1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ARCH_POWERPC_UACCESS_H
3 #define _ARCH_POWERPC_UACCESS_H
4
5 #include <asm/processor.h>
6 #include <asm/page.h>
7 #include <asm/extable.h>
8 #include <asm/kup.h>
9
10 #ifdef __powerpc64__
11 /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */
12 #define TASK_SIZE_MAX TASK_SIZE_USER64
13 #endif
14
15 #include <asm-generic/access_ok.h>
16
17 /*
18 * These are the main single-value transfer routines. They automatically
19 * use the right size if we just have the right pointer type.
20 *
21 * This gets kind of ugly. We want to return _two_ values in "get_user()"
22 * and yet we don't want to do any pointers, because that is too much
23 * of a performance impact. Thus we have a few rather ugly macros here,
24 * and hide all the ugliness from the user.
25 *
26 * The "__xxx" versions of the user access functions are versions that
27 * do not verify the address space, that must have been done previously
28 * with a separate "access_ok()" call (this is used when we do multiple
29 * accesses to the same area of user memory).
30 *
31 * As we use the same address space for kernel and user data on the
32 * PowerPC, we can just do these as direct assignments. (Of course, the
33 * exception handling means that it's no longer "just"...)
34 *
35 */
36 #define __put_user(x, ptr) \
37 ({ \
38 long __pu_err; \
39 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
40 __typeof__(*(ptr)) __pu_val = (__typeof__(*(ptr)))(x); \
41 __typeof__(sizeof(*(ptr))) __pu_size = sizeof(*(ptr)); \
42 \
43 might_fault(); \
44 do { \
45 __label__ __pu_failed; \
46 \
47 allow_write_to_user(__pu_addr, __pu_size); \
48 __put_user_size_goto(__pu_val, __pu_addr, __pu_size, __pu_failed); \
49 prevent_write_to_user(__pu_addr, __pu_size); \
50 __pu_err = 0; \
51 break; \
52 \
53 __pu_failed: \
54 prevent_write_to_user(__pu_addr, __pu_size); \
55 __pu_err = -EFAULT; \
56 } while (0); \
57 \
58 __pu_err; \
59 })
60
61 #define put_user(x, ptr) \
62 ({ \
63 __typeof__(*(ptr)) __user *_pu_addr = (ptr); \
64 \
65 access_ok(_pu_addr, sizeof(*(ptr))) ? \
66 __put_user(x, _pu_addr) : -EFAULT; \
67 })
68
69 /*
70 * We don't tell gcc that we are accessing memory, but this is OK
71 * because we do not write to any memory gcc knows about, so there
72 * are no aliasing issues.
73 */
74 /* -mprefixed can generate offsets beyond range, fall back hack */
75 #ifdef CONFIG_PPC_KERNEL_PREFIXED
76 #define __put_user_asm_goto(x, addr, label, op) \
77 asm goto( \
78 "1: " op " %0,0(%1) # put_user\n" \
79 EX_TABLE(1b, %l2) \
80 : \
81 : "r" (x), "b" (addr) \
82 : \
83 : label)
84 #else
85 #define __put_user_asm_goto(x, addr, label, op) \
86 asm goto( \
87 "1: " op "%U1%X1 %0,%1 # put_user\n" \
88 EX_TABLE(1b, %l2) \
89 : \
90 : "r" (x), "m<>" (*addr) \
91 : \
92 : label)
93 #endif
94
95 #ifdef CONFIG_CC_IS_CLANG
96 #define DS_FORM_CONSTRAINT "Z<>"
97 #else
98 #define DS_FORM_CONSTRAINT "YZ<>"
99 #endif
100
101 #ifdef __powerpc64__
102 #ifdef CONFIG_PPC_KERNEL_PREFIXED
103 #define __put_user_asm2_goto(x, ptr, label) \
104 __put_user_asm_goto(x, ptr, label, "std")
105 #else
106 #define __put_user_asm2_goto(x, addr, label) \
107 asm goto ("1: std%U1%X1 %0,%1 # put_user\n" \
108 EX_TABLE(1b, %l2) \
109 : \
110 : "r" (x), DS_FORM_CONSTRAINT (*addr) \
111 : \
112 : label)
113 #endif // CONFIG_PPC_KERNEL_PREFIXED
114 #else /* __powerpc64__ */
115 #define __put_user_asm2_goto(x, addr, label) \
116 asm goto( \
117 "1: stw%X1 %0, %1\n" \
118 "2: stw%X1 %L0, %L1\n" \
119 EX_TABLE(1b, %l2) \
120 EX_TABLE(2b, %l2) \
121 : \
122 : "r" (x), "m" (*addr) \
123 : \
124 : label)
125 #endif /* __powerpc64__ */
126
127 #define __put_user_size_goto(x, ptr, size, label) \
128 do { \
129 __typeof__(*(ptr)) __user *__pus_addr = (ptr); \
130 \
131 switch (size) { \
132 case 1: __put_user_asm_goto(x, __pus_addr, label, "stb"); break; \
133 case 2: __put_user_asm_goto(x, __pus_addr, label, "sth"); break; \
134 case 4: __put_user_asm_goto(x, __pus_addr, label, "stw"); break; \
135 case 8: __put_user_asm2_goto(x, __pus_addr, label); break; \
136 default: BUILD_BUG(); \
137 } \
138 } while (0)
139
140 /*
141 * This does an atomic 128 byte aligned load from userspace.
