\
		__get_user_err((x), __p, (err));			\
	} else {							\
		(x) = 0; (err) = -EFAULT;				\
	}								\
})

#define __get_user_err(x, ptr, err)					\
do {									\
	unsigned long __gu_val;						\
	__chk_user_ptr(ptr);						\
	switch (sizeof(*(ptr))) {					\
	case 1:								\
		__get_user_asm("lbi", __gu_val, (ptr), (err));		\
		break;							\
	case 2:								\
		__get_user_asm("lhi", __gu_val, (ptr), (err));		\
		break;							\
	case 4:								\
		__get_user_asm("lwi", __gu_val, (ptr), (err));		\
		break;							\
	case 8:								\
		__get_user_asm_dword(__gu_val, (ptr), (err));		\
		break;							\
	default:							\
		BUILD_BUG(); 						\
		break;							\
	}								\
	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
} while (0)

#define __get_user_asm(inst, x, addr, err)				\
	__asm__ __volatile__ (						\
		"1:	"inst"	%1,[%2]\n"				\
		"2:\n"							\
		"	.section .fixup,\"ax\"\n"			\
		"	.align	2\n"					\
		"3:	move %0, %3\n"					\
		"	move %1, #0\n"					\
		"	b	2b\n"					\
		"	.previous\n"					\
		"	.section __ex_table,\"a\"\n"			\
		"	.align	3\n"					\
		"	.long	1b, 3b\n"				\
		"	.previous"					\
		: "+r" (err), "=&r" (x)					\
		: "r" (addr), "i" (-EFAULT)				\
		: "cc")

#ifdef __NDS32_EB__
#define __gu_reg_oper0 "%H1"
#define __gu_reg_oper1 "%L1"
#else
#define __gu_reg_oper0 "%L1"
#define __gu_reg_oper1 "%H1"
#endif

#define __get_user_asm_dword(x, addr, err) 				\
	__asm__ __volatile__ (						\
		"\n1:\tlwi " __gu_reg_oper0 ",[%2]\n"			\
		"\n2:\tlwi " __gu_reg_oper1 ",[%2+4]\n"			\
		"3:\n"							\
		"	.section .fixup,\"ax\"\n"			\
		"	.align	2\n"					\
		"4:	move	%0, %3\n"				\
		"	b	3b\n"					\
		"	.previous\n"					\
		"	.section __ex_table,\"a\"\n"			\
		"	.align	3\n"					\
		"	.long	1b, 4b\n"				\
		"	.long	2b, 4b\n"				\
		"	.previous"					\
		: "+r"(err), "=&r"(x)					\
		: "r"(addr), "i"(-EFAULT)				\
		: "cc")

#define put_user	__put_user					\

#define __put_user(x, ptr)						\
({									\
	long __pu_err = 0;						\
	__put_user_err((x), (ptr), __pu_err);				\
	__pu_err;							\
})

#define __put_user_error(x, ptr, err)					\
({									\
	__put_user_err((x), (ptr), (err));				\
	(void)0;							\
})

#define __put_user_check(x, ptr, err)					\
({									\
	__typeof__(*(ptr)) __user *__p = (ptr);				\
	might_fault();							\
	if (access_ok(__p, sizeof(*__p))) {		\
		__put_user_err((x), __p, (err));			\
	} else	{							\
		(err) = -EFAULT;					\
	}								\
})

#define __put_user_err(x, ptr, err)					\
do {									\
	__typeof__(*(ptr)) __pu_val = (x);				\
	__chk_user_ptr(ptr);						\
	switch (sizeof(*(ptr))) {					\
	case 1:								\
		__put_user_asm("sbi", __pu_val, (ptr), (err));		\
		break;							\
	case 2: 							\
		__put_user_asm("shi", __pu_val, (ptr), (err));		\
		break;							\
	case 4: 							\
		__put_user_asm("swi", __pu_val, (ptr), (err));		\
		break;							\
	case 8:								\
		__put_user_asm_dword(__pu_val, (ptr), (err));		\
		break;							\
	default:							\
		BUILD_BUG(); 						\
		break;							\
	}								\
} while (0)

