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 __put_user(x, ptr) \
47 ({ \
48 long __pu_err; \
49 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
50 __typeof__(*(ptr)) __pu_val = (__typeof__(*(ptr)))(x); \
51 __typeof__(sizeof(*(ptr))) __pu_size = sizeof(*(ptr)); \
52 \
53 might_fault(); \
54 do { \
55 __label__ __pu_failed; \
56 \
57 allow_write_to_user(__pu_addr, __pu_size); \
58 __put_user_size_goto(__pu_val, __pu_addr, __pu_size, __pu_failed); \
59 prevent_write_to_user(__pu_addr, __pu_size); \
60 __pu_err = 0; \
61 break; \
62 \
63 __pu_failed: \
64 prevent_write_to_user(__pu_addr, __pu_size); \
65 __pu_err = -EFAULT; \
66 } while (0); \
67 \
68 __pu_err; \
69 })
70
71 #define put_user(x, ptr) \
72 ({ \
73 __typeof__(*(ptr)) __user *_pu_addr = (ptr); \
74 \
75 access_ok(_pu_addr, sizeof(*(ptr))) ? \
76 __put_user(x, _pu_addr) : -EFAULT; \
77 })
78
79 /*
80 * We don't tell gcc that we are accessing memory, but this is OK
81 * because we do not write to any memory gcc knows about, so there
82 * are no aliasing issues.
83 */
84 #define __put_user_asm_goto(x, addr, label, op) \
85 asm_volatile_goto( \
86 "1: " op "%U1%X1 %0,%1 # put_user\n" \
87 EX_TABLE(1b, %l2) \
88 : \
89 : "r" (x), "m"UPD_CONSTR (*addr) \
90 : \
91 : label)
92
93 #ifdef __powerpc64__
94 #define __put_user_asm2_goto(x, ptr, label) \
95 __put_user_asm_goto(x, ptr, label, "std")
96 #else /* __powerpc64__ */
97 #define __put_user_asm2_goto(x, addr, label) \
98 asm_volatile_goto( \
99 "1: stw%X1 %0, %1\n" \
100 "2: stw%X1 %L0, %L1\n" \
101 EX_TABLE(1b, %l2) \
102 EX_TABLE(2b, %l2) \
103 : \
104 : "r" (x), "m" (*addr) \
105 : \
106 : label)
107 #endif /* __powerpc64__ */
108
109 #define __put_user_size_goto(x, ptr, size, label) \
110 do { \
111 __typeof__(*(ptr)) __user *__pus_addr = (ptr); \
112 \
113 switch (size) { \
114 case 1: __put_user_asm_goto(x, __pus_addr, label, "stb"); break; \
115 case 2: __put_user_asm_goto(x, __pus_addr, label, "sth"); break; \
116 case 4: __put_user_asm_goto(x, __pus_addr, label, "stw"); break; \
117 case 8: __put_user_asm2_goto(x, __pus_addr, label); break; \
118 default: BUILD_BUG(); \
119 } \
120 } while (0)
121
122 /*
123 * This does an atomic 128 byte aligned load from userspace.
124 * Upto caller to do enable_kernel_vmx() before calling!
