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 #include <asm/asm-compat.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 #endif 15 16 #include <asm-generic/access_ok.h> 17 18 /* 19 * These are the main single-value transfer routines. They automatically 20 * use the right size if we just have the right pointer type. 21 * 22 * This gets kind of ugly. We want to return _two_ values in "get_user()" 23 * and yet we don't want to do any pointers, because that is too much 24 * of a performance impact. Thus we have a few rather ugly macros here, 25 * and hide all the ugliness from the user. 26 * 27 * The "__xxx" versions of the user access functions are versions that 28 * do not verify the address space, that must have been done previously 29 * with a separate "access_ok()" call (this is used when we do multiple 30 * accesses to the same area of user memory). 31 * 32 * As we use the same address space for kernel and user data on the 33 * PowerPC, we can just do these as direct assignments. (Of course, the 34 * exception handling means that it's no longer "just"...) 35 * 36 */ 37 #define __put_user(x, ptr) \ 38 ({ \ 39 long __pu_err; \ 40 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 41 __typeof__(*(ptr)) __pu_val = (__typeof__(*(ptr)))(x); \ 42 __typeof__(sizeof(*(ptr))) __pu_size = sizeof(*(ptr)); \ 43 \ 44 might_fault(); \ 45 do { \ 46 __label__ __pu_failed; \ 47 \ 48 allow_write_to_user(__pu_addr, __pu_size); \ 49 __put_user_size_goto(__pu_val, __pu_addr, __pu_size, __pu_failed); \ 50 prevent_write_to_user(__pu_addr, __pu_size); \ 51 __pu_err = 0; \ 52 break; \ 53 \ 54 __pu_failed: \ 55 prevent_write_to_user(__pu_addr, __pu_size); \ 56 __pu_err = -EFAULT; \ 57 } while (0); \ 58 \ 59 __pu_err; \ 60 }) 61 62 #define put_user(x, ptr) \ 63 ({ \ 64 __typeof__(*(ptr)) __user *_pu_addr = (ptr); \ 65 \ 66 access_ok(_pu_addr, sizeof(*(ptr))) ? \ 67 __put_user(x, _pu_addr) : -EFAULT; \ 68 }) 69 70 /* 71 * We don't tell gcc that we are accessing memory, but this is OK 72 * because we do not write to any memory gcc knows about, so there 73 * are no aliasing issues. 74 */ 75 /* -mprefixed can generate offsets beyond range, fall back hack */ 76 #ifdef CONFIG_PPC_KERNEL_PREFIXED 77 #define __put_user_asm_goto(x, addr, label, op) \ 78 asm goto( \ 79 "1: " op " %0,0(%1) # put_user\n" \ 80 EX_TABLE(1b, %l2) \ 81 : \ 82 : "r" (x), "b" (addr) \ 83 : \ 84 : label) 85 #else 86 #define __put_user_asm_goto(x, addr, label, op) \ 87 asm goto( \ 88 "1: " op "%U1%X1 %0,%1 # put_user\n" \ 89 EX_TABLE(1b, %l2) \ 90 : \ 91 : "r" (x), "m<>" (*addr) \ 92 : \ 93 : label) 94 #endif 95 96 #ifdef __powerpc64__ 97 #ifdef CONFIG_PPC_KERNEL_PREFIXED 98 #define __put_user_asm2_goto(x, ptr, label) \ 99 __put_user_asm_goto(x, ptr, label, "std") 100 #else 101 #define __put_user_asm2_goto(x, addr, label) \ 102 asm goto ("1: std%U1%X1 %0,%1 # put_user\n" \ 103 EX_TABLE(1b, %l2) \ 104 : \ 105 : "r" (x), DS_FORM_CONSTRAINT (*addr) \ 106 : \ 107 : label) 108 #endif // CONFIG_PPC_KERNEL_PREFIXED 109 #else /* __powerpc64__ */ 110 #define __put_user_asm2_goto(x, addr, label) \ 111 asm goto( \ 112 "1: stw%X1 %0, %1\n" \ 113 "2: stw%X1 %L0, %L1\n" \ 114 EX_TABLE(1b, %l2) \ 115 EX_TABLE(2b, %l2) \ 116 : \ 117 : "r" (x), "m" (*addr) \ 118 : \ 119 : label) 120 #endif /* __powerpc64__ */ 121 122 #define __put_user_size_goto(x, ptr, size, label) \ 123 do { \ 124 __typeof__(*(ptr)) __user *__pus_addr = (ptr); \ 125 \ 126 switch (size) { \ 127 case 1: __put_user_asm_goto(x, __pus_addr, label, "stb"); break; \ 128 case 2: __put_user_asm_goto(x, __pus_addr, label, "sth"); break; \ 129 case 4: __put_user_asm_goto(x, __pus_addr, label, "stw"); break; \ 130 case 8: __put_user_asm2_goto(x, __pus_addr, label); break; \ 131 default: BUILD_BUG(); \ 132 } \ 133 } while (0) 134 135 /* 136 * This does an atomic 128 byte aligned load from userspace. 