#define __put_user_asm(inst, x, addr, err)				\
	__asm__ __volatile__ (						\
		"1:	"inst"	%1,[%2]\n"				\
		"2:\n"							\
		"	.section .fixup,\"ax\"\n"			\
		"	.align	2\n"					\
		"3:	move	%0, %3\n"				\
		"	b	2b\n"					\
		"	.previous\n"					\
		"	.section __ex_table,\"a\"\n"			\
		"	.align	3\n"					\
		"	.long	1b, 3b\n"				\
		"	.previous"					\
		: "+r" (err)						\
		: "r" (x), "r" (addr), "i" (-EFAULT)			\
		: "cc")

#ifdef __NDS32_EB__
#define __pu_reg_oper0 "%H2"
#define __pu_reg_oper1 "%L2"
#else
#define __pu_reg_oper0 "%L2"
#define __pu_reg_oper1 "%H2"
#endif

#define __put_user_asm_dword(x, addr, err) 				\
	__asm__ __volatile__ (						\
		"\n1:\tswi " __pu_reg_oper0 ",[%1]\n"			\
		"\n2:\tswi " __pu_reg_oper1 ",[%1+4]\n"			\
		"3:\n"							\
		"	.section .fixup,\"ax\"\n"			\
		"	.align	2\n"					\
		"4:	move	%0, %3\n"				\
		"	b	3b\n"					\
		"	.previous\n"					\
		"	.section __ex_table,\"a\"\n"			\
		"	.align	3\n"					\
		"	.long	1b, 4b\n"				\
		"	.long	2b, 4b\n"				\
		"	.previous"					\
		: "+r"(err)						\
		: "r"(addr), "r"(x), "i"(-EFAULT)			\
		: "cc")

extern unsigned long __arch_clear_user(void __user * addr, unsigned long n);
extern long strncpy_from_user(char *dest, const char __user * src, long count);
extern __must_check long strlen_user(const char __user * str);
extern __must_check long strnlen_user(const char __user * str, long n);
extern unsigned long __arch_copy_from_user(void *to, const void __user * from,
                                           unsigned long n);
extern unsigned long __arch_copy_to_user(void __user * to, const void *from,
                                         unsigned long n);

#define raw_copy_from_user __arch_copy_from_user
#define raw_copy_to_user __arch_copy_to_user

#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER
static inline unsigned long clear_user(void __user * to, unsigned long n)
{
	if (access_ok(to, n))
		n = __arch_clear_user(to, n);
	return n;
}

static inline unsigned long __clear_user(void __user * to, unsigned long n)
{
	return __arch_clear_user(to, n);
}