125 */
126 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \
127 __asm__ __volatile__( \
128 ".machine push\n" \
129 ".machine altivec\n" \
130 "1: lvx 0,0,%1 # get user\n" \
131 " stvx 0,0,%2 # put kernel\n" \
132 ".machine pop\n" \
133 "2:\n" \
134 ".section .fixup,\"ax\"\n" \
135 "3: li %0,%3\n" \
136 " b 2b\n" \
137 ".previous\n" \
138 EX_TABLE(1b, 3b) \
139 : "=r" (err) \
140 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err))
141
142 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
143
144 #define __get_user_asm_goto(x, addr, label, op) \
145 asm_volatile_goto( \
146 "1: "op"%U1%X1 %0, %1 # get_user\n" \
147 EX_TABLE(1b, %l2) \
148 : "=r" (x) \
149 : "m"UPD_CONSTR (*addr) \
150 : \
151 : label)
152
153 #ifdef __powerpc64__
154 #define __get_user_asm2_goto(x, addr, label) \
155 __get_user_asm_goto(x, addr, label, "ld")
156 #else /* __powerpc64__ */
157 #define __get_user_asm2_goto(x, addr, label) \
158 asm_volatile_goto( \
159 "1: lwz%X1 %0, %1\n" \
160 "2: lwz%X1 %L0, %L1\n" \
161 EX_TABLE(1b, %l2) \
162 EX_TABLE(2b, %l2) \
163 : "=&r" (x) \
164 : "m" (*addr) \
165 : \
166 : label)
167 #endif /* __powerpc64__ */
168
169 #define __get_user_size_goto(x, ptr, size, label) \
170 do { \
171 BUILD_BUG_ON(size > sizeof(x)); \
172 switch (size) { \
173 case 1: __get_user_asm_goto(x, (u8 __user *)ptr, label, "lbz"); break; \
174 case 2: __get_user_asm_goto(x, (u16 __user *)ptr, label, "lhz"); break; \
175 case 4: __get_user_asm_goto(x, (u32 __user *)ptr, label, "lwz"); break; \
176 case 8: __get_user_asm2_goto(x, (u64 __user *)ptr, label); break; \
177 default: x = 0; BUILD_BUG(); \
178 } \
179 } while (0)
180
181 #define __get_user_size_allowed(x, ptr, size, retval) \
182 do { \
183 __label__ __gus_failed; \
184 \
185 __get_user_size_goto(x, ptr, size, __gus_failed); \
186 retval = 0; \
187 break; \
188 __gus_failed: \
189 x = 0; \
190 retval = -EFAULT; \
191 } while (0)
192
193 #else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
194
195 #define __get_user_asm(x, addr, err, op) \
196 __asm__ __volatile__( \
197 "1: "op"%U2%X2 %1, %2 # get_user\n" \
198 "2:\n" \
199 ".section .fixup,\"ax\"\n" \
200 "3: li %0,%3\n" \
201 " li %1,0\n" \
202 " b 2b\n" \
203 ".previous\n" \
204 EX_TABLE(1b, 3b) \
205 : "=r" (err), "=r" (x) \
206 : "m"UPD_CONSTR (*addr), "i" (-EFAULT), "0" (err))
207
208 #ifdef __powerpc64__
209 #define __get_user_asm2(x, addr, err) \
210 __get_user_asm(x, addr, err, "ld")
211 #else /* __powerpc64__ */
212 #define __get_user_asm2(x, addr, err) \
213 __asm__ __volatile__( \
214 "1: lwz%X2 %1, %2\n" \
215 "2: lwz%X2 %L1, %L2\n" \
216 "3:\n" \
217 ".section .fixup,\"ax\"\n" \
218 "4: li %0,%3\n" \
219 " li %1,0\n" \
220 " li %1+1,0\n" \
221 " b 3b\n" \
222 ".previous\n" \
223 EX_TABLE(1b, 4b) \
224 EX_TABLE(2b, 4b) \
225 : "=r" (err), "=&r" (x) \
226 : "m" (*addr), "i" (-EFAULT), "0" (err))
227 #endif /* __powerpc64__ */
228
229 #define __get_user_size_allowed(x, ptr, size, retval) \
230 do { \
231 retval = 0; \
232 BUILD_BUG_ON(size > sizeof(x)); \
233 switch (size) { \
234 case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; \
235 case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; \
236 case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \
237 case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \
238 default: x = 0; BUILD_BUG(); \
239 } \
240 } while (0)
241
242 #define __get_user_size_goto(x, ptr, size, label) \
243 do { \
244 long __gus_retval; \
245 \
246 __get_user_size_allowed(x, ptr, size, __gus_retval); \
247 if (__gus_retval) \
248 goto label; \
249 } while (0)
250
251 #endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */
252
253 /*
254 * This is a type: either unsigned long, if the argument fits into
255 * that type, or otherwise unsigned long long.
