Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * include/asm-s390/uaccess.h |
| 3 | * |
| 4 | * S390 version |
| 5 | * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation |
| 6 | * Author(s): Hartmut Penner (hp@de.ibm.com), |
| 7 | * Martin Schwidefsky (schwidefsky@de.ibm.com) |
| 8 | * |
| 9 | * Derived from "include/asm-i386/uaccess.h" |
| 10 | */ |
| 11 | #ifndef __S390_UACCESS_H |
| 12 | #define __S390_UACCESS_H |
| 13 | |
| 14 | /* |
| 15 | * User space memory access functions |
| 16 | */ |
| 17 | #include <linux/sched.h> |
| 18 | #include <linux/errno.h> |
| 19 | |
| 20 | #define VERIFY_READ 0 |
| 21 | #define VERIFY_WRITE 1 |
| 22 | |
| 23 | |
| 24 | /* |
| 25 | * The fs value determines whether argument validity checking should be |
| 26 | * performed or not. If get_fs() == USER_DS, checking is performed, with |
| 27 | * get_fs() == KERNEL_DS, checking is bypassed. |
| 28 | * |
| 29 | * For historical reasons, these macros are grossly misnamed. |
| 30 | */ |
| 31 | |
| 32 | #define MAKE_MM_SEG(a) ((mm_segment_t) { (a) }) |
| 33 | |
| 34 | |
| 35 | #define KERNEL_DS MAKE_MM_SEG(0) |
| 36 | #define USER_DS MAKE_MM_SEG(1) |
| 37 | |
| 38 | #define get_ds() (KERNEL_DS) |
| 39 | #define get_fs() (current->thread.mm_segment) |
| 40 | |
| 41 | #ifdef __s390x__ |
| 42 | #define set_fs(x) \ |
| 43 | ({ \ |
| 44 | unsigned long __pto; \ |
| 45 | current->thread.mm_segment = (x); \ |
| 46 | __pto = current->thread.mm_segment.ar4 ? \ |
| 47 | S390_lowcore.user_asce : S390_lowcore.kernel_asce; \ |
| 48 | asm volatile ("lctlg 7,7,%0" : : "m" (__pto) ); \ |
| 49 | }) |
| 50 | #else |
| 51 | #define set_fs(x) \ |
| 52 | ({ \ |
| 53 | unsigned long __pto; \ |
| 54 | current->thread.mm_segment = (x); \ |
| 55 | __pto = current->thread.mm_segment.ar4 ? \ |
| 56 | S390_lowcore.user_asce : S390_lowcore.kernel_asce; \ |
| 57 | asm volatile ("lctl 7,7,%0" : : "m" (__pto) ); \ |
| 58 | }) |
| 59 | #endif |
| 60 | |
| 61 | #define segment_eq(a,b) ((a).ar4 == (b).ar4) |
| 62 | |
| 63 | |
| 64 | #define __access_ok(addr,size) (1) |
| 65 | |
| 66 | #define access_ok(type,addr,size) __access_ok(addr,size) |
| 67 | |
| 68 | /* this function will go away soon - use access_ok() instead */ |
| 69 | extern inline int __deprecated verify_area(int type, const void __user *addr, |
| 70 | unsigned long size) |
| 71 | { |
| 72 | return access_ok(type, addr, size) ? 0 : -EFAULT; |
| 73 | } |
| 74 | |
| 75 | /* |
| 76 | * The exception table consists of pairs of addresses: the first is the |
| 77 | * address of an instruction that is allowed to fault, and the second is |
| 78 | * the address at which the program should continue. No registers are |
| 79 | * modified, so it is entirely up to the continuation code to figure out |
| 80 | * what to do. |
| 81 | * |