137 * Upto caller to do enable_kernel_vmx() before calling! 138 */ 139 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \ 140 __asm__ __volatile__( \ 141 ".machine push\n" \ 142 ".machine altivec\n" \ 143 "1: lvx 0,0,%1 # get user\n" \ 144 " stvx 0,0,%2 # put kernel\n" \ 145 ".machine pop\n" \ 146 "2:\n" \ 147 ".section .fixup,\"ax\"\n" \ 148 "3: li %0,%3\n" \ 149 " b 2b\n" \ 150 ".previous\n" \ 151 EX_TABLE(1b, 3b) \ 152 : "=r" (err) \ 153 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err)) 154 155 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT 156 157 /* -mprefixed can generate offsets beyond range, fall back hack */ 158 #ifdef CONFIG_PPC_KERNEL_PREFIXED 159 #define __get_user_asm_goto(x, addr, label, op) \ 160 asm_goto_output( \ 161 "1: "op" %0,0(%1) # get_user\n" \ 162 EX_TABLE(1b, %l2) \ 163 : "=r" (x) \ 164 : "b" (addr) \ 165 : \ 166 : label) 167 #else 168 #define __get_user_asm_goto(x, addr, label, op) \ 169 asm_goto_output( \ 170 "1: "op"%U1%X1 %0, %1 # get_user\n" \ 171 EX_TABLE(1b, %l2) \ 172 : "=r" (x) \ 173 : "m<>" (*addr) \ 174 : \ 175 : label) 176 #endif 177 178 #ifdef __powerpc64__ 179 #ifdef CONFIG_PPC_KERNEL_PREFIXED 180 #define __get_user_asm2_goto(x, addr, label) \ 181 __get_user_asm_goto(x, addr, label, "ld") 182 #else 183 #define __get_user_asm2_goto(x, addr, label) \ 184 asm_goto_output( \ 185 "1: ld%U1%X1 %0, %1 # get_user\n" \ 186 EX_TABLE(1b, %l2) \ 187 : "=r" (x) \ 188 : DS_FORM_CONSTRAINT (*addr) \ 189 : \ 190 : label) 191 #endif // CONFIG_PPC_KERNEL_PREFIXED 192 #else /* __powerpc64__ */ 193 #define __get_user_asm2_goto(x, addr, label) \ 194 asm_goto_output( \ 195 "1: lwz%X1 %0, %1\n" \ 196 "2: lwz%X1 %L0, %L1\n" \ 197 EX_TABLE(1b, %l2) \ 198 EX_TABLE(2b, %l2) \ 199 : "=&r" (x) \ 200 : "m" (*addr) \ 201 : \ 202 : label) 203 #endif /* __powerpc64__ */ 204 205 #define __get_user_size_goto(x, ptr, size, label) \ 206 do { \ 207 BUILD_BUG_ON(size > sizeof(x)); \ 208 switch (size) { \ 209 case 1: __get_user_asm_goto(x, (u8 __user *)ptr, label, "lbz"); break; \ 210 case 2: __get_user_asm_goto(x, (u16 __user *)ptr, label, "lhz"); break; \ 211 case 4: __get_user_asm_goto(x, (u32 __user *)ptr, label, "lwz"); break; \ 212 case 8: __get_user_asm2_goto(x, (u64 __user *)ptr, label); break; \ 213 default: x = 0; BUILD_BUG(); \ 214 } \ 215 } while (0) 216 217 #define __get_user_size_allowed(x, ptr, size, retval) \ 218 do { \ 219 __label__ __gus_failed; \ 220 \ 221 __get_user_size_goto(x, ptr, size, __gus_failed); \ 222 retval = 0; \ 223 break; \ 224 __gus_failed: \ 225 x = 0; \ 226 retval = -EFAULT; \ 227 } while (0) 228 229 #else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ 230 231 #define __get_user_asm(x, addr, err, op) \ 232 __asm__ __volatile__( \ 233 "1: "op"%U2%X2 %1, %2 # get_user\n" \ 234 "2:\n" \ 235 ".section .fixup,\"ax\"\n" \ 236 "3: li %0,%3\n" \ 237 " li %1,0\n" \ 238 " b 2b\n" \ 239 ".previous\n" \ 240 EX_TABLE(1b, 3b) \ 241 : "=r" (err), "=r" (x) \ 242 : "m<>" (*addr), "i" (-EFAULT), "0" (err)) 243 244 #ifdef __powerpc64__ 245 #define __get_user_asm2(x, addr, err) \ 246 __get_user_asm(x, addr, err, "ld") 247 #else /* __powerpc64__ */ 248 #define __get_user_asm2(x, addr, err) \ 249 __asm__ __volatile__( \ 250 "1: lwz%X2 %1, %2\n" \ 251 "2: lwz%X2 %L1, %L2\n" \ 252 "3:\n" \ 253 ".section .fixup,\"ax\"\n" \ 254 "4: li %0,%3\n" \ 255 " li %1,0\n" \ 256 " li %1+1,0\n" \ 257 " b 3b\n" \ 258 ".previous\n" \ 259 EX_TABLE(1b, 4b) \ 260 EX_TABLE(2b, 4b) \ 261 : "=r" (err), "=&r" (x) \ 262 : "m" (*addr), "i" (-EFAULT), "0" (err)) 263 #endif /* __powerpc64__ */ 264 265 #define __get_user_size_allowed(x, ptr, size, retval) \ 266 do { \ 267 retval = 0; \ 268 