1 #ifndef _ARCH_POWERPC_UACCESS_H 2 #define _ARCH_POWERPC_UACCESS_H 3 4 #include <asm/asm-compat.h> 5 #include <asm/ppc_asm.h> 6 #include <asm/processor.h> 7 #include <asm/page.h> 8 9 /* 10 * The fs value determines whether argument validity checking should be 11 * performed or not. If get_fs() == USER_DS, checking is performed, with 12 * get_fs() == KERNEL_DS, checking is bypassed. 13 * 14 * For historical reasons, these macros are grossly misnamed. 15 * 16 * The fs/ds values are now the highest legal address in the "segment". 17 * This simplifies the checking in the routines below. 18 */ 19 20 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) 21 22 #define KERNEL_DS MAKE_MM_SEG(~0UL) 23 #ifdef __powerpc64__ 24 /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */ 25 #define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1) 26 #else 27 #define USER_DS MAKE_MM_SEG(TASK_SIZE - 1) 28 #endif 29 30 #define get_ds() (KERNEL_DS) 31 #define get_fs() (current->thread.fs) 32 #define set_fs(val) (current->thread.fs = (val)) 33 34 #define segment_eq(a, b) ((a).seg == (b).seg) 35 36 #define user_addr_max() (get_fs().seg) 37 38 #ifdef __powerpc64__ 39 /* 40 * This check is sufficient because there is a large enough 41 * gap between user addresses and the kernel addresses 42 */ 43 #define __access_ok(addr, size, segment) \ 44 (((addr) <= (segment).seg) && ((size) <= (segment).seg)) 45 46 #else 47 48 #define __access_ok(addr, size, segment) \ 49 (((addr) <= (segment).seg) && \ 50 (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr))))) 51 52 #endif 53 54 #define access_ok(type, addr, size) \ 55 (__chk_user_ptr(addr), \ 56 __access_ok((__force unsigned long)(addr), (size), get_fs())) 57 58 /* 59 * The exception table consists of pairs of relative addresses: the first is 60 * the address of an instruction that is allowed to fault, and the second is 61 * the address at which the program should continue. No registers are 62 * modified, so it is entirely up to the continuation code to figure out what 63 * to do. 64 * 65 * All the routines below use bits of fixup code that are out of line with the 66 * main instruction path. This means when everything is well, we don't even 67 * have to jump over them. Further, they do not intrude on our cache or tlb 68 * entries. 69 */ 70 71 #define ARCH_HAS_RELATIVE_EXTABLE 72 73 struct exception_table_entry { 74 int insn; 75 int fixup; 76 }; 77 78 static inline unsigned long extable_fixup(const struct exception_table_entry *x) 79 { 80 return (unsigned long)&x->fixup + x->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 EX_TABLE(1b, 3b) \ 136 : "=r" (err) \ 137 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 138 139 #ifdef __powerpc64__ 140 #define __put_user_asm2(x, ptr, retval) \ 141 __put_user_asm(x, ptr, retval, "std") 142 #else /* __powerpc64__ */ 143 #define __put_user_asm2(x, addr, err) \ 144 __asm__ __volatile__( \ 145 "1: stw %1,0(%2)\n" \ 146 "2: stw %1+1,4(%2)\n" \ 147 "3:\n" \ 148 ".section .fixup,\"ax\"\n" \ 149 "4: li %0,%3\n" \ 150 " b 3b\n" \ 151 ".previous\n" \ 152 EX_TABLE(1b, 4b) \ 153 EX_TABLE(2b, 4b) \ 154 : "=r" (err) \ 155 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err)) 156 #endif /* __powerpc64__ */ 157 158 #define __put_user_size(x, ptr, size, retval) \ 159 do { \ 160 retval = 0; \ 161 switch (size) { \ 162 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \ 163 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \ 164 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ 165 case 8: __put_user_asm2(x, ptr, retval); break; \ 