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), "0" (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 #define __get_user_asm2_goto(x, addr, label) \
185 __get_user_asm_goto(x, addr, label, "ld")
186 #else /* __powerpc64__ */
187 #define __get_user_asm2_goto(x, addr, label) \
188 asm_goto_output( \
189 "1: lwz%X1 %0, %1\n" \
190 "2: lwz%X1 %L0, %L1\n" \
191 EX_TABLE(1b, %l2) \
192 EX_TABLE(2b, %l2) \
193 : "=&r" (x) \
194 : "m" (*addr) \
195 : \
196 : label)
197 #endif /* __powerpc64__ */
198
199 #define __get_user_size_goto(x, ptr, size, label) \
200 do { \
201 BUILD_BUG_ON(size > sizeof(x)); \
202 switch (size) { \
203 case 1: __get_user_asm_goto(x, (u8 __user *)ptr, label, "lbz"); break; \
204 case 2: __get_user_asm_goto(x, (u16 __user *)ptr, label, "lhz"); break; \
205 case 4: __get_user_asm_goto(x, (u32 __user *)ptr, label, "lwz"); break; \
206 case 8: __get_user_asm2_goto(x, (u64 __user *)ptr, label); break; \
207 default: x = 0; BUILD_BUG(); \
208 } \
209 } while (0)
210
211 #define __get_user_size_allowed(x, ptr, size, retval) \
212 do { \
213 __label__ __gus_failed; \
214 \
215 __get_user_size_goto(x, ptr, size, __gus_failed); \
216 retval = 0; \
217 break; \
218 __gus_failed: \
219 x = 0; \
220 retval = -EFAULT; \
221 } while (0)
222
223 #else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
224
225 #define __get_user_asm(x, addr, err, op) \
226 __asm__ __volatile__( \
227 "1: "op"%U2%X2 %1, %2 # get_user\n" \
228 "2:\n" \
229 ".section .fixup,\"ax\"\n" \
230 "3: li %0,%3\n" \
231 " li %1,0\n" \
232 " b 2b\n" \
233 ".previous\n" \
234 EX_TABLE(1b, 3b) \
235 : "=r" (err), "=r" (x) \
236 : "m<>" (*addr), "i" (-EFAULT), "0" (err))
237
238 #ifdef __powerpc64__
239 #define __get_user_asm2(x, addr, err) \
240 __get_user_asm(x, addr, err, "ld")
241 #else /* __powerpc64__ */
242 #define __get_user_asm2(x, addr, err) \
243 __asm__ __volatile__( \
244 "1: lwz%X2 %1, %2\n" \
245 "2: lwz%X2 %L1, %L2\n" \
246 "3:\n" \
247 ".section .fixup,\"ax\"\n" \
248 "4: li %0,%3\n" \
249 " li %1,0\n" \
250 " li %1+1,0\n" \
251 " b 3b\n" \
252 ".previous\n" \
253 EX_TABLE(1b, 4b) \
254 EX_TABLE(2b, 4b) \
255 : "=r" (err), "=&r" (x) \
256 : "m" (*addr), "i" (-EFAULT), "0" (err))
257 #endif /* __powerpc64__ */
258
259 #define __get_user_size_allowed(x, ptr, size, retval) \
260 do { \
261 retval = 0; \
262 BUILD_BUG_ON(size > sizeof(x)); \
263 switch (size) { \
264 case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; \
265 case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; \
266 case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \
267 case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \
268 default: x = 0; BUILD_BUG(); \
269 } \
270 } while (0)
271
272 #define __get_user_size_goto(x, ptr, size, label) \
273 do { \
274 long __gus_retval; \
275 \
276 __get_user_size_allowed(x, ptr, size, __gus_retval); \
277 if (__gus_retval) \
278 goto label; \
279 } while (0)
280
281 #endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
282
283 /*
284 * This is a type: either unsigned long, if the argument fits into
285 * that type, or otherwise unsigned long long.