BUILD_BUG_ON(size > sizeof(x)); \ 269 switch (size) { \ 270 case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; \ 271 case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; \ 272 case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \ 273 case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \ 274 default: x = 0; BUILD_BUG(); \ 275 } \ 276 } while (0) 277 278 #define __get_user_size_goto(x, ptr, size, label) \ 279 do { \ 280 long __gus_retval; \ 281 \ 282 __get_user_size_allowed(x, ptr, size, __gus_retval); \ 283 if (__gus_retval) \ 284 goto label; \ 285 } while (0) 286 287 #endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ 288 289 /* 290 * This is a type: either unsigned long, if the argument fits into 291 * that type, or otherwise unsigned long long. 292 */ 293 #define __long_type(x) \ 294 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) 295 296 #define __get_user(x, ptr) \ 297 ({ \ 298 long __gu_err; \ 299 __long_type(*(ptr)) __gu_val; \ 300 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 301 __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr)); \ 302 \ 303 might_fault(); \ 304 allow_read_from_user(__gu_addr, __gu_size); \ 305 __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \ 306 prevent_read_from_user(__gu_addr, __gu_size); \ 307 (x) = (__typeof__(*(ptr)))__gu_val; \ 308 \ 309 __gu_err; \ 310 }) 311 312 #define get_user(x, ptr) \ 313 ({ \ 314 __typeof__(*(ptr)) __user *_gu_addr = (ptr); \ 315 \ 316 access_ok(_gu_addr, sizeof(*(ptr))) ? \ 317 __get_user(x, _gu_addr) : \ 318 ((x) = (__force __typeof__(*(ptr)))0, -EFAULT); \ 319 }) 320 321 /* more complex routines */ 322 323 extern unsigned long __copy_tofrom_user(void __user *to, 324 const void __user *from, unsigned long size); 325 326 #ifdef __powerpc64__ 327 static inline unsigned long 328 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 329 { 330 unsigned long ret; 331 332 allow_read_write_user(to, from, n); 333 ret = __copy_tofrom_user(to, from, n); 334 prevent_read_write_user(to, from, n); 335 return ret; 336 } 337 #endif /* __powerpc64__ */ 338 339 static inline unsigned long raw_copy_from_user(void *to, 340 const void __user *from, unsigned long n) 341 { 342 unsigned long ret; 343 344 allow_read_from_user(from, n); 345 ret = __copy_tofrom_user((__force void __user *)to, from, n); 346 prevent_read_from_user(from, n); 347 return ret; 348 } 349 350 static inline unsigned long 351 raw_copy_to_user(void __user *to, const void *from, unsigned long n) 352 { 353 unsigned long ret; 354 355 allow_write_to_user(to, n); 356 ret = __copy_tofrom_user(to, (__force const void __user *)from, n); 357 prevent_write_to_user(to, n); 358 return ret; 359 } 360 361 unsigned long __arch_clear_user(void __user *addr, unsigned long size); 362 363 static inline unsigned long __clear_user(void __user *addr, unsigned long size) 364 { 365 unsigned long ret; 366 367 might_fault(); 368 allow_write_to_user(addr, size); 369 ret = __arch_clear_user(addr, size); 370 prevent_write_to_user(addr, size); 371 return ret; 372 } 373 374 static inline unsigned long clear_user(void __user *addr, unsigned long size) 375 { 376 return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size; 377 } 378 379 extern long strncpy_from_user(char *dst, const char __user *src, long count); 380 extern __must_check long strnlen_user(const char __user *str, long n); 381 382 #ifdef CONFIG_ARCH_HAS_COPY_MC 383 unsigned long __must_check 384 copy_mc_generic(void *to, const void *from, unsigned long size); 385 386 static inline unsigned long __must_check 387 copy_mc_to_kernel(void *to, const void *from, unsigned long size) 388 { 389 return copy_mc_generic(to, from, size); 390 } 391 #define copy_mc_to_kernel copy_mc_to_kernel 392 393 static inline