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 #endif 15 16 #include <asm-generic/access_ok.h> 17 18 /* 19 * These are the main single-value transfer routines. They automatically 20 * use the right size if we just have the right pointer type. 21 * 22 * This gets kind of ugly. We want to return _two_ values in "get_user()" 23 * and yet we don't want to do any pointers, because that is too much 24 * of a performance impact. Thus we have a few rather ugly macros here, 25 * and hide all the ugliness from the user. 26 * 27 * The "__xxx" versions of the user access functions are versions that 28 * do not verify the address space, that must have been done previously 29 * with a separate "access_ok()" call (this is used when we do multiple 30 * accesses to the same area of user memory). 31 * 32 * As we use the same address space for kernel and user data on the 33 * PowerPC, we can just do these as direct assignments. (Of course, the 34 * exception handling means that it's no longer "just"...) 35 * 36 */ 37 #define __put_user(x, ptr) \ 38 ({ \ 39 long __pu_err; \ 40 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 41 __typeof__(*(ptr)) __pu_val = (__typeof__(*(ptr)))(x); \ 42 __typeof__(sizeof(*(ptr))) __pu_size = sizeof(*(ptr)); \ 43 \ 44 might_fault(); \ 45 do { \ 46 __label__ __pu_failed; \ 47 \ 48 allow_write_to_user(__pu_addr, __pu_size); \ 49 __put_user_size_goto(__pu_val, __pu_addr, __pu_size, __pu_failed); \ 50 prevent_write_to_user(__pu_addr, __pu_size); \ 51 __pu_err = 0; \ 52 break; \ 53 \ 54 __pu_failed: \ 55 prevent_write_to_user(__pu_addr, __pu_size); \ 56 __pu_err = -EFAULT; \ 57 } while (0); \ 58 \ 59 __pu_err; \ 60 }) 61 62 #define put_user(x, ptr) \ 63 ({ \ 64 __typeof__(*(ptr)) __user *_pu_addr = (ptr); \ 65 \ 66 access_ok(_pu_addr, sizeof(*(ptr))) ? \ 67 __put_user(x, _pu_addr) : -EFAULT; \ 68 }) 69 70 /* 71 * We don't tell gcc that we are accessing memory, but this is OK 72 * because we do not write to any memory gcc knows about, so there 73 * are no aliasing issues. 74 */ 75 #define __put_user_asm_goto(x, addr, label, op) \ 76 asm_volatile_goto( \ 77 "1: " op "%U1%X1 %0,%1 # put_user\n" \ 78 EX_TABLE(1b, %l2) \ 79 : \ 80 : "r" (x), "m<>" (*addr) \ 81 : \ 82 : label) 83 84 #ifdef __powerpc64__ 85 #define __put_user_asm2_goto(x, ptr, label) \ 86 __put_user_asm_goto(x, ptr, label, "std") 87 #else /* __powerpc64__ */ 88 #define __put_user_asm2_goto(x, addr, label) \ 89 asm_volatile_goto( \ 90 "1: stw%X1 %0, %1\n" \ 91 "2: stw%X1 %L0, %L1\n" \ 92 EX_TABLE(1b, %l2) \ 93 EX_TABLE(2b, %l2) \ 94 : \ 95 : "r" (x), "m" (*addr) \ 96 : \ 97 : label) 98 #endif /* __powerpc64__ */ 99 100 #define __put_user_size_goto(x, ptr, size, label) \ 101 do { \ 102 __typeof__(*(ptr)) __user *__pus_addr = (ptr); \ 103 \ 104 switch (size) { \ 105 case 1: __put_user_asm_goto(x, __pus_addr, label, "stb"); break; \ 106 case 2: __put_user_asm_goto(x, __pus_addr, label, "sth"); break; \ 107 case 4: __put_user_asm_goto(x, __pus_addr, label, "stw"); break; \ 108 case 8: __put_user_asm2_goto(x, __pus_addr, label); break; \ 109 default: BUILD_BUG(); \ 110 } \ 111 } while (0) 112 113 /* 114 * This does an atomic 128 byte aligned load from userspace. 115 * Upto caller to do enable_kernel_vmx() before calling! 