1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ARCH_POWERPC_UACCESS_H 3 #define _ARCH_POWERPC_UACCESS_H 4 5 #include <asm/ppc_asm.h> 6 #include <asm/processor.h> 7 #include <asm/page.h> 8 #include <asm/extable.h> 9 #include <asm/kup.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 #else 15 #define TASK_SIZE_MAX TASK_SIZE 16 #endif 17 18 static inline bool __access_ok(unsigned long addr, unsigned long size) 19 { 20 return addr < TASK_SIZE_MAX && size <= TASK_SIZE_MAX - addr; 21 } 22 23 #define access_ok(addr, size) \ 24 (__chk_user_ptr(addr), \ 25 __access_ok((unsigned long)(addr), (size))) 26 27 /* 28 * These are the main single-value transfer routines. They automatically 29 * use the right size if we just have the right pointer type. 30 * 31 * This gets kind of ugly. We want to return _two_ values in "get_user()" 32 * and yet we don't want to do any pointers, because that is too much 33 * of a performance impact. Thus we have a few rather ugly macros here, 34 * and hide all the ugliness from the user. 35 * 36 * The "__xxx" versions of the user access functions are versions that 37 * do not verify the address space, that must have been done previously 38 * with a separate "access_ok()" call (this is used when we do multiple 39 * accesses to the same area of user memory). 40 * 41 * As we use the same address space for kernel and user data on the 42 * PowerPC, we can just do these as direct assignments. (Of course, the 43 * exception handling means that it's no longer "just"...) 44 * 45 */ 46 #define get_user(x, ptr) \ 47 __get_user_check((x), (ptr), sizeof(*(ptr))) 48 #define put_user(x, ptr) \ 49 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 50 51 #define __get_user(x, ptr) \ 52 __get_user_nocheck((x), (ptr), sizeof(*(ptr)), true) 53 #define __put_user(x, ptr) \ 54 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 55 56 #define __get_user_allowed(x, ptr) \ 57 __get_user_nocheck((x), (ptr), sizeof(*(ptr)), false) 58 59 #define __get_user_inatomic(x, ptr) \ 60 __get_user_nosleep((x), (ptr), sizeof(*(ptr))) 61 #define __put_user_inatomic(x, ptr) \ 62 __put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 63 64 #ifdef CONFIG_PPC64 65 66 #define ___get_user_instr(gu_op, dest, ptr) \ 67 ({ \ 68 long __gui_ret = 0; \ 69 unsigned long __gui_ptr = (unsigned long)ptr; \ 70 struct ppc_inst __gui_inst; \ 71 unsigned int __prefix, __suffix; \ 72 __gui_ret = gu_op(__prefix, (unsigned int __user *)__gui_ptr); \ 73 if (__gui_ret == 0) { \ 74 if ((__prefix >> 26) == OP_PREFIX) { \ 75 __gui_ret = gu_op(__suffix, \ 76 (unsigned int __user *)__gui_ptr + 1); \ 77 __gui_inst = ppc_inst_prefix(__prefix, \ 78 __suffix); \ 79 } else { \ 80 __gui_inst = ppc_inst(__prefix); \ 81 } \ 82 if (__gui_ret == 0) \ 83 (dest) = __gui_inst; \ 84 } \ 85 __gui_ret; \ 86 }) 87 88 #define get_user_instr(x, ptr) \ 89 ___get_user_instr(get_user, x, ptr) 90 91 #define __get_user_instr(x, ptr) \ 92 ___get_user_instr(__get_user, x, ptr) 93 94 #define __get_user_instr_inatomic(x, ptr) \ 95 ___get_user_instr(__get_user_inatomic, x, ptr) 96 97 #else /* !CONFIG_PPC64 */ 98 #define get_user_instr(x, ptr) \ 99 get_user((x).val, (u32 __user *)(ptr)) 100 101 #define __get_user_instr(x, ptr) \ 102 __get_user_nocheck((x).val, (u32 __user *)(ptr), sizeof(u32), true) 103 104 #define __get_user_instr_inatomic(x, ptr) \ 105 __get_user_nosleep((x).val, (u32 __user *)(ptr), sizeof(u32)) 106 107 #endif /* CONFIG_PPC64 */ 108 109 extern long __put_user_bad(void); 110 111 #define __put_user_size(x, ptr, size, retval) \ 112 do { \ 113 __label__ __pu_failed; \ 114 \ 115 retval = 0; \ 116 allow_write_to_user(ptr, size); \ 117 __put_user_size_goto(x, ptr, size, __pu_failed); \ 118 prevent_write_to_user(ptr, size); \ 119 break; \ 120 \ 121 __pu_failed: \ 122 retval = -EFAULT; \ 123 prevent_write_to_user(ptr, size); \ 124 } while (0) 125 126 #define __put_user_nocheck(x, ptr, size) \ 127 ({ \ 128 long __pu_err; \ 129 