[mirror_ubuntu-focal-kernel.git] / arch / openrisc / include / asm / uaccess.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * OpenRISC Linux
 *
 * Linux architectural port borrowing liberally from similar works of
 * others.  All original copyrights apply as per the original source
 * declaration.
 *
 * OpenRISC implementation:
 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
 * et al.
 */

#ifndef __ASM_OPENRISC_UACCESS_H
#define __ASM_OPENRISC_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/prefetch.h>
#include <linux/string.h>
#include <asm/page.h>
#include <asm/extable.h>

/*
 * The fs value determines whether argument validity checking should be
 * performed or not.  If get_fs() == USER_DS, checking is performed, with
 * get_fs() == KERNEL_DS, checking is bypassed.
 *
 * For historical reasons, these macros are grossly misnamed.
 */

/* addr_limit is the maximum accessible address for the task. we misuse
 * the KERNEL_DS and USER_DS values to both assign and compare the
 * addr_limit values through the equally misnamed get/set_fs macros.
 * (see above)
 */

#define KERNEL_DS	(~0UL)

#define USER_DS		(TASK_SIZE)
#define get_fs()	(current_thread_info()->addr_limit)
#define set_fs(x)	(current_thread_info()->addr_limit = (x))

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

/* Ensure that the range from addr to addr+size is all within the process'
 * address space
 */
#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size))

/* Ensure that addr is below task's addr_limit */
#define __addr_ok(addr) ((unsigned long) addr < get_fs())

#define access_ok(addr, size)						\
({ 									\
	unsigned long __ao_addr = (unsigned long)(addr);		\
	unsigned long __ao_size = (unsigned long)(size);		\
	__range_ok(__ao_addr, __ao_size);				\
})

/*
 * These are the main single-value transfer routines.  They automatically
 * use the right size if we just have the right pointer type.
 *
 * This gets kind of ugly. We want to return _two_ values in "get_user()"
 * and yet we don't want to do any pointers, because that is too much
 * of a performance impact. Thus we have a few rather ugly macros here,
 * and hide all the uglyness from the user.
 *
 * The "__xxx" versions of the user access functions are versions that
 * do not verify the address space, that must have been done previously
 * with a separate "access_ok()" call (this is used when we do multiple
 * accesses to the same area of user memory).
 *
 * As we use the same address space for kernel and user data on the
 * PowerPC, we can just do these as direct assignments.  (Of course, the
 * exception handling means that it's no longer "just"...)
 */
#define get_user(x, ptr) \
	__get_user_check((x), (ptr), sizeof(*(ptr)))
#define put_user(x, ptr) \
	__put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))

#define __get_user(x, ptr) \
	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
#define __put_user(x, ptr) \
	__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))

extern long __put_user_bad(void);

#define __put_user_nocheck(x, ptr, size)		\
({							\
	long __pu_err;					\
	__put_user_size((x), (ptr), (size), __pu_err);	\
	__pu_err;					\
})

#define __put_user_check(x, ptr, size)					\
({									\
	long __pu_err = -EFAULT;					\
	__typeof__(*(ptr)) *__pu_addr = (ptr);				\
	if (access_ok(__pu_addr, size))			\
		__put_user_size((x), __pu_addr, (size), __pu_err);	\
	__pu_err;							\
})

#define __put_user_size(x, ptr, size, retval)				\
do {									\
	retval = 0;							\
	switch (size) {							\
	case 1: __put_user_asm(x, ptr, retval, "l.sb"); break;		\
	case 2: __put_user_asm(x, ptr, retval, "l.sh"); break;		\
	case 4: __put_user_asm(x, ptr, retval, "l.sw"); break;		\
	case 8: __put_user_asm2(x, ptr, retval); break;			\
	default: __put_user_bad();					\
	}								\
} while (0)

struct __large_struct {
	unsigned long buf[100];
};
#define __m(x) (*(struct __large_struct *)(x))

