1 #ifndef _ARCH_POWERPC_UACCESS_H 2 #define _ARCH_POWERPC_UACCESS_H 3 4 #ifdef __KERNEL__ 5 #ifndef __ASSEMBLY__ 6 7 #include <linux/sched.h> 8 #include <linux/errno.h> 9 #include <asm/asm-compat.h> 10 #include <asm/processor.h> 11 #include <asm/page.h> 12 13 #define VERIFY_READ 0 14 #define VERIFY_WRITE 1 15 16 /* 17 * The fs value determines whether argument validity checking should be 18 * performed or not. If get_fs() == USER_DS, checking is performed, with 19 * get_fs() == KERNEL_DS, checking is bypassed. 20 * 21 * For historical reasons, these macros are grossly misnamed. 22 * 23 * The fs/ds values are now the highest legal address in the "segment". 24 * This simplifies the checking in the routines below. 25 */ 26 27 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 28 29 #define KERNEL_DS MAKE_MM_SEG(~0UL) 30 #ifdef __powerpc64__ 31 /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */ 32 #define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1) 33 #else 34 #define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) 35 #endif 36 37 #define get_ds() (KERNEL_DS) 38 #define get_fs() (current->thread.fs) 39 #define set_fs(val) (current->thread.fs = (val)) 40 41 #define segment_eq(a, b) ((a).seg == (b).seg) 42 43 #define user_addr_max() (get_fs().seg) 44 45 #ifdef __powerpc64__ 46 /* 47 * This check is sufficient because there is a large enough 48 * gap between user addresses and the kernel addresses 49 */ 50 #define __access_ok(addr, size, segment) \ 51 (((addr) <= (segment).seg) && ((size) <= (segment).seg)) 52 53 #else 54 55 #define __access_ok(addr, size, segment) \ 56 (((addr) <= (segment).seg) && \ 57 (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr))))) 58 59 #endif 60 61 #define access_ok(type, addr, size) \ 62 (__chk_user_ptr(addr), \ 63 __access_ok((__force unsigned long)(addr), (size), get_fs())) 64 65 /* 66 * The exception table consists of pairs of addresses: the first is the 67 * address of an instruction that is allowed to fault, and the second is 68 * the address at which the program should continue. No registers are 69 * modified, so it is entirely up to the continuation code to figure out 70 * what to do. 71 * 72 * All the routines below use bits of fixup code that are out of line 73 * with the main instruction path. This means when everything is well, 74 * we don't even have to jump over them. Further, they do not intrude 75 * on our cache or tlb entries. 76 */ 77 78 struct exception_table_entry { 79 unsigned long insn; 80 unsigned long fixup; 81 }; 82 83 /* 84 * These are the main single-value transfer routines. They automatically 85 * use the right size if we just have the right pointer type. 86 * 87 * This gets kind of ugly. We want to return _two_ values in "get_user()" 88 * and yet we don't want to do any pointers, because that is too much 89 * of a performance impact. Thus we have a few rather ugly macros here, 90 * and hide all the ugliness from the user. 91 * 92 * The "__xxx" versions of the user access functions are versions that 93 * do not verify the address space, that must have been done previously 94 * with a separate "access_ok()" call (this is used when we do multiple 95 * accesses to the same area of user memory). 96 * 97 * As we use the same address space for kernel and user data on the 98 * PowerPC, we can just do these as direct assignments. (Of course, the 99 * exception handling means that it's no longer "just"...) 100 * 101 */ 102 #define get_user(x, ptr) \ 103 __get_user_check((x), (ptr), sizeof(*(ptr))) 104 #define put_user(x, ptr) \ 105 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 106 107 #define __get_user(x, ptr) \ 108 __get_user_nocheck((x), (ptr), sizeof(*(ptr))) 109 #define __put_user(x, ptr) \ 110 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 111 112 #define __get_user_inatomic(x, ptr) \ 113 __get_user_nosleep((x), (ptr), sizeof(*(ptr))) 114 #define __put_user_inatomic(x, ptr) \ 115 __put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) 116 117 #define __get_user_unaligned __get_user 118 #define __put_user_unaligned __put_user 119 120 extern long __put_user_bad(void); 121 122 /* 123 * We don't tell gcc that we are accessing memory, but this is OK 124 * because we do not write to any memory gcc knows about, so there 125 * are no aliasing issues. 