116 */ 117 #define __get_user_atomic_128_aligned(kaddr, uaddr, err) \ 118 __asm__ __volatile__( \ 119 "1: lvx 0,0,%1 # get user\n" \ 120 " stvx 0,0,%2 # put kernel\n" \ 121 "2:\n" \ 122 ".section .fixup,\"ax\"\n" \ 123 "3: li %0,%3\n" \ 124 " b 2b\n" \ 125 ".previous\n" \ 126 EX_TABLE(1b, 3b) \ 127 : "=r" (err) \ 128 : "b" (uaddr), "b" (kaddr), "i" (-EFAULT), "0" (err)) 129 130 #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT 131 132 #define __get_user_asm_goto(x, addr, label, op) \ 133 asm_volatile_goto( \ 134 "1: "op"%U1%X1 %0, %1 # get_user\n" \ 135 EX_TABLE(1b, %l2) \ 136 : "=r" (x) \ 137 : "m<>" (*addr) \ 138 : \ 139 : label) 140 141 #ifdef __powerpc64__ 142 #define __get_user_asm2_goto(x, addr, label) \ 143 __get_user_asm_goto(x, addr, label, "ld") 144 #else /* __powerpc64__ */ 145 #define __get_user_asm2_goto(x, addr, label) \ 146 asm_volatile_goto( \ 147 "1: lwz%X1 %0, %1\n" \ 148 "2: lwz%X1 %L0, %L1\n" \ 149 EX_TABLE(1b, %l2) \ 150 EX_TABLE(2b, %l2) \ 151 : "=&r" (x) \ 152 : "m" (*addr) \ 153 : \ 154 : label) 155 #endif /* __powerpc64__ */ 156 157 #define __get_user_size_goto(x, ptr, size, label) \ 158 do { \ 159 BUILD_BUG_ON(size > sizeof(x)); \ 160 switch (size) { \ 161 case 1: __get_user_asm_goto(x, (u8 __user *)ptr, label, "lbz"); break; \ 162 case 2: __get_user_asm_goto(x, (u16 __user *)ptr, label, "lhz"); break; \ 163 case 4: __get_user_asm_goto(x, (u32 __user *)ptr, label, "lwz"); break; \ 164 case 8: __get_user_asm2_goto(x, (u64 __user *)ptr, label); break; \ 165 default: x = 0; BUILD_BUG(); \ 166 } \ 167 } while (0) 168 169 #define __get_user_size_allowed(x, ptr, size, retval) \ 170 do { \ 171 __label__ __gus_failed; \ 172 \ 173 __get_user_size_goto(x, ptr, size, __gus_failed); \ 174 retval = 0; \ 175 break; \ 176 __gus_failed: \ 177 x = 0; \ 178 retval = -EFAULT; \ 179 } while (0) 180 181 #else /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ 182 183 #define __get_user_asm(x, addr, err, op) \ 184 __asm__ __volatile__( \ 185 "1: "op"%U2%X2 %1, %2 # get_user\n" \ 186 "2:\n" \ 187 ".section .fixup,\"ax\"\n" \ 188 "3: li %0,%3\n" \ 189 " li %1,0\n" \ 190 " b 2b\n" \ 191 ".previous\n" \ 192 EX_TABLE(1b, 3b) \ 193 : "=r" (err), "=r" (x) \ 194 : "m<>" (*addr), "i" (-EFAULT), "0" (err)) 195 196 #ifdef __powerpc64__ 197 #define __get_user_asm2(x, addr, err) \ 198 __get_user_asm(x, addr, err, "ld") 199 #else /* __powerpc64__ */ 200 #define __get_user_asm2(x, addr, err) \ 201 __asm__ __volatile__( \ 202 "1: lwz%X2 %1, %2\n" \ 203 "2: lwz%X2 %L1, %L2\n" \ 204 "3:\n" \ 205 ".section .fixup,\"ax\"\n" \ 206 "4: li %0,%3\n" \ 207 " li %1,0\n" \ 208 " li %1+1,0\n" \ 209 " b 3b\n" \ 210 ".previous\n" \ 211 EX_TABLE(1b, 4b) \ 212 EX_TABLE(2b, 4b) \ 213 : "=r" (err), "=&r" (x) \ 214 : "m" (*addr), "i" (-EFAULT), "0" (err)) 215 #endif /* __powerpc64__ */ 216 217 #define __get_user_size_allowed(x, ptr, size, retval) \ 218 do { \ 219 retval = 0; \ 220 BUILD_BUG_ON(size > sizeof(x)); \ 221 switch (size) { \ 222 case 1: __get_user_asm(x, (u8 __user *)ptr, retval, "lbz"); break; \ 223 case 2: __get_user_asm(x, (u16 __user *)ptr, retval, "lhz"); break; \ 224 case 4: __get_user_asm(x, (u32 __user *)ptr, retval, "lwz"); break; \ 225 case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \ 226 default: x = 0; BUILD_BUG(); \ 227 } \ 228 } while (0) 229 230 #define __get_user_size_goto(x, ptr, size, label) \ 231 do { \ 232 long __gus_retval; \ 233 \ 234 __get_user_size_allowed(x, ptr, size, __gus_retval); \ 235 if (__gus_retval) \ 236 goto label; \ 237 } while (0) 238 239 #endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ 240 241 /* 242 * This is a type: either unsigned long, if the argument fits