166 default: __put_user_bad(); \ 167 } \ 168 } while (0) 169 170 #define __put_user_nocheck(x, ptr, size) \ 171 ({ \ 172 long __pu_err; \ 173 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 174 if (!is_kernel_addr((unsigned long)__pu_addr)) \ 175 might_fault(); \ 176 __chk_user_ptr(ptr); \ 177 __put_user_size((x), __pu_addr, (size), __pu_err); \ 178 __pu_err; \ 179 }) 180 181 #define __put_user_check(x, ptr, size) \ 182 ({ \ 183 long __pu_err = -EFAULT; \ 184 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 185 might_fault(); \ 186 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ 187 __put_user_size((x), __pu_addr, (size), __pu_err); \ 188 __pu_err; \ 189 }) 190 191 #define __put_user_nosleep(x, ptr, size) \ 192 ({ \ 193 long __pu_err; \ 194 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \ 195 __chk_user_ptr(ptr); \ 196 __put_user_size((x), __pu_addr, (size), __pu_err); \ 197 __pu_err; \ 198 }) 199 200 201 extern long __get_user_bad(void); 202 203 #define __get_user_asm(x, addr, err, op) \ 204 __asm__ __volatile__( \ 205 "1: "op" %1,0(%2) # get_user\n" \ 206 "2:\n" \ 207 ".section .fixup,\"ax\"\n" \ 208 "3: li %0,%3\n" \ 209 " li %1,0\n" \ 210 " b 2b\n" \ 211 ".previous\n" \ 212 EX_TABLE(1b, 3b) \ 213 : "=r" (err), "=r" (x) \ 214 : "b" (addr), "i" (-EFAULT), "0" (err)) 215 216 #ifdef __powerpc64__ 217 #define __get_user_asm2(x, addr, err) \ 218 __get_user_asm(x, addr, err, "ld") 219 #else /* __powerpc64__ */ 220 #define __get_user_asm2(x, addr, err) \ 221 __asm__ __volatile__( \ 222 "1: lwz %1,0(%2)\n" \ 223 "2: lwz %1+1,4(%2)\n" \ 224 "3:\n" \ 225 ".section .fixup,\"ax\"\n" \ 226 "4: li %0,%3\n" \ 227 " li %1,0\n" \ 228 " li %1+1,0\n" \ 229 " b 3b\n" \ 230 ".previous\n" \ 231 EX_TABLE(1b, 4b) \ 232 EX_TABLE(2b, 4b) \ 233 : "=r" (err), "=&r" (x) \ 234 : "b" (addr), "i" (-EFAULT), "0" (err)) 235 #endif /* __powerpc64__ */ 236 237 #define __get_user_size(x, ptr, size, retval) \ 238 do { \ 239 retval = 0; \ 240 __chk_user_ptr(ptr); \ 241 if (size > sizeof(x)) \ 242 (x) = __get_user_bad(); \ 243 switch (size) { \ 244 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \ 245 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \ 246 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \ 247 case 8: __get_user_asm2(x, ptr, retval); break; \ 248 default: (x) = __get_user_bad(); \ 249 } \ 250 } while (0) 251 252 #define __get_user_nocheck(x, ptr, size) \ 253 ({ \ 254 long __gu_err; \ 255 unsigned long __gu_val; \ 256 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 257 __chk_user_ptr(ptr); \ 258 if (!is_kernel_addr((unsigned long)__gu_addr)) \ 259 might_fault(); \ 260 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 261 (x) = (__typeof__(*(ptr)))__gu_val; \ 262 __gu_err; \ 263 }) 264 265 #define __get_user_check(x, ptr, size) \ 266 ({ \ 267 long __gu_err = -EFAULT; \ 268 unsigned long __gu_val = 0; \ 269 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 270 might_fault(); \ 271 if (access_ok(VERIFY_READ, __gu_addr, (size))) \ 272 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 273 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 274 __gu_err; \ 275 }) 276 277 #define __get_user_nosleep(x, ptr, size) \ 278 ({ \ 279 long __gu_err; \ 280 unsigned long __gu_val; \ 281 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \ 282 __chk_user_ptr(ptr); \ 283 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ 284 (x) = (__force __typeof__(*(ptr)))__gu_val; \ 285 __gu_err; \ 286 }) 287 288 289 /* more complex routines */ 290 291 extern unsigned