summaryrefslogtreecommitdiff
path: root/arch/tile/include/asm/uaccess.h
blob: 0a9c4265763bd1a26f5f38aa20460c475670cea5 (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
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
/*
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 */

#ifndef _ASM_TILE_UACCESS_H
#define _ASM_TILE_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/sched.h>
#include <linux/mm.h>
#include <asm-generic/uaccess-unaligned.h>
#include <asm/processor.h>
#include <asm/page.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(a)  ((mm_segment_t) { (a) })

#define KERNEL_DS	MAKE_MM_SEG(-1UL)
#define USER_DS		MAKE_MM_SEG(PAGE_OFFSET)

#define get_ds()	(KERNEL_DS)
#define get_fs()	(current_thread_info()->addr_limit)
#define set_fs(x)	(current_thread_info()->addr_limit = (x))

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

#ifndef __tilegx__
/*
 * We could allow mapping all 16 MB at 0xfc000000, but we set up a
 * special hack in arch_setup_additional_pages() to auto-create a mapping
 * for the first 16 KB, and it would seem strange to have different
 * user-accessible semantics for memory at 0xfc000000 and above 0xfc004000.
 */
static inline int is_arch_mappable_range(unsigned long addr,
					 unsigned long size)
{
	return (addr >= MEM_USER_INTRPT &&
		addr < (MEM_USER_INTRPT + INTRPT_SIZE) &&
		size <= (MEM_USER_INTRPT + INTRPT_SIZE) - addr);
}
#define is_arch_mappable_range is_arch_mappable_range
#else
#define is_arch_mappable_range(addr, size) 0
#endif

/*
 * Note that using this definition ignores is_arch_mappable_range(),
 * so on tilepro code that uses user_addr_max() is constrained not
 * to reference the tilepro user-interrupt region.
 */
#define user_addr_max() (current_thread_info()->addr_limit.seg)

/*
 * Test whether a block of memory is a valid user space address.
 * Returns 0 if the range is valid, nonzero otherwise.
 */
int __range_ok(unsigned long addr, unsigned long size);

/**
 * access_ok: - Checks if a user space pointer is valid
 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
 *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
 *        to write to a block, it is always safe to read from it.
 * @addr: User space pointer to start of block to check
 * @size: Size of block to check
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * Checks if a pointer to a block of memory in user space is valid.
 *
 * Returns true (nonzero) if the memory block may be valid, false (zero)
 * if it is definitely invalid.
 *
 * Note that, depending on architecture, this function probably just
 * checks that the pointer is in the user space range - after calling
 * this function, memory access functions may still return -EFAULT.
 */
#define access_ok(type, addr, size) ({ \
	__chk_user_ptr(addr); \
	likely(__range_ok((unsigned long)(addr), (size)) == 0);	\
})

/*
 * 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);

/*
 * This is a type: either unsigned long, if the argument fits into
 * that type, or otherwise unsigned long long.
 */
#define __inttype(x) \
	__typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))

/*
 * Support macros for __get_user().
 * Note that __get_user() and __put_user() assume proper alignment.
 */

#ifdef __LP64__
#define _ASM_PTR	".quad"
#define _ASM_ALIGN	".align 8"
#else
#define _ASM_PTR	".long"
#define _ASM_ALIGN	".align 4"
#endif

#define __get_user_asm(OP, x, ptr, ret)					\
	asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n"		\
		     ".pushsection .fixup,\"ax\"\n"			\
		     "0: { movei %1, 0; movei %0, %3 }\n"		\
		     "j 9f\n"						\
		     ".section __ex_table,\"a\"\n"			\
		     _ASM_ALIGN "\n"					\
		     _ASM_PTR " 1b, 0b\n"				\
		     ".popsection\n"					\
		     "9:"						\
		     : "=r" (ret), "=r" (x)				\
		     : "r" (ptr), "i" (-EFAULT))

