1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_UACCESS_H 3 #define _ASM_X86_UACCESS_H 4 /* 5 * User space memory access functions 6 */ 7 #include <linux/compiler.h> 8 #include <linux/instrumented.h> 9 #include <linux/kasan-checks.h> 10 #include <linux/mm_types.h> 11 #include <linux/string.h> 12 #include <linux/mmap_lock.h> 13 #include <asm/asm.h> 14 #include <asm/page.h> 15 #include <asm/smap.h> 16 #include <asm/extable.h> 17 #include <asm/tlbflush.h> 18 19 #ifdef CONFIG_X86_32 20 # include <asm/uaccess_32.h> 21 #else 22 # include <asm/uaccess_64.h> 23 #endif 24 25 #include <asm-generic/access_ok.h> 26 27 extern int __get_user_1(void); 28 extern int __get_user_2(void); 29 extern int __get_user_4(void); 30 extern int __get_user_8(void); 31 extern int __get_user_nocheck_1(void); 32 extern int __get_user_nocheck_2(void); 33 extern int __get_user_nocheck_4(void); 34 extern int __get_user_nocheck_8(void); 35 extern int __get_user_bad(void); 36 37 #define __uaccess_begin() stac() 38 #define __uaccess_end() clac() 39 #define __uaccess_begin_nospec() \ 40 ({ \ 41 stac(); \ 42 barrier_nospec(); \ 43 }) 44 45 /* 46 * This is the smallest unsigned integer type that can fit a value 47 * (up to 'long long') 48 */ 49 #define __inttype(x) __typeof__( \ 50 __typefits(x,char, \ 51 __typefits(x,short, \ 52 __typefits(x,int, \ 53 __typefits(x,long,0ULL))))) 54 55 #define __typefits(x,type,not) \ 56 __builtin_choose_expr(sizeof(x)<=sizeof(type),(unsigned type)0,not) 57 58 /* 59 * This is used for both get_user() and __get_user() to expand to 60 * the proper special function call that has odd calling conventions 61 * due to returning both a value and an error, and that depends on 62 * the size of the pointer passed in. 63 * 64 * Careful: we have to cast the result to the type of the pointer 65 * for sign reasons. 66 * 67 * The use of _ASM_DX as the register specifier is a bit of a 68 * simplification, as gcc only cares about it as the starting point 69 * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits 70 * (%ecx being the next register in gcc's x86 register sequence), and 71 * %rdx on 64 bits. 72 * 73 * Clang/LLVM cares about the size of the register, but still wants 74 * the base register for something that ends up being a pair. 75 */ 76 #define do_get_user_call(fn,x,ptr) \ 77 ({ \ 78 int __ret_gu; \ 79 register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \ 80 __chk_user_ptr(ptr); \ 81 asm volatile("call __" #fn "_%P4" \ 82 : "=a" (__ret_gu), "=r" (__val_gu), \ 83 ASM_CALL_CONSTRAINT \ 84 : "0" (ptr), "i" (sizeof(*(ptr)))); \ 85 instrument_get_user(__val_gu); \ 86 (x) = (__force __typeof__(*(ptr))) __val_gu; \ 87 __builtin_expect(__ret_gu, 0); \ 88 }) 89 90 /** 91 * get_user - Get a simple variable from user space. 92 * @x: Variable to store result. 93 * @ptr: Source address, in user space. 94 * 95 * Context: User context only. This function may sleep if pagefaults are 96 * enabled. 97 * 98 * This macro copies a single simple variable from user space to kernel 99 * space. It supports simple types like char and int, but not larger 100 * data types like structures or arrays. 101 * 102 * @ptr must have pointer-to-simple-variable type, and the result of 103 * dereferencing @ptr must be assignable to @x without a cast. 104 * 105 * Return: zero on success, or -EFAULT on error. 106 * On error, the variable @x is set to zero. 107 */ 108 #define get_user(x,ptr) ({ might_fault(); do_get_user_call(get_user,x,ptr); }) 109 110 /** 111 * __get_user - Get a simple variable from user space, with less checking. 