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Stephen Rothwell2df5e8b2005-10-29 17:51:31 +10001#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>
9#include <asm/processor.h>
10
11#define VERIFY_READ 0
12#define VERIFY_WRITE 1
13
14/*
15 * The fs value determines whether argument validity checking should be
16 * performed or not. If get_fs() == USER_DS, checking is performed, with
17 * get_fs() == KERNEL_DS, checking is bypassed.
18 *
19 * For historical reasons, these macros are grossly misnamed.
20 *
21 * The fs/ds values are now the highest legal address in the "segment".
22 * This simplifies the checking in the routines below.
23 */
24
25#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
26
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +100027#define KERNEL_DS MAKE_MM_SEG(~0UL)
Stephen Rothwell5015b492005-10-31 18:39:20 +110028#ifdef __powerpc64__
29/* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */
30#define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1)
31#else
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +100032#define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
33#endif
34
35#define get_ds() (KERNEL_DS)
36#define get_fs() (current->thread.fs)
37#define set_fs(val) (current->thread.fs = (val))
38
39#define segment_eq(a, b) ((a).seg == (b).seg)
40
41#ifdef __powerpc64__
42/*
Stephen Rothwell5015b492005-10-31 18:39:20 +110043 * This check is sufficient because there is a large enough
44 * gap between user addresses and the kernel addresses
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +100045 */
46#define __access_ok(addr, size, segment) \
Stephen Rothwell5015b492005-10-31 18:39:20 +110047 (((addr) <= (segment).seg) && ((size) <= (segment).seg))
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +100048
49#else
50
51#define __access_ok(addr, size, segment) \
52 (((addr) <= (segment).seg) && \
53 (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr)))))
54
55#endif
56
57#define access_ok(type, addr, size) \
58 (__chk_user_ptr(addr), \
59 __access_ok((__force unsigned long)(addr), (size), get_fs()))
60
61/*
62 * The exception table consists of pairs of addresses: the first is the
63 * address of an instruction that is allowed to fault, and the second is
64 * the address at which the program should continue. No registers are
65 * modified, so it is entirely up to the continuation code to figure out
66 * what to do.
67 *
68 * All the routines below use bits of fixup code that are out of line
69 * with the main instruction path. This means when everything is well,
70 * we don't even have to jump over them. Further, they do not intrude
71 * on our cache or tlb entries.
72 */
73
74struct exception_table_entry {
75 unsigned long insn;
76 unsigned long fixup;
77};
78
79/*
80 * These are the main single-value transfer routines. They automatically
81 * use the right size if we just have the right pointer type.
82 *
83 * This gets kind of ugly. We want to return _two_ values in "get_user()"
84 * and yet we don't want to do any pointers, because that is too much
85 * of a performance impact. Thus we have a few rather ugly macros here,
86 * and hide all the ugliness from the user.
87 *
88 * The "__xxx" versions of the user access functions are versions that
89 * do not verify the address space, that must have been done previously
90 * with a separate "access_ok()" call (this is used when we do multiple
91 * accesses to the same area of user memory).
92 *
93 * As we use the same address space for kernel and user data on the
94 * PowerPC, we can just do these as direct assignments. (Of course, the
95 * exception handling means that it's no longer "just"...)
96 *
97 * The "user64" versions of the user access functions are versions that
98 * allow access of 64-bit data. The "get_user" functions do not
99 * properly handle 64-bit data because the value gets down cast to a long.
100 * The "put_user" functions already handle 64-bit data properly but we add
101 * "user64" versions for completeness
102 */
103#define get_user(x, ptr) \
104 __get_user_check((x), (ptr), sizeof(*(ptr)))
105#define put_user(x, ptr) \
106 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
107
108#define __get_user(x, ptr) \
109 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
110#define __put_user(x, ptr) \
111 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
112#ifndef __powerpc64__
113#define __get_user64(x, ptr) \
114 __get_user64_nocheck((x), (ptr), sizeof(*(ptr)))
115#define __put_user64(x, ptr) __put_user(x, ptr)
116#endif
117
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000118#define __get_user_unaligned __get_user
119#define __put_user_unaligned __put_user
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000120
121extern long __put_user_bad(void);
122
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000123/*
124 * We don't tell gcc that we are accessing memory, but this is OK
125 * because we do not write to any memory gcc knows about, so there
126 * are no aliasing issues.
