summaryrefslogtreecommitdiffstats
path: root/arch/microblaze/include/asm/uaccess.h
blob: b132cd301e6672f9fbbac8ab74a7e990936dc701 (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
/*
 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2008-2009 PetaLogix
 * Copyright (C) 2006 Atmark Techno, Inc.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#ifndef _ASM_MICROBLAZE_UACCESS_H
#define _ASM_MICROBLAZE_UACCESS_H

#include <linux/kernel.h>
#include <linux/mm.h>

#include <asm/mmu.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <linux/string.h>

/*
 * On Microblaze the fs value is actually the top of the corresponding
 * address space.
 *
 * 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.
 *
 * For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal.
 */
# define MAKE_MM_SEG(s)       ((mm_segment_t) { (s) })

#  ifndef CONFIG_MMU
#  define KERNEL_DS	MAKE_MM_SEG(0)
#  define USER_DS	KERNEL_DS
#  else
#  define KERNEL_DS	MAKE_MM_SEG(0xFFFFFFFF)
#  define USER_DS	MAKE_MM_SEG(TASK_SIZE - 1)
#  endif

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

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

/*
 * 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;
};

#ifndef CONFIG_MMU

/* Check against bounds of physical memory */
static inline int ___range_ok(unsigned long addr, unsigned long size)
{
	return ((addr < memory_start) ||
		((addr + size - 1) > (memory_start + memory_size - 1)));
}

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

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

#else

static inline int access_ok(int type, const void __user *addr,
							unsigned long size)
{
	if (!size)
		goto ok;

	if ((get_fs().seg < ((unsigned long)addr)) ||
			(get_fs().seg < ((unsigned long)addr + size - 1))) {
		pr_devel("ACCESS fail: %s at 0x%08x (size 0x%x), seg 0x%08x\n",
			type ? "WRITE" : "READ ", (__force u32)addr, (u32)size,
			(u32)get_fs().seg);
		return 0;
	}
ok:
	pr_devel("ACCESS OK: %s at 0x%08x (size 0x%x), seg 0x%08x\n",
			type ? "WRITE" : "READ ", (__force u32)addr, (u32)size,
			(u32)get_fs().seg);
	return 1;
}
#endif

#ifdef CONFIG_MMU
# define __FIXUP_SECTION	".section .fixup,\"ax\"\n"
# define __EX_TABLE_SECTION	".section __ex_table,\"a\"\n"
#else
# define __FIXUP_SECTION	".section .discard,\"ax\"\n"
# define __EX_TABLE_SECTION	".section .discard,\"ax\"\n"
#endif

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

/* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */
static inline unsigned long __must_check __clear_user(void __user *to,
							unsigned long n)
{
	/* normal memset with two words to __ex_table */
	__asm__ __volatile__ (				\
			"1:	sb	r0, %1, r0;"	\
			"	addik	%0, %0, -1;"	\
			"	bneid	%0, 1b;"	\
			"	addik	%1, %1, 1;"	\
			"2:			"	\
			__EX_TABLE_SECTION		\
			".word	1b,2b;"			\
			".previous;"			\
		: "=r"(n), "=r"(to)			\
		: "0"(n), "1"(to)
	);
	return n;
}

static inline unsigned long __must_check clear_user(void __user *to,
							unsigned long n)
{
	might_fault();
	if (unlikely(!access_ok(VERIFY_WRITE, to, n)))
		return n;

	return __clear_user(to, n);
}

/* put_user and get_user macros */
extern long __user_bad(void);

#define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err)	\
({								\
	__asm__ __volatile__ (					\
			"1:"	insn	" %1, %2, r0;"		\
			"	addk	%0, r0, r0;"		\
			"2:			"		\
			__FIXUP_SECTION				\
			"3:	brid	2b;"			\
			"	addik	%0, r0, %3;"		\
			".previous;"				\
			__EX_TABLE_SECTION			\
			".word	1b,3b;"				\
			".previous;"				\
		: "=&r"(__gu_err), "=r"(__gu_val)		\
		: "r"(__gu_ptr), "i"(-EFAULT)			\
	);							\
})

/**
 * get_user: - Get a simple variable from user space.
 * @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.
 */
#define get_user(x, ptr)						\
	__get_user_check((x), (ptr), sizeof(*(ptr)))

#define __get_user_check(x, ptr, size)					\
({									\
	unsigned long __gu_val = 0;					\
	const typeof(*(ptr)) __user *__gu_addr = (ptr);			\
	int __gu_err = 0;						\
									\
	if (access_ok(VERIFY_READ, __gu_addr, size)) {			\
		switch (size) {						\
		case 1:							\
			__get_user_asm("lbu", __gu_addr, __gu_val,	\
				       __gu_err);			\
			break;						\
		case 2:							\
			__get_user_asm("lhu", __gu_addr, __gu_val,	\
				       __gu_err);			\
			break;						\
		case 4:							\
			__get_user_asm("lw", __gu_addr, __gu_val,	\
				       __gu_err);			\
			break;						\
		default:						\
			__gu_err = __user_bad();			\
			break;						\
		}							\
	} else {							\
		__gu_err = -EFAULT;					\
	}								\
	x = (__force typeof(*(ptr)))__gu_val;				\
	__gu_err;							\
})