#ifdef __tilegx__
#define __get_user_1(x, ptr, ret) __get_user_asm(ld1u, x, ptr, ret)
#define __get_user_2(x, ptr, ret) __get_user_asm(ld2u, x, ptr, ret)
#define __get_user_4(x, ptr, ret) __get_user_asm(ld4s, x, ptr, ret)
#define __get_user_8(x, ptr, ret) __get_user_asm(ld, x, ptr, ret)
#else
#define __get_user_1(x, ptr, ret) __get_user_asm(lb_u, x, ptr, ret)
#define __get_user_2(x, ptr, ret) __get_user_asm(lh_u, x, ptr, ret)
#define __get_user_4(x, ptr, ret) __get_user_asm(lw, x, ptr, ret)
#ifdef __LITTLE_ENDIAN
#define __lo32(a, b) a
#define __hi32(a, b) b
#else
#define __lo32(a, b) b
#define __hi32(a, b) a
#endif
#define __get_user_8(x, ptr, ret)					\
	({								\
		unsigned int __a, __b;					\
		asm volatile("1: { lw %1, %3; addi %2, %3, 4 }\n"	\
			     "2: { lw %2, %2; movei %0, 0 }\n"		\
			     ".pushsection .fixup,\"ax\"\n"		\
			     "0: { movei %1, 0; movei %2, 0 }\n"	\
			     "{ movei %0, %4; j 9f }\n"			\
			     ".section __ex_table,\"a\"\n"		\
			     ".align 4\n"				\
			     ".word 1b, 0b\n"				\
			     ".word 2b, 0b\n"				\
			     ".popsection\n"				\
			     "9:"					\
			     : "=r" (ret), "=r" (__a), "=&r" (__b)	\
			     : "r" (ptr), "i" (-EFAULT));		\
		(x) = (__force __typeof(x))(__inttype(x))		\
			(((u64)__hi32(__a, __b) << 32) |		\
			 __lo32(__a, __b));				\
	})
#endif

extern int __get_user_bad(void)
  __attribute__((warning("sizeof __get_user argument not 1, 2, 4 or 8")));

/**
 * __get_user: - Get a simple variable from user space, with less checking.
 * @x:   Variable to store result.
 * @ptr: Source address, in user space.
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * This macro copies a single simple variable from user space to kernel
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and the result of
 * dereferencing @ptr must be assignable to @x without a cast.
 *
 * Returns zero on success, or -EFAULT on error.
 * On error, the variable @x is set to zero.
 *
 * Caller must check the pointer with access_ok() before calling this
 * function.
 */
#define __get_user(x, ptr)						\
	({								\
		int __ret;						\
		typeof(x) _x;						\
		__chk_user_ptr(ptr);					\
		switch (sizeof(*(ptr))) {				\
		case 1: __get_user_1(_x, ptr, __ret); break;		\
		case 2: __get_user_2(_x, ptr, __ret); break;		\
		case 4: __get_user_4(_x, ptr, __ret); break;		\
		case 8: __get_user_8(_x, ptr, __ret); break;		\
		default: __ret = __get_user_bad(); break;		\
		}							\
		(x) = (typeof(*(ptr))) _x;				\
		__ret;							\
	})

/* Support macros for __put_user(). */

#define __put_user_asm(OP, x, ptr, ret)			\
	asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n"		\
		     ".pushsection .fixup,\"ax\"\n"			\
		     "0: { movei %0, %3; j 9f }\n"			\
		     ".section __ex_table,\"a\"\n"			\
		     _ASM_ALIGN "\n"					\
		     _ASM_PTR " 1b, 0b\n"				\
		     ".popsection\n"					\
		     "9:"						\
		     : "=r" (ret)					\
		     : "r" (ptr), "r" (x), "i" (-EFAULT))

#ifdef __tilegx__
#define __put_user_1(x, ptr, ret) __put_user_asm(st1, x, ptr, ret)
#define __put_user_2(x, ptr, ret) __put_user_asm(st2, x, ptr, ret)
#define __put_user_4(x, ptr, ret) __put_user_asm(st4, x, ptr, ret)
#define __put_user_8(x, ptr, ret) __put_user_asm(st, x, ptr, ret)
#else
#define __put_user_1(x, ptr, ret) __put_user_asm(sb, x, ptr, ret)
#define __put_user_2(x, ptr, ret) __put_user_asm(sh, x, ptr, ret)
#define __put_user_4(x, ptr, ret) __put_user_asm(sw, x, ptr, ret)
#define __put_user_8(x, ptr, ret)					\
	({								\
		u64 __x = (__force __inttype(x))(x);			\
		int __lo = (int) __x, __hi = (int) (__x >> 32);		\
		asm volatile("1: { sw %1, %2; addi %0, %1, 4 }\n"	\
			     "2: { sw %0, %3; movei %0, 0 }\n"		\
			     ".pushsection .fixup,\"ax\"\n"		\
			     "0: { movei %0, %4; j 9f }\n"		\
			     ".section __ex_table,\"a\"\n"		\
			     ".align 4\n"				\
			     ".word 1b, 0b\n"				\
			     ".word 2b, 0b\n"				\
			     ".popsection\n"				\
			     "9:"					\
			     : "=&r" (ret)				\
			     : "r" (ptr), "r" (__lo32(__lo, __hi)),	\
			     "r" (__hi32(__lo, __hi)), "i" (-EFAULT));	\
	})
#endif