127 */
128#define __put_user_asm(x, addr, err, op) \
129 __asm__ __volatile__( \
130 "1: " op " %1,0(%2) # put_user\n" \
131 "2:\n" \
132 ".section .fixup,\"ax\"\n" \
133 "3: li %0,%3\n" \
134 " b 2b\n" \
135 ".previous\n" \
136 ".section __ex_table,\"a\"\n" \
David Gibson3ddfbcf2005-11-10 12:56:55 +1100137 " .balign %5\n" \
138 PPC_LONG "1b,3b\n" \
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000139 ".previous" \
140 : "=r" (err) \
David Gibson3ddfbcf2005-11-10 12:56:55 +1100141 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\
142 "i"(sizeof(unsigned long)))
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000143
Stephen Rothwell5015b492005-10-31 18:39:20 +1100144#ifdef __powerpc64__
145#define __put_user_asm2(x, ptr, retval) \
146 __put_user_asm(x, ptr, retval, "std")
147#else /* __powerpc64__ */
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000148#define __put_user_asm2(x, addr, err) \
149 __asm__ __volatile__( \
150 "1: stw %1,0(%2)\n" \
151 "2: stw %1+1,4(%2)\n" \
152 "3:\n" \
153 ".section .fixup,\"ax\"\n" \
154 "4: li %0,%3\n" \
155 " b 3b\n" \
156 ".previous\n" \
157 ".section __ex_table,\"a\"\n" \
David Gibson3ddfbcf2005-11-10 12:56:55 +1100158 " .balign %5\n" \
159 PPC_LONG "1b,4b\n" \
160 PPC_LONG "2b,4b\n" \
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000161 ".previous" \
162 : "=r" (err) \
David Gibson3ddfbcf2005-11-10 12:56:55 +1100163 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\
164 "i"(sizeof(unsigned long)))
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000165#endif /* __powerpc64__ */
166
167#define __put_user_size(x, ptr, size, retval) \
168do { \
169 retval = 0; \
170 switch (size) { \
171 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \
172 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \
173 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \
174 case 8: __put_user_asm2(x, ptr, retval); break; \
175 default: __put_user_bad(); \
176 } \
177} while (0)
178
179#define __put_user_nocheck(x, ptr, size) \
180({ \
181 long __pu_err; \
182 might_sleep(); \
183 __chk_user_ptr(ptr); \
184 __put_user_size((x), (ptr), (size), __pu_err); \
185 __pu_err; \
186})
187
188#define __put_user_check(x, ptr, size) \
189({ \
190 long __pu_err = -EFAULT; \
191 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
192 might_sleep(); \
193 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
194 __put_user_size((x), __pu_addr, (size), __pu_err); \
195 __pu_err; \
196})
197
198extern long __get_user_bad(void);
199
200#define __get_user_asm(x, addr, err, op) \
201 __asm__ __volatile__( \
Stephen Rothwell5015b492005-10-31 18:39:20 +1100202 "1: "op" %1,0(%2) # get_user\n" \
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000203 "2:\n" \
204 ".section .fixup,\"ax\"\n" \
205 "3: li %0,%3\n" \
206 " li %1,0\n" \
207 " b 2b\n" \
208 ".previous\n" \
209 ".section __ex_table,\"a\"\n" \
David Gibson3ddfbcf2005-11-10 12:56:55 +1100210 " .balign %5\n" \
211 PPC_LONG "1b,3b\n" \
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000212 ".previous" \
213 : "=r" (err), "=r" (x) \
David Gibson3ddfbcf2005-11-10 12:56:55 +1100214 : "b" (addr), "i" (-EFAULT), "0" (err), \
215 "i"(sizeof(unsigned long)))
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000216
Stephen Rothwell5015b492005-10-31 18:39:20 +1100217#ifdef __powerpc64__
218#define __get_user_asm2(x, addr, err) \
219 __get_user_asm(x, addr, err, "ld")
220#else /* __powerpc64__ */
221#define __get_user_asm2(x, addr, err) \
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000222 __asm__ __volatile__( \
223 "1: lwz %1,0(%2)\n" \
224 "2: lwz %1+1,4(%2)\n" \
225 "3:\n" \
226 ".section .fixup,\"ax\"\n" \
227 "4: li %0,%3\n" \
228 " li %1,0\n" \
229 " li %1+1,0\n" \
230 " b 3b\n" \
231 ".previous\n" \
232 ".section __ex_table,\"a\"\n" \
David Gibson3ddfbcf2005-11-10 12:56:55 +1100233 " .balign %5\n" \
234 PPC_LONG "1b,4b\n" \
235 PPC_LONG "2b,4b\n" \
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000236 ".previous" \
237 : "=r" (err), "=&r" (x) \
David Gibson3ddfbcf2005-11-10 12:56:55 +1100238 : "b" (addr), "i" (-EFAULT), "0" (err), \
239 "i"(sizeof(unsigned long)))
