[linux-2.6-block.git] / arch / sparc / include / asm / uaccess_32.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * uaccess.h: User space memore access functions.
 *
 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 */
#ifndef _ASM_UACCESS_H
#define _ASM_UACCESS_H

#include <linux/compiler.h>
#include <linux/string.h>

#include <asm/processor.h>

#define ARCH_HAS_SORT_EXTABLE
#define ARCH_HAS_SEARCH_EXTABLE

/* Sparc is not segmented, however we need to be able to fool access_ok()
 * when doing system calls from kernel mode legitimately.
 *
 * "For historical reasons, these macros are grossly misnamed." -Linus
 */

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

#define get_fs()	(current->thread.current_ds)
#define set_fs(val)	((current->thread.current_ds) = (val))

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

/* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test
 * can be fairly lightweight.
 * No one can read/write anything from userland in the kernel space by setting
 * large size and address near to PAGE_OFFSET - a fault will break his intentions.
 */
#define __user_ok(addr, size) ({ (void)(size); (addr) < STACK_TOP; })
#define __kernel_ok (uaccess_kernel())
#define __access_ok(addr, size) (__user_ok((addr) & get_fs().seg, (size)))
#define access_ok(addr, size) __access_ok((unsigned long)(addr), size)

/*
 * 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.
 *
 * There is a special way how to put a range of potentially faulting
 * insns (like twenty ldd/std's with now intervening other instructions)
 * You specify address of first in insn and 0 in fixup and in the next
 * exception_table_entry you specify last potentially faulting insn + 1
 * and in fixup the routine which should handle the fault.
 * That fixup code will get
 * (faulting_insn_address - first_insn_in_the_range_address)/4
 * in %g2 (ie. index of the faulting instruction in the range).
 */

struct exception_table_entry
{
        unsigned long insn, fixup;
};

/* Returns 0 if exception not found and fixup otherwise.  */
unsigned long search_extables_range(unsigned long addr, unsigned long *g2);

/* Uh, these should become 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 ugliness from the user.
 */
#define put_user(x, ptr) ({ \
	unsigned long __pu_addr = (unsigned long)(ptr); \
	__chk_user_ptr(ptr); \
	__put_user_check((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr))); \
})

#define get_user(x, ptr) ({ \
	unsigned long __gu_addr = (unsigned long)(ptr); \
	__chk_user_ptr(ptr); \
	__get_user_check((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr))); \
})

/*
 * The "__xxx" versions do not do address space checking, useful when
 * doing multiple accesses to the same area (the user has to do the
 * checks by hand with "access_ok()")
 */
#define __put_user(x, ptr) \
	__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
#define __get_user(x, ptr) \
    __get_user_nocheck((x), (ptr), sizeof(*(ptr)), __typeof__(*(ptr)))

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

#define __put_user_check(x, addr, size) ({ \
	register int __pu_ret; \
	if (__access_ok(addr, size)) { \
		switch (size) { \
		case 1: \
			__put_user_asm(x, b, addr, __pu_ret); \
			break; \
		case 2: \
			__put_user_asm(x, h, addr, __pu_ret); \
			break; \
		case 4: \
			__put_user_asm(x, , addr, __pu_ret); \
			break; \
		case 8: \
			__put_user_asm(x, d, addr, __pu_ret); \
			break; \
		default: \
			__pu_ret = __put_user_bad(); \
			break; \
		} \
	} else { \
		__pu_ret = -EFAULT; \
	} \
	__pu_ret; \
})

#define __put_user_nocheck(x, addr, size) ({			\
	register int __pu_ret;					\
	switch (size) {						\
	case 1: __put_user_asm(x, b, addr, __pu_ret); break;	\
	case 2: __put_user_asm(x, h, addr, __pu_ret); break;	\
	case 4: __put_user_asm(x, , addr, __pu_ret); break;	\
	case 8: __put_user_asm(x, d, addr, __pu_ret); break;	\
	default: __pu_ret = __put_user_bad(); break;		\
	} \
	__pu_ret; \
})