/*
 * We don't tell gcc that we are accessing memory, but this is OK
 * because we do not write to any memory gcc knows about, so there
 * are no aliasing issues.
 */
#define __put_user_asm(x, addr, err, op)			\
	__asm__ __volatile__(					\
		"1:	"op" 0(%2),%1\n"			\
		"2:\n"						\
		".section .fixup,\"ax\"\n"			\
		"3:	l.addi %0,r0,%3\n"			\
		"	l.j 2b\n"				\
		"	l.nop\n"				\
		".previous\n"					\
		".section __ex_table,\"a\"\n"			\
		"	.align 2\n"				\
		"	.long 1b,3b\n"				\
		".previous"					\
		: "=r"(err)					\
		: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))

#define __put_user_asm2(x, addr, err)				\
	__asm__ __volatile__(					\
		"1:	l.sw 0(%2),%1\n"			\
		"2:	l.sw 4(%2),%H1\n"			\
		"3:\n"						\
		".section .fixup,\"ax\"\n"			\
		"4:	l.addi %0,r0,%3\n"			\
		"	l.j 3b\n"				\
		"	l.nop\n"				\
		".previous\n"					\
		".section __ex_table,\"a\"\n"			\
		"	.align 2\n"				\
		"	.long 1b,4b\n"				\
		"	.long 2b,4b\n"				\
		".previous"					\
		: "=r"(err)					\
		: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))

#define __get_user_nocheck(x, ptr, size)			\
({								\
	long __gu_err, __gu_val;				\
	__get_user_size(__gu_val, (ptr), (size), __gu_err);	\
	(x) = (__force __typeof__(*(ptr)))__gu_val;		\
	__gu_err;						\
})

#define __get_user_check(x, ptr, size)					\
({									\
	long __gu_err = -EFAULT, __gu_val = 0;				\
	const __typeof__(*(ptr)) * __gu_addr = (ptr);			\
	if (access_ok(__gu_addr, size))			\
		__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
	__gu_err;							\
})

extern long __get_user_bad(void);

#define __get_user_size(x, ptr, size, retval)				\
do {									\
	retval = 0;							\
	switch (size) {							\
	case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break;		\
	case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break;		\
	case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break;		\
	case 8: __get_user_asm2(x, ptr, retval); break;			\
	default: (x) = __get_user_bad();				\
	}								\
} while (0)

#define __get_user_asm(x, addr, err, op)		\
	__asm__ __volatile__(				\
		"1:	"op" %1,0(%2)\n"		\
		"2:\n"					\
		".section .fixup,\"ax\"\n"		\
		"3:	l.addi %0,r0,%3\n"		\
		"	l.addi %1,r0,0\n"		\
		"	l.j 2b\n"			\
		"	l.nop\n"			\
		".previous\n"				\
		".section __ex_table,\"a\"\n"		\
		"	.align 2\n"			\
		"	.long 1b,3b\n"			\
		".previous"				\
		: "=r"(err), "=r"(x)			\
		: "r"(addr), "i"(-EFAULT), "0"(err))

#define __get_user_asm2(x, addr, err)			\
	__asm__ __volatile__(				\
		"1:	l.lwz %1,0(%2)\n"		\
		"2:	l.lwz %H1,4(%2)\n"		\
		"3:\n"					\
		".section .fixup,\"ax\"\n"		\
		"4:	l.addi %0,r0,%3\n"		\
		"	l.addi %1,r0,0\n"		\
		"	l.addi %H1,r0,0\n"		\
		"	l.j 3b\n"			\
		"	l.nop\n"			\
		".previous\n"				\
		".section __ex_table,\"a\"\n"		\
		"	.align 2\n"			\
		"	.long 1b,4b\n"			\
		"	.long 2b,4b\n"			\
		".previous"				\
		: "=r"(err), "=&r"(x)			\
		: "r"(addr), "i"(-EFAULT), "0"(err))

