Merge remote-tracking branch 'mfd/for-mfd-next'
[deliverable/linux.git] / arch / powerpc / include / asm / uaccess.h
CommitLineData
2df5e8bc
SR
1#ifndef _ARCH_POWERPC_UACCESS_H
2#define _ARCH_POWERPC_UACCESS_H
3
4#ifdef __KERNEL__
5#ifndef __ASSEMBLY__
6
7#include <linux/sched.h>
8#include <linux/errno.h>
551c3c04 9#include <asm/asm-compat.h>
2df5e8bc 10#include <asm/processor.h>
6bfd93c3 11#include <asm/page.h>
2df5e8bc
SR
12
13#define VERIFY_READ 0
14#define VERIFY_WRITE 1
15
16/*
17 * The fs value determines whether argument validity checking should be
18 * performed or not. If get_fs() == USER_DS, checking is performed, with
19 * get_fs() == KERNEL_DS, checking is bypassed.
20 *
21 * For historical reasons, these macros are grossly misnamed.
22 *
23 * The fs/ds values are now the highest legal address in the "segment".
24 * This simplifies the checking in the routines below.
25 */
26
27#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
28
5015b494 29#define KERNEL_DS MAKE_MM_SEG(~0UL)
2df5e8bc 30#ifdef __powerpc64__
5015b494
SR
31/* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */
32#define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1)
2df5e8bc 33#else
2df5e8bc
SR
34#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
35#endif
36
37#define get_ds() (KERNEL_DS)
38#define get_fs() (current->thread.fs)
39#define set_fs(val) (current->thread.fs = (val))
40
41#define segment_eq(a, b) ((a).seg == (b).seg)
42
1629372c
PM
43#define user_addr_max() (get_fs().seg)
44
2df5e8bc
SR
45#ifdef __powerpc64__
46/*
5015b494
SR
47 * This check is sufficient because there is a large enough
48 * gap between user addresses and the kernel addresses
2df5e8bc
SR
49 */
50#define __access_ok(addr, size, segment) \
5015b494 51 (((addr) <= (segment).seg) && ((size) <= (segment).seg))
2df5e8bc
SR
52
53#else
54
55#define __access_ok(addr, size, segment) \
56 (((addr) <= (segment).seg) && \
57 (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr)))))
58
59#endif
60
61#define access_ok(type, addr, size) \
62 (__chk_user_ptr(addr), \
63 __access_ok((__force unsigned long)(addr), (size), get_fs()))
64
65/*
66 * The exception table consists of pairs of addresses: the first is the
67 * address of an instruction that is allowed to fault, and the second is
68 * the address at which the program should continue. No registers are
69 * modified, so it is entirely up to the continuation code to figure out
70 * what to do.
71 *
72 * All the routines below use bits of fixup code that are out of line
73 * with the main instruction path. This means when everything is well,
74 * we don't even have to jump over them. Further, they do not intrude
75 * on our cache or tlb entries.
76 */
77
78struct exception_table_entry {
79 unsigned long insn;
80 unsigned long fixup;
81};
82
83/*
84 * These are the main single-value transfer routines. They automatically
85 * use the right size if we just have the right pointer type.
86 *
87 * This gets kind of ugly. We want to return _two_ values in "get_user()"
88 * and yet we don't want to do any pointers, because that is too much
89 * of a performance impact. Thus we have a few rather ugly macros here,
90 * and hide all the ugliness from the user.
91 *
92 * The "__xxx" versions of the user access functions are versions that
93 * do not verify the address space, that must have been done previously
94 * with a separate "access_ok()" call (this is used when we do multiple
95 * accesses to the same area of user memory).
96 *
97 * As we use the same address space for kernel and user data on the
98 * PowerPC, we can just do these as direct assignments. (Of course, the
99 * exception handling means that it's no longer "just"...)
100 *
2df5e8bc
SR
101 */
102#define get_user(x, ptr) \
103 __get_user_check((x), (ptr), sizeof(*(ptr)))
104#define put_user(x, ptr) \
105 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
106
107#define __get_user(x, ptr) \
108 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
109#define __put_user(x, ptr) \
110 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
e68c825b 111
e68c825b
BH
112#define __get_user_inatomic(x, ptr) \
113 __get_user_nosleep((x), (ptr), sizeof(*(ptr)))
114#define __put_user_inatomic(x, ptr) \
115 __put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
116
2df5e8bc
SR
117#define __get_user_unaligned __get_user
118#define __put_user_unaligned __put_user
2df5e8bc
SR
119
120extern long __put_user_bad(void);
121
2df5e8bc
SR
122/*
123 * We don't tell gcc that we are accessing memory, but this is OK
124 * because we do not write to any memory gcc knows about, so there
125 * are no aliasing issues.
