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-rw-r--r--include/asm-powerpc/uaccess.h504
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diff --git a/include/asm-powerpc/uaccess.h b/include/asm-powerpc/uaccess.h
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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>
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
27#ifdef __powerpc64__
28#define KERNEL_DS MAKE_MM_SEG(0UL)
29#define USER_DS MAKE_MM_SEG(0xf000000000000000UL)
30#else
31#define KERNEL_DS MAKE_MM_SEG(~0UL)
32#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/*
43 * Use the alpha trick for checking ranges:
44 *
45 * Is a address valid? This does a straightforward calculation rather
46 * than tests.
47 *
48 * Address valid if:
49 * - "addr" doesn't have any high-bits set
50 * - AND "size" doesn't have any high-bits set
51 * - OR we are in kernel mode.
52 *
53 * We dont have to check for high bits in (addr+size) because the first
54 * two checks force the maximum result to be below the start of the
55 * kernel region.
56 */
57#define __access_ok(addr, size, segment) \
58 (((segment).seg & (addr | size )) == 0)
59
60#else
61
62#define __access_ok(addr, size, segment) \
63 (((addr) <= (segment).seg) && \
64 (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr)))))
65
66#endif
67
68#define access_ok(type, addr, size) \
69 (__chk_user_ptr(addr), \
70 __access_ok((__force unsigned long)(addr), (size), get_fs()))
71
72/*
73 * The exception table consists of pairs of addresses: the first is the
74 * address of an instruction that is allowed to fault, and the second is
75 * the address at which the program should continue. No registers are
76 * modified, so it is entirely up to the continuation code to figure out
77 * what to do.
78 *
79 * All the routines below use bits of fixup code that are out of line
80 * with the main instruction path. This means when everything is well,
81 * we don't even have to jump over them. Further, they do not intrude
82 * on our cache or tlb entries.
83 */
84
85struct exception_table_entry {
86 unsigned long insn;
87 unsigned long fixup;
88};
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 ugliness 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 * The "user64" versions of the user access functions are versions that
109 * allow access of 64-bit data. The "get_user" functions do not
110 * properly handle 64-bit data because the value gets down cast to a long.
111 * The "put_user" functions already handle 64-bit data properly but we add
112 * "user64" versions for completeness
113 */
114#define get_user(x, ptr) \
115 __get_user_check((x), (ptr), sizeof(*(ptr)))
116#define put_user(x, ptr) \
117 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
118
119#define __get_user(x, ptr) \
120 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
121#define __put_user(x, ptr) \
122 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
123#ifndef __powerpc64__
124#define __get_user64(x, ptr) \
125 __get_user64_nocheck((x), (ptr), sizeof(*(ptr)))
126#define __put_user64(x, ptr) __put_user(x, ptr)
127#endif
128
129#ifdef __powerpc64__
130#define __get_user_unaligned __get_user
131#define __put_user_unaligned __put_user
132#endif
133
134extern long __put_user_bad(void);
135
136#ifdef __powerpc64__
137#define __EX_TABLE_ALIGN "3"
138#define __EX_TABLE_TYPE "llong"
139#else
140#define __EX_TABLE_ALIGN "2"
141#define __EX_TABLE_TYPE "long"
142#endif
143
144/*
145 * We don't tell gcc that we are accessing memory, but this is OK
146 * because we do not write to any memory gcc knows about, so there
147 * are no aliasing issues.
148 */
149#define __put_user_asm(x, addr, err, op) \
150 __asm__ __volatile__( \
151 "1: " op " %1,0(%2) # put_user\n" \
152 "2:\n" \
153 ".section .fixup,\"ax\"\n" \
154 "3: li %0,%3\n" \
155 " b 2b\n" \
156 ".previous\n" \
157 ".section __ex_table,\"a\"\n" \
158 " .align " __EX_TABLE_ALIGN "\n" \
159 " ."__EX_TABLE_TYPE" 1b,3b\n" \
160 ".previous" \
161 : "=r" (err) \
162 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))
163
164#ifndef __powerpc64__
165#define __put_user_asm2(x, addr, err) \
166 __asm__ __volatile__( \
167 "1: stw %1,0(%2)\n" \
168 "2: stw %1+1,4(%2)\n" \
169 "3:\n" \
170 ".section .fixup,\"ax\"\n" \
171 "4: li %0,%3\n" \
172 " b 3b\n" \
173 ".previous\n" \
174 ".section __ex_table,\"a\"\n" \
175 " .align " __EX_TABLE_ALIGN "\n" \
176 " ." __EX_TABLE_TYPE " 1b,4b\n" \
177 " ." __EX_TABLE_TYPE " 2b,4b\n" \
178 ".previous" \
179 : "=r" (err) \
180 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err))
181#else /* __powerpc64__ */
182#define __put_user_asm2(x, ptr, retval) \
183 __put_user_asm(x, ptr, retval, "std")