#define __put_user_asm(x, size, addr, ret)				\
__asm__ __volatile__(							\
		"/* Put user asm, inline. */\n"				\
	"1:\t"	"st"#size " %1, %2\n\t"					\
		"clr	%0\n"						\
	"2:\n\n\t"							\
		".section .fixup,#alloc,#execinstr\n\t"			\
		".align	4\n"						\
	"3:\n\t"							\
		"b	2b\n\t"						\
		" mov	%3, %0\n\t"					\
		".previous\n\n\t"					\
		".section __ex_table,#alloc\n\t"			\
		".align	4\n\t"						\
		".word	1b, 3b\n\t"					\
		".previous\n\n\t"					\
	       : "=&r" (ret) : "r" (x), "m" (*__m(addr)),		\
		 "i" (-EFAULT))

int __put_user_bad(void);

#define __get_user_check(x, addr, size, type) ({ \
	register int __gu_ret; \
	register unsigned long __gu_val; \
	if (__access_ok(addr, size)) { \
		switch (size) { \
		case 1: \
			 __get_user_asm(__gu_val, ub, addr, __gu_ret); \
			break; \
		case 2: \
			__get_user_asm(__gu_val, uh, addr, __gu_ret); \
			break; \
		case 4: \
			__get_user_asm(__gu_val, , addr, __gu_ret); \
			break; \
		case 8: \
			__get_user_asm(__gu_val, d, addr, __gu_ret); \
			break; \
		default: \
			__gu_val = 0; \
			__gu_ret = __get_user_bad(); \
			break; \
		} \
	 } else { \
		 __gu_val = 0; \
		 __gu_ret = -EFAULT; \
	} \
	x = (__force type) __gu_val; \
	__gu_ret; \
})

#define __get_user_nocheck(x, addr, size, type) ({			\
	register int __gu_ret;						\
	register unsigned long __gu_val;				\
	switch (size) {							\
	case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break;	\
	case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break;	\
	case 4: __get_user_asm(__gu_val, , addr, __gu_ret); break;	\
	case 8: __get_user_asm(__gu_val, d, addr, __gu_ret); break;	\
	default:							\
		__gu_val = 0;						\
		__gu_ret = __get_user_bad();				\
		break;							\
	}								\
	x = (__force type) __gu_val;					\
	__gu_ret;							\
})

#define __get_user_asm(x, size, addr, ret)				\
__asm__ __volatile__(							\
		"/* Get user asm, inline. */\n"				\
	"1:\t"	"ld"#size " %2, %1\n\t"					\
		"clr	%0\n"						\
	"2:\n\n\t"							\
		".section .fixup,#alloc,#execinstr\n\t"			\
		".align	4\n"						\
	"3:\n\t"							\
		"clr	%1\n\t"						\
		"b	2b\n\t"						\
		" mov	%3, %0\n\n\t"					\
		".previous\n\t"						\
		".section __ex_table,#alloc\n\t"			\
		".align	4\n\t"						\
		".word	1b, 3b\n\n\t"					\
		".previous\n\t"						\
	       : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)),		\
		 "i" (-EFAULT))

int __get_user_bad(void);

unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size);

static inline unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
{
	return __copy_user(to, (__force void __user *) from, n);
}

static inline unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
{
	return __copy_user((__force void __user *) to, from, n);
}

#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER

static inline unsigned long __clear_user(void __user *addr, unsigned long size)
{
	unsigned long ret;

	__asm__ __volatile__ (
		".section __ex_table,#alloc\n\t"
		".align 4\n\t"
		".word 1f,3\n\t"
		".previous\n\t"
		"mov %2, %%o1\n"
		"1:\n\t"
		"call __bzero\n\t"
		" mov %1, %%o0\n\t"
		"mov %%o0, %0\n"
		: "=r" (ret) : "r" (addr), "r" (size) :
		"o0", "o1", "o2", "o3", "o4", "o5", "o7",
		"g1", "g2", "g3", "g4", "g5", "g7", "cc");

	return ret;
}

static inline unsigned long clear_user(void __user *addr, unsigned long n)
{
	if (n && __access_ok((unsigned long) addr, n))
		return __clear_user(addr, n);
	else
		return n;
}