286 */
287 #define __long_type(x) \
288 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
289
290 #define __get_user(x, ptr) \
291 ({ \
292 long __gu_err; \
293 __long_type(*(ptr)) __gu_val; \
294 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
295 __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr)); \
296 \
297 might_fault(); \
298 allow_read_from_user(__gu_addr, __gu_size); \
299 __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \
300 prevent_read_from_user(__gu_addr, __gu_size); \
301 (x) = (__typeof__(*(ptr)))__gu_val; \
302 \
303 __gu_err; \
304 })
305
306 #define get_user(x, ptr) \
307 ({ \
308 __typeof__(*(ptr)) __user *_gu_addr = (ptr); \
309 \
310 access_ok(_gu_addr, sizeof(*(ptr))) ? \
311 __get_user(x, _gu_addr) : \
312 ((x) = (__force __typeof__(*(ptr)))0, -EFAULT); \
313 })
314
315 /* more complex routines */
316
317 extern unsigned long __copy_tofrom_user(void __user *to,
318 const void __user *from, unsigned long size);
319
320 #ifdef __powerpc64__
321 static inline unsigned long
raw_copy_in_user(void __user * to,const void __user * from,unsigned long n)322 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
323 {
324 unsigned long ret;
325
326 allow_read_write_user(to, from, n);
327 ret = __copy_tofrom_user(to, from, n);
328 prevent_read_write_user(to, from, n);
329 return ret;
330 }
331 #endif /* __powerpc64__ */
332
raw_copy_from_user(void * to,const void __user * from,unsigned long n)333 static inline unsigned long raw_copy_from_user(void *to,
334 const void __user *from, unsigned long n)
335 {
336 unsigned long ret;
337
338 allow_read_from_user(from, n);
339 ret = __copy_tofrom_user((__force void __user *)to, from, n);
340 prevent_read_from_user(from, n);
341 return ret;
342 }
343
344 static inline unsigned long
raw_copy_to_user(void __user * to,const void * from,unsigned long n)345 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
346 {
347 unsigned long ret;
348
349 allow_write_to_user(to, n);
350 ret = __copy_tofrom_user(to, (__force const void __user *)from, n);
351 prevent_write_to_user(to, n);
352 return ret;
353 }
354
355 unsigned long __arch_clear_user(void __user *addr, unsigned long size);
356
__clear_user(void __user * addr,unsigned long size)357 static inline unsigned long __clear_user(void __user *addr, unsigned long size)
358 {
359 unsigned long ret;
360
361 might_fault();
362 allow_write_to_user(addr, size);
363 ret = __arch_clear_user(addr, size);
364 prevent_write_to_user(addr, size);
365 return ret;
366 }
367
clear_user(void __user * addr,unsigned long size)368 static inline unsigned long clear_user(void __user *addr, unsigned long size)
369 {
370 return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size;
371 }
372
373 extern long strncpy_from_user(char *dst, const char __user *src, long count);
374 extern __must_check long strnlen_user(const char __user *str, long n);
375
376 #ifdef CONFIG_ARCH_HAS_COPY_MC
377 unsigned long __must_check
378 copy_mc_generic(void *to, const void *from, unsigned long size);
379
380 static inline unsigned long __must_check
copy_mc_to_kernel(void * to,const void * from,unsigned long size)381 copy_mc_to_kernel(void *to, const void *from, unsigned long size)
382 {
383 return copy_mc_generic(to, from, size);
384 }
385 #define copy_mc_to_kernel copy_mc_to_kernel
386
387 static inline unsigned long __must_check
copy_mc_to_user(void __user * to,const void * from,unsigned long n)388 copy_mc_to_user(void __user *to, const void *from, unsigned long n)
389 {
390 if (check_copy_size(from, n, true)) {
391 if (access_ok(to, n)) {
392 allow_write_to_user(to, n);
393 n = copy_mc_generic((void *)to, from, n);