#endif /* _ASMNDS32_UACCESS_H */
Commit	Line	Data
ace02e2b GH	1	// SPDX-License-Identifier: GPL-2.0
	2	// Copyright (C) 2005-2017 Andes Technology Corporation
	3
	4	#ifndef _ASMANDES_UACCESS_H
	5	#define _ASMANDES_UACCESS_H
	6
	7	/*
	8	* User space memory access functions
	9	*/
	10	#include <linux/sched.h>
	11	#include <asm/errno.h>
	12	#include <asm/memory.h>
	13	#include <asm/types.h>
	14	#include <linux/mm.h>
	15
ace02e2b GH	16	#define __asmeq(x, y) ".ifnc " x "," y " ; .err ; .endif\n\t"
	17
	18	/*
	19	* The exception table consists of pairs of addresses: the first is the
	20	* address of an instruction that is allowed to fault, and the second is
	21	* the address at which the program should continue. No registers are
	22	* modified, so it is entirely up to the continuation code to figure out
	23	* what to do.
	24	*
	25	* All the routines below use bits of fixup code that are out of line
	26	* with the main instruction path. This means when everything is well,
	27	* we don't even have to jump over them. Further, they do not intrude
	28	* on our cache or tlb entries.
	29	*/
	30
	31	struct exception_table_entry {
	32	unsigned long insn, fixup;
	33	};
	34
	35	extern int fixup_exception(struct pt_regs *regs);
	36
	37	#define KERNEL_DS ((mm_segment_t) { ~0UL })
7ef39548	38	#define USER_DS ((mm_segment_t) {TASK_SIZE - 1})
ace02e2b	39
ace02e2b GH	40	#define get_fs() (current_thread_info()->addr_limit)
	41	#define user_addr_max get_fs
	42
	43	static inline void set_fs(mm_segment_t fs)
	44	{
	45	current_thread_info()->addr_limit = fs;
	46	}
	47
7ef39548	48	#define segment_eq(a, b) ((a) == (b))
ace02e2b GH	49
	50	#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs() -size))
	51
96d4f267	52	#define access_ok(addr, size) \
ace02e2b GH	53	__range_ok((unsigned long)addr, (unsigned long)size)
	54	/*
	55	* Single-value transfer routines. They automatically use the right
	56	* size if we just have the right pointer type. Note that the functions
	57	* which read from user space (get_) need to take care not to leak
	58	* kernel data even if the calling code is buggy and fails to check
	59	* the return value. This means zeroing out the destination variable
	60	* or buffer on error. Normally this is done out of line by the
	61	* fixup code, but there are a few places where it intrudes on the
	62	* main code path. When we only write to user space, there is no
	63	* problem.
	64	*
	65	* The "__xxx" versions of the user access functions do not verify the
	66	* address space - it must have been done previously with a separate
	67	* "access_ok()" call.
	68	*
	69	* The "xxx_error" versions set the third argument to EFAULT if an
	70	* error occurs, and leave it unchanged on success. Note that these
	71	* versions are void (ie, don't return a value as such).
	72	*/
	73
487913ab	74	#define get_user __get_user \
7ef39548 ZL	75
7ef39548 ZL	76	#define __get_user(x, ptr) \
ace02e2b GH	77	({ \
ace02e2b GH	78	long __gu_err = 0; \
487913ab	79	__get_user_check((x), (ptr), __gu_err); \
ace02e2b GH	80	__gu_err; \
	81	})
	82