| 82 | * All the routines below use bits of fixup code that are out of line |
| 83 | * with the main instruction path. This means when everything is well, |
| 84 | * we don't even have to jump over them. Further, they do not intrude |
| 85 | * on our cache or tlb entries. |
| 86 | */ |
| 87 | |
| 88 | struct exception_table_entry |
| 89 | { |
| 90 | unsigned long insn, fixup; |
| 91 | }; |
| 92 | |
| 93 | #ifndef __s390x__ |
| 94 | #define __uaccess_fixup \ |
| 95 | ".section .fixup,\"ax\"\n" \ |
| 96 | "2: lhi %0,%4\n" \ |
| 97 | " bras 1,3f\n" \ |
| 98 | " .long 1b\n" \ |
| 99 | "3: l 1,0(1)\n" \ |
| 100 | " br 1\n" \ |
| 101 | ".previous\n" \ |
| 102 | ".section __ex_table,\"a\"\n" \ |
| 103 | " .align 4\n" \ |
| 104 | " .long 0b,2b\n" \ |
| 105 | ".previous" |
| 106 | #define __uaccess_clobber "cc", "1" |
| 107 | #else /* __s390x__ */ |
| 108 | #define __uaccess_fixup \ |
| 109 | ".section .fixup,\"ax\"\n" \ |
| 110 | "2: lghi %0,%4\n" \ |
| 111 | " jg 1b\n" \ |
| 112 | ".previous\n" \ |
| 113 | ".section __ex_table,\"a\"\n" \ |
| 114 | " .align 8\n" \ |
| 115 | " .quad 0b,2b\n" \ |
| 116 | ".previous" |
| 117 | #define __uaccess_clobber "cc" |
| 118 | #endif /* __s390x__ */ |
| 119 | |
| 120 | /* |
| 121 | * These are the main single-value transfer routines. They automatically |
| 122 | * use the right size if we just have the right pointer type. |
| 123 | */ |
| 124 | #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2) |
| 125 | #define __put_user_asm(x, ptr, err) \ |
| 126 | ({ \ |
| 127 | err = 0; \ |
| 128 | asm volatile( \ |
| 129 | "0: mvcs 0(%1,%2),%3,%0\n" \ |
| 130 | "1:\n" \ |
| 131 | __uaccess_fixup \ |
| 132 | : "+&d" (err) \ |
| 133 | : "d" (sizeof(*(ptr))), "a" (ptr), "Q" (x), \ |
| 134 | "K" (-EFAULT) \ |
| 135 | : __uaccess_clobber ); \ |
| 136 | }) |
| 137 | #else |
| 138 | #define __put_user_asm(x, ptr, err) \ |
| 139 | ({ \ |
| 140 | err = 0; \ |
| 141 | asm volatile( \ |
| 142 | "0: mvcs 0(%1,%2),0(%3),%0\n" \ |
| 143 | "1:\n" \ |
| 144 | __uaccess_fixup \ |
| 145 | : "+&d" (err) \ |
| 146 | : "d" (sizeof(*(ptr))), "a" (ptr), "a" (&(x)), \ |
| 147 | "K" (-EFAULT), "m" (x) \ |
| 148 | : __uaccess_clobber ); \ |
| 149 | }) |
| 150 | #endif |
| 151 | |
| 152 | #ifndef __CHECKER__ |
| 153 | #define __put_user(x, ptr) \ |
| 154 | ({ \ |
| 155 | __typeof__(*(ptr)) __x = (x); \ |
| 156 | int __pu_err; \ |
| 157 | switch (sizeof (*(ptr))) { \ |
| 158 | case 1: \ |
| 159 | case 2: \ |
| 160 | case 4: \ |
| 161 | case 8: \ |
| 162 | __put_user_asm(__x, ptr, __pu_err); \ |
| 163 | break; \ |
| 164 | default: \ |
| 165 | __put_user_bad(); \ |
| 166 | break; \ |
| 167 | } \ |
| 168 | __pu_err; \ |
| 169 | }) |
| 170 | #else |
| 171 | #define __put_user(x, ptr) \ |
| 172 | ({ \ |
| 173 | void __user *p; \ |
| 174 | p = (ptr); \ |
| 175 | 0; \ |
| 176 | }) |
| 177 | #endif |
| 178 | |
