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 #ifdef CONFIG_PPC_KERNEL_PREFIXED 185 #define __get_user_asm2_goto(x, addr, label) \ 186 __get_user_asm_goto(x, addr, label, "ld") 187 #else 188 #define __get_user_asm2_goto(x, addr, label) \ 189 asm_goto_output( \ 190 "1: ld%U1%X1 %0, %1 # get_user\n" \ 191 EX_TABLE(1b, %l2) \ 192 : "=r" (x) \ 193 : DS_FORM_CONSTRAINT (*addr) \ 194 : \ 195 : label) 196 #endif // CONFIG_PPC_KERNEL_PREFIXED 197 #else /* __powerpc64__ */ 198 #define __get_user_asm2_goto(x, addr, label) \ 199 asm_goto_output( \ 200 "1: lwz%X1 %0, %1\n" \ 201 "2: lwz%X1 %L0, %L1\n" \ 202 EX_TABLE(1b, %l2) \ 203 EX_TABLE(2b, %l2) \ 204 : "=&r" (x) \ 205 : "m" (*addr) \ 206 : \ 207 : label) 208 #endif /* __powerpc64__ */ 209 210 #define __get_user_size_goto(x, ptr, size, label) \ 211 do { \ 212 BUILD_BUG_ON(size > sizeof(x)); \ 213 switch (size) { \ 214 case 1: __get_user_asm_goto(x, (u8 __user *)ptr, label, "lbz"); break; \ 215 case 2: __get_user_asm_goto(x, (u16 __user *)ptr, label, "lhz"); break; \ 216 case 4: __get_user_asm_goto(x, (u32 __user *)ptr, label, "lwz"); break; \ 217 case 8: __get_user_asm2_goto(x, (u64 __user *)ptr, label); break; \ 218 default: x = 0; BUILD_BUG(); \ 219 } \ 220 } while (0) 221 222 #define __get_user_size_allowed(x, ptr, size, retval) \ 223 do { \ 224 __label__ __gus_failed; \ 225 \ 226 __get_user_size_goto(x, ptr, size, __gus_failed); \ 227 retval = 0; \ 228 break; \ 229 __gus_failed: \ 230 x = 0; \ 231 retval = -EFAULT; \ 232 } while (0) 233 234 #else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ 235 236 #define __get_user_asm(x, addr, err, op) \ 237 __asm__ __volatile__( \ 238 "1: "op"%U2%X2 %1, %2 # get_user\n" \ 239 "2:\n" \ 240 ".section .fixup,\"ax\"\n" \ 241 "3: li %0,%3\n" \ 242 " li %1,0\n" \ 243 " b 2b\n" \ 244 ".previous\n" \ 245 EX_TABLE(1b, 3b) \ 246 : "=r" (err), "=r" (x) \ 247 : "m<>" (*addr), "i" (-EFAULT), "0" (err)) 248 249 #ifdef __powerpc64__ 250 #define __get_user_asm2(x, addr, err) \ 251 __get_user_asm(x, addr, err, "ld") 252 #else /* __powerpc64__ */ 253 #define __get_user_asm2(x, addr, err) \ 254 __asm__ __volatile__( \ 255 "1: lwz%X2 %1, %2\n" \ 256 "2: lwz%X2 %L1, %L2\n" \ 257 "3:\n" \ 258 ".section .fixup,\"ax\"\n" \ 259 "4: li %0,%3\n" \ 260 " li %1,0\n" \ 261 " li %1+1,0\n" \ 262 " b 3b\n" \ 263 ".previous\n" \ 264 EX_TABLE(1b, 4b) \ 265 EX_TABLE(2b, 4b) \ 266 : "=r" (err), "=&r" (x) \ 267 : "m" (*addr), "i" (-EFAULT), "0" (err)) 268 #endif /* __powerpc64__ */ 269 270 #define __get_user_size_allowed(x, ptr, size, retval) \ 271 do { \ 272 retval = 0; \ 273 BUILD_BUG_ON(size > sizeof(x)); \ 274 switch (size) { \ 275 case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; \ 276 case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; \ 277 case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \ 278 case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \ 279 default: x = 0; BUILD_BUG(); \ 280 } \ 281 } while (0) 282 283 #define __get_user_size_goto(x, ptr, size, label) \ 284 do { \ 285 long __gus_retval; \ 286 \ 287 __get_user_size_allowed(x, ptr, size, __gus_retval); \ 288 if (__gus_retval) \ 289 goto label; \ 290 } while (0) 291 292 #endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ 293 294 /* 295 * This is a type: either unsigned long, if the argument fits into 296 * that type, or otherwise unsigned long long. 