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

#endif /* _ASM_UACCESS_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
f5e706ad SR	2	/*
	3	* uaccess.h: User space memore access functions.
	4	*
	5	* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
	6	* Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
	7	*/
	8	#ifndef _ASM_UACCESS_H
	9	#define _ASM_UACCESS_H
	10
f5e706ad	11	#include <linux/compiler.h>
f5e706ad	12	#include <linux/string.h>
f5e706ad	13
2c66f623 DM	14	#include <asm/processor.h>
2c66f623 DM	15
ad6561df RR	16	#define ARCH_HAS_SORT_EXTABLE
	17	#define ARCH_HAS_SEARCH_EXTABLE
	18
f5e706ad SR	19	/* Sparc is not segmented, however we need to be able to fool access_ok()
	20	* when doing system calls from kernel mode legitimately.
	21	*
	22	* "For historical reasons, these macros are grossly misnamed." -Linus
	23	*/
	24
	25	#define KERNEL_DS ((mm_segment_t) { 0 })
	26	#define USER_DS ((mm_segment_t) { -1 })
	27
f5e706ad SR	28	#define get_fs() (current->thread.current_ds)
	29	#define set_fs(val) ((current->thread.current_ds) = (val))
	30
8ccf7b25	31	#define segment_eq(a, b) ((a).seg == (b).seg)
f5e706ad SR	32
	33	/* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test
	34	* can be fairly lightweight.
	35	* No one can read/write anything from userland in the kernel space by setting
	36	* large size and address near to PAGE_OFFSET - a fault will break his intentions.
	37	*/
	38	#define __user_ok(addr, size) ({ (void)(size); (addr) < STACK_TOP; })
db68ce10	39	#define __kernel_ok (uaccess_kernel())
8ccf7b25	40	#define __access_ok(addr, size) (__user_ok((addr) & get_fs().seg, (size)))
4caf4ebf	41	#define access_ok(addr, size) __access_ok((unsigned long)(addr), size)
f5e706ad SR	42
	43	/*
	44	* The exception table consists of pairs of addresses: the first is the
	45	* address of an instruction that is allowed to fault, and the second is
	46	* the address at which the program should continue. No registers are
	47	* modified, so it is entirely up to the continuation code to figure out
	48	* what to do.
	49	*
	50	* All the routines below use bits of fixup code that are out of line
	51	* with the main instruction path. This means when everything is well,
	52	* we don't even have to jump over them. Further, they do not intrude
	53	* on our cache or tlb entries.
	54	*
	55	* There is a special way how to put a range of potentially faulting
	56	* insns (like twenty ldd/std's with now intervening other instructions)
	57	* You specify address of first in insn and 0 in fixup and in the next
	58	* exception_table_entry you specify last potentially faulting insn + 1
	59	* and in fixup the routine which should handle the fault.
	60	* That fixup code will get
	61	* (faulting_insn_address - first_insn_in_the_range_address)/4
	62	* in %g2 (ie. index of the faulting instruction in the range).
	63	*/
	64
	65	struct exception_table_entry
	66	{
	67	unsigned long insn, fixup;
	68	};
	69
	70	/* Returns 0 if exception not found and fixup otherwise. */
f05a6865	71	unsigned long search_extables_range(unsigned long addr, unsigned long *g2);
f5e706ad	72
f5e706ad SR	73	/* Uh, these should become the main single-value transfer routines..
	74	* They automatically use the right size if we just have the right
