aboutsummaryrefslogtreecommitdiff
path: root/arch/mn10300/include/asm/uaccess.h
blob: d7966e0f76988cfb2d36d0b480277961dcef7e3a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
/* MN10300 userspace access functions
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */
#ifndef _ASM_UACCESS_H
#define _ASM_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/thread_info.h>
#include <linux/kernel.h>
#include <asm/page.h>
#include <asm/errno.h>

#define VERIFY_READ 0
#define VERIFY_WRITE 1

/*
 * 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.
 */
#define MAKE_MM_SEG(s)	((mm_segment_t) { (s) })

#define KERNEL_XDS	MAKE_MM_SEG(0xBFFFFFFF)
#define KERNEL_DS	MAKE_MM_SEG(0x9FFFFFFF)
#define USER_DS		MAKE_MM_SEG(TASK_SIZE)

#define get_ds()	(KERNEL_DS)
#define get_fs()	(current_thread_info()->addr_limit)
#define set_fs(x)	(current_thread_info()->addr_limit = (x))
#define __kernel_ds_p() (current_thread_info()->addr_limit.seg == 0x9FFFFFFF)

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

#define __addr_ok(addr) \
	((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))

/*
 * check that a range of addresses falls within the current address limit
 */
static inline int ___range_ok(unsigned long addr, unsigned int size)
{
	int flag = 1, tmp;

	asm("	add	%3,%1	\n"	/* set C-flag if addr + size > 4Gb */
	    "	bcs	0f	\n"
	    "	cmp	%4,%1	\n"	/* jump if addr+size>limit (error) */
	    "	bhi	0f	\n"
	    "	clr	%0	\n"	/* mark okay */
	    "0:			\n"
	    : "=r"(flag), "=&r"(tmp)
	    : "1"(addr), "ir"(size),
	      "r"(current_thread_info()->addr_limit.seg), "0"(flag)
	    : "cc"
	    );

	return flag;
}

#define __range_ok(addr, size) ___range_ok((unsigned long)(addr), (u32)(size))

#define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
#define __access_ok(addr, size)     (__range_ok((addr), (size)) == 0)

static inline int verify_area(int type, const void *addr, unsigned long size)
{
	return access_ok(type, addr, size) ? 0 : -EFAULT;
}


/*
 * 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;
};

/* Returns 0 if exception not found and fixup otherwise.  */
extern int fixup_exception(struct pt_regs *regs);

#define put_user(x, ptr) __put_user_check((x), (ptr), sizeof(*(ptr)))
#define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(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((x), (ptr), sizeof(*(ptr)))
#define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr)))

/*
 * The "xxx_ret" versions return constant specified in third argument, if
 * something bad happens. These macros can be optimized for the
 * case of just returning from the function xxx_ret is used.
 */

#define put_user_ret(x, ptr, ret) \
	({ if (put_user((x), (ptr)))	return (ret); })
#define get_user_ret(x, ptr, ret) \
	({ if (get_user((x), (ptr)))	return (ret); })
#define __put_user_ret(x, ptr, ret) \
	({ if (__put_user((x), (ptr)))	return (ret); })
#define __get_user_ret(x, ptr, ret) \
	({ if (__get_user((x), (ptr)))	return (ret); })

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

#define __get_user_nocheck(x, ptr, size)				\
({									\
	unsigned long __gu_addr;					\
	int __gu_err;							\
	__gu_addr = (unsigned long) (ptr);				\
	switch (size) {							\
	case 1: {							\
		unsigned char __gu_val;					\
		__get_user_asm("bu");					\
		(x) = *(__force __typeof__(*(ptr))*) &__gu_val;		\
		break;							\
	}								\
	case 2: {							\
		unsigned short __gu_val;				\
		__get_user_asm("hu");					\
		(x) = *(__force __typeof__(*(ptr))*) &__gu_val;		\
		break;							\
	}								\
	case 4: {							\
		unsigned int __gu_val;					\
		__get_user_asm("");					\
		(x) = *(__force __typeof__(*(ptr))*) &__gu_val;		\
		break;							\
	}								\
	default:							\
		__get_user_unknown();					\
		break;							\
	}								\
	__gu_err;							\
})

#define __get_user_check(x, ptr, size)					\
({									\
	const __typeof__(*(ptr))* __guc_ptr = (ptr);			\
	int _e;								\
	if (likely(__access_ok((unsigned long) __guc_ptr, (size))))	\
		_e = __get_user_nocheck((x), __guc_ptr, (size));	\
	else {								\
		_e = -EFAULT;						\
		(x) = (__typeof__(x))0;					\
	}								\
	_e;								\
})

#define __get_user_asm(INSN)					\
({								\
	asm volatile(					\
		"1:\n"						\
		"	mov"INSN"	%2,%1\n"		\
		"	mov		0,%0\n"			\
		"2:\n"						\
		"	.section	.fixup,\"ax\"\n"	\
		"3:\n\t"					\
		"	mov		%3,%0\n"		\
		"	jmp		2b\n"			\
		"	.previous\n"				\
		"	.section	__ex_table,\"a\"\n"	\
		"	.balign		4\n"			\
		"	.long		1b, 3b\n"		\
		"	.previous"				\
		: "=&r" (__gu_err), "=&r" (__gu_val)		\
		: "m" (__m(__gu_addr)), "i" (-EFAULT));		\
})

extern int __get_user_unknown(void);

