Loading...
1/*
2 * OpenRISC Linux
3 *
4 * Linux architectural port borrowing liberally from similar works of
5 * others. All original copyrights apply as per the original source
6 * declaration.
7 *
8 * OpenRISC implementation:
9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
11 * et al.
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 */
18
19#ifndef __ASM_OPENRISC_UACCESS_H
20#define __ASM_OPENRISC_UACCESS_H
21
22/*
23 * User space memory access functions
24 */
25#include <linux/errno.h>
26#include <linux/thread_info.h>
27#include <linux/prefetch.h>
28#include <linux/string.h>
29#include <linux/thread_info.h>
30#include <asm/page.h>
31
32#define VERIFY_READ 0
33#define VERIFY_WRITE 1
34
35/*
36 * The fs value determines whether argument validity checking should be
37 * performed or not. If get_fs() == USER_DS, checking is performed, with
38 * get_fs() == KERNEL_DS, checking is bypassed.
39 *
40 * For historical reasons, these macros are grossly misnamed.
41 */
42
43/* addr_limit is the maximum accessible address for the task. we misuse
44 * the KERNEL_DS and USER_DS values to both assign and compare the
45 * addr_limit values through the equally misnamed get/set_fs macros.
46 * (see above)
47 */
48
49#define KERNEL_DS (~0UL)
50#define get_ds() (KERNEL_DS)
51
52#define USER_DS (TASK_SIZE)
53#define get_fs() (current_thread_info()->addr_limit)
54#define set_fs(x) (current_thread_info()->addr_limit = (x))
55
56#define segment_eq(a, b) ((a) == (b))
57
58/* Ensure that the range from addr to addr+size is all within the process'
59 * address space
60 */
61#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size))
62
63/* Ensure that addr is below task's addr_limit */
64#define __addr_ok(addr) ((unsigned long) addr < get_fs())
65
66#define access_ok(type, addr, size) \
67 __range_ok((unsigned long)addr, (unsigned long)size)
68
69/*
70 * The exception table consists of pairs of addresses: the first is the
71 * address of an instruction that is allowed to fault, and the second is
72 * the address at which the program should continue. No registers are
73 * modified, so it is entirely up to the continuation code to figure out
74 * what to do.
75 *
76 * All the routines below use bits of fixup code that are out of line
77 * with the main instruction path. This means when everything is well,
78 * we don't even have to jump over them. Further, they do not intrude
79 * on our cache or tlb entries.
80 */
81
82struct exception_table_entry {
83 unsigned long insn, fixup;
84};
85
86/* Returns 0 if exception not found and fixup otherwise. */
87extern unsigned long search_exception_table(unsigned long);
88extern void sort_exception_table(void);
89
90/*
91 * These are the main single-value transfer routines. They automatically
92 * use the right size if we just have the right pointer type.
93 *
94 * This gets kind of ugly. We want to return _two_ values in "get_user()"
95 * and yet we don't want to do any pointers, because that is too much
96 * of a performance impact. Thus we have a few rather ugly macros here,
97 * and hide all the uglyness from the user.
98 *
99 * The "__xxx" versions of the user access functions are versions that
100 * do not verify the address space, that must have been done previously
101 * with a separate "access_ok()" call (this is used when we do multiple
102 * accesses to the same area of user memory).
103 *
104 * As we use the same address space for kernel and user data on the
105 * PowerPC, we can just do these as direct assignments. (Of course, the
106 * exception handling means that it's no longer "just"...)
107 */
108#define get_user(x, ptr) \
109 __get_user_check((x), (ptr), sizeof(*(ptr)))
110#define put_user(x, ptr) \
111 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
112
113#define __get_user(x, ptr) \
114 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
115#define __put_user(x, ptr) \
116 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
117
118extern long __put_user_bad(void);
119
120#define __put_user_nocheck(x, ptr, size) \
121({ \
122 long __pu_err; \
123 __put_user_size((x), (ptr), (size), __pu_err); \
124 __pu_err; \
125})
126
127#define __put_user_check(x, ptr, size) \
128({ \
129 long __pu_err = -EFAULT; \
130 __typeof__(*(ptr)) *__pu_addr = (ptr); \
131 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
132 __put_user_size((x), __pu_addr, (size), __pu_err); \
133 __pu_err; \
134})
135
136#define __put_user_size(x, ptr, size, retval) \
137do { \
138 retval = 0; \
139 switch (size) { \
140 case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \
141 case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \
142 case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \
143 case 8: __put_user_asm2(x, ptr, retval); break; \
144 default: __put_user_bad(); \
145 } \
146} while (0)
147
148struct __large_struct {
149 unsigned long buf[100];
150};
151#define __m(x) (*(struct __large_struct *)(x))
152
153/*
154 * We don't tell gcc that we are accessing memory, but this is OK
155 * because we do not write to any memory gcc knows about, so there
156 * are no aliasing issues.