/* more complex routines */

extern unsigned long __must_check
__copy_tofrom_user(void *to, const void *from, unsigned long size);
static inline unsigned long
raw_copy_from_user(void *to, const void __user *from, unsigned long size)
{
	return __copy_tofrom_user(to, (__force const void *)from, size);
}
static inline unsigned long
raw_copy_to_user(void *to, const void __user *from, unsigned long size)
{
	return __copy_tofrom_user((__force void *)to, from, size);
}
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER

extern unsigned long __clear_user(void *addr, unsigned long size);

static inline __must_check unsigned long
clear_user(void *addr, unsigned long size)
{
	if (likely(access_ok(addr, size)))
		size = __clear_user(addr, size);
	return size;
}

#define user_addr_max() \
	(uaccess_kernel() ? ~0UL : TASK_SIZE)

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

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

#endif /* __ASM_OPENRISC_UACCESS_H */
Commit	Line	Data
2874c5fd	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
61e85e36 JB	2	/*
	3	* OpenRISC Linux
	4	*
	5	* Linux architectural port borrowing liberally from similar works of
	6	* others. All original copyrights apply as per the original source
	7	* declaration.
	8	*
	9	* OpenRISC implementation:
	10	* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
	11	* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
	12	* et al.
61e85e36 JB	13	*/
	14
	15	#ifndef __ASM_OPENRISC_UACCESS_H
	16	#define __ASM_OPENRISC_UACCESS_H
	17
	18	/*
	19	* User space memory access functions
	20	*/
61e85e36 JB	21	#include <linux/prefetch.h>
61e85e36 JB	22	#include <linux/string.h>
61e85e36	23	#include <asm/page.h>
6c36a4eb	24	#include <asm/extable.h>
61e85e36 JB	25
	26	/*
	27	* The fs value determines whether argument validity checking should be
	28	* performed or not. If get_fs() == USER_DS, checking is performed, with
	29	* get_fs() == KERNEL_DS, checking is bypassed.
	30	*
	31	* For historical reasons, these macros are grossly misnamed.
	32	*/
	33
	34	/* addr_limit is the maximum accessible address for the task. we misuse
	35	* the KERNEL_DS and USER_DS values to both assign and compare the
	36	* addr_limit values through the equally misnamed get/set_fs macros.
	37	* (see above)
	38	*/
	39
	40	#define KERNEL_DS (~0UL)
61e85e36 JB	41
	42	#define USER_DS (TASK_SIZE)
	43	#define get_fs() (current_thread_info()->addr_limit)
	44	#define set_fs(x) (current_thread_info()->addr_limit = (x))
	45
	46	#define segment_eq(a, b) ((a) == (b))
	47
	48	/* Ensure that the range from addr to addr+size is all within the process'
	49	* address space
	50	*/
	51	#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size))
	52
	53	/* Ensure that addr is below task's addr_limit */
	54	#define __addr_ok(addr) ((unsigned long) addr < get_fs())
	55
9cb2feb4 SH	56	#define access_ok(addr, size) \
	57	({ \
	58	unsigned long __ao_addr = (unsigned long)(addr); \
	59	unsigned long __ao_size = (unsigned long)(size); \
	60	__range_ok(__ao_addr, __ao_size); \
	61	})
61e85e36	62
61e85e36 JB	63	/*
	64	* These are the main single-value transfer routines. They automatically
	65	* use the right size if we just have the right pointer type.
	66	*
	67	* This gets kind of ugly. We want to return _two_ values in "get_user()"
