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