126 */ 127 #define __put_user_asm(x, addr, err, op) \ 128 __asm__ __volatile__( \ 129 "1: " op " %1,0(%2) # put_user\n" \ 130 "2:\n" \ 131 ".section .fixup,\"ax\"\n" \ 132 "3: li %0,%3\n" \ 133 " b 2b\n" \ 134 ".previous\n" \ 135 ".section __ex_table,\"a\"\n" \ 136 PPC_LONG_ALIGN "\n" \ 137 PPC_LONG "1b,3b\n" \ 138 ".previous" \ 139 : "=r" (err) \ 140 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 141 142 #ifdef __powerpc64__ 143 #define __put_user_asm2(x, ptr, retval) \ 144 __put_user_asm(x, ptr, retval, "std") 145 #else /* __powerpc64__ */ 146 #define __put_user_asm2(x, addr, err) \ 147 __asm__ __volatile__( \ 148 "1: stw %1,0(%2)\n" \ 149 "2: stw %1+1,4(%2)\n" \ 150 "3:\n" \ 151 ".section .fixup,\"ax\"\n" \ 152 "4: li %0,%3\n" \ 153 " b 3b\n" \ 154 ".previous\n" \ 155 ".section __ex_table,\"a\"\n" \ 156 PPC_LONG_ALIGN "\n" \ 157 PPC_LONG "1b,4b\n" \ 158 PPC_LONG "2b,4b\n" \ 159 ".previous" \ 160 : "=r" (err) \ 161 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 162 #endif /* __powerpc64__ */ 163 164 #define __put_user_size(x, ptr, size, retval) \ 165 do { \ 166 retval = 0; \ 167 switch (size) { \ 168 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \ 169 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \ 170 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ 171 case 8: __put_user_asm2(x, ptr, retval); break; \ 172 default: __put_user_bad(); \ 173 } \ 174 } while (0) 175 176 #define __put_user_nocheck(x, ptr, size) \ 177 ({ \ 178 long __pu_err; \ 179 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 180 if (!is_kernel_addr((unsigned long)__pu_addr)) \ 181 might_fault(); \ 182 __chk_user_ptr(ptr); \ 183 __put_user_size((x), __pu_addr, (size), __pu_err); \ 184 __pu_err; \ 185 }) 186 187 #define __put_user_check(x, ptr, size) \ 188 ({ \ 189 long __pu_err = -EFAULT; \ 190 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 191 might_fault(); \ 192 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ 193 __put_user_size((x), __pu_addr, (size), __pu_err); \ 194 __pu_err; \ 195 }) 196 197 #define __put_user_nosleep(x, ptr, size) \ 198 ({ \ 199 long __pu_err; \ 200 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 201 __chk_user_ptr(ptr); \ 202 __put_user_size((x), __pu_addr, (size), __pu_err); \ 203 __pu_err; \ 204 }) 205 206 207 extern long __get_user_bad(void); 208 209 #define __get_user_asm(x, addr, err, op) \ 210 __asm__ __volatile__( \ 211 "1: "op" %1,0(%2) # get_user\n" \ 212 "2:\n" \ 213 ".section .fixup,\"ax\"\n" \ 214 "3: li %0,%3\n" \ 215 " li %1,0\n" \ 216 " b 2b\n" \ 217 ".previous\n" \ 218 ".section __ex_table,\"a\"\n" \ 219 PPC_LONG_ALIGN "\n" \ 220 PPC_LONG "1b,3b\n" \ 221 ".previous" \ 222 : "=r" (err), "=r" (x) \ 223 : "b" (addr), "i" (-EFAULT), "0" (err)) 224 225 #ifdef __powerpc64__ 226 #define __get_user_asm2(x, addr, err) \ 227 __get_user_asm(x, addr, err, "ld") 228 #else /* __powerpc64__ */ 229 #define __get_user_asm2(x, addr, err) \ 230 __asm__ __volatile__( \ 231 "1: lwz %1,0(%2)\n" \ 232 "2: lwz %1+1,4(%2)\n" \ 233 "3:\n" \ 234 ".section .fixup,\"ax\"\n" \ 235 "4: li %0,%3\n" \ 236 " li %1,0\n" \ 237 " li %1+1,0\n" \ 238 " b 3b\n" \ 239 ".previous\n" \ 240 ".section __ex_table,\"a\"\n" \ 241 PPC_LONG_ALIGN "\n" \ 242 PPC_LONG "1b,4b\n" \ 243 PPC_LONG "2b,4b\n" \ 244 ".previous" \ 245 : "=r" (err), "=&r" (x) \ 246 : "b" (addr), "i" (-EFAULT), "0" (err)) 247 #endif /* __powerpc64__ */ 248 249 #define __get_user_size(x, ptr, size, retval) \ 250 do { \ 251 retval = 0; \ 252 __chk_user_ptr(ptr); \ 253 if (size > sizeof(x)) \ 254 (x) = __get_user_bad(); \ 255 switch (size) { \ 256 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ 257 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ 258 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ 259 case 8: __get_user_asm2(x, ptr, retval); break; \ 260 default: (x) = __get_user_bad(); \ 261 } \ 262 } while (0) 263 264 #define __get_user_nocheck(x, ptr, size) \ 265 ({ \ 266 long __gu_err; \ 267 unsigned long __gu_val; \ 268 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 269 __chk_user_ptr(ptr); \ 270 if (!is_kernel_addr((unsigned long)__gu_addr)) \ 271 might_fault(); \ 272 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 273 (x) = (__typeof__(*(ptr)))__gu_val; \ 274 __gu_err; \ 275 }) 276 277 #define __get_user_check(x, ptr, size) \ 278 ({ \ 279 long __gu_err = -EFAULT; \ 280 unsigned long __gu_val = 0; \ 281 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 282 might_fault(); \ 283 if (access_ok(VERIFY_READ, __gu_addr, (size))) \ 284 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 285 