112 * @x: Variable to store result. 113 * @ptr: Source address, in user space. 114 * 115 * Context: User context only. This function may sleep if pagefaults are 116 * enabled. 117 * 118 * This macro copies a single simple variable from user space to kernel 119 * space. It supports simple types like char and int, but not larger 120 * data types like structures or arrays. 121 * 122 * @ptr must have pointer-to-simple-variable type, and the result of 123 * dereferencing @ptr must be assignable to @x without a cast. 124 * 125 * Caller must check the pointer with access_ok() before calling this 126 * function. 127 * 128 * Return: zero on success, or -EFAULT on error. 129 * On error, the variable @x is set to zero. 130 */ 131 #define __get_user(x,ptr) do_get_user_call(get_user_nocheck,x,ptr) 132 133 134 #ifdef CONFIG_X86_32 135 #define __put_user_goto_u64(x, addr, label) \ 136 asm_volatile_goto("\n" \ 137 "1: movl %%eax,0(%1)\n" \ 138 "2: movl %%edx,4(%1)\n" \ 139 _ASM_EXTABLE_UA(1b, %l2) \ 140 _ASM_EXTABLE_UA(2b, %l2) \ 141 : : "A" (x), "r" (addr) \ 142 : : label) 143 144 #else 145 #define __put_user_goto_u64(x, ptr, label) \ 146 __put_user_goto(x, ptr, "q", "er", label) 147 #endif 148 149 extern void __put_user_bad(void); 150 151 /* 152 * Strange magic calling convention: pointer in %ecx, 153 * value in %eax(:%edx), return value in %ecx. clobbers %rbx 154 */ 155 extern void __put_user_1(void); 156 extern void __put_user_2(void); 157 extern void __put_user_4(void); 158 extern void __put_user_8(void); 159 extern void __put_user_nocheck_1(void); 160 extern void __put_user_nocheck_2(void); 161 extern void __put_user_nocheck_4(void); 162 extern void __put_user_nocheck_8(void); 163 164 /* 165 * ptr must be evaluated and assigned to the temporary __ptr_pu before 166 * the assignment of x to __val_pu, to avoid any function calls 167 * involved in the ptr expression (possibly implicitly generated due 168 * to KASAN) from clobbering %ax. 169 */ 170 #define do_put_user_call(fn,x,ptr) \ 171 ({ \ 172 int __ret_pu; \ 173 void __user *__ptr_pu; \ 174 register __typeof__(*(ptr)) __val_pu asm("%"_ASM_AX); \ 175 __typeof__(*(ptr)) __x = (x); /* eval x once */ \ 176 __typeof__(ptr) __ptr = (ptr); /* eval ptr once */ \ 177 __chk_user_ptr(__ptr); \ 178 __ptr_pu = __ptr; \ 179 __val_pu = __x; \ 180 asm volatile("call __" #fn "_%P[size]" \ 181 : "=c" (__ret_pu), \ 182 ASM_CALL_CONSTRAINT \ 183 : "0" (__ptr_pu), \ 184 "r" (__val_pu), \ 185 [size] "i" (sizeof(*(ptr))) \ 186 :"ebx"); \ 187 instrument_put_user(__x, __ptr, sizeof(*(ptr))); \ 188 __builtin_expect(__ret_pu, 0); \ 189 }) 190 191 /** 192 * put_user - Write a simple value into user space. 193 * @x: Value to copy to user space. 194 * @ptr: Destination address, in user space. 195 * 196 * Context: User context only. This function may sleep if pagefaults are 197 * enabled. 198 * 199 * This macro copies a single simple value from kernel space to user 200 * space. It supports simple types like char and int, but not larger 201 * data types like structures or arrays. 202 * 203 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 204 * to the result of dereferencing @ptr. 205 * 206 * Return: zero on success, or -EFAULT on error. 207 */ 208 #define put_user(x, ptr) ({ might_fault(); do_put_user_call(put_user,x,ptr); }) 209 210 /** 211 * __put_user - Write a simple value into user space, with less checking. 