157 */
158#define __put_user_asm(x, addr, err, op) \
159 __asm__ __volatile__( \
160 "1: "op" 0(%2),%1\n" \
161 "2:\n" \
162 ".section .fixup,\"ax\"\n" \
163 "3: l.addi %0,r0,%3\n" \
164 " l.j 2b\n" \
165 " l.nop\n" \
166 ".previous\n" \
167 ".section __ex_table,\"a\"\n" \
168 " .align 2\n" \
169 " .long 1b,3b\n" \
170 ".previous" \
171 : "=r"(err) \
172 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
173
174#define __put_user_asm2(x, addr, err) \
175 __asm__ __volatile__( \
176 "1: l.sw 0(%2),%1\n" \
177 "2: l.sw 4(%2),%H1\n" \
178 "3:\n" \
179 ".section .fixup,\"ax\"\n" \
180 "4: l.addi %0,r0,%3\n" \
181 " l.j 3b\n" \
182 " l.nop\n" \
183 ".previous\n" \
184 ".section __ex_table,\"a\"\n" \
185 " .align 2\n" \
186 " .long 1b,4b\n" \
187 " .long 2b,4b\n" \
188 ".previous" \
189 : "=r"(err) \
190 : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err))
191
192#define __get_user_nocheck(x, ptr, size) \
193({ \
194 long __gu_err, __gu_val; \
195 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
196 (x) = (__typeof__(*(ptr)))__gu_val; \
197 __gu_err; \
198})
199
200#define __get_user_check(x, ptr, size) \
201({ \
202 long __gu_err = -EFAULT, __gu_val = 0; \
203 const __typeof__(*(ptr)) * __gu_addr = (ptr); \
204 if (access_ok(VERIFY_READ, __gu_addr, size)) \
205 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
206 (x) = (__typeof__(*(ptr)))__gu_val; \
207 __gu_err; \
208})
209
210extern long __get_user_bad(void);
211
212#define __get_user_size(x, ptr, size, retval) \
213do { \
214 retval = 0; \
215 switch (size) { \
216 case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \
217 case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \
218 case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \
219 case 8: __get_user_asm2(x, ptr, retval); \
220 default: (x) = __get_user_bad(); \
221 } \
222} while (0)
223
224#define __get_user_asm(x, addr, err, op) \
225 __asm__ __volatile__( \
226 "1: "op" %1,0(%2)\n" \
227 "2:\n" \
228 ".section .fixup,\"ax\"\n" \
229 "3: l.addi %0,r0,%3\n" \
230 " l.addi %1,r0,0\n" \
231 " l.j 2b\n" \
232 " l.nop\n" \
233 ".previous\n" \
234 ".section __ex_table,\"a\"\n" \
235 " .align 2\n" \
236 " .long 1b,3b\n" \
237 ".previous" \
238 : "=r"(err), "=r"(x) \
239 : "r"(addr), "i"(-EFAULT), "0"(err))
240
241#define __get_user_asm2(x, addr, err) \
242 __asm__ __volatile__( \
243 "1: l.lwz %1,0(%2)\n" \
244 "2: l.lwz %H1,4(%2)\n" \
245 "3:\n" \
246 ".section .fixup,\"ax\"\n" \
247 "4: l.addi %0,r0,%3\n" \
248 " l.addi %1,r0,0\n" \
249 " l.addi %H1,r0,0\n" \
250 " l.j 3b\n" \
251 " l.nop\n" \
252 ".previous\n" \
253 ".section __ex_table,\"a\"\n" \
254 " .align 2\n" \
255 " .long 1b,4b\n" \
256 " .long 2b,4b\n" \
257 ".previous" \
258 : "=r"(err), "=&r"(x) \
259 : "r"(addr), "i"(-EFAULT), "0"(err))
260
261/* more complex routines */
262
263extern unsigned long __must_check
264__copy_tofrom_user(void *to, const void *from, unsigned long size);
265
266#define __copy_from_user(to, from, size) \
267 __copy_tofrom_user(to, from, size)
268#define __copy_to_user(to, from, size) \
269 __copy_tofrom_user(to, from, size)
270
271#define __copy_to_user_inatomic __copy_to_user
272#define __copy_from_user_inatomic __copy_from_user
273
274static inline unsigned long
275copy_from_user(void *to, const void *from, unsigned long n)
276{
277 unsigned long over;
278
279 if (access_ok(VERIFY_READ, from, n))
280 return __copy_tofrom_user(to, from, n);
281 if ((unsigned long)from < TASK_SIZE) {
282 over = (unsigned long)from + n - TASK_SIZE;
283 return __copy_tofrom_user(to, from, n - over) + over;
284 }
285 return n;
286}
287
288static inline unsigned long
289copy_to_user(void *to, const void *from, unsigned long n)
290{
291 unsigned long over;
292
293 if (access_ok(VERIFY_WRITE, to, n))
294 return __copy_tofrom_user(to, from, n);
295 if ((unsigned long)to < TASK_SIZE) {
296 over = (unsigned long)to + n - TASK_SIZE;
297 return __copy_tofrom_user(to, from, n - over) + over;
298 }
299 return n;
300}
301
302extern unsigned long __clear_user(void *addr, unsigned long size);
303