297 */ 298 #define __long_type(x) \ 299 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) 300 301 #define __get_user(x, ptr) \ 302 ({ \ 303 long __gu_err; \ 304 __long_type(*(ptr)) __gu_val; \ 305 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 306 __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr)); \ 307 \ 308 might_fault(); \ 309 allow_read_from_user(__gu_addr, __gu_size); \ 310 __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \ 311 prevent_read_from_user(__gu_addr, __gu_size); \ 312 (x) = (__typeof__(*(ptr)))__gu_val; \ 313 \ 314 __gu_err; \ 315 }) 316 317 #define get_user(x, ptr) \ 318 ({ \ 319 __typeof__(*(ptr)) __user *_gu_addr = (ptr); \ 320 \ 321 access_ok(_gu_addr, sizeof(*(ptr))) ? \ 322 __get_user(x, _gu_addr) : \ 323 ((x) = (__force __typeof__(*(ptr)))0, -EFAULT); \ 324 }) 325 326 /* more complex routines */ 327 328 extern unsigned long __copy_tofrom_user(void __user *to, 329 const void __user *from, unsigned long size); 330 331 #ifdef __powerpc64__ 332 static inline unsigned long 333 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 334 { 335 unsigned long ret; 336 337 allow_read_write_user(to, from, n); 338 ret = __copy_tofrom_user(to, from, n); 339 prevent_read_write_user(to, from, n); 340 return ret; 341 } 342 #endif /* __powerpc64__ */ 343 344 static inline unsigned long raw_copy_from_user(void *to, 345 const void __user *from, unsigned long n) 346 { 347 unsigned long ret; 348 349 allow_read_from_user(from, n); 350 ret = __copy_tofrom_user((__force void __user *)to, from, n); 351 prevent_read_from_user(from, n); 352 return ret; 353 } 354 355 static inline unsigned long 356 raw_copy_to_user(void __user *to, const void *from, unsigned long n) 357 { 358 unsigned long ret; 359 360 allow_write_to_user(to, n); 361 ret = __copy_tofrom_user(to, (__force const void __user *)from, n); 362 prevent_write_to_user(to, n); 363 return ret; 364 } 365 366 unsigned long __arch_clear_user(void __user *addr, unsigned long size); 367 368 static inline unsigned long __clear_user(void __user *addr, unsigned long size) 369 { 370 unsigned long ret; 371 372 might_fault(); 373 allow_write_to_user(addr, size); 374 ret = __arch_clear_user(addr, size); 375 prevent_write_to_user(addr, size); 376 return ret; 377 } 378 379 static inline unsigned long clear_user(void __user *addr, unsigned long size) 380 { 381 return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size; 382 } 383 384 extern long strncpy_from_user(char *dst, const char __user *src, long count); 385 extern __must_check long strnlen_user(const char __user *str, long n); 386 387 #ifdef CONFIG_ARCH_HAS_COPY_MC 388 unsigned long __must_check 389 copy_mc_generic(void *to, const void *from, unsigned long size); 390 391 static inline unsigned long __must_check 392 copy_mc_to_kernel(void *to, const void *from, unsigned long size) 393 { 394 return copy_mc_generic(to, from, size); 395 } 396 #define copy_mc_to_kernel copy_mc_to_kernel 397 398 static inline unsigned long __must_check 399 copy_mc_to_user(void __user *to, const void *from, unsigned long n) 400 { 401 if (check_copy_size(from, n, true)) { 402 if (access_ok(to, n)) { 403 allow_write_to_user(to, n); 404 n = copy_mc_generic((void __force *)to, from, n); 405 prevent_write_to_user(to, n); 406 } 407 } 408 409 return n; 410 } 411 #endif 412 413 extern long __copy_from_user_flushcache(void *dst, const void __user *src, 414 unsigned size); 415 416 static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len) 417 { 418 if (unlikely(!access_ok(ptr, len))) 419 return false; 420 421 might_fault(); 422 423 allow_read_write_user((void __user *)ptr, ptr, len); 424 return true; 425 } 426 #define user_access_begin user_access_begin 427 #define user_access_end prevent_current_access_user 428 #define user_access_save prevent_user_access_return 429 #define user_access_restore restore_user_access 430 431 static __must_check __always_inline bool 432 user_read_access_begin(const void __user *ptr, size_t len) 433 { 434 if (unlikely(!access_ok(ptr, len))) 435 return false; 436 437 might_fault(); 438 439 allow_read_from_user(ptr, len); 440 return true; 441 } 442 #define user_read_access_begin user_read_access_begin 443 #define user_read_access_end prevent_current_read_from_user 444 445 static __must_check __always_inline bool 446 user_write_access_begin(const void __user *ptr, size_t len) 447 { 448 if (unlikely(!access_ok(ptr, len))) 449 return false; 450 451 might_fault(); 452 453 allow_write_to_user((void __user *)ptr, len); 454 return true; 455 } 456 #define user_write_access_begin user_write_access_begin 457 #define user_write_access_end prevent_current_write_to_user 458 459 #define unsafe_get_user(x, p, e) do { \ 460 __long_type(*(p)) __gu_val; \ 461 __typeof__(*(p)) __user *__gu_addr = (p); \ 462 \ 463 __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \ 464 (x) = (__typeof__(*(p)))__gu_val; \ 465 } while (0) 466 467 #define unsafe_put_user(x, p, e) \ 468 __put_user_size_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e) 469 470 #define unsafe_copy_from_user(d, s, l, e) \ 471 do { \ 472 u8 *_dst = (u8 *)(d); \ 473 const u8 __user *_src = (const u8 __user *)(s); \ 474 size_t _len = (l); \ 475 int _i; \ 476 \ 477 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \ 478 unsafe_get_user(*(u64 *)(_dst + _i), (u64 __user *)(_src + _i), e); \ 479 if (_len & 4) { \ 480 unsafe_get_user(*(u32 *)(_dst + _i), (u32 __user *)(_src + _i), e); \ 481 _i += 4; \ 482 } \ 483 if (_len & 2) { \ 484 unsafe_get_user(*(u16 *)(_dst + _i), (u16 __user *)(_src + _i), e); \ 485 _i += 2; \ 486 } \ 487 if (_len & 1) \ 488 unsafe_get_user(*(u8 *)(_dst + _i), (u8 __user *)(_src + _i), e); \ 489 } while (0) 490 491 #define unsafe_copy_to_user(d, s, l, e) \ 492 do { \ 493 u8 __user *_dst = (u8 __user *)(d); \ 494 const u8 *_src = (const u8 *)(s); \ 495 size_t _len = (l); \ 496 int _i; \ 497 \ 498 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \ 499 unsafe_put_user(*(u64 *)(_src + _i), (u64 __user *)(_dst + _i), e); \ 500 if (_len & 4) { \ 501 unsafe_put_user(*(u32*)(_src + _i), (u32 __user *)(_dst + _i), e); \ 502 _i += 4; \ 503 } \ 504 if (_len & 2) { \ 505 unsafe_put_user(*(u16*)(_src + _i), (u16 __user *)(_dst + _i), e); \ 506 _i += 2; \ 507 } \ 508 if (_len & 1) \ 509 unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \ 510 } while (0) 511 512 #define __get_kernel_nofault(dst, src, type, err_label) \ 513 __get_user_size_goto(*((type *)(dst)), \ 514 (__force type __user *)(src), sizeof(type), err_label) 515 516 #define __put_kernel_nofault(dst, src, type, err_label) \ 517 __put_user_size_goto(*((type *)(src)), \ 518 (__force type __user *)(dst), sizeof(type), err_label) 519 520 #endif /* _ARCH_POWERPC_UACCESS_H */ 521