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000240#endif /* __powerpc64__ */
241
242#define __get_user_size(x, ptr, size, retval) \
243do { \
244 retval = 0; \
245 __chk_user_ptr(ptr); \
Stephen Rothwell5015b492005-10-31 18:39:20 +1100246 if (size > sizeof(x)) \
247 (x) = __get_user_bad(); \
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000248 switch (size) { \
249 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \
250 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \
251 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \
252 case 8: __get_user_asm2(x, ptr, retval); break; \
253 default: (x) = __get_user_bad(); \
254 } \
255} while (0)
256
257#define __get_user_nocheck(x, ptr, size) \
258({ \
259 long __gu_err; \
260 unsigned long __gu_val; \
261 __chk_user_ptr(ptr); \
262 might_sleep(); \
263 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
264 (x) = (__typeof__(*(ptr)))__gu_val; \
265 __gu_err; \
266})
267
268#ifndef __powerpc64__
269#define __get_user64_nocheck(x, ptr, size) \
270({ \
271 long __gu_err; \
272 long long __gu_val; \
273 __chk_user_ptr(ptr); \
274 might_sleep(); \
275 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
276 (x) = (__typeof__(*(ptr)))__gu_val; \
277 __gu_err; \
278})
279#endif /* __powerpc64__ */
280
281#define __get_user_check(x, ptr, size) \
282({ \
283 long __gu_err = -EFAULT; \
284 unsigned long __gu_val = 0; \
285 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
Stephen Rothwell5015b492005-10-31 18:39:20 +1100286 might_sleep(); \
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000287 if (access_ok(VERIFY_READ, __gu_addr, (size))) \
288 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
289 (x) = (__typeof__(*(ptr)))__gu_val; \
290 __gu_err; \
291})
292
293/* more complex routines */
294
295extern unsigned long __copy_tofrom_user(void __user *to,
296 const void __user *from, unsigned long size);
297
298#ifndef __powerpc64__
Stephen Rothwell5015b492005-10-31 18:39:20 +1100299
300extern inline unsigned long copy_from_user(void *to,
301 const void __user *from, unsigned long n)
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000302{
303 unsigned long over;
304
305 if (access_ok(VERIFY_READ, from, n))
306 return __copy_tofrom_user((__force void __user *)to, from, n);
307 if ((unsigned long)from < TASK_SIZE) {
308 over = (unsigned long)from + n - TASK_SIZE;
309 return __copy_tofrom_user((__force void __user *)to, from,
310 n - over) + over;
311 }
312 return n;
313}
314
Stephen Rothwell5015b492005-10-31 18:39:20 +1100315extern inline unsigned long copy_to_user(void __user *to,
316 const void *from, unsigned long n)
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000317{
318 unsigned long over;
319
320 if (access_ok(VERIFY_WRITE, to, n))
321 return __copy_tofrom_user(to, (__force void __user *)from, n);
322 if ((unsigned long)to < TASK_SIZE) {
323 over = (unsigned long)to + n - TASK_SIZE;
324 return __copy_tofrom_user(to, (__force void __user *)from,
325 n - over) + over;
326 }
327 return n;
328}
329
330#else /* __powerpc64__ */
331
Stephen Rothwell5015b492005-10-31 18:39:20 +1100332#define __copy_in_user(to, from, size) \
333 __copy_tofrom_user((to), (from), (size))
334
335extern unsigned long copy_from_user(void *to, const void __user *from,
336 unsigned long n);
337extern unsigned long copy_to_user(void __user *to, const void *from,
338 unsigned long n);
339extern unsigned long copy_in_user(void __user *to, const void __user *from,
340 unsigned long n);
341
Stephen Rothwell48fe4872005-11-01 15:53:19 +1100342#endif /* __powerpc64__ */
343
Stephen Rothwell5015b492005-10-31 18:39:20 +1100344static inline unsigned long __copy_from_user_inatomic(void *to,
345 const void __user *from, unsigned long n)
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000346{
347 if (__builtin_constant_p(n) && (n <= 8)) {
348 unsigned long ret;
349
350 switch (n) {
351 case 1:
352 __get_user_size(*(u8 *)to, from, 1, ret);
353 break;
354 case 2:
355 __get_user_size(*(u16 *)to, from, 2, ret);
356 break;
357 case 4:
358 __get_user_size(*(u32 *)to, from, 4, ret);
359 break;
360 case 8:
361 __get_user_size(*(u64 *)to, from, 8, ret);
362 break;
363 }
