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_volatile_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_volatile_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 __powerpc64__ 96 #define __put_user_asm2_goto(x, ptr, label) \ 97 __put_user_asm_goto(x, ptr, label, "std") 98 #else /* __powerpc64__ */ 99 #define __put_user_asm2_goto(x, addr, label) \ 100 asm_volatile_goto( \ 101 "1: stw%X1 %0, %1\n" \ 102 "2: stw%X1 %L0, %L1\n" \ 103 EX_TABLE(1b, %l2) \ 104 EX_TABLE(2b, %l2) \ 105 : \ 106 : "r" (x), "m" (*addr) \ 107 : \ 108 : label) 109 #endif /* __powerpc64__ */ 110 111 #define __put_user_size_goto(x, ptr, size, label) \ 112 do { \ 113 __typeof__(*(ptr)) __user *__pus_addr = (ptr); \ 114 \ 115 switch (size) { \ 116 case 1: __put_user_asm_goto(x, __pus_addr, label, "stb"); break; \ 117 case 2: __put_user_asm_goto(x, __pus_addr, label, "sth"); break; \ 118 case 4: __put_user_asm_goto(x, __pus_addr, label, "stw"); break; \ 119 case 8: __put_user_asm2_goto(x, __pus_addr, label); break; \ 120 default: BUILD_BUG(); \ 121 } \ 122 } while (0) 123 124 /* 125 * This does an atomic 128 byte aligned load from userspace. 126 * Upto caller to do enable_kernel_vmx() before calling! 127 */ 128 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \ 129 __asm__ __volatile__( \ 130 ".machine push\n" \ 131 ".machine altivec\n" \ 132 "1: lvx 0,0,%1 # get user\n" \ 133 " stvx 0,0,%2 # put kernel\n" \ 134 ".machine pop\n" \ 135 "2:\n" \ 136 ".section .fixup,\"ax\"\n" \ 137 "3: li %0,%3\n" \ 138 " b 2b\n" \ 139 ".previous\n" \ 140 EX_TABLE(1b, 3b) \ 141 : "=r" (err) \ 142 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err)) 143 144 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT 145 146 /* -mprefixed can generate offsets beyond range, fall back hack */ 147 #ifdef CONFIG_PPC_KERNEL_PREFIXED 148 #define __get_user_asm_goto(x, addr, label, op) \ 149 asm_volatile_goto( \ 150 "1: "op" %0,0(%1) # get_user\n" \ 151 EX_TABLE(1b, %l2) \ 152 : "=r" (x) \ 153 : "b" (addr) \ 154 : \ 155 : label) 156 #else 157 #define __get_user_asm_goto(x, addr, label, op) \ 158 asm_volatile_goto( \ 159 "1: "op"%U1%X1 %0, %1 # get_user\n" \ 160 EX_TABLE(1b, %l2) \ 161 : "=r" (x) \ 162 : "m<>" (*addr) \ 163 : \ 164 : label) 165 #endif 166 167 #ifdef __powerpc64__ 168 #define __get_user_asm2_goto(x, addr, label) \ 169 __get_user_asm_goto(x, addr, label, "ld") 170 #else /* __powerpc64__ */ 171 #define __get_user_asm2_goto(x, addr, label) \ 172 asm_volatile_goto( \ 173 "1: lwz%X1 %0, %1\n" \ 174 "2: lwz%X1 %L0, %L1\n" \ 175 EX_TABLE(1b, %l2) \ 176 EX_TABLE(2b, %l2) \ 177 : "=&r" (x) \ 178 : "m" (*addr) \ 179 : \ 180 : label) 181 #endif /* __powerpc64__ */ 182 183 #define __get_user_size_goto(x, ptr, size, label) \ 184 do { \ 185 BUILD_BUG_ON(size > sizeof(x)); \ 186 switch (size) { \ 187 case 1: __get_user_asm_goto(x, (u8 __user *)ptr, label, "lbz"); break; \ 188 case 2: __get_user_asm_goto(x, (u16 __user *)ptr, label, "lhz"); break; \ 189 case 4: __get_user_asm_goto(x, (u32 __user *)ptr, label, "lwz"); break; \ 190 case 8: __get_user_asm2_goto(x, (u64 __user *)ptr, label); break; \ 191 default: x = 0; BUILD_BUG(); \ 192 } \ 193 } while (0) 194 195 #define __get_user_size_allowed(x, ptr, size, retval) \ 196 do { \ 197 __label__ __gus_failed; \ 198 \ 199 __get_user_size_goto(x, ptr, size, __gus_failed); \ 200 retval = 0; \ 201 break; \ 202 __gus_failed: \ 203 x = 0; \ 204 retval = -EFAULT; \ 205 } while (0) 206 207 #else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ 208 209 #define __get_user_asm(x, addr, err, op) \ 210 __asm__ __volatile__( \ 211 "1: "op"%U2%X2 %1, %2 # get_user\n" \ 212 "2:\n" \ 213 ".section .fixup,\"ax\"\n" \ 214 "3: li %0,%3\n" \ 215 " li %1,0\n" \ 216 " b 2b\n" \ 217 ".previous\n" \ 218 EX_TABLE(1b, 3b) \ 219 : "=r" (err), "=r" (x) \ 220 : "m<>" (*addr), "i" (-EFAULT), "0" (err)) 221 222 #ifdef __powerpc64__ 223 #define __get_user_asm2(x, addr, err) \ 224 __get_user_asm(x, addr, err, "ld") 225 #else /* __powerpc64__ */ 226 #define __get_user_asm2(x, addr, err) \ 227 __asm__ __volatile__( \ 228 "1: lwz%X2 %1, %2\n" \ 229 "2: lwz%X2 %L1, %L2\n" \ 230 "3:\n" \ 231 ".section .fixup,\"ax\"\n" \ 232 "4: li %0,%3\n" \ 233 " li %1,0\n" \ 234 " li %1+1,0\n" \ 235 " b 3b\n" \ 236 ".previous\n" \ 237 EX_TABLE(1b, 4b) \ 238 EX_TABLE(2b, 4b) \ 239 : "=r" (err), "=&r" (x) \ 240 : "m" (*addr), "i" (-EFAULT), "0" (err)) 241 #endif /* __powerpc64__ */ 242 243 #define __get_user_size_allowed(x, ptr, size, retval) \ 244 do { \ 245 retval = 0; \ 246 BUILD_BUG_ON(size > sizeof(x)); \ 247 switch (size) { \ 248 case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; \ 249 case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; \ 250 case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \ 251 case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \ 252 default: x = 0; BUILD_BUG(); \ 253 } \ 254 } while (0) 255 256 #define __get_user_size_goto(x, ptr, size, label) \ 257 do { \ 258 long __gus_retval; \ 259 \ 260 __get_user_size_allowed(x, ptr, size, __gus_retval); \ 261 if (__gus_retval) \ 262 goto label; \ 263 } while (0) 264 265 #endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ 266 267 /* 268 * This is a type: either unsigned long, if the argument fits into 269 * that type, or otherwise unsigned long long. 270 */ 271 #define __long_type(x) \ 272 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) 273 274 #define __get_user(x, ptr) \ 275 ({ \ 276 long __gu_err; \ 277 __long_type(*(ptr)) __gu_val; \ 278 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 279 __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr)); \ 280 \ 281 might_fault(); \ 282 allow_read_from_user(__gu_addr, __gu_size); \ 283 __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \ 284 prevent_read_from_user(__gu_addr, __gu_size); \ 285 (x) = (__typeof__(*(ptr)))__gu_val; \ 286 \ 287 __gu_err; \ 288 }) 289 290 #define get_user(x, ptr) \ 291 ({ \ 292 __typeof__(*(ptr)) __user *_gu_addr = (ptr); \ 293 \ 294 access_ok(_gu_addr, sizeof(*(ptr))) ? \ 295 __get_user(x, _gu_addr) : \ 296 ((x) = (__force __typeof__(*(ptr)))0, -EFAULT); \ 297 }) 298 299 /* more complex routines */ 300 301 extern unsigned long __copy_tofrom_user(void __user *to, 302 const void __user *from, unsigned long size); 303 304 #ifdef __powerpc64__ 305 static inline unsigned long 306 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 307 { 308 unsigned long ret; 309 310 allow_read_write_user(to, from, n); 311 ret = __copy_tofrom_user(to, from, n); 312 prevent_read_write_user(to, from, n); 313 return ret; 314 } 315 #endif /* __powerpc64__ */ 316 317 static inline unsigned long raw_copy_from_user(void *to, 318 const void __user *from, unsigned long n) 319 { 320 unsigned long ret; 321 322 allow_read_from_user(from, n); 323 ret = __copy_tofrom_user((__force void __user *)to, from, n); 324 prevent_read_from_user(from, n); 325 return ret; 326 } 327 328 static inline unsigned long 329 raw_copy_to_user(void __user *to, const void *from, unsigned long n) 330 { 331 unsigned long ret; 332 333 allow_write_to_user(to, n); 334 ret = __copy_tofrom_user(to, (__force const void __user *)from, n); 335 prevent_write_to_user(to, n); 336 return ret; 337 } 338 339 unsigned long __arch_clear_user(void __user *addr, unsigned long size); 340 341 static inline unsigned long __clear_user(void __user *addr, unsigned long size) 342 { 343 unsigned long ret; 344 345 might_fault(); 346 allow_write_to_user(addr, size); 347 ret = __arch_clear_user(addr, size); 348 prevent_write_to_user(addr, size); 349 return ret; 350 } 351 352 static inline unsigned long clear_user(void __user *addr, unsigned long size) 353 { 354 return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size; 355 } 356 357 extern long strncpy_from_user(char *dst, const char __user *src, long count); 358 extern __must_check long strnlen_user(const char __user *str, long n); 359 360 #ifdef CONFIG_ARCH_HAS_COPY_MC 361 unsigned long __must_check 362 copy_mc_generic(void *to, const void *from, unsigned long size); 363 364 static inline unsigned long __must_check 365 copy_mc_to_kernel(void *to, const void *from, unsigned long size) 366 { 367 return copy_mc_generic(to, from, size); 368 } 369 #define copy_mc_to_kernel copy_mc_to_kernel 370 371 static inline unsigned long __must_check 372 copy_mc_to_user(void __user *to, const void *from, unsigned long n) 373 { 374 if (check_copy_size(from, n, true)) { 375 if (access_ok(to, n)) { 376 allow_write_to_user(to, n); 377 n = copy_mc_generic((void *)to, from, n); 378 prevent_write_to_user(to, n); 379 } 380 } 381 382 return n; 383 } 384 #endif 385 386 extern long __copy_from_user_flushcache(void *dst, const void __user *src, 387 unsigned size); 388 389 static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len) 390 { 391 if (unlikely(!access_ok(ptr, len))) 392 return false; 393 394 might_fault(); 395 396 allow_read_write_user((void __user *)ptr, ptr, len); 397 return true; 398 } 399 #define user_access_begin user_access_begin 400 #define user_access_end prevent_current_access_user 401 #define user_access_save prevent_user_access_return 402 #define user_access_restore restore_user_access 403 404 static __must_check __always_inline bool 405 user_read_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_from_user(ptr, len); 413 return true; 414 } 415 #define user_read_access_begin user_read_access_begin 416 #define user_read_access_end prevent_current_read_from_user 417 418 static __must_check __always_inline bool 419 user_write_access_begin(const void __user *ptr, size_t len) 420 { 421 if (unlikely(!access_ok(ptr, len))) 422 return false; 423 424 might_fault(); 425 426 allow_write_to_user((void __user *)ptr, len); 427 return true; 428 } 429 #define user_write_access_begin user_write_access_begin 430 #define user_write_access_end prevent_current_write_to_user 431 432 #define unsafe_get_user(x, p, e) do { \ 433 __long_type(*(p)) __gu_val; \ 434 __typeof__(*(p)) __user *__gu_addr = (p); \ 435 \ 436 __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \ 437 (x) = (__typeof__(*(p)))__gu_val; \ 438 } while (0) 439 440 #define unsafe_put_user(x, p, e) \ 441 __put_user_size_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e) 442 443 #define unsafe_copy_from_user(d, s, l, e) \ 444 do { \ 445 u8 *_dst = (u8 *)(d); \ 446 const u8 __user *_src = (const u8 __user *)(s); \ 447 size_t _len = (l); \ 448 int _i; \ 449 \ 450 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \ 451 unsafe_get_user(*(u64 *)(_dst + _i), (u64 __user *)(_src + _i), e); \ 452 if (_len & 4) { \ 453 unsafe_get_user(*(u32 *)(_dst + _i), (u32 __user *)(_src + _i), e); \ 454 _i += 4; \ 455 } \ 456 if (_len & 2) { \ 457 unsafe_get_user(*(u16 *)(_dst + _i), (u16 __user *)(_src + _i), e); \ 458 _i += 2; \ 459 } \ 460 if (_len & 1) \ 461 unsafe_get_user(*(u8 *)(_dst + _i), (u8 __user *)(_src + _i), e); \ 462 } while (0) 463 464 #define unsafe_copy_to_user(d, s, l, e) \ 465 do { \ 466 u8 __user *_dst = (u8 __user *)(d); \ 467 const u8 *_src = (const u8 *)(s); \ 468 size_t _len = (l); \ 469 int _i; \ 470 \ 471 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \ 472 unsafe_put_user(*(u64 *)(_src + _i), (u64 __user *)(_dst + _i), e); \ 473 if (_len & 4) { \ 474 unsafe_put_user(*(u32*)(_src + _i), (u32 __user *)(_dst + _i), e); \ 475 _i += 4; \ 476 } \ 477 if (_len & 2) { \ 478 unsafe_put_user(*(u16*)(_src + _i), (u16 __user *)(_dst + _i), e); \ 479 _i += 2; \ 480 } \ 481 if (_len & 1) \ 482 unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \ 483 } while (0) 484 485 #define __get_kernel_nofault(dst, src, type, err_label) \ 486 __get_user_size_goto(*((type *)(dst)), \ 487 (__force type __user *)(src), sizeof(type), err_label) 488 489 #define __put_kernel_nofault(dst, src, type, err_label) \ 490 __put_user_size_goto(*((type *)(src)), \ 491 (__force type __user *)(dst), sizeof(type), err_label) 492 493 #endif /* _ARCH_POWERPC_UACCESS_H */ 494