extern int __put_user_bad(void)
  __attribute__((warning("sizeof __put_user argument not 1, 2, 4 or 8")));

/**
 * __put_user: - Write a simple value into user space, with less checking.
 * @x:   Value to copy to user space.
 * @ptr: Destination address, in user space.
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * This macro copies a single simple value from kernel space to user
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 * to the result of dereferencing @ptr.
 *
 * Caller must check the pointer with access_ok() before calling this
 * function.
 *
 * Returns zero on success, or -EFAULT on error.
 */
#define __put_user(x, ptr)						\
({									\
	int __ret;							\
	typeof(*(ptr)) _x = (x);					\
	__chk_user_ptr(ptr);						\
	switch (sizeof(*(ptr))) {					\
	case 1: __put_user_1(_x, ptr, __ret); break;			\
	case 2: __put_user_2(_x, ptr, __ret); break;			\
	case 4: __put_user_4(_x, ptr, __ret); break;			\
	case 8: __put_user_8(_x, ptr, __ret); break;			\
	default: __ret = __put_user_bad(); break;			\
	}								\
	__ret;								\
})

/*
 * The versions of get_user and put_user without initial underscores
 * check the address of their arguments to make sure they are not
 * in kernel space.
 */
#define put_user(x, ptr)						\
({									\
	__typeof__(*(ptr)) __user *__Pu_addr = (ptr);			\
	access_ok(VERIFY_WRITE, (__Pu_addr), sizeof(*(__Pu_addr))) ?	\
		__put_user((x), (__Pu_addr)) :				\
		-EFAULT;						\
})

#define get_user(x, ptr)						\
({									\
	__typeof__(*(ptr)) const __user *__Gu_addr = (ptr);		\
	access_ok(VERIFY_READ, (__Gu_addr), sizeof(*(__Gu_addr))) ?	\
		__get_user((x), (__Gu_addr)) :				\
		((x) = 0, -EFAULT);					\
})

/**
 * __copy_to_user() - copy data into user space, with less checking.
 * @to:   Destination address, in user space.
 * @from: Source address, in kernel space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * Copy data from kernel space to user space.  Caller must check
 * the specified block with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 *
 * An alternate version - __copy_to_user_inatomic() - is designed
 * to be called from atomic context, typically bracketed by calls
 * to pagefault_disable() and pagefault_enable().
 */
extern unsigned long __must_check __copy_to_user_inatomic(
	void __user *to, const void *from, unsigned long n);

static inline unsigned long __must_check
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
	might_fault();
	return __copy_to_user_inatomic(to, from, n);
}

static inline unsigned long __must_check
copy_to_user(void __user *to, const void *from, unsigned long n)
{
	if (access_ok(VERIFY_WRITE, to, n))
		n = __copy_to_user(to, from, n);
	return n;
}

/**
 * __copy_from_user() - copy data from user space, with less checking.
 * @to:   Destination address, in kernel space.
 * @from: Source address, in user space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * Copy data from user space to kernel space.  Caller must check
 * the specified block with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 *
 * If some data could not be copied, this function will pad the copied
 * data to the requested size using zero bytes.
 *
 * An alternate version - __copy_from_user_inatomic() - is designed
 * to be called from atomic context, typically bracketed by calls
 * to pagefault_disable() and pagefault_enable().  This version
 * does *NOT* pad with zeros.
 */
extern unsigned long __must_check __copy_from_user_inatomic(
	void *to, const void __user *from, unsigned long n);
extern unsigned long __must_check __copy_from_user_zeroing(
	void *to, const void __user *from, unsigned long n);

static inline unsigned long __must_check
__copy_from_user(void *to, const void __user *from, unsigned long n)
{
       might_fault();
       return __copy_from_user_zeroing(to, from, n);
}

static inline unsigned long __must_check
_copy_from_user(void *to, const void __user *from, unsigned long n)
{
	if (access_ok(VERIFY_READ, from, n))
		n = __copy_from_user(to, from, n);
	else
		memset(to, 0, n);
	return n;
}