184#endif /* __powerpc64__ */
185
186#define __put_user_size(x, ptr, size, retval) \
187do { \
188 retval = 0; \
189 switch (size) { \
190 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \
191 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \
192 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \
193 case 8: __put_user_asm2(x, ptr, retval); break; \
194 default: __put_user_bad(); \
195 } \
196} while (0)
197
198#define __put_user_nocheck(x, ptr, size) \
199({ \
200 long __pu_err; \
201 might_sleep(); \
202 __chk_user_ptr(ptr); \
203 __put_user_size((x), (ptr), (size), __pu_err); \
204 __pu_err; \
205})
206
207#define __put_user_check(x, ptr, size) \
208({ \
209 long __pu_err = -EFAULT; \
210 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
211 might_sleep(); \
212 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
213 __put_user_size((x), __pu_addr, (size), __pu_err); \
214 __pu_err; \
215})
216
217extern long __get_user_bad(void);
218
219#define __get_user_asm(x, addr, err, op) \
220 __asm__ __volatile__( \
221 "1: "op" %1,0(%2) # get_user\n" \
222 "2:\n" \
223 ".section .fixup,\"ax\"\n" \
224 "3: li %0,%3\n" \
225 " li %1,0\n" \
226 " b 2b\n" \
227 ".previous\n" \
228 ".section __ex_table,\"a\"\n" \
229 " .align "__EX_TABLE_ALIGN "\n" \
230 " ." __EX_TABLE_TYPE " 1b,3b\n" \
231 ".previous" \
232 : "=r" (err), "=r" (x) \
233 : "b" (addr), "i" (-EFAULT), "0" (err))
234
235#ifndef __powerpc64__
236#define __get_user_asm2(x, addr, err) \
237 __asm__ __volatile__( \
238 "1: lwz %1,0(%2)\n" \
239 "2: lwz %1+1,4(%2)\n" \
240 "3:\n" \
241 ".section .fixup,\"ax\"\n" \
242 "4: li %0,%3\n" \
243 " li %1,0\n" \
244 " li %1+1,0\n" \
245 " b 3b\n" \
246 ".previous\n" \
247 ".section __ex_table,\"a\"\n" \
248 " .align " __EX_TABLE_ALIGN "\n" \
249 " ." __EX_TABLE_TYPE " 1b,4b\n" \
250 " ." __EX_TABLE_TYPE " 2b,4b\n" \
251 ".previous" \
252 : "=r" (err), "=&r" (x) \
253 : "b" (addr), "i" (-EFAULT), "0" (err))
254#else
255#define __get_user_asm2(x, addr, err) \
256 __get_user_asm(x, addr, err, "ld")
257#endif /* __powerpc64__ */
258
259#define __get_user_size(x, ptr, size, retval) \
260do { \
261 retval = 0; \
262 __chk_user_ptr(ptr); \
263 if (size > sizeof(x)) \
264 (x) = __get_user_bad(); \
265 switch (size) { \
266 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \
267 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \
268 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \
269 case 8: __get_user_asm2(x, ptr, retval); break; \
270 default: (x) = __get_user_bad(); \
271 } \
272} while (0)
273
274#define __get_user_nocheck(x, ptr, size) \
275({ \
276 long __gu_err; \
277 unsigned long __gu_val; \
278 __chk_user_ptr(ptr); \
279 might_sleep(); \
280 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
281 (x) = (__typeof__(*(ptr)))__gu_val; \
282 __gu_err; \
283})
284
285#ifndef __powerpc64__
286#define __get_user64_nocheck(x, ptr, size) \
287({ \
288 long __gu_err; \
289 long long __gu_val; \
290 __chk_user_ptr(ptr); \
291 might_sleep(); \
292 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
293 (x) = (__typeof__(*(ptr)))__gu_val; \
294 __gu_err; \
295})
296#endif /* __powerpc64__ */
297
298#define __get_user_check(x, ptr, size) \
299({ \
300 long __gu_err = -EFAULT; \
301 unsigned long __gu_val = 0; \
302 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
303 might_sleep(); \
304 if (access_ok(VERIFY_READ, __gu_addr, (size))) \
305 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
306 (x) = (__typeof__(*(ptr)))__gu_val; \
307 __gu_err; \
308})
309
310/* more complex routines */
311
312extern unsigned long __copy_tofrom_user(void __user *to,
313 const void __user *from, unsigned long size);
314
315#ifndef __powerpc64__
316extern inline unsigned long
317copy_from_user(void *to, const void __user *from, unsigned long n)
318{
319 unsigned long over;
320
321 if (access_ok(VERIFY_READ, from, n))
322 return __copy_tofrom_user((__force void __user *)to, from, n);
323 if ((unsigned long)from < TASK_SIZE) {
324 over = (unsigned long)from + n - TASK_SIZE;
325 return __copy_tofrom_user((__force void __user *)to, from,
326 n - over) + over;
327 }
328 return n;
329}
330
331extern inline unsigned long
332copy_to_user(void __user *to, const void *from, unsigned long n)
333{
334 unsigned long over;
335
336 if (access_ok(VERIFY_WRITE, to, n))
337 return __copy_tofrom_user(to, (__force void __user *)from, n);
338 if ((unsigned long)to < TASK_SIZE) {
339 over = (unsigned long)to + n - TASK_SIZE;
340 return __copy_tofrom_user(to, (__force void __user *)from,
341 n - over) + over;
342 }
343 return n;
344}
345
346#else /* __powerpc64__ */
347
348static inline unsigned long