212 * @x: Value to copy to user space. 213 * @ptr: Destination address, in user space. 214 * 215 * Context: User context only. This function may sleep if pagefaults are 216 * enabled. 217 * 218 * This macro copies a single simple value from kernel space to user 219 * space. It supports simple types like char and int, but not larger 220 * data types like structures or arrays. 221 * 222 * @ptr must have pointer-to-simple-variable type, and @x must be assignable 223 * to the result of dereferencing @ptr. 224 * 225 * Caller must check the pointer with access_ok() before calling this 226 * function. 227 * 228 * Return: zero on success, or -EFAULT on error. 229 */ 230 #define __put_user(x, ptr) do_put_user_call(put_user_nocheck,x,ptr) 231 232 #define __put_user_size(x, ptr, size, label) \ 233 do { \ 234 __typeof__(*(ptr)) __x = (x); /* eval x once */ \ 235 __typeof__(ptr) __ptr = (ptr); /* eval ptr once */ \ 236 __chk_user_ptr(__ptr); \ 237 switch (size) { \ 238 case 1: \ 239 __put_user_goto(__x, __ptr, "b", "iq", label); \ 240 break; \ 241 case 2: \ 242 __put_user_goto(__x, __ptr, "w", "ir", label); \ 243 break; \ 244 case 4: \ 245 __put_user_goto(__x, __ptr, "l", "ir", label); \ 246 break; \ 247 case 8: \ 248 __put_user_goto_u64(__x, __ptr, label); \ 249 break; \ 250 default: \ 251 __put_user_bad(); \ 252 } \ 253 instrument_put_user(__x, __ptr, size); \ 254 } while (0) 255 256 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT 257 258 #ifdef CONFIG_X86_32 259 #define __get_user_asm_u64(x, ptr, label) do { \ 260 unsigned int __gu_low, __gu_high; \ 261 const unsigned int __user *__gu_ptr; \ 262 __gu_ptr = (const void __user *)(ptr); \ 263 __get_user_asm(__gu_low, __gu_ptr, "l", "=r", label); \ 264 __get_user_asm(__gu_high, __gu_ptr+1, "l", "=r", label); \ 265 (x) = ((unsigned long long)__gu_high << 32) | __gu_low; \ 266 } while (0) 267 #else 268 #define __get_user_asm_u64(x, ptr, label) \ 269 __get_user_asm(x, ptr, "q", "=r", label) 270 #endif 271 272 #define __get_user_size(x, ptr, size, label) \ 273 do { \ 274 __chk_user_ptr(ptr); \ 275 switch (size) { \ 276 case 1: { \ 277 unsigned char x_u8__; \ 278 __get_user_asm(x_u8__, ptr, "b", "=q", label); \ 279 (x) = x_u8__; \ 280 break; \ 281 } \ 282 case 2: \ 283 __get_user_asm(x, ptr, "w", "=r", label); \ 284 break; \ 285 case 4: \ 286 __get_user_asm(x, ptr, "l", "=r", label); \ 287 break; \ 288 case 8: \ 289 __get_user_asm_u64(x, ptr, label); \ 290 break; \ 291 default: \ 292 (x) = __get_user_bad(); \ 293 } \ 294 instrument_get_user(x); \ 295 } while (0) 296 297 #define __get_user_asm(x, addr, itype, ltype, label) \ 298 asm_volatile_goto("\n" \ 299 "1: mov"itype" %[umem],%[output]\n" \ 300 _ASM_EXTABLE_UA(1b, %l2) \ 301 : [output] ltype(x) \ 302 : [umem] "m" (__m(addr)) \ 303 : : label) 304 305 #else // !CONFIG_CC_HAS_ASM_GOTO_OUTPUT 306 307 #ifdef CONFIG_X86_32 308 #define __get_user_asm_u64(x, ptr, retval) \ 309 ({ \ 310 __typeof__(ptr) __ptr = (ptr); \ 311 asm volatile("\n" \ 312 "1: movl %[lowbits],%%eax\n" \ 313 "2: movl %[highbits],%%edx\n" \ 314 "3:\n" \ 315 _ASM_EXTABLE_TYPE_REG(1b, 3b, EX_TYPE_EFAULT_REG | \ 316 EX_FLAG_CLEAR_AX_DX, \ 317 %[errout]) \ 318 _ASM_EXTABLE_TYPE_REG(2b, 3b, EX_TYPE_EFAULT_REG | \ 319 EX_FLAG_CLEAR_AX_DX, \ 320 %[errout]) \ 321 : [errout] "=r" (retval), \ 322 [output] "=&A"(x) \ 323 : [lowbits] "m" (__m(__ptr)), \ 324 [highbits] "m" __m(((u32 __user *)(__ptr)) + 1), \ 325 "0" (retval)); \ 326 }) 327 328 #else 329 #define __get_user_asm_u64(x, ptr, retval) \ 