Stephen Rothwell48fe4872005-11-01 15:53:19 +1100364 if (ret == 0)
365 return 0;
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000366 }
Stephen Rothwell48fe4872005-11-01 15:53:19 +1100367 return __copy_tofrom_user((__force void __user *)to, from, n);
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000368}
369
Stephen Rothwell5015b492005-10-31 18:39:20 +1100370static inline unsigned long __copy_to_user_inatomic(void __user *to,
371 const void *from, unsigned long n)
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000372{
373 if (__builtin_constant_p(n) && (n <= 8)) {
374 unsigned long ret;
375
376 switch (n) {
377 case 1:
378 __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret);
379 break;
380 case 2:
381 __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret);
382 break;
383 case 4:
384 __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret);
385 break;
386 case 8:
387 __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret);
388 break;
389 }
Stephen Rothwell48fe4872005-11-01 15:53:19 +1100390 if (ret == 0)
391 return 0;
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000392 }
Stephen Rothwell48fe4872005-11-01 15:53:19 +1100393 return __copy_tofrom_user(to, (__force const void __user *)from, n);
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000394}
395
Stephen Rothwell5015b492005-10-31 18:39:20 +1100396static inline unsigned long __copy_from_user(void *to,
397 const void __user *from, unsigned long size)
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000398{
399 might_sleep();
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000400 return __copy_from_user_inatomic(to, from, size);
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000401}
402
Stephen Rothwell5015b492005-10-31 18:39:20 +1100403static inline unsigned long __copy_to_user(void __user *to,
404 const void *from, unsigned long size)
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000405{
406 might_sleep();
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000407 return __copy_to_user_inatomic(to, from, size);
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000408}
409
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000410extern unsigned long __clear_user(void __user *addr, unsigned long size);
411
412static inline unsigned long clear_user(void __user *addr, unsigned long size)
413{
414 might_sleep();
415 if (likely(access_ok(VERIFY_WRITE, addr, size)))
416 return __clear_user(addr, size);
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000417 if ((unsigned long)addr < TASK_SIZE) {
418 unsigned long over = (unsigned long)addr + size - TASK_SIZE;
419 return __clear_user(addr, size - over) + over;
420 }
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000421 return size;
422}
423
424extern int __strncpy_from_user(char *dst, const char __user *src, long count);
425
426static inline long strncpy_from_user(char *dst, const char __user *src,
427 long count)
428{
429 might_sleep();
430 if (likely(access_ok(VERIFY_READ, src, 1)))
431 return __strncpy_from_user(dst, src, count);
432 return -EFAULT;
433}
434
435/*
436 * Return the size of a string (including the ending 0)
437 *
438 * Return 0 for error
439 */
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000440extern int __strnlen_user(const char __user *str, long len, unsigned long top);
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000441
442/*
443 * Returns the length of the string at str (including the null byte),
444 * or 0 if we hit a page we can't access,
445 * or something > len if we didn't find a null byte.
446 *
447 * The `top' parameter to __strnlen_user is to make sure that
448 * we can never overflow from the user area into kernel space.
449 */
450static inline int strnlen_user(const char __user *str, long len)
451{
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000452 unsigned long top = current->thread.fs.seg;
453
454 if ((unsigned long)str > top)
455 return 0;
456 return __strnlen_user(str, len, top);
Stephen Rothwell2df5e8b2005-10-29 17:51:31 +1000457}
458
459#define strlen_user(str) strnlen_user((str), 0x7ffffffe)
460
461#endif /* __ASSEMBLY__ */
462#endif /* __KERNEL__ */
463
464#endif /* _ARCH_POWERPC_UACCESS_H */