394 prevent_write_to_user(to, n);
395 }
396 }
397
398 return n;
399 }
400 #endif
401
402 extern long __copy_from_user_flushcache(void *dst, const void __user *src,
403 unsigned size);
404
user_access_begin(const void __user * ptr,size_t len)405 static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len)
406 {
407 if (unlikely(!access_ok(ptr, len)))
408 return false;
409
410 might_fault();
411
412 allow_read_write_user((void __user *)ptr, ptr, len);
413 return true;
414 }
415 #define user_access_begin user_access_begin
416 #define user_access_end prevent_current_access_user
417 #define user_access_save prevent_user_access_return
418 #define user_access_restore restore_user_access
419
420 static __must_check __always_inline bool
user_read_access_begin(const void __user * ptr,size_t len)421 user_read_access_begin(const void __user *ptr, size_t len)
422 {
423 if (unlikely(!access_ok(ptr, len)))
424 return false;
425
426 might_fault();
427
428 allow_read_from_user(ptr, len);
429 return true;
430 }
431 #define user_read_access_begin user_read_access_begin
432 #define user_read_access_end prevent_current_read_from_user
433
434 static __must_check __always_inline bool
user_write_access_begin(const void __user * ptr,size_t len)435 user_write_access_begin(const void __user *ptr, size_t len)
436 {
437 if (unlikely(!access_ok(ptr, len)))
438 return false;
439
440 might_fault();
441
442 allow_write_to_user((void __user *)ptr, len);
443 return true;
444 }
445 #define user_write_access_begin user_write_access_begin
446 #define user_write_access_end prevent_current_write_to_user
447
448 #define unsafe_get_user(x, p, e) do { \
449 __long_type(*(p)) __gu_val; \
450 __typeof__(*(p)) __user *__gu_addr = (p); \
451 \
452 __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
453 (x) = (__typeof__(*(p)))__gu_val; \
454 } while (0)
455
456 #define unsafe_put_user(x, p, e) \
457 __put_user_size_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e)
458
459 #define unsafe_copy_from_user(d, s, l, e) \
460 do { \
461 u8 *_dst = (u8 *)(d); \
462 const u8 __user *_src = (const u8 __user *)(s); \
463 size_t _len = (l); \
464 int _i; \
465 \
466 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \
467 unsafe_get_user(*(u64 *)(_dst + _i), (u64 __user *)(_src + _i), e); \
468 if (_len & 4) { \
469 unsafe_get_user(*(u32 *)(_dst + _i), (u32 __user *)(_src + _i), e); \
470 _i += 4; \
471 } \
472 if (_len & 2) { \
473 unsafe_get_user(*(u16 *)(_dst + _i), (u16 __user *)(_src + _i), e); \
474 _i += 2; \
475 } \
476 if (_len & 1) \
477 unsafe_get_user(*(u8 *)(_dst + _i), (u8 __user *)(_src + _i), e); \
478 } while (0)
479
480 #define unsafe_copy_to_user(d, s, l, e) \
481 do { \
482 u8 __user *_dst = (u8 __user *)(d); \
483 const u8 *_src = (const u8 *)(s); \
484 size_t _len = (l); \
485 int _i; \
486 \
487 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \
488 unsafe_put_user(*(u64 *)(_src + _i), (u64 __user *)(_dst + _i), e); \
489 if (_len & 4) { \
490 unsafe_put_user(*(u32*)(_src + _i), (u32 __user *)(_dst + _i), e); \
491 _i += 4; \
492 } \
493 if (_len & 2) { \
494 unsafe_put_user(*(u16*)(_src + _i), (u16 __user *)(_dst + _i), e); \
495 _i += 2; \
496 } \
497 if (_len & 1) \
498 unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \
499 } while (0)
500
501 #define __get_kernel_nofault(dst, src, type, err_label) \
502 __get_user_size_goto(*((type *)(dst)), \
503 (__force type __user *)(src), sizeof(type), err_label)
504
505 #define __put_kernel_nofault(dst, src, type, err_label) \
506 __put_user_size_goto(*((type *)(src)), \
507 (__force type __user *)(dst), sizeof(type), err_label)
508
509 #endif /* _ARCH_POWERPC_UACCESS_H */
510