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