1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ARCH_POWERPC_UACCESS_H
3 #define _ARCH_POWERPC_UACCESS_H
4
5 #include <asm/ppc_asm.h>
6 #include <asm/processor.h>
7 #include <asm/page.h>
8 #include <asm/extable.h>
9 #include <asm/kup.h>
10
11 #ifdef __powerpc64__
12 /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */
13 #define TASK_SIZE_MAX TASK_SIZE_USER64
14 #else
15 #define TASK_SIZE_MAX TASK_SIZE
16 #endif
17
__access_ok(unsigned long addr,unsigned long size)18 static inline bool __access_ok(unsigned long addr, unsigned long size)
19 {
20 return addr < TASK_SIZE_MAX && size <= TASK_SIZE_MAX - addr;
21 }
22
23 #define access_ok(addr, size) \
24 (__chk_user_ptr(addr), \
25 __access_ok((unsigned long)(addr), (size)))
26
27 /*
28 * These are the main single-value transfer routines. They automatically
29 * use the right size if we just have the right pointer type.
30 *
31 * This gets kind of ugly. We want to return _two_ values in "get_user()"
32 * and yet we don't want to do any pointers, because that is too much
33 * of a performance impact. Thus we have a few rather ugly macros here,
34 * and hide all the ugliness from the user.
35 *
36 * The "__xxx" versions of the user access functions are versions that
37 * do not verify the address space, that must have been done previously
38 * with a separate "access_ok()" call (this is used when we do multiple
39 * accesses to the same area of user memory).
40 *
41 * As we use the same address space for kernel and user data on the
42 * PowerPC, we can just do these as direct assignments. (Of course, the
43 * exception handling means that it's no longer "just"...)
44 *
45 */
46 #define get_user(x, ptr) \
47 __get_user_check((x), (ptr), sizeof(*(ptr)))
48 #define put_user(x, ptr) \
49 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
50
51 #define __get_user(x, ptr) \
52 __get_user_nocheck((x), (ptr), sizeof(*(ptr)), true)
53 #define __put_user(x, ptr) \
54 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
55 #define __put_user_goto(x, ptr, label) \
56 __put_user_nocheck_goto((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), label)
57
58 #define __get_user_allowed(x, ptr) \
59 __get_user_nocheck((x), (ptr), sizeof(*(ptr)), false)
60
61 #define __get_user_inatomic(x, ptr) \
62 __get_user_nosleep((x), (ptr), sizeof(*(ptr)))
63 #define __put_user_inatomic(x, ptr) \
64 __put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
65
66 #ifdef CONFIG_PPC64
67
68 #define ___get_user_instr(gu_op, dest, ptr) \
69 ({ \
70 long __gui_ret = 0; \
71 unsigned long __gui_ptr = (unsigned long)ptr; \
72 struct ppc_inst __gui_inst; \
73 unsigned int __prefix, __suffix; \
74 __gui_ret = gu_op(__prefix, (unsigned int __user *)__gui_ptr); \
75 if (__gui_ret == 0) { \
76 if ((__prefix >> 26) == OP_PREFIX) { \
77 __gui_ret = gu_op(__suffix, \
78 (unsigned int __user *)__gui_ptr + 1); \
79 __gui_inst = ppc_inst_prefix(__prefix, \
80 __suffix); \
81 } else { \
82 __gui_inst = ppc_inst(__prefix); \
83 } \
84 if (__gui_ret == 0) \
85 (dest) = __gui_inst; \
86 } \
87 __gui_ret; \
88 })
89
90 #define get_user_instr(x, ptr) \
91 ___get_user_instr(get_user, x, ptr)
92
93 #define __get_user_instr(x, ptr) \
94 ___get_user_instr(__get_user, x, ptr)
95
96 #define __get_user_instr_inatomic(x, ptr) \
97 ___get_user_instr(__get_user_inatomic, x, ptr)
98
99 #else /* !CONFIG_PPC64 */
100 #define get_user_instr(x, ptr) \
101 get_user((x).val, (u32 __user *)(ptr))
102
103 #define __get_user_instr(x, ptr) \
104 __get_user_nocheck((x).val, (u32 __user *)(ptr), sizeof(u32), true)