	68	* and yet we don't want to do any pointers, because that is too much
	69	* of a performance impact. Thus we have a few rather ugly macros here,
	70	* and hide all the uglyness from the user.
	71	*
	72	* The "__xxx" versions of the user access functions are versions that
	73	* do not verify the address space, that must have been done previously
	74	* with a separate "access_ok()" call (this is used when we do multiple
	75	* accesses to the same area of user memory).
	76	*
	77	* As we use the same address space for kernel and user data on the
	78	* PowerPC, we can just do these as direct assignments. (Of course, the
	79	* exception handling means that it's no longer "just"...)
	80	*/
	81	#define get_user(x, ptr) \
	82	__get_user_check((x), (ptr), sizeof(*(ptr)))
	83	#define put_user(x, ptr) \
	84	__put_user_check((__typeof__((ptr)))(x), (ptr), sizeof((ptr)))
	85
	86	#define __get_user(x, ptr) \
	87	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
	88	#define __put_user(x, ptr) \
	89	__put_user_nocheck((__typeof__((ptr)))(x), (ptr), sizeof((ptr)))
	90
	91	extern long __put_user_bad(void);
	92
	93	#define __put_user_nocheck(x, ptr, size) \
	94	({ \
	95	long __pu_err; \
	96	__put_user_size((x), (ptr), (size), __pu_err); \
	97	__pu_err; \
	98	})
	99
	100	#define __put_user_check(x, ptr, size) \
	101	({ \
	102	long __pu_err = -EFAULT; \
	103	__typeof__((ptr)) __pu_addr = (ptr); \
96d4f267	104	if (access_ok(__pu_addr, size)) \
61e85e36 JB	105	__put_user_size((x), __pu_addr, (size), __pu_err); \
	106	__pu_err; \
	107	})
	108
	109	#define __put_user_size(x, ptr, size, retval) \
	110	do { \
	111	retval = 0; \
	112	switch (size) { \
	113	case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \
	114	case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \
	115	case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \
	116	case 8: __put_user_asm2(x, ptr, retval); break; \
	117	default: __put_user_bad(); \
	118	} \
	119	} while (0)
	120
	121	struct __large_struct {
	122	unsigned long buf[100];
	123	};
	124	#define __m(x) ((struct __large_struct )(x))
	125
	126	/*
	127	* We don't tell gcc that we are accessing memory, but this is OK
	128	* because we do not write to any memory gcc knows about, so there
	129	* are no aliasing issues.
	130	*/
	131	#define __put_user_asm(x, addr, err, op) \
	132	__asm__ __volatile__( \
	133	"1: "op" 0(%2),%1\n" \
	134	"2:\n" \
	135	".section .fixup,\"ax\"\n" \
	136	"3: l.addi %0,r0,%3\n" \
	137	" l.j 2b\n" \
	138	" l.nop\n" \
	139	".previous\n" \
	140	".section __ex_table,\"a\"\n" \
	141	" .align 2\n" \
	142	" .long 1b,3b\n" \
	143	".previous" \
	144	: "=r"(err) \
	145	: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
	146
	147	#define __put_user_asm2(x, addr, err) \
	148	__asm__ __volatile__( \
	149	"1: l.sw 0(%2),%1\n" \
	150	"2: l.sw 4(%2),%H1\n" \
	151	"3:\n" \
	152	".section .fixup,\"ax\"\n" \
	153	"4: l.addi %0,r0,%3\n" \
	154	" l.j 3b\n" \
	155	" l.nop\n" \
	156	".previous\n" \
	157	".section __ex_table,\"a\"\n" \
	158	" .align 2\n" \
	159	" .long 1b,4b\n" \
	160	" .long 2b,4b\n" \
	161	".previous" \
	162	: "=r"(err) \
	163	: "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
	164
	165	#define __get_user_nocheck(x, ptr, size) \
	166	({ \
	167	long __gu_err, __gu_val; \
	168	__get_user_size(__gu_val, (ptr), (size), __gu_err); \