330 __get_user_asm(x, ptr, retval, "q") 331 #endif 332 333 #define __get_user_size(x, ptr, size, retval) \ 334 do { \ 335 unsigned char x_u8__; \ 336 \ 337 retval = 0; \ 338 __chk_user_ptr(ptr); \ 339 switch (size) { \ 340 case 1: \ 341 __get_user_asm(x_u8__, ptr, retval, "b"); \ 342 (x) = x_u8__; \ 343 break; \ 344 case 2: \ 345 __get_user_asm(x, ptr, retval, "w"); \ 346 break; \ 347 case 4: \ 348 __get_user_asm(x, ptr, retval, "l"); \ 349 break; \ 350 case 8: \ 351 __get_user_asm_u64(x, ptr, retval); \ 352 break; \ 353 default: \ 354 (x) = __get_user_bad(); \ 355 } \ 356 } while (0) 357 358 #define __get_user_asm(x, addr, err, itype) \ 359 asm volatile("\n" \ 360 "1: mov"itype" %[umem],%[output]\n" \ 361 "2:\n" \ 362 _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG | \ 363 EX_FLAG_CLEAR_AX, \ 364 %[errout]) \ 365 : [errout] "=r" (err), \ 366 [output] "=a" (x) \ 367 : [umem] "m" (__m(addr)), \ 368 "0" (err)) 369 370 #endif // CONFIG_CC_HAS_ASM_GOTO_OUTPUT 371 372 #ifdef CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT 373 #define __try_cmpxchg_user_asm(itype, ltype, _ptr, _pold, _new, label) ({ \ 374 bool success; \ 375 __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \ 376 __typeof__(*(_ptr)) __old = *_old; \ 377 __typeof__(*(_ptr)) __new = (_new); \ 378 asm_volatile_goto("\n" \ 379 "1: " LOCK_PREFIX "cmpxchg"itype" %[new], %[ptr]\n"\ 380 _ASM_EXTABLE_UA(1b, %l[label]) \ 381 : CC_OUT(z) (success), \ 382 [ptr] "+m" (*_ptr), \ 383 [old] "+a" (__old) \ 384 : [new] ltype (__new) \ 385 : "memory" \ 386 : label); \ 387 if (unlikely(!success)) \ 388 *_old = __old; \ 389 likely(success); }) 390 391 #ifdef CONFIG_X86_32 392 #define __try_cmpxchg64_user_asm(_ptr, _pold, _new, label) ({ \ 393 bool success; \ 394 __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \ 395 __typeof__(*(_ptr)) __old = *_old; \ 396 __typeof__(*(_ptr)) __new = (_new); \ 397 asm_volatile_goto("\n" \ 398 "1: " LOCK_PREFIX "cmpxchg8b %[ptr]\n" \ 399 _ASM_EXTABLE_UA(1b, %l[label]) \ 400 : CC_OUT(z) (success), \ 401 "+A" (__old), \ 402 [ptr] "+m" (*_ptr) \ 403 : "b" ((u32)__new), \ 404 "c" ((u32)((u64)__new >> 32)) \ 405 : "memory" \ 406 : label); \ 407 if (unlikely(!success)) \ 408 *_old = __old; \ 409 likely(success); }) 410 #endif // CONFIG_X86_32 411 #else // !CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT 412 #define __try_cmpxchg_user_asm(itype, ltype, _ptr, _pold, _new, label) ({ \ 413 int __err = 0; \ 414 bool success; \ 415 __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \ 416 __typeof__(*(_ptr)) __old = *_old; \ 417 __typeof__(*(_ptr)) __new = (_new); \ 418 asm volatile("\n" \ 419 "1: " LOCK_PREFIX "cmpxchg"itype" %[new], %[ptr]\n"\ 420 CC_SET(z) \ 421 "2:\n" \ 422 _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, \ 423 %[errout]) \ 424 : CC_OUT(z) (success), \ 425 [errout] "+r" (__err), \ 426 [ptr] "+m" (*_ptr), \ 427 [old] "+a" (__old) \ 428 : [new] ltype (__new) \ 429 : "memory"); \ 430 if (unlikely(__err)) \ 431 goto label; \ 432 if (unlikely(!success)) \ 433 *_old = __old; \ 434 likely(success); }) 435 436 #ifdef CONFIG_X86_32 437 /* 438 * Unlike the normal CMPXCHG, use output GPR for both success/fail and error. 439 * There are only six GPRs available and four (EAX, EBX, ECX, and EDX) are 440 * hardcoded by CMPXCHG8B, leaving only ESI and EDI. If the compiler uses 441 * both ESI and EDI for the memory operand, compilation will fail if the error 442 * is an input+output as there will be no register available for input. 