#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
/*
 * There are still unprovable places in the generic code as of 2.6.34, so this
 * option is not really compatible with -Werror, which is more useful in
 * general.
 */
extern void copy_from_user_overflow(void)
	__compiletime_warning("copy_from_user() size is not provably correct");

static inline unsigned long __must_check copy_from_user(void *to,
					  const void __user *from,
					  unsigned long n)
{
	int sz = __compiletime_object_size(to);

	if (likely(sz == -1 || sz >= n))
		n = _copy_from_user(to, from, n);
	else
		copy_from_user_overflow();

	return n;
}
#else
#define copy_from_user _copy_from_user
#endif

#ifdef __tilegx__
/**
 * __copy_in_user() - copy data within user space, with less checking.
 * @to:   Destination address, in user space.
 * @from: Source address, in user space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * Copy data from user space to user space.  Caller must check
 * the specified blocks with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 */
extern unsigned long __copy_in_user_inatomic(
	void __user *to, const void __user *from, unsigned long n);

static inline unsigned long __must_check
__copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
	might_fault();
	return __copy_in_user_inatomic(to, from, n);
}

static inline unsigned long __must_check
copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
	if (access_ok(VERIFY_WRITE, to, n) && access_ok(VERIFY_READ, from, n))
		n = __copy_in_user(to, from, n);
	return n;
}
#endif


extern long strnlen_user(const char __user *str, long n);
extern long strlen_user(const char __user *str);
extern long strncpy_from_user(char *dst, const char __user *src, long);

/**
 * clear_user: - Zero a block of memory in user space.
 * @mem:   Destination address, in user space.
 * @len:   Number of bytes to zero.
 *
 * Zero a block of memory in user space.
 *
 * Returns number of bytes that could not be cleared.
 * On success, this will be zero.
 */
extern unsigned long clear_user_asm(void __user *mem, unsigned long len);
static inline unsigned long __must_check __clear_user(
	void __user *mem, unsigned long len)
{
	might_fault();
	return clear_user_asm(mem, len);
}
static inline unsigned long __must_check clear_user(
	void __user *mem, unsigned long len)
{
	if (access_ok(VERIFY_WRITE, mem, len))
		return __clear_user(mem, len);
	return len;
}

/**
 * flush_user: - Flush a block of memory in user space from cache.
 * @mem:   Destination address, in user space.
 * @len:   Number of bytes to flush.
 *
 * Returns number of bytes that could not be flushed.
 * On success, this will be zero.
 */
extern unsigned long flush_user_asm(void __user *mem, unsigned long len);
static inline unsigned long __must_check __flush_user(
	void __user *mem, unsigned long len)
{
	int retval;

	might_fault();
	retval = flush_user_asm(mem, len);
	mb_incoherent();
	return retval;
}

static inline unsigned long __must_check flush_user(
	void __user *mem, unsigned long len)
{
	if (access_ok(VERIFY_WRITE, mem, len))
		return __flush_user(mem, len);
	return len;
}

/**
 * finv_user: - Flush-inval a block of memory in user space from cache.
 * @mem:   Destination address, in user space.
 * @len:   Number of bytes to invalidate.
 *
 * Returns number of bytes that could not be flush-invalidated.
 * On success, this will be zero.
 */
extern unsigned long finv_user_asm(void __user *mem, unsigned long len);
static inline unsigned long __must_check __finv_user(
	void __user *mem, unsigned long len)
{
	int retval;

	might_fault();
	retval = finv_user_asm(mem, len);
	mb_incoherent();
	return retval;
}
static inline unsigned long __must_check finv_user(
	void __user *mem, unsigned long len)
{
	if (access_ok(VERIFY_WRITE, mem, len))
		return __finv_user(mem, len);
	return len;
}

#endif /* _ASM_TILE_UACCESS_H */