105
106 #define __get_user_instr_inatomic(x, ptr) \
107 __get_user_nosleep((x).val, (u32 __user *)(ptr), sizeof(u32))
108
109 #endif /* CONFIG_PPC64 */
110
111 extern long __put_user_bad(void);
112
113 #define __put_user_size_allowed(x, ptr, size, retval) \
114 do { \
115 __label__ __pu_failed; \
116 \
117 retval = 0; \
118 __put_user_size_goto(x, ptr, size, __pu_failed); \
119 break; \
120 \
121 __pu_failed: \
122 retval = -EFAULT; \
123 } while (0)
124
125 #define __put_user_size(x, ptr, size, retval) \
126 do { \
127 allow_write_to_user(ptr, size); \
128 __put_user_size_allowed(x, ptr, size, retval); \
129 prevent_write_to_user(ptr, size); \
130 } while (0)
131
132 #define __put_user_nocheck(x, ptr, size) \
133 ({ \
134 long __pu_err; \
135 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
136 __typeof__(*(ptr)) __pu_val = (x); \
137 __typeof__(size) __pu_size = (size); \
138 \
139 if (!is_kernel_addr((unsigned long)__pu_addr)) \
140 might_fault(); \
141 __chk_user_ptr(__pu_addr); \
142 __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \
143 \
144 __pu_err; \
145 })
146
147 #define __put_user_check(x, ptr, size) \
148 ({ \
149 long __pu_err = -EFAULT; \
150 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
151 __typeof__(*(ptr)) __pu_val = (x); \
152 __typeof__(size) __pu_size = (size); \
153 \
154 might_fault(); \
155 if (access_ok(__pu_addr, __pu_size)) \
156 __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \
157 \
158 __pu_err; \
159 })
160
161 #define __put_user_nosleep(x, ptr, size) \
162 ({ \
163 long __pu_err; \
164 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
165 __typeof__(*(ptr)) __pu_val = (x); \
166 __typeof__(size) __pu_size = (size); \
167 \
168 __chk_user_ptr(__pu_addr); \
169 __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \
170 \
171 __pu_err; \
172 })
173
174
175 /*
176 * We don't tell gcc that we are accessing memory, but this is OK
177 * because we do not write to any memory gcc knows about, so there
178 * are no aliasing issues.
179 */
180 #define __put_user_asm_goto(x, addr, label, op) \
181 asm_volatile_goto( \
182 "1: " op "%U1%X1 %0,%1 # put_user\n" \
183 EX_TABLE(1b, %l2) \
184 : \
185 : "r" (x), "m"UPD_CONSTR (*addr) \
186 : \
187 : label)
188
189 #ifdef __powerpc64__
190 #define __put_user_asm2_goto(x, ptr, label) \
191 __put_user_asm_goto(x, ptr, label, "std")
192 #else /* __powerpc64__ */
193 #define __put_user_asm2_goto(x, addr, label) \
194 asm_volatile_goto( \
195 "1: stw%X1 %0, %1\n" \
196 "2: stw%X1 %L0, %L1\n" \
197 EX_TABLE(1b, %l2) \
198 EX_TABLE(2b, %l2) \
199 : \
200 : "r" (x), "m" (*addr) \
201 : \
202 : label)
203 #endif /* __powerpc64__ */
204
205 #define __put_user_size_goto(x, ptr, size, label) \
206 do { \
207 switch (size) { \
208 case 1: __put_user_asm_goto(x, ptr, label, "stb"); break; \
209 case 2: __put_user_asm_goto(x, ptr, label, "sth"); break; \
210 case 4: __put_user_asm_goto(x, ptr, label, "stw"); break; \
211 case 8: __put_user_asm2_goto(x, ptr, label); break; \
212 default: __put_user_bad(); \
213 } \
214 } while (0)
215
216 #define __put_user_nocheck_goto(x, ptr, size, label) \
217 do { \
218 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
219 if (!is_kernel_addr((unsigned long)__pu_addr)) \
220 might_fault(); \
221 __chk_user_ptr(ptr); \
222 __put_user_size_goto((x), __pu_addr, (size), label); \
223 } while (0)
224
225
226 extern long __get_user_bad(void);
227
228 /*
229 * This does an atomic 128 byte aligned load from userspace.
230 * Upto caller to do enable_kernel_vmx() before calling!