7ef39548	83	#define __get_user_error(x, ptr, err) \
ace02e2b	84	({ \
487913ab	85	__get_user_check((x), (ptr), (err)); \
7ef39548	86	(void)0; \
ace02e2b GH	87	})
ace02e2b GH	88
487913ab ZL	89	#define __get_user_check(x, ptr, err) \
	90	({ \
	91	const __typeof__((ptr)) __user __p = (ptr); \
	92	might_fault(); \
96d4f267	93	if (access_ok(__p, sizeof(*__p))) { \
487913ab ZL	94	__get_user_err((x), __p, (err)); \
	95	} else { \
	96	(x) = 0; (err) = -EFAULT; \
	97	} \
	98	})
	99
7ef39548	100	#define __get_user_err(x, ptr, err) \
ace02e2b	101	do { \
ace02e2b	102	unsigned long __gu_val; \
487913ab ZL	103	__chk_user_ptr(ptr); \
487913ab ZL	104	switch (sizeof(*(ptr))) { \
ace02e2b	105	case 1: \
487913ab	106	__get_user_asm("lbi", __gu_val, (ptr), (err)); \
ace02e2b GH	107	break; \
ace02e2b GH	108	case 2: \
487913ab	109	__get_user_asm("lhi", __gu_val, (ptr), (err)); \
ace02e2b GH	110	break; \
ace02e2b GH	111	case 4: \
487913ab	112	__get_user_asm("lwi", __gu_val, (ptr), (err)); \
ace02e2b GH	113	break; \
ace02e2b GH	114	case 8: \
487913ab	115	__get_user_asm_dword(__gu_val, (ptr), (err)); \
ace02e2b GH	116	break; \
	117	default: \
	118	BUILD_BUG(); \
	119	break; \
	120	} \
487913ab	121	(x) = (__force __typeof__(*(ptr)))__gu_val; \
ace02e2b GH	122	} while (0)
ace02e2b GH	123
7ef39548 ZL	124	#define __get_user_asm(inst, x, addr, err) \
	125	__asm__ __volatile__ ( \
	126	"1: "inst" %1,[%2]\n" \
	127	"2:\n" \
	128	" .section .fixup,\"ax\"\n" \
	129	" .align 2\n" \
	130	"3: move %0, %3\n" \
	131	" move %1, #0\n" \
	132	" b 2b\n" \
	133	" .previous\n" \
	134	" .section __ex_table,\"a\"\n" \
	135	" .align 3\n" \
	136	" .long 1b, 3b\n" \
	137	" .previous" \
	138	: "+r" (err), "=&r" (x) \
	139	: "r" (addr), "i" (-EFAULT) \
	140	: "cc")
ace02e2b GH	141
	142	#ifdef __NDS32_EB__
	143	#define __gu_reg_oper0 "%H1"
	144	#define __gu_reg_oper1 "%L1"
	145	#else
	146	#define __gu_reg_oper0 "%L1"
	147	#define __gu_reg_oper1 "%H1"
	148	#endif
	149
	150	#define __get_user_asm_dword(x, addr, err) \
7ef39548 ZL	151	__asm__ __volatile__ ( \
	152	"\n1:\tlwi " __gu_reg_oper0 ",[%2]\n" \
	153	"\n2:\tlwi " __gu_reg_oper1 ",[%2+4]\n" \
	154	"3:\n" \
	155	" .section .fixup,\"ax\"\n" \
	156	" .align 2\n" \
	157	"4: move %0, %3\n" \
	158	" b 3b\n" \
	159	" .previous\n" \
	160	" .section __ex_table,\"a\"\n" \
	161	" .align 3\n" \
	162	" .long 1b, 4b\n" \
	163	" .long 2b, 4b\n" \
	164	" .previous" \
	165	: "+r"(err), "=&r"(x) \
	166	: "r"(addr), "i"(-EFAULT) \
	167	: "cc")
	168
487913ab	169	#define put_user __put_user \
7ef39548 ZL	170
7ef39548 ZL	171	#define __put_user(x, ptr) \
ace02e2b GH	172	({ \
ace02e2b GH	173	long __pu_err = 0; \
7ef39548	174	__put_user_err((x), (ptr), __pu_err); \
ace02e2b GH	175	__pu_err; \
	176	})
	177
7ef39548	178	#define __put_user_error(x, ptr, err) \
ace02e2b	179	({ \
487913ab	180	__put_user_err((x), (ptr), (err)); \
7ef39548	181	(void)0; \
ace02e2b GH	182	})
ace02e2b GH	183
487913ab ZL	184	#define __put_user_check(x, ptr, err) \
	185	({ \
	186	__typeof__((ptr)) __user __p = (ptr); \
	187	might_fault(); \
96d4f267	188	if (access_ok(__p, sizeof(*__p))) { \