126 */
127#define __put_user_asm(x, addr, err, op) \
128 __asm__ __volatile__( \
129 "1: " op " %1,0(%2) # put_user\n" \
130 "2:\n" \
131 ".section .fixup,\"ax\"\n" \
132 "3: li %0,%3\n" \
133 " b 2b\n" \
134 ".previous\n" \
135 ".section __ex_table,\"a\"\n" \
551c3c04 136 PPC_LONG_ALIGN "\n" \
3ddfbcf1 137 PPC_LONG "1b,3b\n" \
2df5e8bc
SR
138 ".previous" \
139 : "=r" (err) \
551c3c04 140 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))
2df5e8bc 141
5015b494
SR
142#ifdef __powerpc64__
143#define __put_user_asm2(x, ptr, retval) \
144 __put_user_asm(x, ptr, retval, "std")
145#else /* __powerpc64__ */
2df5e8bc
SR
146#define __put_user_asm2(x, addr, err) \
147 __asm__ __volatile__( \
148 "1: stw %1,0(%2)\n" \
149 "2: stw %1+1,4(%2)\n" \
150 "3:\n" \
151 ".section .fixup,\"ax\"\n" \
152 "4: li %0,%3\n" \
153 " b 3b\n" \
154 ".previous\n" \
155 ".section __ex_table,\"a\"\n" \
551c3c04 156 PPC_LONG_ALIGN "\n" \
3ddfbcf1
DG
157 PPC_LONG "1b,4b\n" \
158 PPC_LONG "2b,4b\n" \
2df5e8bc
SR
159 ".previous" \
160 : "=r" (err) \
551c3c04 161 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))
2df5e8bc
SR
162#endif /* __powerpc64__ */
163
164#define __put_user_size(x, ptr, size, retval) \
165do { \
166 retval = 0; \
167 switch (size) { \
168 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \
169 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \
170 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \
171 case 8: __put_user_asm2(x, ptr, retval); break; \
172 default: __put_user_bad(); \
173 } \
174} while (0)
175
176#define __put_user_nocheck(x, ptr, size) \
177({ \
178 long __pu_err; \
6bfd93c3
PM
179 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
180 if (!is_kernel_addr((unsigned long)__pu_addr)) \
1af1717d 181 might_fault(); \
2df5e8bc 182 __chk_user_ptr(ptr); \
6bfd93c3 183 __put_user_size((x), __pu_addr, (size), __pu_err); \
2df5e8bc
SR
184 __pu_err; \
185})
186
187#define __put_user_check(x, ptr, size) \
188({ \
189 long __pu_err = -EFAULT; \
190 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
1af1717d 191 might_fault(); \
2df5e8bc
SR
192 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
193 __put_user_size((x), __pu_addr, (size), __pu_err); \
194 __pu_err; \
195})
196
e68c825b
BH
197#define __put_user_nosleep(x, ptr, size) \
198({ \
199 long __pu_err; \
200 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
201 __chk_user_ptr(ptr); \
202 __put_user_size((x), __pu_addr, (size), __pu_err); \
203 __pu_err; \
204})
205
206
2df5e8bc
SR
207extern long __get_user_bad(void);
208
209#define __get_user_asm(x, addr, err, op) \
210 __asm__ __volatile__( \
5015b494 211 "1: "op" %1,0(%2) # get_user\n" \
2df5e8bc
SR
212 "2:\n" \
213 ".section .fixup,\"ax\"\n" \
214 "3: li %0,%3\n" \
215 " li %1,0\n" \
216 " b 2b\n" \
217 ".previous\n" \
218 ".section __ex_table,\"a\"\n" \
551c3c04 219 PPC_LONG_ALIGN "\n" \
3ddfbcf1 220 PPC_LONG "1b,3b\n" \
2df5e8bc
SR
221 ".previous" \
222 : "=r" (err), "=r" (x) \
551c3c04 223 : "b" (addr), "i" (-EFAULT), "0" (err))
2df5e8bc 224
5015b494
SR
225#ifdef __powerpc64__
226#define __get_user_asm2(x, addr, err) \
227 __get_user_asm(x, addr, err, "ld")
228#else /* __powerpc64__ */
229#define __get_user_asm2(x, addr, err) \
2df5e8bc
SR
230 __asm__ __volatile__( \
231 "1: lwz %1,0(%2)\n" \
232 "2: lwz %1+1,4(%2)\n" \
233 "3:\n" \
234 ".section .fixup,\"ax\"\n" \
235 "4: li %0,%3\n" \
236 " li %1,0\n" \
237 " li %1+1,0\n" \
238 " b 3b\n" \
239 ".previous\n" \
240 ".section __ex_table,\"a\"\n" \