231 */
232 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \
233 __asm__ __volatile__( \
234 "1: lvx 0,0,%1 # get user\n" \
235 " stvx 0,0,%2 # put kernel\n" \
236 "2:\n" \
237 ".section .fixup,\"ax\"\n" \
238 "3: li %0,%3\n" \
239 " b 2b\n" \
240 ".previous\n" \
241 EX_TABLE(1b, 3b) \
242 : "=r" (err) \
243 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err))
244
245 #define __get_user_asm(x, addr, err, op) \
246 __asm__ __volatile__( \
247 "1: "op"%U2%X2 %1, %2 # get_user\n" \
248 "2:\n" \
249 ".section .fixup,\"ax\"\n" \
250 "3: li %0,%3\n" \
251 " li %1,0\n" \
252 " b 2b\n" \
253 ".previous\n" \
254 EX_TABLE(1b, 3b) \
255 : "=r" (err), "=r" (x) \
256 : "m"UPD_CONSTR (*addr), "i" (-EFAULT), "0" (err))
257
258 #ifdef __powerpc64__
259 #define __get_user_asm2(x, addr, err) \
260 __get_user_asm(x, addr, err, "ld")
261 #else /* __powerpc64__ */
262 #define __get_user_asm2(x, addr, err) \
263 __asm__ __volatile__( \
264 "1: lwz%X2 %1, %2\n" \
265 "2: lwz%X2 %L1, %L2\n" \
266 "3:\n" \
267 ".section .fixup,\"ax\"\n" \
268 "4: li %0,%3\n" \
269 " li %1,0\n" \
270 " li %1+1,0\n" \
271 " b 3b\n" \
272 ".previous\n" \
273 EX_TABLE(1b, 4b) \
274 EX_TABLE(2b, 4b) \
275 : "=r" (err), "=&r" (x) \
276 : "m" (*addr), "i" (-EFAULT), "0" (err))
277 #endif /* __powerpc64__ */
278
279 #define __get_user_size_allowed(x, ptr, size, retval) \
280 do { \
281 retval = 0; \
282 __chk_user_ptr(ptr); \
283 if (size > sizeof(x)) \
284 (x) = __get_user_bad(); \
285 switch (size) { \
286 case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; \
287 case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; \
288 case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \
289 case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \
290 default: (x) = __get_user_bad(); \
291 } \
292 } while (0)
293
294 #define __get_user_size(x, ptr, size, retval) \
295 do { \
296 allow_read_from_user(ptr, size); \
297 __get_user_size_allowed(x, ptr, size, retval); \
298 prevent_read_from_user(ptr, size); \
299 } while (0)
300
301 /*
302 * This is a type: either unsigned long, if the argument fits into
303 * that type, or otherwise unsigned long long.
304 */
305 #define __long_type(x) \
306 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
307
308 #define __get_user_nocheck(x, ptr, size, do_allow) \
309 ({ \
310 long __gu_err; \
311 __long_type(*(ptr)) __gu_val; \
312 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
313 __typeof__(size) __gu_size = (size); \
314 \
315 __chk_user_ptr(__gu_addr); \
316 if (!is_kernel_addr((unsigned long)__gu_addr)) \
317 might_fault(); \
318 barrier_nospec(); \
319 if (do_allow) \
320 __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \
321 else \
322 __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \
323 (x) = (__typeof__(*(ptr)))__gu_val; \
324 \
325 __gu_err; \
326 })
327
328 #define __get_user_check(x, ptr, size) \
329 ({ \
330 long __gu_err = -EFAULT; \
331 __long_type(*(ptr)) __gu_val = 0; \
332 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
333 __typeof__(size) __gu_size = (size); \
334 \
335 might_fault(); \
336 if (access_ok(__gu_addr, __gu_size)) { \
337 barrier_nospec(); \
338 __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \
339 } \
340 (x) = (__force __typeof__(*(ptr)))__gu_val; \
341 \
342 __gu_err; \
343 })
344
345 #define __get_user_nosleep(x, ptr, size) \
346 ({ \
347 long __gu_err; \
348 __long_type(*(ptr)) __gu_val; \
349 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
350 __typeof__(size) __gu_size = (size); \
351 \
352 __chk_user_ptr(__gu_addr); \
353 barrier_nospec(); \
354 __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \
355 (x) = (__force __typeof__(*(ptr)))__gu_val; \
356 \
357 __gu_err; \
358 })
359
360
361 /* more complex routines */
362
363 extern unsigned long __copy_tofrom_user(void __user *to,
364 const void __user *from, unsigned long size);
365
366 #ifdef CONFIG_ARCH_HAS_COPY_MC
367 unsigned long __must_check
368 copy_mc_generic(void *to, const void *from, unsigned long size);
369
370 static inline unsigned long __must_check
copy_mc_to_kernel(void * to,const void * from,unsigned long size)371 copy_mc_to_kernel(void *to, const void *from, unsigned long size)
372 {
373 return copy_mc_generic(to, from, size);
374 }
375 #define copy_mc_to_kernel copy_mc_to_kernel
376
377 static inline unsigned long __must_check
copy_mc_to_user(void __user * to,const void * from,unsigned long n)378 copy_mc_to_user(void __user *to, const void *from, unsigned long n)
379 {
380 if (likely(check_copy_size(from, n, true))) {
381 if (access_ok(to, n)) {
382 allow_write_to_user(to, n);
383 n = copy_mc_generic((void *)to, from, n);
384 prevent_write_to_user(to, n);
385 }
386 }
387
388 return n;
389 }
390 #endif
391
392 #ifdef __powerpc64__
393 static inline unsigned long
raw_copy_in_user(void __user * to,const void __user * from,unsigned long n)394 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
395 {
396 unsigned long ret;
397
398 barrier_nospec();
399 allow_read_write_user(to, from, n);
400 ret = __copy_tofrom_user(to, from, n);
401 prevent_read_write_user(to, from, n);
402 return ret;
403 }
404 #endif /* __powerpc64__ */
405
raw_copy_from_user(void * to,const void __user * from,unsigned long n)406 static inline unsigned long raw_copy_from_user(void *to,
407 const void __user *from, unsigned long n)
408 {
409 unsigned long ret;
410 if (__builtin_constant_p(n) && (n <= 8)) {
411 ret = 1;
412
413 switch (n) {
414 case 1:
415 barrier_nospec();
416 __get_user_size(*(u8 *)to, from, 1, ret);
417 break;
418 case 2:
419 barrier_nospec();
420 __get_user_size(*(u16 *)to, from, 2, ret);
421 break;
422 case 4:
423 barrier_nospec();
424 __get_user_size(*(u32 *)to, from, 4, ret);
425 break;
426 case 8:
427 barrier_nospec();
428 __get_user_size(*(u64 *)to, from, 8, ret);
429 break;
430 }
431 if (ret == 0)
432 return 0;
433 }
434
435 barrier_nospec();
436 allow_read_from_user(from, n);
437 ret = __copy_tofrom_user((__force void __user *)to, from, n);
438 prevent_read_from_user(from, n);
439 return ret;
440 }
441
442 static inline unsigned long
raw_copy_to_user_allowed(void __user * to,const void * from,unsigned long n)443 raw_copy_to_user_allowed(void __user *to, const void *from, unsigned long n)
444 {
445 if (__builtin_constant_p(n) && (n <= 8)) {
446 unsigned long ret = 1;
447
448 switch (n) {
449 case 1:
450 __put_user_size_allowed(*(u8 *)from, (u8 __user *)to, 1, ret);
451 break;
452 case 2:
453 __put_user_size_allowed(*(u16 *)from, (u16 __user *)to, 2, ret);
454 break;
455 case 4:
456 __put_user_size_allowed(*(u32 *)from, (u32 __user *)to, 4, ret);
457 break;
458 case 8:
459 __put_user_size_allowed(*(u64 *)from, (u64 __user *)to, 8, ret);
460 break;
461 }
462 if (ret == 0)
463 return 0;
464 }
465
466 return __copy_tofrom_user(to, (__force const void __user *)from, n);
467 }
468
469 static inline unsigned long
raw_copy_to_user(void __user * to,const void * from,unsigned long n)470 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
471 {
472 unsigned long ret;
473
474 allow_write_to_user(to, n);
475 ret = raw_copy_to_user_allowed(to, from, n);
476 prevent_write_to_user(to, n);
477 return ret;
478 }
479
480 unsigned long __arch_clear_user(void __user *addr, unsigned long size);
481
