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 #define __put_user_asm_goto(x, addr, label, op) \
75 asm_volatile_goto( \
76 "1: " op "%U1%X1 %0,%1 # put_user\n" \
77 EX_TABLE(1b, %l2) \
78 : \
79 : "r" (x), "m<>" (*addr) \
80 : \
81 : label)
82
83 #ifdef __powerpc64__
84 #define __put_user_asm2_goto(x, ptr, label) \
85 __put_user_asm_goto(x, ptr, label, "std")
86 #else /* __powerpc64__ */
87 #define __put_user_asm2_goto(x, addr, label) \
88 asm_volatile_goto( \
89 "1: stw%X1 %0, %1\n" \
90 "2: stw%X1 %L0, %L1\n" \
91 EX_TABLE(1b, %l2) \
92 EX_TABLE(2b, %l2) \
93 : \
94 : "r" (x), "m" (*addr) \
95 : \
96 : label)
97 #endif /* __powerpc64__ */
98
99 #define __put_user_size_goto(x, ptr, size, label) \
100 do { \
101 __typeof__(*(ptr)) __user *__pus_addr = (ptr); \
102 \
103 switch (size) { \
104 case 1: __put_user_asm_goto(x, __pus_addr, label, "stb"); break; \
105 case 2: __put_user_asm_goto(x, __pus_addr, label, "sth"); break; \
106 case 4: __put_user_asm_goto(x, __pus_addr, label, "stw"); break; \
107 case 8: __put_user_asm2_goto(x, __pus_addr, label); break; \
108 default: BUILD_BUG(); \
109 } \
110 } while (0)
111
112 /*
113 * This does an atomic 128 byte aligned load from userspace.
114 * Upto caller to do enable_kernel_vmx() before calling!
115 */
116 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \
117 __asm__ __volatile__( \
118 ".machine push\n" \
119 ".machine altivec\n" \
120 "1: lvx 0,0,%1 # get user\n" \
121 " stvx 0,0,%2 # put kernel\n" \
122 ".machine pop\n" \
123 "2:\n" \
124 ".section .fixup,\"ax\"\n" \
125 "3: li %0,%3\n" \
126 " b 2b\n" \
127 ".previous\n" \
128 EX_TABLE(1b, 3b) \
129 : "=r" (err) \
130 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err))
131
132 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
133
134 #define __get_user_asm_goto(x, addr, label, op) \
135 asm_volatile_goto( \
136 "1: "op"%U1%X1 %0, %1 # get_user\n" \
137 EX_TABLE(1b, %l2) \
138 : "=r" (x) \
139 : "m<>" (*addr) \
140 : \
141 : label)
142
143 #ifdef __powerpc64__
144 #define __get_user_asm2_goto(x, addr, label) \
145 __get_user_asm_goto(x, addr, label, "ld")
146 #else /* __powerpc64__ */
147 #define __get_user_asm2_goto(x, addr, label) \
148 asm_volatile_goto( \
149 "1: lwz%X1 %0, %1\n" \
150 "2: lwz%X1 %L0, %L1\n" \
151 EX_TABLE(1b, %l2) \
152 EX_TABLE(2b, %l2) \
153 : "=&r" (x) \
154 : "m" (*addr) \
155 : \
156 : label)
157 #endif /* __powerpc64__ */
158
159 #define __get_user_size_goto(x, ptr, size, label) \
160 do { \
161 BUILD_BUG_ON(size > sizeof(x)); \
162 switch (size) { \
163 case 1: __get_user_asm_goto(x, (u8 __user *)ptr, label, "lbz"); break; \
164 case 2: __get_user_asm_goto(x, (u16 __user *)ptr, label, "lhz"); break; \
165 case 4: __get_user_asm_goto(x, (u32 __user *)ptr, label, "lwz"); break; \
166 case 8: __get_user_asm2_goto(x, (u64 __user *)ptr, label); break; \
167 default: x = 0; BUILD_BUG(); \
168 } \
169 } while (0)
170
171 #define __get_user_size_allowed(x, ptr, size, retval) \
172 do { \
173 __label__ __gus_failed; \
174 \
175 __get_user_size_goto(x, ptr, size, __gus_failed); \
176 retval = 0; \
177 break; \
178 __gus_failed: \
179 x = 0; \
180 retval = -EFAULT; \
181 } while (0)
182
183 #else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
184
185 #define __get_user_asm(x, addr, err, op) \
186 __asm__ __volatile__( \
187 "1: "op"%U2%X2 %1, %2 # get_user\n" \
188 "2:\n" \
189 ".section .fixup,\"ax\"\n" \
190 "3: li %0,%3\n" \
191 " li %1,0\n" \
192 " b 2b\n" \
193 ".previous\n" \
194 EX_TABLE(1b, 3b) \
195 : "=r" (err), "=r" (x) \
196 : "m<>" (*addr), "i" (-EFAULT), "0" (err))
197
198 #ifdef __powerpc64__
199 #define __get_user_asm2(x, addr, err) \
200 __get_user_asm(x, addr, err, "ld")
201 #else /* __powerpc64__ */
202 #define __get_user_asm2(x, addr, err) \
203 __asm__ __volatile__( \
204 "1: lwz%X2 %1, %2\n" \
205 "2: lwz%X2 %L1, %L2\n" \
206 "3:\n" \
207 ".section .fixup,\"ax\"\n" \
208 "4: li %0,%3\n" \
209 " li %1,0\n" \
210 " li %1+1,0\n" \
211 " b 3b\n" \
212 ".previous\n" \
213 EX_TABLE(1b, 4b) \
214 EX_TABLE(2b, 4b) \
215 : "=r" (err), "=&r" (x) \
216 : "m" (*addr), "i" (-EFAULT), "0" (err))
217 #endif /* __powerpc64__ */