256 */
257 #define __long_type(x) \
258 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
259
260 #define __get_user(x, ptr) \
261 ({ \
262 long __gu_err; \
263 __long_type(*(ptr)) __gu_val; \
264 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
265 __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr)); \
266 \
267 might_fault(); \
268 allow_read_from_user(__gu_addr, __gu_size); \
269 __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \
270 prevent_read_from_user(__gu_addr, __gu_size); \
271 (x) = (__typeof__(*(ptr)))__gu_val; \
272 \
273 __gu_err; \
274 })
275
276 #define get_user(x, ptr) \
277 ({ \
278 __typeof__(*(ptr)) __user *_gu_addr = (ptr); \
279 \
280 access_ok(_gu_addr, sizeof(*(ptr))) ? \
281 __get_user(x, _gu_addr) : \
282 ((x) = (__force __typeof__(*(ptr)))0, -EFAULT); \
283 })
284
285 /* more complex routines */
286
287 extern unsigned long __copy_tofrom_user(void __user *to,
288 const void __user *from, unsigned long size);
289
290 #ifdef __powerpc64__
291 static inline unsigned long
raw_copy_in_user(void __user * to,const void __user * from,unsigned long n)292 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
293 {
294 unsigned long ret;
295
296 allow_read_write_user(to, from, n);
297 ret = __copy_tofrom_user(to, from, n);
298 prevent_read_write_user(to, from, n);
299 return ret;
300 }
301 #endif /* __powerpc64__ */
302
raw_copy_from_user(void * to,const void __user * from,unsigned long n)303 static inline unsigned long raw_copy_from_user(void *to,
304 const void __user *from, unsigned long n)
305 {
306 unsigned long ret;
307
308 allow_read_from_user(from, n);
309 ret = __copy_tofrom_user((__force void __user *)to, from, n);
310 prevent_read_from_user(from, n);
311 return ret;
312 }
313
314 static inline unsigned long
raw_copy_to_user(void __user * to,const void * from,unsigned long n)315 raw_copy_to_user(void __user *to, const void *from, unsigned long n)
316 {
317 unsigned long ret;
318
319 allow_write_to_user(to, n);
320 ret = __copy_tofrom_user(to, (__force const void __user *)from, n);
321 prevent_write_to_user(to, n);
322 return ret;
323 }
324
325 unsigned long __arch_clear_user(void __user *addr, unsigned long size);
326
__clear_user(void __user * addr,unsigned long size)327 static inline unsigned long __clear_user(void __user *addr, unsigned long size)
328 {
329 unsigned long ret;
330
331 might_fault();
332 allow_write_to_user(addr, size);
333 ret = __arch_clear_user(addr, size);
334 prevent_write_to_user(addr, size);
335 return ret;
336 }
337
clear_user(void __user * addr,unsigned long size)338 static inline unsigned long clear_user(void __user *addr, unsigned long size)
339 {
340 return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size;
341 }
342
343 extern long strncpy_from_user(char *dst, const char __user *src, long count);
344 extern __must_check long strnlen_user(const char __user *str, long n);
345
346 #ifdef CONFIG_ARCH_HAS_COPY_MC
347 unsigned long __must_check
348 copy_mc_generic(void *to, const void *from, unsigned long size);
349
350 static inline unsigned long __must_check
copy_mc_to_kernel(void * to,const void * from,unsigned long size)351 copy_mc_to_kernel(void *to, const void *from, unsigned long size)
352 {
353 return copy_mc_generic(to, from, size);
354 }
355 #define copy_mc_to_kernel copy_mc_to_kernel
356
357 static inline unsigned long __must_check
copy_mc_to_user(void __user * to,const void * from,unsigned long n)358 copy_mc_to_user(void __user *to, const void *from, unsigned long n)
359 {
360 if (likely(check_copy_size(from, n, true))) {
361 if (access_ok(to, n)) {
362 allow_write_to_user(to, n);
363 n = copy_mc_generic((void *)to, from, n);
364 prevent_write_to_user(to, n);
365 }
366 }
367