long __copy_tofrom_user(void __user *to, 292 const void __user *from, unsigned long size); 293 294 #ifndef __powerpc64__ 295 296 static inline unsigned long copy_from_user(void *to, 297 const void __user *from, unsigned long n) 298 { 299 if (likely(access_ok(VERIFY_READ, from, n))) { 300 check_object_size(to, n, false); 301 return __copy_tofrom_user((__force void __user *)to, from, n); 302 } 303 memset(to, 0, n); 304 return n; 305 } 306 307 static inline unsigned long copy_to_user(void __user *to, 308 const void *from, unsigned long n) 309 { 310 if (access_ok(VERIFY_WRITE, to, n)) { 311 check_object_size(from, n, true); 312 return __copy_tofrom_user(to, (__force void __user *)from, n); 313 } 314 return n; 315 } 316 317 #else /* __powerpc64__ */ 318 319 #define __copy_in_user(to, from, size) \ 320 __copy_tofrom_user((to), (from), (size)) 321 322 extern unsigned long copy_from_user(void *to, const void __user *from, 323 unsigned long n); 324 extern unsigned long copy_to_user(void __user *to, const void *from, 325 unsigned long n); 326 extern unsigned long copy_in_user(void __user *to, const void __user *from, 327 unsigned long n); 328 329 #endif /* __powerpc64__ */ 330 331 static inline unsigned long __copy_from_user_inatomic(void *to, 332 const void __user *from, unsigned long n) 333 { 334 if (__builtin_constant_p(n) && (n <= 8)) { 335 unsigned long ret = 1; 336 337 switch (n) { 338 case 1: 339 __get_user_size(*(u8 *)to, from, 1, ret); 340 break; 341 case 2: 342 __get_user_size(*(u16 *)to, from, 2, ret); 343 break; 344 case 4: 345 __get_user_size(*(u32 *)to, from, 4, ret); 346 break; 347 case 8: 348 __get_user_size(*(u64 *)to, from, 8, ret); 349 break; 350 } 351 if (ret == 0) 352 return 0; 353 } 354 355 check_object_size(to, n, false); 356 357 return __copy_tofrom_user((__force void __user *)to, from, n); 358 } 359 360 static inline unsigned long __copy_to_user_inatomic(void __user *to, 361 const void *from, unsigned long n) 362 { 363 if (__builtin_constant_p(n) && (n <= 8)) { 364 unsigned long ret = 1; 365 366 switch (n) { 367 case 1: 368 __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret); 369 break; 370 case 2: 371 __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret); 372 break; 373 case 4: 374 __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret); 375 break; 376 case 8: 377 __put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret); 378 break; 379 } 380 if (ret == 0) 381 return 0; 382 } 383 384 check_object_size(from, n, true); 385 386 return __copy_tofrom_user(to, (__force const void __user *)from, n); 387 } 388 389 static inline unsigned long __copy_from_user(void *to, 390 const void __user *from, unsigned long size) 391 { 392 might_fault(); 393 return __copy_from_user_inatomic(to, from, size); 394 } 395 396 static inline unsigned long __copy_to_user(void __user *to, 397 const void *from, unsigned long size) 398 { 399 might_fault(); 400 return __copy_to_user_inatomic(to, from, size); 401 } 402 403 extern unsigned long __clear_user(void __user *addr, unsigned long size); 404 405 static inline unsigned long clear_user(void __user *addr, unsigned long size) 406 { 407 might_fault(); 408 if (likely(access_ok(VERIFY_WRITE, addr, size))) 409 return __clear_user(addr, size); 410 return size; 411 } 412 413 extern long strncpy_from_user(char *dst, const char __user *src, long count); 414 extern __must_check long strlen_user(const char __user *str); 415 extern __must_check long strnlen_user(const char __user *str, long n); 416 417 #endif /* _ARCH_POWERPC_UACCESS_H */ 418