551c3c04 241 PPC_LONG_ALIGN "\n" \
3ddfbcf1
DG
242 PPC_LONG "1b,4b\n" \
243 PPC_LONG "2b,4b\n" \
2df5e8bc
SR
244 ".previous" \
245 : "=r" (err), "=&r" (x) \
551c3c04 246 : "b" (addr), "i" (-EFAULT), "0" (err))
2df5e8bc
SR
247#endif /* __powerpc64__ */
248
249#define __get_user_size(x, ptr, size, retval) \
250do { \
251 retval = 0; \
252 __chk_user_ptr(ptr); \
5015b494
SR
253 if (size > sizeof(x)) \
254 (x) = __get_user_bad(); \
2df5e8bc
SR
255 switch (size) { \
256 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \
257 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \
258 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \
259 case 8: __get_user_asm2(x, ptr, retval); break; \
260 default: (x) = __get_user_bad(); \
261 } \
262} while (0)
263
264#define __get_user_nocheck(x, ptr, size) \
265({ \
266 long __gu_err; \
267 unsigned long __gu_val; \
b91c1e3e 268 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
2df5e8bc 269 __chk_user_ptr(ptr); \
6bfd93c3 270 if (!is_kernel_addr((unsigned long)__gu_addr)) \
1af1717d 271 might_fault(); \
6bfd93c3 272 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
2df5e8bc
SR
273 (x) = (__typeof__(*(ptr)))__gu_val; \
274 __gu_err; \
275})
276
2df5e8bc
SR
277#define __get_user_check(x, ptr, size) \
278({ \
279 long __gu_err = -EFAULT; \
280 unsigned long __gu_val = 0; \
b91c1e3e 281 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
1af1717d 282 might_fault(); \
2df5e8bc
SR
283 if (access_ok(VERIFY_READ, __gu_addr, (size))) \
284 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
505e4283 285 (x) = (__force __typeof__(*(ptr)))__gu_val; \
2df5e8bc
SR
286 __gu_err; \
287})
288
e68c825b
BH
289#define __get_user_nosleep(x, ptr, size) \
290({ \
291 long __gu_err; \
292 unsigned long __gu_val; \
b91c1e3e 293 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
e68c825b
BH
294 __chk_user_ptr(ptr); \
295 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
505e4283 296 (x) = (__force __typeof__(*(ptr)))__gu_val; \
e68c825b
BH
297 __gu_err; \
298})
299
300
2df5e8bc
SR
301/* more complex routines */
302
303extern unsigned long __copy_tofrom_user(void __user *to,
304 const void __user *from, unsigned long size);
305
306#ifndef __powerpc64__
5015b494 307
4cfbdfff 308static inline unsigned long copy_from_user(void *to,
5015b494 309 const void __user *from, unsigned long n)
2df5e8bc
SR
310{
311 unsigned long over;
312
1d3c1324 313 if (access_ok(VERIFY_READ, from, n)) {
81409e9e 314 check_object_size(to, n, false);
2df5e8bc 315 return __copy_tofrom_user((__force void __user *)to, from, n);
1d3c1324 316 }
2df5e8bc
SR
317 if ((unsigned long)from < TASK_SIZE) {
318 over = (unsigned long)from + n - TASK_SIZE;
81409e9e 319 check_object_size(to, n - over, false);
2df5e8bc
SR
320 return __copy_tofrom_user((__force void __user *)to, from,
321 n - over) + over;
322 }
323 return n;
324}
325
4cfbdfff 326static inline unsigned long copy_to_user(void __user *to,
5015b494 327 const void *from, unsigned long n)
2df5e8bc
SR
328{
329 unsigned long over;
330
1d3c1324 331 if (access_ok(VERIFY_WRITE, to, n)) {
81409e9e 332 check_object_size(from, n, true);
2df5e8bc 333 return __copy_tofrom_user(to, (__force void __user *)from, n);
1d3c1324 334 }
2df5e8bc
SR
335 if ((unsigned long)to < TASK_SIZE) {
336 over = (unsigned long)to + n - TASK_SIZE;
81409e9e 337 check_object_size(from, n - over, true);
2df5e8bc
SR
338 return __copy_tofrom_user(to, (__force void __user *)from,
339 n - over) + over;
340 }
341 return n;
342}
343