582a6783	169	(x) = (__force __typeof__(*(ptr)))__gu_val; \
61e85e36 JB	170	__gu_err; \
	171	})
	172
	173	#define __get_user_check(x, ptr, size) \
	174	({ \
	175	long __gu_err = -EFAULT, __gu_val = 0; \
	176	const __typeof__((ptr)) __gu_addr = (ptr); \
96d4f267	177	if (access_ok(__gu_addr, size)) \
61e85e36	178	__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
582a6783	179	(x) = (__force __typeof__(*(ptr)))__gu_val; \
61e85e36 JB	180	__gu_err; \
	181	})
	182
	183	extern long __get_user_bad(void);
	184
	185	#define __get_user_size(x, ptr, size, retval) \
	186	do { \
	187	retval = 0; \
	188	switch (size) { \
	189	case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \
	190	case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \
	191	case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \
154e67cd	192	case 8: __get_user_asm2(x, ptr, retval); break; \
61e85e36 JB	193	default: (x) = __get_user_bad(); \
	194	} \
	195	} while (0)
	196
	197	#define __get_user_asm(x, addr, err, op) \
	198	__asm__ __volatile__( \
	199	"1: "op" %1,0(%2)\n" \
	200	"2:\n" \
	201	".section .fixup,\"ax\"\n" \
	202	"3: l.addi %0,r0,%3\n" \
	203	" l.addi %1,r0,0\n" \
	204	" l.j 2b\n" \
	205	" l.nop\n" \
	206	".previous\n" \
	207	".section __ex_table,\"a\"\n" \
	208	" .align 2\n" \
	209	" .long 1b,3b\n" \
	210	".previous" \
	211	: "=r"(err), "=r"(x) \
	212	: "r"(addr), "i"(-EFAULT), "0"(err))
	213
	214	#define __get_user_asm2(x, addr, err) \
	215	__asm__ __volatile__( \
	216	"1: l.lwz %1,0(%2)\n" \
	217	"2: l.lwz %H1,4(%2)\n" \
	218	"3:\n" \
	219	".section .fixup,\"ax\"\n" \
	220	"4: l.addi %0,r0,%3\n" \
	221	" l.addi %1,r0,0\n" \
	222	" l.addi %H1,r0,0\n" \
	223	" l.j 3b\n" \
	224	" l.nop\n" \
	225	".previous\n" \
	226	".section __ex_table,\"a\"\n" \
	227	" .align 2\n" \
	228	" .long 1b,4b\n" \
	229	" .long 2b,4b\n" \
	230	".previous" \
	231	: "=r"(err), "=&r"(x) \
	232	: "r"(addr), "i"(-EFAULT), "0"(err))
	233
	234	/* more complex routines */
	235
	236	extern unsigned long __must_check
	237	__copy_tofrom_user(void to, const void from, unsigned long size);
61e85e36	238	static inline unsigned long
ab89866b	239	raw_copy_from_user(void to, const void __user from, unsigned long size)
61e85e36	240	{
ab89866b	241	return __copy_tofrom_user(to, (__force const void *)from, size);
61e85e36	242	}
61e85e36	243	static inline unsigned long
ab89866b	244	raw_copy_to_user(void to, const void __user from, unsigned long size)
61e85e36	245	{
ab89866b	246	return __copy_tofrom_user((__force void *)to, from, size);
61e85e36	247	}
ab89866b AV	248	#define INLINE_COPY_FROM_USER
ab89866b AV	249	#define INLINE_COPY_TO_USER
61e85e36 JB	250
	251	extern unsigned long __clear_user(void *addr, unsigned long size);
	252
	253	static inline __must_check unsigned long
	254	clear_user(void *addr, unsigned long size)
	255	{
96d4f267	256	if (likely(access_ok(addr, size)))
acb2505d	257	size = __clear_user(addr, size);
61e85e36 JB	258	return size;
	259	}
	260
603d6637	261	#define user_addr_max() \
db68ce10	262	(uaccess_kernel() ? ~0UL : TASK_SIZE)
61e85e36	263
603d6637	264	extern long strncpy_from_user(char dest, const char __user src, long count);
61e85e36	265
b48b2c3e	266	extern __must_check long strnlen_user(const char __user *str, long n);
61e85e36 JB	267
61e85e36 JB	268	#endif /* __ASM_OPENRISC_UACCESS_H */