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 130 __typeof__(*(ptr)) __pu_val = (x); \ 131 __typeof__(size) __pu_size = (size); \ 132 \ 133 if (!is_kernel_addr((unsigned long)__pu_addr)) \ 134 might_fault(); \ 135 __chk_user_ptr(__pu_addr); \ 136 __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \ 137 \ 138 __pu_err; \ 139 }) 140 141 #define __put_user_check(x, ptr, size) \ 142 ({ \ 143 long __pu_err = -EFAULT; \ 144 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 145 __typeof__(*(ptr)) __pu_val = (x); \ 146 __typeof__(size) __pu_size = (size); \ 147 \ 148 might_fault(); \ 149 if (access_ok(__pu_addr, __pu_size)) \ 150 __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \ 151 \ 152 __pu_err; \ 153 }) 154 155 #define __put_user_nosleep(x, ptr, size) \ 156 ({ \ 157 long __pu_err; \ 158 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 159 __typeof__(*(ptr)) __pu_val = (x); \ 160 __typeof__(size) __pu_size = (size); \ 161 \ 162 __chk_user_ptr(__pu_addr); \ 163 __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \ 164 \ 165 __pu_err; \ 166 }) 167 168 169 /* 170 * We don't tell gcc that we are accessing memory, but this is OK 171 * because we do not write to any memory gcc knows about, so there 172 * are no aliasing issues. 173 */ 174 #define __put_user_asm_goto(x, addr, label, op) \ 175 asm_volatile_goto( \ 176 "1: " op "%U1%X1 %0,%1 # put_user\n" \ 177 EX_TABLE(1b, %l2) \ 178 : \ 179 : "r" (x), "m"UPD_CONSTR (*addr) \ 180 : \ 181 : label) 182 183 #ifdef __powerpc64__ 184 #define __put_user_asm2_goto(x, ptr, label) \ 185 __put_user_asm_goto(x, ptr, label, "std") 186 #else /* __powerpc64__ */ 187 #define __put_user_asm2_goto(x, addr, label) \ 188 asm_volatile_goto( \ 189 "1: stw%X1 %0, %1\n" \ 190 "2: stw%X1 %L0, %L1\n" \ 191 EX_TABLE(1b, %l2) \ 192 EX_TABLE(2b, %l2) \ 193 : \ 194 : "r" (x), "m" (*addr) \ 195 : \ 196 : label) 197 #endif /* __powerpc64__ */ 198 199 #define __put_user_size_goto(x, ptr, size, label) \ 200 do { \ 201 switch (size) { \ 202 case 1: __put_user_asm_goto(x, ptr, label, "stb"); break; \ 203 case 2: __put_user_asm_goto(x, ptr, label, "sth"); break; \ 204 case 4: __put_user_asm_goto(x, ptr, label, "stw"); break; \ 205 case 8: __put_user_asm2_goto(x, ptr, label); break; \ 206 default: __put_user_bad(); \ 207 } \ 208 } while (0) 209 210 #define __unsafe_put_user_goto(x, ptr, size, label) \ 211 do { \ 212 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 213 __chk_user_ptr(ptr); \ 214 __put_user_size_goto((x), __pu_addr, (size), label); \ 215 } while (0) 216 217 218 extern long __get_user_bad(void); 219 220 /* 221 * This does an atomic 128 byte aligned load from userspace. 222 * Upto caller to do enable_kernel_vmx() before calling! 223 */ 224 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \ 225 __asm__ __volatile__( \ 226 "1: lvx 0,0,%1 # get user\n" \ 227 " stvx 0,0,%2 # put kernel\n" \ 228 "2:\n" \ 229 ".section .fixup,\"ax\"\n" \ 230 "3: li %0,%3\n" \ 231 " b 2b\n" \ 232 ".previous\n" \ 233 EX_TABLE(1b, 3b) \ 234 : "=r" (err) \ 235 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err)) 236 237 #define __get_user_asm(x, addr, err, op) \ 238 __asm__ __volatile__( \ 239 "1: "op"%U2%X2 %1, %2 # get_user\n" \ 240 "2:\n" \ 241 ".section .fixup,\"ax\"\n" \ 242 "3: li %0,%3\n" \ 243 " li %1,0\n" \ 244 " b 2b\n" \ 245 ".previous\n" \ 246 EX_TABLE(1b, 3b) \ 247 : "=r" (err), "=r" (x) \ 248 : "m"UPD_CONSTR (*addr), "i" (-EFAULT), "0" (err)) 249 250 #ifdef __powerpc64__ 251 #define __get_user_asm2(x, addr, err) \ 252 __get_user_asm(x, addr, err, "ld") 253 #else /* __powerpc64__ */ 254 #define __get_user_asm2(x, addr, err) \ 255 __asm__ __volatile__( \ 256 "1: lwz%X2 %1, %2\n" \ 257 "2: lwz%X2 %L1, %L2\n" \ 258 "3:\n" \ 259 ".section .fixup,\"ax\"\n" \ 260 "4: li %0,%3\n" \ 261 " li %1,0\n" \ 262 " li %1+1,0\n" \ 263 " b 3b\n" \ 264 ".previous\n" \ 265 EX_TABLE(1b, 4b) \ 266 EX_TABLE(2b, 4b) \ 267 : "=r" (err), "=&r" (x) \ 268 : "m" (*addr), "i" (-EFAULT), "0" (err)) 