443 */ 444 #define __try_cmpxchg64_user_asm(_ptr, _pold, _new, label) ({ \ 445 int __result; \ 446 __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \ 447 __typeof__(*(_ptr)) __old = *_old; \ 448 __typeof__(*(_ptr)) __new = (_new); \ 449 asm volatile("\n" \ 450 "1: " LOCK_PREFIX "cmpxchg8b %[ptr]\n" \ 451 "mov $0, %[result]\n\t" \ 452 "setz %b[result]\n" \ 453 "2:\n" \ 454 _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, \ 455 %[result]) \ 456 : [result] "=q" (__result), \ 457 "+A" (__old), \ 458 [ptr] "+m" (*_ptr) \ 459 : "b" ((u32)__new), \ 460 "c" ((u32)((u64)__new >> 32)) \ 461 : "memory", "cc"); \ 462 if (unlikely(__result < 0)) \ 463 goto label; \ 464 if (unlikely(!__result)) \ 465 *_old = __old; \ 466 likely(__result); }) 467 #endif // CONFIG_X86_32 468 #endif // CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT 469 470 /* FIXME: this hack is definitely wrong -AK */ 471 struct __large_struct { unsigned long buf[100]; }; 472 #define __m(x) (*(struct __large_struct __user *)(x)) 473 474 /* 475 * Tell gcc we read from memory instead of writing: this is because 476 * we do not write to any memory gcc knows about, so there are no 477 * aliasing issues. 478 */ 479 #define __put_user_goto(x, addr, itype, ltype, label) \ 480 asm_volatile_goto("\n" \ 481 "1: mov"itype" %0,%1\n" \ 482 _ASM_EXTABLE_UA(1b, %l2) \ 483 : : ltype(x), "m" (__m(addr)) \ 484 : : label) 485 486 extern unsigned long 487 copy_from_user_nmi(void *to, const void __user *from, unsigned long n); 488 extern __must_check long 489 strncpy_from_user(char *dst, const char __user *src, long count); 490 491 extern __must_check long strnlen_user(const char __user *str, long n); 492 493 #ifdef CONFIG_ARCH_HAS_COPY_MC 494 unsigned long __must_check 495 copy_mc_to_kernel(void *to, const void *from, unsigned len); 496 #define copy_mc_to_kernel copy_mc_to_kernel 497 498 unsigned long __must_check 499 copy_mc_to_user(void *to, const void *from, unsigned len); 500 #endif 501 502 /* 503 * movsl can be slow when source and dest are not both 8-byte aligned 504 */ 505 #ifdef CONFIG_X86_INTEL_USERCOPY 506 extern struct movsl_mask { 507 int mask; 508 } ____cacheline_aligned_in_smp movsl_mask; 509 #endif 510 511 #define ARCH_HAS_NOCACHE_UACCESS 1 512 513 /* 514 * The "unsafe" user accesses aren't really "unsafe", but the naming 515 * is a big fat warning: you have to not only do the access_ok() 516 * checking before using them, but you have to surround them with the 517 * user_access_begin/end() pair. 518 */ 519 static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len) 520 { 521 if (unlikely(!access_ok(ptr,len))) 522 return 0; 523 __uaccess_begin_nospec(); 524 return 1; 525 } 526 #define user_access_begin(a,b) user_access_begin(a,b) 527 #define user_access_end() __uaccess_end() 528 529 #define user_access_save() smap_save() 530 #define user_access_restore(x) smap_restore(x) 531 532 #define unsafe_put_user(x, ptr, label) \ 533 __put_user_size((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), label) 534 535 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT 536 #define unsafe_get_user(x, ptr, err_label) \ 537 do { \ 538 __inttype(*(ptr)) __gu_val; \ 539 __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), err_label); \ 540 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 541 } while (0) 542 #else // !CONFIG_CC_HAS_ASM_GOTO_OUTPUT 543 #define unsafe_get_user(x, ptr, err_label) \ 544 do { \ 545 int __gu_err; \ 546 __inttype(*(ptr)) __gu_val; \ 547 __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), __gu_err); \ 548 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 549 if (unlikely(__gu_err)) goto err_label; \ 550 } while (0) 551 #endif // CONFIG_CC_HAS_ASM_GOTO_OUTPUT 552 553 extern void __try_cmpxchg_user_wrong_size(void); 554 555 #ifndef CONFIG_X86_32 556 #define __try_cmpxchg64_user_asm(_ptr, _oldp, _nval, _label) \ 557 __try_cmpxchg_user_asm("q", "r", (_ptr), (_oldp), (_nval), _label) 558 #endif 559 560 /* 561 * Force the pointer to u<size> to match the size expected by the asm helper. 562 * clang/LLVM compiles all cases and only discards the unused paths after 563 * processing errors, which breaks i386 if the pointer is an 8-byte value. 564 */ 565 #define unsafe_try_cmpxchg_user(_ptr, _oldp, _nval, _label) ({ \ 566 bool __ret; \ 567 __chk_user_ptr(_ptr); \ 568 switch (sizeof(*(_ptr))) { \ 569 case 1: __ret = __try_cmpxchg_user_asm("b", "q", \ 570 (__force u8 *)(_ptr), (_oldp), \ 571 (_nval), _label); \ 572 break; \ 573 case 2: __ret = __try_cmpxchg_user_asm("w", "r", \ 574 (__force u16 *)(_ptr), (_oldp), \ 575 (_nval), _label); \ 576 break; \ 577 case 4: __ret = __try_cmpxchg_user_asm("l", "r", \ 578 (__force u32 *)(_ptr), (_oldp), \ 579 (_nval), _label); \ 580 break; \ 581 case 8: __ret = __try_cmpxchg64_user_asm((__force u64 *)(_ptr), (_oldp),\ 582 (_nval), _label); \ 583 break; \ 584 default: __try_cmpxchg_user_wrong_size(); \ 585 } \ 586 __ret; }) 587 588 /* "Returns" 0 on success, 1 on failure, -EFAULT if the access faults. */ 589 #define __try_cmpxchg_user(_ptr, _oldp, _nval, _label) ({ \ 590 int __ret = -EFAULT; \ 591 __uaccess_begin_nospec(); \ 592 __ret = !unsafe_try_cmpxchg_user(_ptr, _oldp, _nval, _label); \ 593 _label: \ 594 __uaccess_end(); \ 595 __ret; \ 596 }) 597 598 /* 599 * We want the unsafe accessors to always be inlined and use 600 * the error labels - thus the macro games. 601 */ 602 #define unsafe_copy_loop(dst, src, len, type, label) \ 603 while (len >= sizeof(type)) { \ 604 unsafe_put_user(*(type *)(src),(type __user *)(dst),label); \ 605 dst += sizeof(type); \ 606 src += sizeof(type); \ 607 len -= sizeof(type); \ 608 } 609 610 #define unsafe_copy_to_user(_dst,_src,_len,label) \ 611 do { \ 612 char __user *__ucu_dst = (_dst); \ 613 const char *__ucu_src = (_src); \ 614 size_t __ucu_len = (_len); \ 615 unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u64, label); \ 616 unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u32, label); \ 617 unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u16, label); \ 618 unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u8, label); \ 619 } while (0) 620 621 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT 622 #define __get_kernel_nofault(dst, src, type, err_label) \ 623 __get_user_size(*((type *)(dst)), (__force type __user *)(src), \ 624 sizeof(type), err_label) 625 #else // !CONFIG_CC_HAS_ASM_GOTO_OUTPUT 626 #define __get_kernel_nofault(dst, src, type, err_label) \ 627 do { \ 628 int __kr_err; \ 629 \ 630 __get_user_size(*((type *)(dst)), (__force type __user *)(src), \ 631 sizeof(type), __kr_err); \ 632 if (unlikely(__kr_err)) \ 633 goto err_label; \ 634 } while (0) 635 #endif // CONFIG_CC_HAS_ASM_GOTO_OUTPUT 636 637 #define __put_kernel_nofault(dst, src, type, err_label) \ 638 __put_user_size(*((type *)(src)), (__force type __user *)(dst), \ 639 sizeof(type), err_label) 640 641 #endif /* _ASM_X86_UACCESS_H */ 642 643