#define __get_user(x, ptr)						\
({									\
	unsigned long __gu_val = 0;					\
	/*unsigned long __gu_ptr = (unsigned long)(ptr);*/		\
	long __gu_err;							\
	switch (sizeof(*(ptr))) {					\
	case 1:								\
		__get_user_asm("lbu", (ptr), __gu_val, __gu_err);	\
		break;							\
	case 2:								\
		__get_user_asm("lhu", (ptr), __gu_val, __gu_err);	\
		break;							\
	case 4:								\
		__get_user_asm("lw", (ptr), __gu_val, __gu_err);	\
		break;							\
	default:							\
		/* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
	}								\
	x = (__force __typeof__(*(ptr))) __gu_val;			\
	__gu_err;							\
})


#define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err)	\
({								\
	__asm__ __volatile__ (					\
			"1:"	insn	" %1, %2, r0;"		\
			"	addk	%0, r0, r0;"		\
			"2:			"		\
			__FIXUP_SECTION				\
			"3:	brid	2b;"			\
			"	addik	%0, r0, %3;"		\
			".previous;"				\
			__EX_TABLE_SECTION			\
			".word	1b,3b;"				\
			".previous;"				\
		: "=&r"(__gu_err)				\
		: "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT)	\
	);							\
})

#define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err)		\
({								\
	__asm__ __volatile__ ("	lwi	%0, %1, 0;"		\
			"1:	swi	%0, %2, 0;"		\
			"	lwi	%0, %1, 4;"		\
			"2:	swi	%0, %2, 4;"		\
			"	addk	%0, r0, r0;"		\
			"3:			"		\
			__FIXUP_SECTION				\
			"4:	brid	3b;"			\
			"	addik	%0, r0, %3;"		\
			".previous;"				\
			__EX_TABLE_SECTION			\
			".word	1b,4b,2b,4b;"			\
			".previous;"				\
		: "=&r"(__gu_err)				\
		: "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT)	\
		);						\
})

/**
 * put_user: - Write a simple value into user space.
 * @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.
 *
 * Returns zero on success, or -EFAULT on error.
 */
#define put_user(x, ptr)						\
	__put_user_check((x), (ptr), sizeof(*(ptr)))

#define __put_user_check(x, ptr, size)					\
({									\
	typeof(*(ptr)) volatile __pu_val = x;				\
	typeof(*(ptr)) __user *__pu_addr = (ptr);			\
	int __pu_err = 0;						\
									\
	if (access_ok(VERIFY_WRITE, __pu_addr, size)) {			\
		switch (size) {						\
		case 1:							\
			__put_user_asm("sb", __pu_addr, __pu_val,	\
				       __pu_err);			\
			break;						\
		case 2:							\
			__put_user_asm("sh", __pu_addr, __pu_val,	\
				       __pu_err);			\
			break;						\
		case 4:							\
			__put_user_asm("sw", __pu_addr, __pu_val,	\
				       __pu_err);			\
			break;						\
		case 8:							\
			__put_user_asm_8(__pu_addr, __pu_val, __pu_err);\
			break;						\
		default:						\
			__pu_err = __user_bad();			\
			break;						\
		}							\
	} else {							\
		__pu_err = -EFAULT;					\
	}								\
	__pu_err;							\
})

#define __put_user(x, ptr)						\
({									\
	__typeof__(*(ptr)) volatile __gu_val = (x);			\
	long __gu_err = 0;						\
	switch (sizeof(__gu_val)) {					\
	case 1:								\
		__put_user_asm("sb", (ptr), __gu_val, __gu_err);	\
		break;							\
	case 2:								\
		__put_user_asm("sh", (ptr), __gu_val, __gu_err);	\
		break;							\
	case 4:								\
		__put_user_asm("sw", (ptr), __gu_val, __gu_err);	\
		break;							\
	case 8:								\
		__put_user_asm_8((ptr), __gu_val, __gu_err);		\
		break;							\
	default:							\
		/*__gu_err = -EINVAL;*/	__gu_err = __user_bad();	\
	}								\
	__gu_err;							\
})


/* copy_to_from_user */
#define __copy_from_user(to, from, n)	\
	__copy_tofrom_user((__force void __user *)(to), \
				(void __user *)(from), (n))
#define __copy_from_user_inatomic(to, from, n) \
		__copy_from_user((to), (from), (n))

static inline long copy_from_user(void *to,
		const void __user *from, unsigned long n)
{
	unsigned long res = n;
	might_fault();
	if (likely(access_ok(VERIFY_READ, from, n)))
		res = __copy_from_user(to, from, n);
	if (unlikely(res))
		memset(to + (n - res), 0, res);
	return res;
}

#define __copy_to_user(to, from, n)	\
		__copy_tofrom_user((void __user *)(to), \
			(__force const void __user *)(from), (n))
#define __copy_to_user_inatomic(to, from, n) __copy_to_user((to), (from), (n))

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

/*
 * Copy a null terminated string from userspace.
 */
extern int __strncpy_user(char *to, const char __user *from, int len);

#define __strncpy_from_user	__strncpy_user

static inline long
strncpy_from_user(char *dst, const char __user *src, long count)
{
	if (!access_ok(VERIFY_READ, src, 1))
		return -EFAULT;
	return __strncpy_from_user(dst, src, count);
}

/*
 * Return the size of a string (including the ending 0)
 *
 * Return 0 on exception, a value greater than N if too long
 */
extern int __strnlen_user(const char __user *sstr, int len);

static inline long strnlen_user(const char __user *src, long n)
{
	if (!access_ok(VERIFY_READ, src, 1))
		return 0;
	return __strnlen_user(src, n);
}

#endif /* _ASM_MICROBLAZE_UACCESS_H */