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