	75	* pointer type..
	76	*
	77	* This gets kind of ugly. We want to return _two_ values in "get_user()"
	78	* and yet we don't want to do any pointers, because that is too much
	79	* of a performance impact. Thus we have a few rather ugly macros here,
	80	* and hide all the ugliness from the user.
	81	*/
8ccf7b25 MT	82	#define put_user(x, ptr) ({ \
	83	unsigned long __pu_addr = (unsigned long)(ptr); \
	84	__chk_user_ptr(ptr); \
	85	__put_user_check((__typeof__((ptr)))(x), __pu_addr, sizeof((ptr))); \
	86	})
	87
	88	#define get_user(x, ptr) ({ \
	89	unsigned long __gu_addr = (unsigned long)(ptr); \
	90	__chk_user_ptr(ptr); \
	91	__get_user_check((x), __gu_addr, sizeof((ptr)), __typeof__((ptr))); \
	92	})
f5e706ad SR	93
	94	/*
	95	* The "__xxx" versions do not do address space checking, useful when
	96	* doing multiple accesses to the same area (the user has to do the
	97	* checks by hand with "access_ok()")
	98	*/
8ccf7b25 MT	99	#define __put_user(x, ptr) \
	100	__put_user_nocheck((__typeof__((ptr)))(x), (ptr), sizeof((ptr)))
	101	#define __get_user(x, ptr) \
	102	__get_user_nocheck((x), (ptr), sizeof((ptr)), __typeof__((ptr)))
f5e706ad SR	103
	104	struct __large_struct { unsigned long buf[100]; };
	105	#define __m(x) ((struct __large_struct __user *)(x))
	106
8ccf7b25 MT	107	#define __put_user_check(x, addr, size) ({ \
	108	register int __pu_ret; \
	109	if (__access_ok(addr, size)) { \
	110	switch (size) { \
	111	case 1: \
	112	__put_user_asm(x, b, addr, __pu_ret); \
	113	break; \
	114	case 2: \
	115	__put_user_asm(x, h, addr, __pu_ret); \
	116	break; \
	117	case 4: \
	118	__put_user_asm(x, , addr, __pu_ret); \
	119	break; \
	120	case 8: \
	121	__put_user_asm(x, d, addr, __pu_ret); \
	122	break; \
	123	default: \
	124	__pu_ret = __put_user_bad(); \
	125	break; \
	126	} \
	127	} else { \
	128	__pu_ret = -EFAULT; \
	129	} \
	130	__pu_ret; \
	131	})
	132
0795cb1b MT	133	#define __put_user_nocheck(x, addr, size) ({ \
	134	register int __pu_ret; \
	135	switch (size) { \
	136	case 1: __put_user_asm(x, b, addr, __pu_ret); break; \
	137	case 2: __put_user_asm(x, h, addr, __pu_ret); break; \
	138	case 4: __put_user_asm(x, , addr, __pu_ret); break; \
	139	case 8: __put_user_asm(x, d, addr, __pu_ret); break; \
	140	default: __pu_ret = __put_user_bad(); break; \
8ccf7b25 MT	141	} \
	142	__pu_ret; \
	143	})
	144
	145	#define __put_user_asm(x, size, addr, ret) \
f5e706ad	146	__asm__ __volatile__( \
8ccf7b25 MT	147	"/* Put user asm, inline. */\n" \
	148	"1:\t" "st"#size " %1, %2\n\t" \
	149	"clr %0\n" \
	150	"2:\n\n\t" \
	151	".section .fixup,#alloc,#execinstr\n\t" \
	152	".align 4\n" \
	153	"3:\n\t" \
	154	"b 2b\n\t" \
	155	" mov %3, %0\n\t" \
	156	".previous\n\n\t" \
	157	".section __ex_table,#alloc\n\t" \
	158	".align 4\n\t" \
	159	".word 1b, 3b\n\t" \
	160	".previous\n\n\t" \
	161	: "=&r" (ret) : "r" (x), "m" (*__m(addr)), \
	162	"i" (-EFAULT))
f5e706ad	163
f05a6865	164	int __put_user_bad(void);
f5e706ad	165
8ccf7b25 MT	166	#define __get_user_check(x, addr, size, type) ({ \
	167	register int __gu_ret; \
	168	register unsigned long __gu_val; \
	169	if (__access_ok(addr, size)) { \
	170	switch (size) { \
	171	case 1: \
	172	__get_user_asm(__gu_val, ub, addr, __gu_ret); \