218
219 #define __get_user_size_allowed(x, ptr, size, retval) \
220 do { \
221 retval = 0; \
222 BUILD_BUG_ON(size > sizeof(x)); \
223 switch (size) { \
224 case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; \
225 case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; \
226 case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \
227 case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \
228 default: x = 0; BUILD_BUG(); \
229 } \
230 } while (0)
231
232 #define __get_user_size_goto(x, ptr, size, label) \
233 do { \
234 long __gus_retval; \
235 \
236 __get_user_size_allowed(x, ptr, size, __gus_retval); \
237 if (__gus_retval) \
238 goto label; \
239 } while (0)
240
241 #endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
242
243 /*
244 * This is a type: either unsigned long, if the argument fits into
245 * that type, or otherwise unsigned long long.
246 */
247 #define __long_type(x) \
248 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
249
250 #define __get_user(x, ptr) \
251 ({ \
252 long __gu_err; \
253 __long_type(*(ptr)) __gu_val; \
254 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
255 __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr)); \
256 \
257 might_fault(); \
258 allow_read_from_user(__gu_addr, __gu_size); \
259 __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \
260 prevent_read_from_user(__gu_addr, __gu_size); \
261 (x) = (__typeof__(*(ptr)))__gu_val; \
262 \
263 __gu_err; \
264 })
265
266 #define get_user(x, ptr) \
267 ({ \
268 __typeof__(*(ptr)) __user *_gu_addr = (ptr); \
269 \
270 access_ok(_gu_addr, sizeof(*(ptr))) ? \
271 __get_user(x, _gu_addr) : \
272 ((x) = (__force __typeof__(*(ptr)))0, -EFAULT); \
273 })
274
275 /* more complex routines */
276
277 extern unsigned long __copy_tofrom_user(void __user *to,
278 const void __user *from, unsigned long size);
279
280 #ifdef __powerpc64__
281 static inline unsigned long
raw_copy_in_user(void __user * to,const void __user * from,unsigned long n)282 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
283 {
284 unsigned long ret;
285
286 allow_read_write_user(to, from, n);
287 ret = __copy_tofrom_user(to, from, n);
288 prevent_read_write_user(to, from, n);
289 return ret;
290 }
291 #endif /* __powerpc64__ */
292
raw_copy_from_user(void * to,const void __user * from,unsigned long n)293 static inline unsigned long raw_copy_from_user(void *to,
294 const void __user *from, unsigned long n)
295 {
296 unsigned long ret;
297
298 allow_read_from_user(from, n);
299 ret = __copy_tofrom_user((__force void __user *)to, from, n);
300 prevent_read_from_user(from, n);
301 return ret;
302 }
303
304 static inline unsigned long
raw_copy_to_user(void __user * to,const void * from,unsigned long n)305 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
306 {
307 unsigned long ret;
308
309 allow_write_to_user(to, n);
310 ret = __copy_tofrom_user(to, (__force const void __user *)from, n);
311 prevent_write_to_user(to, n);
312 return ret;
313 }
314
315 unsigned long __arch_clear_user(void __user *addr, unsigned long size);
316
__clear_user(void __user * addr,unsigned long size)317 static inline unsigned long __clear_user(void __user *addr, unsigned long size)
318 {
319 unsigned long ret;
320
321 might_fault();
322 allow_write_to_user(addr, size);
323 ret = __arch_clear_user(addr, size);
324 prevent_write_to_user(addr, size);
325 return ret;
326 }
327
clear_user(void __user * addr,unsigned long size)328 static inline unsigned long clear_user(void __user *addr, unsigned long size)
329 {
330 return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size;
331 }
332
333 extern long strncpy_from_user(char *dst, const char __user *src, long count);
334 extern __must_check long strnlen_user(const char __user *str, long n);
335
336 #ifdef CONFIG_ARCH_HAS_COPY_MC
337 unsigned long __must_check
338 copy_mc_generic(void *to, const void *from, unsigned long size);
339
340 static inline unsigned long __must_check
copy_mc_to_kernel(void * to,const void * from,unsigned long size)341 copy_mc_to_kernel(void *to, const void *from, unsigned long size)
342 {
343 return copy_mc_generic(to, from, size);