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 286 __gu_err; \ 287 }) 288 289 #define __get_user_nosleep(x, ptr, size) \ 290 ({ \ 291 long __gu_err; \ 292 unsigned long __gu_val; \ 293 __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 294 __chk_user_ptr(ptr); \ 295 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 296 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 297 __gu_err; \ 298 }) 299 300 301 /* more complex routines */ 302 303 extern unsigned long __copy_tofrom_user(void __user *to, 304 const void __user *from, unsigned long size); 305 306 #ifndef __powerpc64__ 307 308 static inline unsigned long copy_from_user(void *to, 309 const void __user *from, unsigned long n) 310 { 311 unsigned long over; 312 313 if (access_ok(VERIFY_READ, from, n)) 314 return __copy_tofrom_user((__force void __user *)to, from, n); 315 if ((unsigned long)from < TASK_SIZE) { 316 over = (unsigned long)from + n - TASK_SIZE; 317 return __copy_tofrom_user((__force void __user *)to, from, 318 n - over) + over; 319 } 320 return n; 321 } 322 323 static inline unsigned long copy_to_user(void __user *to, 324 const void *from, unsigned long n) 325 { 326 unsigned long over; 327 328 if (access_ok(VERIFY_WRITE, to, n)) 329 return __copy_tofrom_user(to, (__force void __user *)from, n); 330 if ((unsigned long)to < TASK_SIZE) { 331 over = (unsigned long)to + n - TASK_SIZE; 332 return __copy_tofrom_user(to, (__force void __user *)from, 333 n - over) + over; 334 } 335 return n; 336 } 337 338 #else /* __powerpc64__ */ 339 340 #define __copy_in_user(to, from, size) \ 341 __copy_tofrom_user((to), (from), (size)) 342 343 extern unsigned long copy_from_user(void *to, const void __user *from, 344 unsigned long n); 345 extern unsigned long copy_to_user(void __user *to, const void *from, 346 unsigned long n); 347 extern unsigned long copy_in_user(void __user *to, const void __user *from, 348 unsigned long n); 349 350 #endif /* __powerpc64__ */ 351 352 static inline unsigned long __copy_from_user_inatomic(void *to, 353 const void __user *from, unsigned long n) 354 { 355 if (__builtin_constant_p(n) && (n <= 8)) { 356 unsigned long ret = 1; 357 358 switch (n) { 359 case 1: 360 __get_user_size(*(u8 *)to, from, 1, ret); 361 break; 362 case 2: 363 __get_user_size(*(u16 *)to, from, 2, ret); 364 break; 365 case 4: 366 __get_user_size(*(u32 *)to, from, 4, ret); 367 break; 368 case 8: 369 __get_user_size(*(u64 *)to, from, 8, ret); 370 break; 371 } 372 if (ret == 0) 373 return 0; 374 } 375 return __copy_tofrom_user((__force void __user *)to, from, n); 376 } 377 378 static inline unsigned long __copy_to_user_inatomic(void __user *to, 379 const void *from, unsigned long n) 380 { 381 if (__builtin_constant_p(n) && (n <= 8)) { 382 unsigned long ret = 1; 383 384 switch (n) { 385 case 1: 386 __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret); 387 break; 388 case 2: 389 __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret); 390 break; 391 case 4: 392 __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret); 393 break; 394 case 8: 395 __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret); 396 break; 397 } 398 if (ret == 0) 399 return 0; 400 } 401 return __copy_tofrom_user(to, (__force const void __user *)from, n); 402 } 403 404 static inline unsigned long __copy_from_user(void *to, 405 const void __user *from, unsigned long size) 406 { 407 might_fault(); 408 return __copy_from_user_inatomic(to, from, size); 409 } 410 411 static inline unsigned long __copy_to_user(void __user *to, 412 const void *from, unsigned long size) 413 { 414 might_fault(); 415 return __copy_to_user_inatomic(to, from, size); 416 } 417 418 extern unsigned long __clear_user(void __user *addr, unsigned long size); 419 420 static inline unsigned long clear_user(void __user *addr, unsigned long size) 421 { 422 might_fault(); 423 if (likely(access_ok(VERIFY_WRITE, addr, size))) 424 return __clear_user(addr, size); 425 if ((unsigned long)addr < TASK_SIZE) { 426 unsigned long over = (unsigned long)addr + size - TASK_SIZE; 427 return __clear_user(addr, size - over) + over; 428 } 429 return size; 430 } 431 432 extern long strncpy_from_user(char *dst, const char __user *src, long count); 433 extern __must_check long strlen_user(const char __user *str); 434 extern __must_check long strnlen_user(const char __user *str, long n); 435 436 #endif /* __ASSEMBLY__ */ 437 #endif /* __KERNEL__ */ 438 439 #endif /* _ARCH_POWERPC_UACCESS_H */ 440