#define __put_user_nocheck(x, ptr, size)			\
({								\
	union {							\
		__typeof__(*(ptr)) val;				\
		u32 bits[2];					\
	} __pu_val;						\
	unsigned long __pu_addr;				\
	int __pu_err;						\
	__pu_val.val = (x);					\
	__pu_addr = (unsigned long) (ptr);			\
	switch (size) {						\
	case 1:  __put_user_asm("bu"); break;			\
	case 2:  __put_user_asm("hu"); break;			\
	case 4:  __put_user_asm(""  ); break;			\
	case 8:  __put_user_asm8();    break;			\
	default: __pu_err = __put_user_unknown(); break;	\
	}							\
	__pu_err;						\
})

#define __put_user_check(x, ptr, size)					\
({									\
	union {								\
		__typeof__(*(ptr)) val;					\
		u32 bits[2];						\
	} __pu_val;							\
	unsigned long __pu_addr;					\
	int __pu_err;							\
	__pu_val.val = (x);						\
	__pu_addr = (unsigned long) (ptr);				\
	if (likely(__access_ok(__pu_addr, size))) {			\
		switch (size) {						\
		case 1:  __put_user_asm("bu"); break;			\
		case 2:  __put_user_asm("hu"); break;			\
		case 4:  __put_user_asm(""  ); break;			\
		case 8:  __put_user_asm8();    break;			\
		default: __pu_err = __put_user_unknown(); break;	\
		}							\
	}								\
	else {								\
		__pu_err = -EFAULT;					\
	}								\
	__pu_err;							\
})

#define __put_user_asm(INSN)					\
({								\
	asm volatile(						\
		"1:\n"						\
		"	mov"INSN"	%1,%2\n"		\
		"	mov		0,%0\n"			\
		"2:\n"						\
		"	.section	.fixup,\"ax\"\n"	\
		"3:\n"						\
		"	mov		%3,%0\n"		\
		"	jmp		2b\n"			\
		"	.previous\n"				\
		"	.section	__ex_table,\"a\"\n"	\
		"	.balign		4\n"			\
		"	.long		1b, 3b\n"		\
		"	.previous"				\
		: "=&r" (__pu_err)				\
		: "r" (__pu_val.val), "m" (__m(__pu_addr)),	\
		  "i" (-EFAULT)					\
		);						\
})

#define __put_user_asm8()						\
({									\
	asm volatile(							\
		"1:	mov		%1,%3		\n"		\
		"2:	mov		%2,%4		\n"		\
		"	mov		0,%0		\n"		\
		"3:					\n"		\
		"	.section	.fixup,\"ax\"	\n"		\
		"4:					\n"		\
		"	mov		%5,%0		\n"		\
		"	jmp		3b		\n"		\
		"	.previous			\n"		\
		"	.section	__ex_table,\"a\"\n"		\
		"	.balign		4		\n"		\
		"	.long		1b, 4b		\n"		\
		"	.long		2b, 4b		\n"		\
		"	.previous			\n"		\
		: "=&r" (__pu_err)					\
		: "r" (__pu_val.bits[0]), "r" (__pu_val.bits[1]),	\
		  "m" (__m(__pu_addr)), "m" (__m(__pu_addr+4)),		\
		  "i" (-EFAULT)						\
		);							\
})

extern int __put_user_unknown(void);


/*
 * Copy To/From Userspace
 */
/* Generic arbitrary sized copy.  */
#define __copy_user(to, from, size)					\
do {									\
	if (size) {							\
		void *__to = to;					\
		const void *__from = from;				\
		int w;							\
		asm volatile(						\
			"0:     movbu	(%0),%3;\n"			\
			"1:     movbu	%3,(%1);\n"			\
			"	inc	%0;\n"				\
			"	inc	%1;\n"				\
			"       add	-1,%2;\n"			\
			"       bne	0b;\n"				\
			"2:\n"						\
			"	.section .fixup,\"ax\"\n"		\
			"3:	jmp	2b\n"				\
			"	.previous\n"				\
			"	.section __ex_table,\"a\"\n"		\
			"       .balign	4\n"				\
			"       .long	0b,3b\n"			\
			"       .long	1b,3b\n"			\
			"	.previous\n"				\
			: "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
			: "0"(__from), "1"(__to), "2"(size)		\
			: "cc", "memory");				\
	}								\
} while (0)