into 243 * that type, or otherwise unsigned long long. 244 */ 245 #define __long_type(x) \ 246 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) 247 248 #define __get_user(x, ptr) \ 249 ({ \ 250 long __gu_err; \ 251 __long_type(*(ptr)) __gu_val; \ 252 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 253 __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr)); \ 254 \ 255 might_fault(); \ 256 allow_read_from_user(__gu_addr, __gu_size); \ 257 __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \ 258 prevent_read_from_user(__gu_addr, __gu_size); \ 259 (x) = (__typeof__(*(ptr)))__gu_val; \ 260 \ 261 __gu_err; \ 262 }) 263 264 #define get_user(x, ptr) \ 265 ({ \ 266 __typeof__(*(ptr)) __user *_gu_addr = (ptr); \ 267 \ 268 access_ok(_gu_addr, sizeof(*(ptr))) ? \ 269 __get_user(x, _gu_addr) : \ 270 ((x) = (__force __typeof__(*(ptr)))0, -EFAULT); \ 271 }) 272 273 /* more complex routines */ 274 275 extern unsigned long __copy_tofrom_user(void __user *to, 276 const void __user *from, unsigned long size); 277 278 #ifdef __powerpc64__ 279 static inline unsigned long 280 raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) 281 { 282 unsigned long ret; 283 284 allow_read_write_user(to, from, n); 285 ret = __copy_tofrom_user(to, from, n); 286 prevent_read_write_user(to, from, n); 287 return ret; 288 } 289 #endif /* __powerpc64__ */ 290 291 static inline unsigned long raw_copy_from_user(void *to, 292 const void __user *from, unsigned long n) 293 { 294 unsigned long ret; 295 296 allow_read_from_user(from, n); 297 ret = __copy_tofrom_user((__force void __user *)to, from, n); 298 prevent_read_from_user(from, n); 299 return ret; 300 } 301 302 static inline unsigned long 303 raw_copy_to_user(void __user *to, const void *from, unsigned long n) 304 { 305 unsigned long ret; 306 307 allow_write_to_user(to, n); 308 ret = __copy_tofrom_user(to, (__force const void __user *)from, n); 309 prevent_write_to_user(to, n); 310 return ret; 311 } 312 313 unsigned long __arch_clear_user(void __user *addr, unsigned long size); 314 315 static inline unsigned long __clear_user(void __user *addr, unsigned long size) 316 { 317 unsigned long ret; 318 319 might_fault(); 320 allow_write_to_user(addr, size); 321 ret = __arch_clear_user(addr, size); 322 prevent_write_to_user(addr, size); 323 return ret; 324 } 325 326 static inline unsigned long clear_user(void __user *addr, unsigned long size) 327 { 328 return likely(access_ok(addr, size)) ? __clear_user(addr, size) : size; 329 } 330 331 extern long strncpy_from_user(char *dst, const char __user *src, long count); 332 extern __must_check long strnlen_user(const char __user *str, long n); 333 334 #ifdef CONFIG_ARCH_HAS_COPY_MC 335 unsigned long __must_check 336 copy_mc_generic(void *to, const void *from, unsigned long size); 337 338 static inline unsigned long __must_check 339 copy_mc_to_kernel(void *to, const void *from, unsigned long size) 340 { 341 return copy_mc_generic(to, from, size); 342 } 343 #define copy_mc_to_kernel copy_mc_to_kernel 344 345 static inline unsigned long __must_check 346 copy_mc_to_user(void __user *to, const void *from, unsigned long n) 347 { 348 if (likely(check_copy_size(from, n, true))) { 349 if (access_ok(to, n)) { 350 allow_write_to_user(to, n); 351 n = copy_mc_generic((void *)to, from, n); 352 prevent_write_to_user(to, n); 353 } 354 } 355 356 return n; 357 } 358 #endif 359 360 extern long __copy_from_user_flushcache(void *dst, const void __user *src, 361 unsigned size); 362 extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset, 363 size_t len); 364 365 static __must_check inline bool user_access_begin(const void __user *ptr, size_t len) 366 { 367 if (unlikely(!access_ok(ptr, len))) 368 return false; 369 370 might_fault(); 371 372 allow_read_write_user((void __user *)ptr, ptr, len); 373 return true; 374 } 375 #define user_access_begin user_access_begin 376 #define user_access_end prevent_current_access_user 377 #define user_access_save prevent_user_access_return 378 #define user_access_restore restore_user_access 379 380 static __must_check inline bool 381 user_read_access_begin(const void __user *ptr, size_t len) 382 { 383 if (unlikely(!access_ok(ptr, len))) 384 return false; 385 386 might_fault(); 387 388 allow_read_from_user(ptr, len); 389 return true; 390 } 391 #define user_read_access_begin user_read_access_begin 392 #define user_read_access_end prevent_current_read_from_user 393 394 static __must_check inline bool 395 user_write_access_begin(const void __user *ptr, size_t len) 396 { 397 if (unlikely(!access_ok(ptr, len))) 398 return false; 399 400 might_fault(); 401 402 allow_write_to_user((void __user *)ptr, len); 403 return true; 404 } 405 #define user_write_access_begin user_write_access_begin 406 #define user_write_access_end prevent_current_write_to_user 407 408 #define unsafe_get_user(x, p, e) do { \ 409 __long_type(*(p)) __gu_val; \ 410 __typeof__(*(p)) __user *__gu_addr = (p); \ 411 \ 412 __get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \ 413 (x) = (__typeof__(*(p)))__gu_val; \ 414 } while (0) 415 416 #define unsafe_put_user(x, p, e) \ 417 __put_user_size_goto((__typeof__(*(p)))(x), (p), sizeof(*(p)), e) 418 419 #define unsafe_copy_from_user(d, s, l, e) \ 420 do { \ 421 u8 *_dst = (u8 *)(d); \ 422 const u8 __user *_src = (const u8 __user *)(s); \ 423 size_t _len = (l); \ 424 int _i; \ 425 \ 426 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \ 427 unsafe_get_user(*(u64 *)(_dst + _i), (u64 __user *)(_src + _i), e); \ 428 if (_len & 4) { \ 429 unsafe_get_user(*(u32 *)(_dst + _i), (u32 __user *)(_src + _i), e); \ 430 _i += 4; \ 431 } \ 432 if (_len & 2) { \ 433 unsafe_get_user(*(u16 *)(_dst + _i), (u16 __user *)(_src + _i), e); \ 434 _i += 2; \ 435 } \ 436 if (_len & 1) \ 437 unsafe_get_user(*(u8 *)(_dst + _i), (u8 __user *)(_src + _i), e); \ 438 } while (0) 439 440 #define unsafe_copy_to_user(d, s, l, e) \ 441 do { \ 442 u8 __user *_dst = (u8 __user *)(d); \ 443 const u8 *_src = (const u8 *)(s); \ 444 size_t _len = (l); \ 445 int _i; \ 446 \ 447 for (_i = 0; _i < (_len & ~(sizeof(u64) - 1)); _i += sizeof(u64)) \ 448 unsafe_put_user(*(u64 *)(_src + _i), (u64 __user *)(_dst + _i), e); \ 449 if (_len & 4) { \ 450 unsafe_put_user(*(u32*)(_src + _i), (u32 __user *)(_dst + _i), e); \ 451 _i += 4; \ 452 } \ 453 if (_len & 2) { \ 454 unsafe_put_user(*(u16*)(_src + _i), (u16 __user *)(_dst + _i), e); \ 455 _i += 2; \ 456 } \ 457 if (_len & 1) \ 458 unsafe_put_user(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e); \ 459 } while (0) 460 461 #define __get_kernel_nofault(dst, src, type, err_label) \ 462 __get_user_size_goto(*((type *)(dst)), \ 463 (__force type __user *)(src), sizeof(type), err_label) 464 465 #define __put_kernel_nofault(dst, src, type, err_label) \ 466 __put_user_size_goto(*((type *)(src)), \ 467 (__force type __user *)(dst), sizeof(type), err_label) 468 469 #endif /* _ARCH_POWERPC_UACCESS_H */ 470