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 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__ */ 332 333 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 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); 356 357 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 } 367 368 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 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 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); 404 405 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 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 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