344 }
345 #define copy_mc_to_kernel copy_mc_to_kernel
346
347 static inline unsigned long __must_check
copy_mc_to_user(void __user * to,const void * from,unsigned long n)348 copy_mc_to_user(void __user *to, const void *from, unsigned long n)
349 {
350 if (check_copy_size(from, n, true)) {
351 if (access_ok(to, n)) {
352 allow_write_to_user(to, n);
353 n = copy_mc_generic((void *)to, from, n);
354 prevent_write_to_user(to, n);
355 }
356 }
357
358 return n;
359 }
360 #endif
361
362 extern long __copy_from_user_flushcache(void *dst, const void __user *src,
363 unsigned size);
364 extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
365 size_t len);
366
user_access_begin(const void __user * ptr,size_t len)367 static __must_check inline bool user_access_begin(const void __user *ptr, size_t len)
368 {
369 if (unlikely(!access_ok(ptr, len)))
370 return false;
371
372 might_fault();
373
374 allow_read_write_user((void __user *)ptr, ptr, len);
375 return true;
376 }
377 #define user_access_begin user_access_begin
378 #define user_access_end prevent_current_access_user
379 #define user_access_save prevent_user_access_return
380 #define user_access_restore restore_user_access
381
382 static __must_check inline bool
user_read_access_begin(const void __user * ptr,size_t len)383 user_read_access_begin(const void __user *ptr, size_t len)
384 {
385 if (unlikely(!access_ok(ptr, len)))
386 return false;
387
388 might_fault();
389
390 allow_read_from_user(ptr, len);
391 return true;
392 }
393 #define user_read_access_begin user_read_access_begin
394 #define user_read_access_end prevent_current_read_from_user
395
396 static __must_check inline bool
user_write_access_begin(const void __user * ptr,size_t len)397 user_write_access_begin(const void __user *ptr, size_t len)
398 {
399 if (unlikely(!access_ok(ptr, len)))
400 return false;
401
402 might_fault();
403
404 allow_write_to_user((void __user *)ptr, len);
405 return true;
406 }
407 #define user_write_access_begin user_write_access_begin
408 #define user_write_access_end prevent_current_write_to_user
409
410 #define unsafe_get_user(x, p, e) do { \
411 __long_type(*(p)) __gu_val; \
412 __typeof__(*(p)) __user *__gu_addr = (p); \
413 \
414 __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
415 (x) = (__typeof__(*(p)))__gu_val; \
416 } while (0)
417
418 #define unsafe_put_user(x, p, e) \
419 __put_user_size_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e)
420
421 #define unsafe_copy_from_user(d, s, l, e) \
422 do { \
423 u8 *_dst = (u8 *)(d); \
424 const u8 __user *_src = (const u8 __user *)(s); \
425 size_t _len = (l); \
426 int _i; \
427 \
428 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \
429 unsafe_get_user(*(u64 *)(_dst + _i), (u64 __user *)(_src + _i), e); \
430 if (_len & 4) { \
431 unsafe_get_user(*(u32 *)(_dst + _i), (u32 __user *)(_src + _i), e); \
432 _i += 4; \
433 } \
434 if (_len & 2) { \
435 unsafe_get_user(*(u16 *)(_dst + _i), (u16 __user *)(_src + _i), e); \
436 _i += 2; \
437 } \
438 if (_len & 1) \
439 unsafe_get_user(*(u8 *)(_dst + _i), (u8 __user *)(_src + _i), e); \
440 } while (0)
441
442 #define unsafe_copy_to_user(d, s, l, e) \
443 do { \
444 u8 __user *_dst = (u8 __user *)(d); \
445 const u8 *_src = (const u8 *)(s); \
446 size_t _len = (l); \
447 int _i; \
448 \
449 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \
450 unsafe_put_user(*(u64 *)(_src + _i), (u64 __user *)(_dst + _i), e); \
451 if (_len & 4) { \
452 unsafe_put_user(*(u32*)(_src + _i), (u32 __user *)(_dst + _i), e); \
453 _i += 4; \
454 } \
455 if (_len & 2) { \
456 unsafe_put_user(*(u16*)(_src + _i), (u16 __user *)(_dst + _i), e); \
457 _i += 2; \
458 } \
459 if (_len & 1) \
460 unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \
461 } while (0)
462
463 #define __get_kernel_nofault(dst, src, type, err_label) \
464 __get_user_size_goto(*((type *)(dst)), \
465 (__force type __user *)(src), sizeof(type), err_label)
466
467 #define __put_kernel_nofault(dst, src, type, err_label) \
468 __put_user_size_goto(*((type *)(src)), \
469 (__force type __user *)(dst), sizeof(type), err_label)
470
471 #endif /* _ARCH_POWERPC_UACCESS_H */
472