142 * Upto caller to do enable_kernel_vmx() before calling!
143 */
144 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \
145 __asm__ __volatile__( \
146 ".machine push\n" \
147 ".machine altivec\n" \
148 "1: lvx 0,0,%1 # get user\n" \
149 " stvx 0,0,%2 # put kernel\n" \
150 ".machine pop\n" \
151 "2:\n" \
152 ".section .fixup,\"ax\"\n" \
153 "3: li %0,%3\n" \
154 " b 2b\n" \
155 ".previous\n" \
156 EX_TABLE(1b, 3b) \
157 : "=r" (err) \
158 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "" (err))
159
160 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
161
162 /* -mprefixed can generate offsets beyond range, fall back hack */
163 #ifdef CONFIG_PPC_KERNEL_PREFIXED
164 #define __get_user_asm_goto(x, addr, label, op) \
165 asm_goto_output( \
166 "1: "op" %0,0(%1) # get_user\n" \
167 EX_TABLE(1b, %l2) \
168 : "=r" (x) \
169 : "b" (addr) \
170 : \
171 : label)
172 #else
173 #define __get_user_asm_goto(x, addr, label, op) \
174 asm_goto_output( \
175 "1: "op"%U1%X1 %0, %1 # get_user\n" \
176 EX_TABLE(1b, %l2) \
177 : "=r" (x) \
178 : "m<>" (*addr) \
179 : \
180 : label)
181 #endif
182
183 #ifdef __powerpc64__
184 #ifdef CONFIG_PPC_KERNEL_PREFIXED
185 #define __get_user_asm2_goto(x, addr, label) \
186 __get_user_asm_goto(x, addr, label, "ld")
187 #else
188 #define __get_user_asm2_goto(x, addr, label) \
189 asm_goto_output( \
190 "1: ld%U1%X1 %0, %1 # get_user\n" \
191 EX_TABLE(1b, %l2) \
192 : "=r" (x) \
193 : DS_FORM_CONSTRAINT (*addr) \
194 : \
195 : label)
196 #endif // CONFIG_PPC_KERNEL_PREFIXED
197 #else /* __powerpc64__ */
198 #define __get_user_asm2_goto(x, addr, label) \
199 asm_goto_output( \
200 "1: lwz%X1 %0, %1\n" \
201 "2: lwz%X1 %L0, %L1\n" \
202 EX_TABLE(1b, %l2) \
203 EX_TABLE(2b, %l2) \
204 : "=&r" (x) \
205 : "m" (*addr) \
206 : \
207 : label)
208 #endif /* __powerpc64__ */
209
210 #define __get_user_size_goto(x, ptr, size, label) \
211 do { \
212 BUILD_BUG_ON(size > sizeof(x)); \
213 switch (size) { \
214 case 1: __get_user_asm_goto(x, (u8 __user *)ptr, label, "lbz"); break; \
215 case 2: __get_user_asm_goto(x, (u16 __user *)ptr, label, "lhz"); break; \
216 case 4: __get_user_asm_goto(x, (u32 __user *)ptr, label, "lwz"); break; \
217 case 8: __get_user_asm2_goto(x, (u64 __user *)ptr, label); break; \
218 default: x = 0; BUILD_BUG(); \
219 } \
220 } while (0)
221
222 #define __get_user_size_allowed(x, ptr, size, retval) \
223 do { \
224 __label__ __gus_failed; \
225 \
226 __get_user_size_goto(x, ptr, size, __gus_failed); \
227 retval = 0; \
228 break; \
229 __gus_failed: \
230 x = 0; \
231 retval = -EFAULT; \
232 } while (0)
233
234 #else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
235
236 #define __get_user_asm(x, addr, err, op) \
237 __asm__ __volatile__( \
238 "1: "op"%U2%X2 %1, %2 # get_user\n" \
239 "2:\n" \
240 ".section .fixup,\"ax\"\n" \
241 "3: li %0,%3\n" \
242 " li %1,0\n" \
243 " b 2b\n" \
244 ".previous\n" \
245 EX_TABLE(1b, 3b) \
246 : "=r" (err), "=r" (x) \
247 : "m<>" (*addr), "i" (-EFAULT), "" (err))
248
249 #ifdef __powerpc64__
250 #define __get_user_asm2(x, addr, err) \
251 __get_user_asm(x, addr, err, "ld")
252 #else /* __powerpc64__ */
253 #define __get_user_asm2(x, addr, err) \
254 __asm__ __volatile__( \
255 "1: lwz%X2 %1, %2\n" \
256 "2: lwz%X2 %L1, %L2\n" \
257 "3:\n" \
258 ".section .fixup,\"ax\"\n" \
259 "4: li %0,%3\n" \
260 " li %1,0\n" \
261 " li %1+1,0\n" \
262 " b 3b\n" \
263 ".previous\n" \
264 EX_TABLE(1b, 4b) \
265 EX_TABLE(2b, 4b) \
266 : "=r" (err), "=&r" (x) \
267 : "m" (*addr), "i" (-EFAULT), "" (err))
268 #endif /* __powerpc64__ */
269
270 #define __get_user_size_allowed(x, ptr, size, retval) \
271 do { \
272 retval = 0; \
273 BUILD_BUG_ON(size > sizeof(x)); \
274 switch (size) { \