clear_user(void __user * addr,unsigned long size)482 static inline unsigned long clear_user(void __user *addr, unsigned long size)
483 {
484 unsigned long ret = size;
485 might_fault();
486 if (likely(access_ok(addr, size))) {
487 allow_write_to_user(addr, size);
488 ret = __arch_clear_user(addr, size);
489 prevent_write_to_user(addr, size);
490 }
491 return ret;
492 }
493
__clear_user(void __user * addr,unsigned long size)494 static inline unsigned long __clear_user(void __user *addr, unsigned long size)
495 {
496 return clear_user(addr, size);
497 }
498
499 extern long strncpy_from_user(char *dst, const char __user *src, long count);
500 extern __must_check long strnlen_user(const char __user *str, long n);
501
502 extern long __copy_from_user_flushcache(void *dst, const void __user *src,
503 unsigned size);
504 extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
505 size_t len);
506
user_access_begin(const void __user * ptr,size_t len)507 static __must_check inline bool user_access_begin(const void __user *ptr, size_t len)
508 {
509 if (unlikely(!access_ok(ptr, len)))
510 return false;
511 allow_read_write_user((void __user *)ptr, ptr, len);
512 return true;
513 }
514 #define user_access_begin user_access_begin
515 #define user_access_end prevent_current_access_user
516 #define user_access_save prevent_user_access_return
517 #define user_access_restore restore_user_access
518
519 static __must_check inline bool
user_read_access_begin(const void __user * ptr,size_t len)520 user_read_access_begin(const void __user *ptr, size_t len)
521 {
522 if (unlikely(!access_ok(ptr, len)))
523 return false;
524 allow_read_from_user(ptr, len);
525 return true;
526 }
527 #define user_read_access_begin user_read_access_begin
528 #define user_read_access_end prevent_current_read_from_user
529
530 static __must_check inline bool
user_write_access_begin(const void __user * ptr,size_t len)531 user_write_access_begin(const void __user *ptr, size_t len)
532 {
533 if (unlikely(!access_ok(ptr, len)))
534 return false;
535 allow_write_to_user((void __user *)ptr, len);
536 return true;
537 }
538 #define user_write_access_begin user_write_access_begin
539 #define user_write_access_end prevent_current_write_to_user
540
541 #define unsafe_op_wrap(op, err) do { if (unlikely(op)) goto err; } while (0)
542 #define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e)
543 #define unsafe_put_user(x, p, e) __put_user_goto(x, p, e)
544
545 #define unsafe_copy_to_user(d, s, l, e) \
546 do { \
547 u8 __user *_dst = (u8 __user *)(d); \
548 const u8 *_src = (const u8 *)(s); \
549 size_t _len = (l); \
550 int _i; \
551 \
552 for (_i = 0; _i < (_len & ~(sizeof(long) - 1)); _i += sizeof(long)) \
553 __put_user_goto(*(long*)(_src + _i), (long __user *)(_dst + _i), e);\
554 if (IS_ENABLED(CONFIG_PPC64) && (_len & 4)) { \
555 __put_user_goto(*(u32*)(_src + _i), (u32 __user *)(_dst + _i), e); \
556 _i += 4; \
557 } \
558 if (_len & 2) { \
559 __put_user_goto(*(u16*)(_src + _i), (u16 __user *)(_dst + _i), e); \
560 _i += 2; \
561 } \
562 if (_len & 1) \
563 __put_user_goto(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e);\
564 } while (0)
565
566 #define HAVE_GET_KERNEL_NOFAULT
567
568 #define __get_kernel_nofault(dst, src, type, err_label) \
569 do { \
570 int __kr_err; \
571 \
572 __get_user_size_allowed(*((type *)(dst)), (__force type __user *)(src),\
573 sizeof(type), __kr_err); \
574 if (unlikely(__kr_err)) \
575 goto err_label; \
576 } while (0)
577
578 #define __put_kernel_nofault(dst, src, type, err_label) \
579 __put_user_size_goto(*((type *)(src)), \
580 (__force type __user *)(dst), sizeof(type), err_label)
581
582 #endif /* _ARCH_POWERPC_UACCESS_H */
583