269 #endif /* __powerpc64__ */ 270 271 #define __get_user_size_allowed(x, ptr, size, retval) \ 272 do { \ 273 retval = 0; \ 274 __chk_user_ptr(ptr); \ 275 if (size > sizeof(x)) \ 276 (x) = __get_user_bad(); \ 277 switch (size) { \ 278 case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; \ 279 case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; \ 280 case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \ 281 case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \ 282 default: (x) = __get_user_bad(); \ 283 } \ 284 } while (0) 285 286 #define __get_user_size(x, ptr, size, retval) \ 287 do { \ 288 allow_read_from_user(ptr, size); \ 289 __get_user_size_allowed(x, ptr, size, retval); \ 290 prevent_read_from_user(ptr, size); \ 291 } while (0) 292 293 /* 294 * This is a type: either unsigned long, if the argument fits into 295 * that type, or otherwise unsigned long long. 296 */ 297 #define __long_type(x) \ 298 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) 299 300 #define __get_user_nocheck(x, ptr, size, do_allow) \ 301 ({ \ 302 long __gu_err; \ 303 __long_type(*(ptr)) __gu_val; \ 304 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 305 __typeof__(size) __gu_size = (size); \ 306 \ 307 __chk_user_ptr(__gu_addr); \ 308 if (do_allow && !is_kernel_addr((unsigned long)__gu_addr)) \ 309 might_fault(); \ 310 if (do_allow) \ 311 __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \ 312 else \ 313 __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \ 314 (x) = (__typeof__(*(ptr)))__gu_val; \ 315 \ 316 __gu_err; \ 317 }) 318 319 #define __get_user_check(x, ptr, size) \ 320 ({ \ 321 long __gu_err = -EFAULT; \ 322 __long_type(*(ptr)) __gu_val = 0; \ 323 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 324 __typeof__(size) __gu_size = (size); \ 325 \ 326 might_fault(); \ 327 if (access_ok(__gu_addr, __gu_size)) \ 328 __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \ 329 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 330 \ 331 __gu_err; \ 332 }) 333 334 #define __get_user_nosleep(x, ptr, size) \ 335 ({ \ 336 long __gu_err; \ 337 __long_type(*(ptr)) __gu_val; \ 338 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 339 __typeof__(size) __gu_size = (size); \ 340 \ 341 __chk_user_ptr(__gu_addr); \ 342 __get_user_size(__gu_val, __gu_addr, __gu_size, __gu_err); \ 343 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 344 \ 345 __gu_err; \ 346 }) 347 348 349 /* more complex routines */ 350 351 extern unsigned long __copy_tofrom_user(void __user *to, 352 const void __user *from, unsigned long size); 353 354 #ifdef CONFIG_ARCH_HAS_COPY_MC 355 unsigned long __must_check 356 copy_mc_generic(void *to, const void *from, unsigned long size); 357 358 static inline unsigned long __must_check 359 copy_mc_to_kernel(void *to, const void *from, unsigned long size) 360 { 361 return copy_mc_generic(to, from, size); 362 } 363 #define copy_mc_to_kernel copy_mc_to_kernel 364 365 static inline unsigned long __must_check 366 copy_mc_to_user(void __user *to, const void *from, unsigned long n) 367 { 368 if (likely(check_copy_size(from, n, true))) { 369 if (access_ok(to, n)) { 370 allow_write_to_user(to, n); 371 n = copy_mc_generic((void *)to, from, n); 372 prevent_write_to_user(to, n); 373 } 374 } 375 376 return n; 377 } 378 #endif 379 380 #ifdef __powerpc64__ 381 static inline unsigned long 382 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 383 { 384 unsigned long ret; 385 386 allow_read_write_user(to, from, n); 387 ret = __copy_tofrom_user(to, from, n); 388 prevent_read_write_user(to, from, n); 389 return ret; 390 } 391 #endif /* __powerpc64__ */ 392 393 static inline unsigned long raw_copy_from_user(void *to, 394 const void __user *from, unsigned long n) 395 { 396 unsigned long ret; 397 398 allow_read_from_user(from, n); 399 ret = __copy_tofrom_user((__force void __user *)to, from, n); 400 prevent_read_from_user(from, n); 401 return ret; 402 } 403 404 static inline unsigned long 405 raw_copy_to_user(void __user *to, const void *from, unsigned long n) 406 { 407 unsigned long ret; 408 409 allow_write_to_user(to, n); 410 ret = __copy_tofrom_user(to, (__force const void __user *)from, n); 411 prevent_write_to_user(to, n); 412 return ret; 413 } 414 415 unsigned long __arch_clear_user(void __user *addr, unsigned long size); 416 417 static inline unsigned long clear_user(void __user *addr, unsigned long size) 418 { 419 unsigned long ret = size; 420 might_fault(); 421 if (likely(access_ok(addr, size))) { 422 allow_write_to_user(addr, size); 423 ret = __arch_clear_user(addr, size); 424 prevent_write_to_user(addr, size); 425 } 426 return ret; 427 } 428 429 static inline unsigned long __clear_user(void __user *addr, unsigned long size) 430 { 431 return clear_user(addr, size); 432 } 433 434 extern long strncpy_from_user(char *dst, const char __user *src, long count); 435 extern __must_check long strnlen_user(const char __user *str, long n); 436 437 extern long __copy_from_user_flushcache(void *dst, const void __user *src, 438 unsigned size); 439 extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset, 440 size_t len); 441 442 static __must_check inline bool user_access_begin(const void __user *ptr, size_t len) 443 { 444 if (unlikely(!access_ok(ptr, len))) 445 return false; 446 447 might_fault(); 448 449 allow_read_write_user((void __user *)ptr, ptr, len); 450 return true; 451 } 452 #define user_access_begin user_access_begin 453 #define user_access_end prevent_current_access_user 454 #define user_access_save prevent_user_access_return 455 #define user_access_restore restore_user_access 456 457 static __must_check inline bool 458 user_read_access_begin(const void __user *ptr, size_t len) 459 { 460 if (unlikely(!access_ok(ptr, len))) 461 return false; 462 463 might_fault(); 464 465 allow_read_from_user(ptr, len); 466 return true; 467 } 468 #define user_read_access_begin user_read_access_begin 469 #define user_read_access_end prevent_current_read_from_user 470 471 static __must_check inline bool 472 user_write_access_begin(const void __user *ptr, size_t len) 473 { 474 if (unlikely(!access_ok(ptr, len))) 475 return false; 476 477 might_fault(); 478 479 allow_write_to_user((void __user *)ptr, len); 480 return true; 481 } 482 #define user_write_access_begin user_write_access_begin 483 #define user_write_access_end prevent_current_write_to_user 484 485 #define unsafe_op_wrap(op, err) do { if (unlikely(op)) goto err; } while (0) 486 #define unsafe_get_user(x, p, e) unsafe_op_wrap(__get_user_allowed(x, p), e) 487 #define unsafe_put_user(x, p, e) \ 488 __unsafe_put_user_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e) 489 490 #define unsafe_copy_to_user(d, s, l, e) \ 491 do { \ 492 u8 __user *_dst = (u8 __user *)(d); \ 493 const u8 *_src = (const u8 *)(s); \ 494 size_t _len = (l); \ 495 int _i; \ 496 \ 497 for (_i = 0; _i < (_len & ~(sizeof(long) - 1)); _i += sizeof(long)) \ 498 unsafe_put_user(*(long*)(_src + _i), (long __user *)(_dst + _i), e); \ 499 if (IS_ENABLED(CONFIG_PPC64) && (_len & 4)) { \ 500 unsafe_put_user(*(u32*)(_src + _i), (u32 __user *)(_dst + _i), e); \ 501 _i += 4; \ 502 } \ 503 if (_len & 2) { \ 504 unsafe_put_user(*(u16*)(_src + _i), (u16 __user *)(_dst + _i), e); \ 505 _i += 2; \ 506 } \ 507 if (_len & 1) \ 508 unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \ 509 } while (0) 510 511 #define HAVE_GET_KERNEL_NOFAULT 512 513 #define __get_kernel_nofault(dst, src, type, err_label) \ 514 do { \ 515 int __kr_err; \ 516 \ 517 __get_user_size_allowed(*((type *)(dst)), (__force type __user *)(src),\ 518 sizeof(type), __kr_err); \ 519 if (unlikely(__kr_err)) \ 520 goto err_label; \ 521 } while (0) 522 523 #define __put_kernel_nofault(dst, src, type, err_label) \ 524 __put_user_size_goto(*((type *)(src)), \ 525 (__force type __user *)(dst), sizeof(type), err_label) 526 527 #endif /* _ARCH_POWERPC_UACCESS_H */ 528