275 case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; \
276 case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; \
277 case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \
278 case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \
279 default: x = 0; BUILD_BUG(); \
280 } \
281 } while (0)
282
283 #define __get_user_size_goto(x, ptr, size, label) \
284 do { \
285 long __gus_retval; \
286 \
287 __get_user_size_allowed(x, ptr, size, __gus_retval); \
288 if (__gus_retval) \
289 goto label; \
290 } while (0)
291
292 #endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
293
294 /*
295 * This is a type: either unsigned long, if the argument fits into
296 * that type, or otherwise unsigned long long.
297 */
298 #define __long_type(x) \
299 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
300
301 #define __get_user(x, ptr) \
302 ({ \
303 long __gu_err; \
304 __long_type(*(ptr)) __gu_val; \
305 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
306 __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr)); \
307 \
308 might_fault(); \
309 allow_read_from_user(__gu_addr, __gu_size); \
310 __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \
311 prevent_read_from_user(__gu_addr, __gu_size); \
312 (x) = (__typeof__(*(ptr)))__gu_val; \
313 \
314 __gu_err; \
315 })
316
317 #define get_user(x, ptr) \
318 ({ \
319 __typeof__(*(ptr)) __user *_gu_addr = (ptr); \
320 \
321 access_ok(_gu_addr, sizeof(*(ptr))) ? \
322 __get_user(x, _gu_addr) : \
323 ((x) = (__force __typeof__(*(ptr)))0, -EFAULT); \
324 })
325
326 /* more complex routines */
327
328 extern unsigned long __copy_tofrom_user(void __user *to,
329 const void __user *from, unsigned long size);
330
331 #ifdef __powerpc64__
332 static inline unsigned long
333 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
334 {
335 unsigned long ret;
336
337 allow_read_write_user(to, from, n);
338 ret = __copy_tofrom_user(to, from, n);
339 prevent_read_write_user(to, from, n);
340 return ret;
341 }
342 #endif /* __powerpc64__ */
343
344 static inline unsigned long raw_copy_from_user(void *to,
345 const void __user *from, unsigned long n)
346 {
347 unsigned long ret;
348
349 allow_read_from_user(from, n);
350 ret = __copy_tofrom_user((__force void __user *)to, from, n);
351 prevent_read_from_user(from, n);
352 return ret;
353 }
354
355 static inline unsigned long
356 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
357 {
358 unsigned long ret;
359
360 allow_write_to_user(to, n);
361 ret = __copy_tofrom_user(to, (__force const void __user *)from, n);
362 prevent_write_to_user(to, n);
363 return ret;
364 }
365
366 unsigned long __arch_clear_user(void __user *addr, unsigned long size);
367
368 static inline unsigned long __clear_user(void __user *addr, unsigned long size)
369 {
370 unsigned long ret;
371
372 might_fault();
373 allow_write_to_user(addr, size);
374 ret = __arch_clear_user(addr, size);
375 prevent_write_to_user(addr, size);
376 return ret;
377 }
378
379 static inline unsigned long clear_user(void __user *addr, unsigned long size)
380 {
381 return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size;
382 }
383
384 extern long strncpy_from_user(char *dst, const char __user *src, long count);
385 extern __must_check long strnlen_user(const char __user *str, long n);
386
387 #ifdef CONFIG_ARCH_HAS_COPY_MC
388 unsigned long __must_check
389 copy_mc_generic(void *to, const void *from, unsigned long size);
390
391 static inline unsigned long __must_check
392 copy_mc_to_kernel(void *to, const void *from, unsigned long size)
393 {
394 return copy_mc_generic(to, from, size);
395 }
396 #define copy_mc_to_kernel copy_mc_to_kernel
397
398 static inline unsigned long __must_check
399 copy_mc_to_user(void __user *to, const void *from, unsigned long n)