#define __copy_user_zeroing(to, from, size)				\
do {									\
	if (size) {							\
		void *__to = to;					\
		const void *__from = from;				\
		int w;							\
		asm volatile(						\
			"0:     movbu	(%0),%3;\n"			\
			"1:     movbu	%3,(%1);\n"			\
			"	inc	%0;\n"				\
			"	inc	%1;\n"				\
			"       add	-1,%2;\n"			\
			"       bne	0b;\n"				\
			"2:\n"						\
			"	.section .fixup,\"ax\"\n"		\
			"3:\n"						\
			"	mov	%2,%0\n"			\
			"	clr	%3\n"				\
			"4:     movbu	%3,(%1);\n"			\
			"	inc	%1;\n"				\
			"       add	-1,%2;\n"			\
			"       bne	4b;\n"				\
			"	mov	%0,%2\n"			\
			"	jmp	2b\n"				\
			"	.previous\n"				\
			"	.section __ex_table,\"a\"\n"		\
			"       .balign	4\n"				\
			"       .long	0b,3b\n"			\
			"       .long	1b,3b\n"			\
			"	.previous\n"				\
			: "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
			: "0"(__from), "1"(__to), "2"(size)		\
			: "cc", "memory");				\
	}								\
} while (0)

/* We let the __ versions of copy_from/to_user inline, because they're often
 * used in fast paths and have only a small space overhead.
 */
static inline
unsigned long __generic_copy_from_user_nocheck(void *to, const void *from,
					       unsigned long n)
{
	__copy_user_zeroing(to, from, n);
	return n;
}

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


#if 0
#error "don't use - these macros don't increment to & from pointers"
/* Optimize just a little bit when we know the size of the move. */
#define __constant_copy_user(to, from, size)	\
do {						\
	asm volatile(				\
		"       mov %0,a0;\n"		\
		"0:     movbu (%1),d3;\n"	\
		"1:     movbu d3,(%2);\n"	\
		"       add -1,a0;\n"		\
		"       bne 0b;\n"		\
		"2:;"				\
		".section .fixup,\"ax\"\n"	\
		"3:	jmp 2b\n"		\
		".previous\n"			\
		".section __ex_table,\"a\"\n"	\
		"       .balign 4\n"		\
		"       .long 0b,3b\n"		\
		"       .long 1b,3b\n"		\
		".previous"			\
		:				\
		: "d"(size), "d"(to), "d"(from)	\
		: "d3", "a0");			\
} while (0)

/* Optimize just a little bit when we know the size of the move. */
#define __constant_copy_user_zeroing(to, from, size)	\
do {							\
	asm volatile(					\
		"       mov %0,a0;\n"			\
		"0:     movbu (%1),d3;\n"		\
		"1:     movbu d3,(%2);\n"		\
		"       add -1,a0;\n"			\
		"       bne 0b;\n"			\
		"2:;"					\
		".section .fixup,\"ax\"\n"		\
		"3:	jmp 2b\n"			\
		".previous\n"				\
		".section __ex_table,\"a\"\n"		\
		"       .balign 4\n"			\
		"       .long 0b,3b\n"			\
		"       .long 1b,3b\n"			\
		".previous"				\
		:					\
		: "d"(size), "d"(to), "d"(from)		\
		: "d3", "a0");				\
} while (0)

static inline
unsigned long __constant_copy_to_user(void *to, const void *from,
				      unsigned long n)
{
	if (access_ok(VERIFY_WRITE, to, n))
		__constant_copy_user(to, from, n);
	return n;
}

static inline
unsigned long __constant_copy_from_user(void *to, const void *from,
					unsigned long n)
{
	if (access_ok(VERIFY_READ, from, n))
		__constant_copy_user_zeroing(to, from, n);
	return n;
}

static inline
unsigned long __constant_copy_to_user_nocheck(void *to, const void *from,
					      unsigned long n)
{
	__constant_copy_user(to, from, n);
	return n;
}

static inline
unsigned long __constant_copy_from_user_nocheck(void *to, const void *from,
						unsigned long n)
{
	__constant_copy_user_zeroing(to, from, n);
	return n;
}
#endif

extern unsigned long __generic_copy_to_user(void __user *, const void *,
					    unsigned long);
extern unsigned long __generic_copy_from_user(void *, const void __user *,
					      unsigned long);

#define __copy_to_user_inatomic(to, from, n) \
	__generic_copy_to_user_nocheck((to), (from), (n))
#define __copy_from_user_inatomic(to, from, n) \
	__generic_copy_from_user_nocheck((to), (from), (n))

#define __copy_to_user(to, from, n)			\
({							\
	might_sleep();					\
	__copy_to_user_inatomic((to), (from), (n));	\
})

#define __copy_from_user(to, from, n)			\
({							\
	might_sleep();					\
	__copy_from_user_inatomic((to), (from), (n));	\
})


#define copy_to_user(to, from, n)   __generic_copy_to_user((to), (from), (n))
#define copy_from_user(to, from, n) __generic_copy_from_user((to), (from), (n))

extern long strncpy_from_user(char *dst, const char __user *src, long count);
extern long __strncpy_from_user(char *dst, const char __user *src, long count);
extern long strnlen_user(const char __user *str, long n);
#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
extern unsigned long clear_user(void __user *mem, unsigned long len);
extern unsigned long __clear_user(void __user *mem, unsigned long len);

#endif /* _ASM_UACCESS_H */