349__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
350{
351 if (__builtin_constant_p(n) && (n <= 8)) {
352 unsigned long ret;
353
354 switch (n) {
355 case 1:
356 __get_user_size(*(u8 *)to, from, 1, ret);
357 break;
358 case 2:
359 __get_user_size(*(u16 *)to, from, 2, ret);
360 break;
361 case 4:
362 __get_user_size(*(u32 *)to, from, 4, ret);
363 break;
364 case 8:
365 __get_user_size(*(u64 *)to, from, 8, ret);
366 break;
367 }
368 return (ret == -EFAULT) ? n : 0;
369 }
370 return __copy_tofrom_user((__force void __user *) to, from, n);
371}
372
373static inline unsigned long
374__copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
375{
376 if (__builtin_constant_p(n) && (n <= 8)) {
377 unsigned long ret;
378
379 switch (n) {
380 case 1:
381 __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret);
382 break;
383 case 2:
384 __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret);
385 break;
386 case 4:
387 __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret);
388 break;
389 case 8:
390 __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret);
391 break;
392 }
393 return (ret == -EFAULT) ? n : 0;
394 }
395 return __copy_tofrom_user(to, (__force const void __user *) from, n);
396}
397
398#endif /* __powerpc64__ */
399
400static inline unsigned long
401__copy_from_user(void *to, const void __user *from, unsigned long size)
402{
403 might_sleep();
404#ifndef __powerpc64__
405 return __copy_tofrom_user((__force void __user *)to, from, size);
406#else /* __powerpc64__ */
407 return __copy_from_user_inatomic(to, from, size);
408#endif /* __powerpc64__ */
409}
410
411static inline unsigned long
412__copy_to_user(void __user *to, const void *from, unsigned long size)
413{
414 might_sleep();
415#ifndef __powerpc64__
416 return __copy_tofrom_user(to, (__force void __user *)from, size);
417#else /* __powerpc64__ */
418 return __copy_to_user_inatomic(to, from, size);
419#endif /* __powerpc64__ */
420}
421
422#ifndef __powerpc64__
423#define __copy_to_user_inatomic __copy_to_user
424#define __copy_from_user_inatomic __copy_from_user
425#else /* __powerpc64__ */
426#define __copy_in_user(to, from, size) \
427 __copy_tofrom_user((to), (from), (size))
428
429extern unsigned long copy_from_user(void *to, const void __user *from,
430 unsigned long n);
431extern unsigned long copy_to_user(void __user *to, const void *from,
432 unsigned long n);
433extern unsigned long copy_in_user(void __user *to, const void __user *from,
434 unsigned long n);
435#endif /* __powerpc64__ */
436
437extern unsigned long __clear_user(void __user *addr, unsigned long size);
438
439static inline unsigned long clear_user(void __user *addr, unsigned long size)
440{
441 might_sleep();
442 if (likely(access_ok(VERIFY_WRITE, addr, size)))
443 return __clear_user(addr, size);
444#ifndef __powerpc64__
445 if ((unsigned long)addr < TASK_SIZE) {
446 unsigned long over = (unsigned long)addr + size - TASK_SIZE;
447 return __clear_user(addr, size - over) + over;
448 }
449#endif /* __powerpc64__ */
450 return size;
451}
452
453extern int __strncpy_from_user(char *dst, const char __user *src, long count);
454
455static inline long strncpy_from_user(char *dst, const char __user *src,
456 long count)
457{
458 might_sleep();
459 if (likely(access_ok(VERIFY_READ, src, 1)))
460 return __strncpy_from_user(dst, src, count);
461 return -EFAULT;
462}
463
464/*
465 * Return the size of a string (including the ending 0)
466 *
467 * Return 0 for error
468 */
469#ifndef __powerpc64__
470extern int __strnlen_user(const char __user *str, long len, unsigned long top);
471#else /* __powerpc64__ */
472extern int __strnlen_user(const char __user *str, long len);
473#endif /* __powerpc64__ */
474
475/*
476 * Returns the length of the string at str (including the null byte),
477 * or 0 if we hit a page we can't access,
478 * or something > len if we didn't find a null byte.
479 *
480 * The `top' parameter to __strnlen_user is to make sure that
481 * we can never overflow from the user area into kernel space.
482 */
483static inline int strnlen_user(const char __user *str, long len)
484{
485#ifndef __powerpc64__
486 unsigned long top = current->thread.fs.seg;
487
488 if ((unsigned long)str > top)
489 return 0;
490 return __strnlen_user(str, len, top);
491#else /* __powerpc64__ */
492 might_sleep();
493 if (likely(access_ok(VERIFY_READ, str, 1)))
494 return __strnlen_user(str, len);
495 return 0;
496#endif /* __powerpc64__ */
497}
498
499#define strlen_user(str) strnlen_user((str), 0x7ffffffe)
500
501#endif /* __ASSEMBLY__ */
502#endif /* __KERNEL__ */
503
504#endif /* _ARCH_POWERPC_UACCESS_H */
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