400 {
401 if (check_copy_size(from, n, true)) {
402 if (access_ok(to, n)) {
403 allow_write_to_user(to, n);
404 n = copy_mc_generic((void __force *)to, from, n);
405 prevent_write_to_user(to, n);
406 }
407 }
408
409 return n;
410 }
411 #endif
412
413 extern long __copy_from_user_flushcache(void *dst, const void __user *src,
414 unsigned size);
415
416 static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len)
417 {
418 if (unlikely(!access_ok(ptr, len)))
419 return false;
420
421 might_fault();
422
423 allow_read_write_user((void __user *)ptr, ptr, len);
424 return true;
425 }
426 #define user_access_begin user_access_begin
427 #define user_access_end prevent_current_access_user
428 #define user_access_save prevent_user_access_return
429 #define user_access_restore restore_user_access
430
431 static __must_check __always_inline bool
432 user_read_access_begin(const void __user *ptr, size_t len)
433 {
434 if (unlikely(!access_ok(ptr, len)))
435 return false;
436
437 might_fault();
438
439 allow_read_from_user(ptr, len);
440 return true;
441 }
442 #define user_read_access_begin user_read_access_begin
443 #define user_read_access_end prevent_current_read_from_user
444
445 static __must_check __always_inline bool
446 user_write_access_begin(const void __user *ptr, size_t len)
447 {
448 if (unlikely(!access_ok(ptr, len)))
449 return false;
450
451 might_fault();
452
453 allow_write_to_user((void __user *)ptr, len);
454 return true;
455 }
456 #define user_write_access_begin user_write_access_begin
457 #define user_write_access_end prevent_current_write_to_user
458
459 #define unsafe_get_user(x, p, e) do { \
460 __long_type(*(p)) __gu_val; \
461 __typeof__(*(p)) __user *__gu_addr = (p); \
462 \
463 __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
464 (x) = (__typeof__(*(p)))__gu_val; \
465 } while (0)
466
467 #define unsafe_put_user(x, p, e) \
468 __put_user_size_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e)
469
470 #define unsafe_copy_from_user(d, s, l, e) \
471 do { \
472 u8 *_dst = (u8 *)(d); \
473 const u8 __user *_src = (const u8 __user *)(s); \
474 size_t _len = (l); \
475 int _i; \
476 \
477 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \
478 unsafe_get_user(*(u64 *)(_dst + _i), (u64 __user *)(_src + _i), e); \
479 if (_len & 4) { \
480 unsafe_get_user(*(u32 *)(_dst + _i), (u32 __user *)(_src + _i), e); \
481 _i += 4; \
482 } \
483 if (_len & 2) { \
484 unsafe_get_user(*(u16 *)(_dst + _i), (u16 __user *)(_src + _i), e); \
485 _i += 2; \
486 } \
487 if (_len & 1) \
488 unsafe_get_user(*(u8 *)(_dst + _i), (u8 __user *)(_src + _i), e); \
489 } while (0)
490
491 #define unsafe_copy_to_user(d, s, l, e) \
492 do { \
493 u8 __user *_dst = (u8 __user *)(d); \
494 const u8 *_src = (const u8 *)(s); \
495 size_t _len = (l); \
496 int _i; \
497 \
498 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \
499 unsafe_put_user(*(u64 *)(_src + _i), (u64 __user *)(_dst + _i), e); \
500 if (_len & 4) { \
501 unsafe_put_user(*(u32*)(_src + _i), (u32 __user *)(_dst + _i), e); \
502 _i += 4; \
503 } \
504 if (_len & 2) { \
505 unsafe_put_user(*(u16*)(_src + _i), (u16 __user *)(_dst + _i), e); \
506 _i += 2; \
507 } \
508 if (_len & 1) \
509 unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \
510 } while (0)
511
512 #define __get_kernel_nofault(dst, src, type, err_label) \
513 __get_user_size_goto(*((type *)(dst)), \
514 (__force type __user *)(src), sizeof(type), err_label)
515
516 #define __put_kernel_nofault(dst, src, type, err_label) \
517 __put_user_size_goto(*((type *)(src)), \
518 (__force type __user *)(dst), sizeof(type), err_label)
519
520 #endif /* _ARCH_POWERPC_UACCESS_H */
521
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