368 return n;
369 }
370 #endif
371
372 extern long __copy_from_user_flushcache(void *dst, const void __user *src,
373 unsigned size);
374 extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
375 size_t len);
376
user_access_begin(const void __user * ptr,size_t len)377 static __must_check inline bool user_access_begin(const void __user *ptr, size_t len)
378 {
379 if (unlikely(!access_ok(ptr, len)))
380 return false;
381
382 might_fault();
383
384 allow_read_write_user((void __user *)ptr, ptr, len);
385 return true;
386 }
387 #define user_access_begin user_access_begin
388 #define user_access_end prevent_current_access_user
389 #define user_access_save prevent_user_access_return
390 #define user_access_restore restore_user_access
391
392 static __must_check inline bool
user_read_access_begin(const void __user * ptr,size_t len)393 user_read_access_begin(const void __user *ptr, size_t len)
394 {
395 if (unlikely(!access_ok(ptr, len)))
396 return false;
397
398 might_fault();
399
400 allow_read_from_user(ptr, len);
401 return true;
402 }
403 #define user_read_access_begin user_read_access_begin
404 #define user_read_access_end prevent_current_read_from_user
405
406 static __must_check inline bool
user_write_access_begin(const void __user * ptr,size_t len)407 user_write_access_begin(const void __user *ptr, size_t len)
408 {
409 if (unlikely(!access_ok(ptr, len)))
410 return false;
411
412 might_fault();
413
414 allow_write_to_user((void __user *)ptr, len);
415 return true;
416 }
417 #define user_write_access_begin user_write_access_begin
418 #define user_write_access_end prevent_current_write_to_user
419
420 #define unsafe_get_user(x, p, e) do { \
421 __long_type(*(p)) __gu_val; \
422 __typeof__(*(p)) __user *__gu_addr = (p); \
423 \
424 __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
425 (x) = (__typeof__(*(p)))__gu_val; \
426 } while (0)
427
428 #define unsafe_put_user(x, p, e) \
429 __put_user_size_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e)
430
431 #define unsafe_copy_from_user(d, s, l, e) \
432 do { \
433 u8 *_dst = (u8 *)(d); \
434 const u8 __user *_src = (const u8 __user *)(s); \
435 size_t _len = (l); \
436 int _i; \
437 \
438 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \
439 unsafe_get_user(*(u64 *)(_dst + _i), (u64 __user *)(_src + _i), e); \
440 if (_len & 4) { \
441 unsafe_get_user(*(u32 *)(_dst + _i), (u32 __user *)(_src + _i), e); \
442 _i += 4; \
443 } \
444 if (_len & 2) { \
445 unsafe_get_user(*(u16 *)(_dst + _i), (u16 __user *)(_src + _i), e); \
446 _i += 2; \
447 } \
448 if (_len & 1) \
449 unsafe_get_user(*(u8 *)(_dst + _i), (u8 __user *)(_src + _i), e); \
450 } while (0)
451
452 #define unsafe_copy_to_user(d, s, l, e) \
453 do { \
454 u8 __user *_dst = (u8 __user *)(d); \
455 const u8 *_src = (const u8 *)(s); \
456 size_t _len = (l); \
457 int _i; \
458 \
459 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \
460 unsafe_put_user(*(u64 *)(_src + _i), (u64 __user *)(_dst + _i), e); \
461 if (_len & 4) { \
462 unsafe_put_user(*(u32*)(_src + _i), (u32 __user *)(_dst + _i), e); \
463 _i += 4; \
464 } \
465 if (_len & 2) { \
466 unsafe_put_user(*(u16*)(_src + _i), (u16 __user *)(_dst + _i), e); \
467 _i += 2; \
468 } \
469 if (_len & 1) \
470 unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \
471 } while (0)
472
473 #define HAVE_GET_KERNEL_NOFAULT
474
475 #define __get_kernel_nofault(dst, src, type, err_label) \
476 __get_user_size_goto(*((type *)(dst)), \
477 (__force type __user *)(src), sizeof(type), err_label)
478
479 #define __put_kernel_nofault(dst, src, type, err_label) \
480 __put_user_size_goto(*((type *)(src)), \
481 (__force type __user *)(dst), sizeof(type), err_label)
482
483 #endif /* _ARCH_POWERPC_UACCESS_H */
484