unsigned long __must_check 394 copy_mc_to_user(void __user *to, const void *from, unsigned long n) 395 { 396 if (check_copy_size(from, n, true)) { 397 if (access_ok(to, n)) { 398 allow_write_to_user(to, n); 399 n = copy_mc_generic((void __force *)to, from, n); 400 prevent_write_to_user(to, n); 401 } 402 } 403 404 return n; 405 } 406 #endif 407 408 extern long __copy_from_user_flushcache(void *dst, const void __user *src, 409 unsigned size); 410 411 static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len) 412 { 413 if (unlikely(!access_ok(ptr, len))) 414 return false; 415 416 might_fault(); 417 418 allow_read_write_user((void __user *)ptr, ptr, len); 419 return true; 420 } 421 #define user_access_begin user_access_begin 422 #define user_access_end prevent_current_access_user 423 #define user_access_save prevent_user_access_return 424 #define user_access_restore restore_user_access 425 426 static __must_check __always_inline bool 427 user_read_access_begin(const void __user *ptr, size_t len) 428 { 429 if (unlikely(!access_ok(ptr, len))) 430 return false; 431 432 might_fault(); 433 434 allow_read_from_user(ptr, len); 435 return true; 436 } 437 #define user_read_access_begin user_read_access_begin 438 #define user_read_access_end prevent_current_read_from_user 439 440 static __must_check __always_inline bool 441 user_write_access_begin(const void __user *ptr, size_t len) 442 { 443 if (unlikely(!access_ok(ptr, len))) 444 return false; 445 446 might_fault(); 447 448 allow_write_to_user((void __user *)ptr, len); 449 return true; 450 } 451 #define user_write_access_begin user_write_access_begin 452 #define user_write_access_end prevent_current_write_to_user 453 454 #define unsafe_get_user(x, p, e) do { \ 455 __long_type(*(p)) __gu_val; \ 456 __typeof__(*(p)) __user *__gu_addr = (p); \ 457 \ 458 __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \ 459 (x) = (__typeof__(*(p)))__gu_val; \ 460 } while (0) 461 462 #define unsafe_put_user(x, p, e) \ 463 __put_user_size_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e) 464 465 #define unsafe_copy_from_user(d, s, l, e) \ 466 do { \ 467 u8 *_dst = (u8 *)(d); \ 468 const u8 __user *_src = (const u8 __user *)(s); \ 469 size_t _len = (l); \ 470 int _i; \ 471 \ 472 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \ 473 unsafe_get_user(*(u64 *)(_dst + _i), (u64 __user *)(_src + _i), e); \ 474 if (_len & 4) { \ 475 unsafe_get_user(*(u32 *)(_dst + _i), (u32 __user *)(_src + _i), e); \ 476 _i += 4; \ 477 } \ 478 if (_len & 2) { \ 479 unsafe_get_user(*(u16 *)(_dst + _i), (u16 __user *)(_src + _i), e); \ 480 _i += 2; \ 481 } \ 482 if (_len & 1) \ 483 unsafe_get_user(*(u8 *)(_dst + _i), (u8 __user *)(_src + _i), e); \ 484 } while (0) 485 486 #define unsafe_copy_to_user(d, s, l, e) \ 487 do { \ 488 u8 __user *_dst = (u8 __user *)(d); \ 489 const u8 *_src = (const u8 *)(s); \ 490 size_t _len = (l); \ 491 int _i; \ 492 \ 493 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \ 494 unsafe_put_user(*(u64 *)(_src + _i), (u64 __user *)(_dst + _i), e); \ 495 if (_len & 4) { \ 496 unsafe_put_user(*(u32*)(_src + _i), (u32 __user *)(_dst + _i), e); \ 497 _i += 4; \ 498 } \ 499 if (_len & 2) { \ 500 unsafe_put_user(*(u16*)(_src + _i), (u16 __user *)(_dst + _i), e); \ 501 _i += 2; \ 502 } \ 503 if (_len & 1) \ 504 unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \ 505 } while (0) 506 507 #define __get_kernel_nofault(dst, src, type, err_label) \ 508 __get_user_size_goto(*((type *)(dst)), \ 509 (__force type __user *)(src), sizeof(type), err_label) 510 511 #define __put_kernel_nofault(dst, src, type, err_label) \ 512 __put_user_size_goto(*((type *)(src)), \ 513 (__force type __user *)(dst), sizeof(type), err_label) 514 515 #endif /* _ARCH_POWERPC_UACCESS_H */ 516