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