	173	break; \
	174	case 2: \
	175	__get_user_asm(__gu_val, uh, addr, __gu_ret); \
	176	break; \
	177	case 4: \
	178	__get_user_asm(__gu_val, , addr, __gu_ret); \
	179	break; \
	180	case 8: \
	181	__get_user_asm(__gu_val, d, addr, __gu_ret); \
	182	break; \
	183	default: \
	184	__gu_val = 0; \
	185	__gu_ret = __get_user_bad(); \
	186	break; \
	187	} \
	188	} else { \
	189	__gu_val = 0; \
	190	__gu_ret = -EFAULT; \
	191	} \
	192	x = (__force type) __gu_val; \
	193	__gu_ret; \
	194	})
	195
0795cb1b MT	196	#define __get_user_nocheck(x, addr, size, type) ({ \
	197	register int __gu_ret; \
	198	register unsigned long __gu_val; \
	199	switch (size) { \
	200	case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \
	201	case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \
	202	case 4: __get_user_asm(__gu_val, , addr, __gu_ret); break; \
	203	case 8: __get_user_asm(__gu_val, d, addr, __gu_ret); break; \
	204	default: \
	205	__gu_val = 0; \
	206	__gu_ret = __get_user_bad(); \
	207	break; \
	208	} \
	209	x = (__force type) __gu_val; \
	210	__gu_ret; \
8ccf7b25 MT	211	})
8ccf7b25 MT	212
8ccf7b25	213	#define __get_user_asm(x, size, addr, ret) \
f5e706ad	214	__asm__ __volatile__( \
8ccf7b25 MT	215	"/* Get user asm, inline. */\n" \
	216	"1:\t" "ld"#size " %2, %1\n\t" \
	217	"clr %0\n" \
	218	"2:\n\n\t" \
	219	".section .fixup,#alloc,#execinstr\n\t" \
	220	".align 4\n" \
	221	"3:\n\t" \
	222	"clr %1\n\t" \
	223	"b 2b\n\t" \
	224	" mov %3, %0\n\n\t" \
	225	".previous\n\t" \
	226	".section __ex_table,#alloc\n\t" \
	227	".align 4\n\t" \
	228	".word 1b, 3b\n\n\t" \
	229	".previous\n\t" \
	230	: "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \
	231	"i" (-EFAULT))
	232
f05a6865	233	int __get_user_bad(void);
f5e706ad	234
f05a6865	235	unsigned long __copy_user(void __user to, const void __user from, unsigned long size);
f5e706ad	236
31af2f36	237	static inline unsigned long raw_copy_to_user(void __user to, const void from, unsigned long n)
f5e706ad	238	{
f5e706ad SR	239	return __copy_user(to, (__force void __user *) from, n);
	240	}
	241
31af2f36	242	static inline unsigned long raw_copy_from_user(void to, const void __user from, unsigned long n)
f5e706ad SR	243	{
	244	return __copy_user((__force void __user *) to, from, n);
	245	}
	246
31af2f36 AV	247	#define INLINE_COPY_FROM_USER
31af2f36 AV	248	#define INLINE_COPY_TO_USER
f5e706ad SR	249
	250	static inline unsigned long __clear_user(void __user *addr, unsigned long size)
	251	{
	252	unsigned long ret;
	253
	254	__asm__ __volatile__ (
	255	".section __ex_table,#alloc\n\t"
	256	".align 4\n\t"
	257	".word 1f,3\n\t"
	258	".previous\n\t"
	259	"mov %2, %%o1\n"
	260	"1:\n\t"
	261	"call __bzero\n\t"
	262	" mov %1, %%o0\n\t"
	263	"mov %%o0, %0\n"
	264	: "=r" (ret) : "r" (addr), "r" (size) :
	265	"o0", "o1", "o2", "o3", "o4", "o5", "o7",
	266	"g1", "g2", "g3", "g4", "g5", "g7", "cc");
	267
	268	return ret;
	269	}
	270
	271	static inline unsigned long clear_user(void __user *addr, unsigned long n)
	272	{
	273	if (n && __access_ok((unsigned long) addr, n))
	274	return __clear_user(addr, n);
	275	else
	276	return n;
	277	}
	278
f05a6865	279	__must_check long strnlen_user(const char __user *str, long n);
f5e706ad	280
f5e706ad	281	#endif /* _ASM_UACCESS_H */