304static inline __must_check unsigned long
305clear_user(void *addr, unsigned long size)
306{
307
308 if (access_ok(VERIFY_WRITE, addr, size))
309 return __clear_user(addr, size);
310 if ((unsigned long)addr < TASK_SIZE) {
311 unsigned long over = (unsigned long)addr + size - TASK_SIZE;
312 return __clear_user(addr, size - over) + over;
313 }
314 return size;
315}
316
317extern int __strncpy_from_user(char *dst, const char *src, long count);
318
319static inline long strncpy_from_user(char *dst, const char *src, long count)
320{
321 if (access_ok(VERIFY_READ, src, 1))
322 return __strncpy_from_user(dst, src, count);
323 return -EFAULT;
324}
325
326/*
327 * Return the size of a string (including the ending 0)
328 *
329 * Return 0 for error
330 */
331
332extern int __strnlen_user(const char *str, long len, unsigned long top);
333
334/*
335 * Returns the length of the string at str (including the null byte),
336 * or 0 if we hit a page we can't access,
337 * or something > len if we didn't find a null byte.
338 *
339 * The `top' parameter to __strnlen_user is to make sure that
340 * we can never overflow from the user area into kernel space.
341 */
342static inline long strnlen_user(const char __user *str, long len)
343{
344 unsigned long top = (unsigned long)get_fs();
345 unsigned long res = 0;
346
347 if (__addr_ok(str))
348 res = __strnlen_user(str, len, top);
349
350 return res;
351}
352
353#define strlen_user(str) strnlen_user(str, TASK_SIZE-1)
354
355#endif /* __ASM_OPENRISC_UACCESS_H */
1/* SPDX-License-Identifier: GPL-2.0-or-later */
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.
13 */
14
15#ifndef __ASM_OPENRISC_UACCESS_H
16#define __ASM_OPENRISC_UACCESS_H
17
18/*
19 * User space memory access functions
20 */
21#include <linux/prefetch.h>
22#include <linux/string.h>
23#include <asm/page.h>
24#include <asm/extable.h>
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)
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
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})
62
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
91extern 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); \
104 if (access_ok(__pu_addr, size)) \
105 __put_user_size((x), __pu_addr, (size), __pu_err); \
106 __pu_err; \
107})
108
109#define __put_user_size(x, ptr, size, retval) \
110do { \
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
121struct __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); \
169 (x) = (__force __typeof__(*(ptr)))__gu_val; \
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); \
177 if (access_ok(__gu_addr, size)) \
178 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
179 (x) = (__force __typeof__(*(ptr)))__gu_val; \
180 __gu_err; \
181})
182
183extern long __get_user_bad(void);
184
185#define __get_user_size(x, ptr, size, retval) \
186do { \
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; \
192 case 8: __get_user_asm2(x, ptr, retval); break; \
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
236extern unsigned long __must_check
237__copy_tofrom_user(void *to, const void *from, unsigned long size);
238static inline unsigned long
239raw_copy_from_user(void *to, const void __user *from, unsigned long size)
240{
241 return __copy_tofrom_user(to, (__force const void *)from, size);
242}
243static inline unsigned long
244raw_copy_to_user(void *to, const void __user *from, unsigned long size)
245{
246 return __copy_tofrom_user((__force void *)to, from, size);
247}
248#define INLINE_COPY_FROM_USER
249#define INLINE_COPY_TO_USER
250
251extern unsigned long __clear_user(void *addr, unsigned long size);
252
253static inline __must_check unsigned long
254clear_user(void *addr, unsigned long size)
255{
256 if (likely(access_ok(addr, size)))
257 size = __clear_user(addr, size);
258 return size;
259}
260
261#define user_addr_max() \
262 (uaccess_kernel() ? ~0UL : TASK_SIZE)
263
264extern long strncpy_from_user(char *dest, const char __user *src, long count);
265
266extern __must_check long strnlen_user(const char __user *str, long n);
267
268#endif /* __ASM_OPENRISC_UACCESS_H */