344#else /* __powerpc64__ */
345
5015b494
SR
346#define __copy_in_user(to, from, size) \
347 __copy_tofrom_user((to), (from), (size))
348
349extern unsigned long copy_from_user(void *to, const void __user *from,
350 unsigned long n);
351extern unsigned long copy_to_user(void __user *to, const void *from,
352 unsigned long n);
353extern unsigned long copy_in_user(void __user *to, const void __user *from,
354 unsigned long n);
355
48fe4871
SR
356#endif /* __powerpc64__ */
357
5015b494
SR
358static inline unsigned long __copy_from_user_inatomic(void *to,
359 const void __user *from, unsigned long n)
2df5e8bc
SR
360{
361 if (__builtin_constant_p(n) && (n <= 8)) {
9c8387af 362 unsigned long ret = 1;
2df5e8bc
SR
363
364 switch (n) {
365 case 1:
366 __get_user_size(*(u8 *)to, from, 1, ret);
367 break;
368 case 2:
369 __get_user_size(*(u16 *)to, from, 2, ret);
370 break;
371 case 4:
372 __get_user_size(*(u32 *)to, from, 4, ret);
373 break;
374 case 8:
375 __get_user_size(*(u64 *)to, from, 8, ret);
376 break;
377 }
48fe4871
SR
378 if (ret == 0)
379 return 0;
2df5e8bc 380 }
1d3c1324 381
81409e9e 382 check_object_size(to, n, false);
1d3c1324 383
48fe4871 384 return __copy_tofrom_user((__force void __user *)to, from, n);
2df5e8bc
SR
385}
386
5015b494
SR
387static inline unsigned long __copy_to_user_inatomic(void __user *to,
388 const void *from, unsigned long n)
2df5e8bc
SR
389{
390 if (__builtin_constant_p(n) && (n <= 8)) {
9c8387af 391 unsigned long ret = 1;
2df5e8bc
SR
392
393 switch (n) {
394 case 1:
395 __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret);
396 break;
397 case 2:
398 __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret);
399 break;
400 case 4:
401 __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret);
402 break;
403 case 8:
404 __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret);
405 break;
406 }
48fe4871
SR
407 if (ret == 0)
408 return 0;
2df5e8bc 409 }
81409e9e
KC
410
411 check_object_size(from, n, true);
1d3c1324 412
48fe4871 413 return __copy_tofrom_user(to, (__force const void __user *)from, n);
2df5e8bc
SR
414}
415
5015b494
SR
416static inline unsigned long __copy_from_user(void *to,
417 const void __user *from, unsigned long size)
2df5e8bc 418{
1af1717d 419 might_fault();
2df5e8bc 420 return __copy_from_user_inatomic(to, from, size);
2df5e8bc
SR
421}
422
5015b494
SR
423static inline unsigned long __copy_to_user(void __user *to,
424 const void *from, unsigned long size)
2df5e8bc 425{
1af1717d 426 might_fault();
2df5e8bc 427 return __copy_to_user_inatomic(to, from, size);
2df5e8bc
SR
428}
429
2df5e8bc
SR
430extern unsigned long __clear_user(void __user *addr, unsigned long size);
431
432static inline unsigned long clear_user(void __user *addr, unsigned long size)
433{
1af1717d 434 might_fault();
2df5e8bc
SR
435 if (likely(access_ok(VERIFY_WRITE, addr, size)))
436 return __clear_user(addr, size);
2df5e8bc
SR
437 if ((unsigned long)addr < TASK_SIZE) {
438 unsigned long over = (unsigned long)addr + size - TASK_SIZE;
439 return __clear_user(addr, size - over) + over;
440 }
2df5e8bc
SR
441 return size;
442}
443
1629372c
PM
444extern long strncpy_from_user(char *dst, const char __user *src, long count);
445extern __must_check long strlen_user(const char __user *str);
446extern __must_check long strnlen_user(const char __user *str, long n);
2df5e8bc
SR
447
448#endif /* __ASSEMBLY__ */
449#endif /* __KERNEL__ */
450
451#endif /* _ARCH_POWERPC_UACCESS_H */
This page took 0.723463 seconds and 5 git commands to generate.