487913ab ZL	189	__put_user_err((x), __p, (err)); \
	190	} else { \
	191	(err) = -EFAULT; \
	192	} \
	193	})
	194
7ef39548	195	#define __put_user_err(x, ptr, err) \
ace02e2b	196	do { \
487913ab ZL	197	__typeof__(*(ptr)) __pu_val = (x); \
	198	__chk_user_ptr(ptr); \
	199	switch (sizeof(*(ptr))) { \
ace02e2b	200	case 1: \
487913ab	201	__put_user_asm("sbi", __pu_val, (ptr), (err)); \
ace02e2b GH	202	break; \
ace02e2b GH	203	case 2: \
487913ab	204	__put_user_asm("shi", __pu_val, (ptr), (err)); \
ace02e2b GH	205	break; \
ace02e2b GH	206	case 4: \
487913ab	207	__put_user_asm("swi", __pu_val, (ptr), (err)); \
ace02e2b GH	208	break; \
ace02e2b GH	209	case 8: \
487913ab	210	__put_user_asm_dword(__pu_val, (ptr), (err)); \
ace02e2b GH	211	break; \
	212	default: \
	213	BUILD_BUG(); \
	214	break; \
	215	} \
	216	} while (0)
	217
7ef39548 ZL	218	#define __put_user_asm(inst, x, addr, err) \
	219	__asm__ __volatile__ ( \
	220	"1: "inst" %1,[%2]\n" \
	221	"2:\n" \
	222	" .section .fixup,\"ax\"\n" \
	223	" .align 2\n" \
	224	"3: move %0, %3\n" \
	225	" b 2b\n" \
	226	" .previous\n" \
	227	" .section __ex_table,\"a\"\n" \
	228	" .align 3\n" \
	229	" .long 1b, 3b\n" \
	230	" .previous" \
	231	: "+r" (err) \
	232	: "r" (x), "r" (addr), "i" (-EFAULT) \
	233	: "cc")
ace02e2b GH	234
	235	#ifdef __NDS32_EB__
	236	#define __pu_reg_oper0 "%H2"
	237	#define __pu_reg_oper1 "%L2"
	238	#else
	239	#define __pu_reg_oper0 "%L2"
	240	#define __pu_reg_oper1 "%H2"
	241	#endif
	242
	243	#define __put_user_asm_dword(x, addr, err) \
7ef39548 ZL	244	__asm__ __volatile__ ( \
	245	"\n1:\tswi " __pu_reg_oper0 ",[%1]\n" \
	246	"\n2:\tswi " __pu_reg_oper1 ",[%1+4]\n" \
	247	"3:\n" \
	248	" .section .fixup,\"ax\"\n" \
	249	" .align 2\n" \
	250	"4: move %0, %3\n" \
	251	" b 3b\n" \
	252	" .previous\n" \
	253	" .section __ex_table,\"a\"\n" \
	254	" .align 3\n" \
	255	" .long 1b, 4b\n" \
	256	" .long 2b, 4b\n" \
	257	" .previous" \
	258	: "+r"(err) \
	259	: "r"(addr), "r"(x), "i"(-EFAULT) \
	260	: "cc")
	261
ace02e2b GH	262	extern unsigned long __arch_clear_user(void __user * addr, unsigned long n);
	263	extern long strncpy_from_user(char dest, const char __user src, long count);
	264	extern __must_check long strlen_user(const char __user * str);
	265	extern __must_check long strnlen_user(const char __user * str, long n);
	266	extern unsigned long __arch_copy_from_user(void to, const void __user from,
	267	unsigned long n);
	268	extern unsigned long __arch_copy_to_user(void __user * to, const void *from,
	269	unsigned long n);
	270
	271	#define raw_copy_from_user __arch_copy_from_user
	272	#define raw_copy_to_user __arch_copy_to_user
	273
	274	#define INLINE_COPY_FROM_USER
	275	#define INLINE_COPY_TO_USER
	276	static inline unsigned long clear_user(void __user * to, unsigned long n)
	277	{
96d4f267	278	if (access_ok(to, n))
ace02e2b GH	279	n = __arch_clear_user(to, n);
	280	return n;
	281	}
	282
	283	static inline unsigned long __clear_user(void __user * to, unsigned long n)
	284	{
	285	return __arch_clear_user(to, n);
	286	}
	287
	288	#endif /* _ASMNDS32_UACCESS_H */