| 179 | #define put_user(x, ptr) \ |
| 180 | ({ \ |
| 181 | might_sleep(); \ |
| 182 | __put_user(x, ptr); \ |
| 183 | }) |
| 184 | |
| 185 | |
| 186 | extern int __put_user_bad(void) __attribute__((noreturn)); |
| 187 | |
| 188 | #if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2) |
| 189 | #define __get_user_asm(x, ptr, err) \ |
| 190 | ({ \ |
| 191 | err = 0; \ |
| 192 | asm volatile ( \ |
| 193 | "0: mvcp %O1(%2,%R1),0(%3),%0\n" \ |
| 194 | "1:\n" \ |
| 195 | __uaccess_fixup \ |
| 196 | : "+&d" (err), "=Q" (x) \ |
| 197 | : "d" (sizeof(*(ptr))), "a" (ptr), \ |
| 198 | "K" (-EFAULT) \ |
| 199 | : __uaccess_clobber ); \ |
| 200 | }) |
| 201 | #else |
| 202 | #define __get_user_asm(x, ptr, err) \ |
| 203 | ({ \ |
| 204 | err = 0; \ |
| 205 | asm volatile ( \ |
| 206 | "0: mvcp 0(%2,%5),0(%3),%0\n" \ |
| 207 | "1:\n" \ |
| 208 | __uaccess_fixup \ |
| 209 | : "+&d" (err), "=m" (x) \ |
| 210 | : "d" (sizeof(*(ptr))), "a" (ptr), \ |
| 211 | "K" (-EFAULT), "a" (&(x)) \ |
| 212 | : __uaccess_clobber ); \ |
| 213 | }) |
| 214 | #endif |
| 215 | |
| 216 | #ifndef __CHECKER__ |
| 217 | #define __get_user(x, ptr) \ |
| 218 | ({ \ |
| 219 | __typeof__(*(ptr)) __x; \ |
| 220 | int __gu_err; \ |
| 221 | switch (sizeof(*(ptr))) { \ |
| 222 | case 1: \ |
| 223 | case 2: \ |
| 224 | case 4: \ |
| 225 | case 8: \ |
| 226 | __get_user_asm(__x, ptr, __gu_err); \ |
| 227 | break; \ |
| 228 | default: \ |
| 229 | __get_user_bad(); \ |
| 230 | break; \ |
| 231 | } \ |
| 232 | (x) = __x; \ |
| 233 | __gu_err; \ |
| 234 | }) |
| 235 | #else |
| 236 | #define __get_user(x, ptr) \ |
| 237 | ({ \ |
| 238 | void __user *p; \ |
| 239 | p = (ptr); \ |
| 240 | 0; \ |
| 241 | }) |
| 242 | #endif |
| 243 | |
| 244 | |
| 245 | #define get_user(x, ptr) \ |
| 246 | ({ \ |
| 247 | might_sleep(); \ |
| 248 | __get_user(x, ptr); \ |
| 249 | }) |
| 250 | |
| 251 | extern int __get_user_bad(void) __attribute__((noreturn)); |
| 252 | |
| 253 | #define __put_user_unaligned __put_user |
| 254 | #define __get_user_unaligned __get_user |
| 255 | |
| 256 | extern long __copy_to_user_asm(const void *from, long n, void __user *to); |
| 257 | |
| 258 | /** |
| 259 | * __copy_to_user: - Copy a block of data into user space, with less checking. |
| 260 | * @to: Destination address, in user space. |
| 261 | * @from: Source address, in kernel space. |
| 262 | * @n: Number of bytes to copy. |
| 263 | * |
| 264 | * Context: User context only. This function may sleep. |
| 265 | * |
| 266 | * Copy data from kernel space to user space. Caller must check |
| 267 | * the specified block with access_ok() before calling this function. |
| 268 | * |
| 269 | * Returns number of bytes that could not be copied. |
| 270 | * On success, this will be zero. |
| 271 | */ |
| 272 | static inline unsigned long |
| 273 | __copy_to_user(void __user *to, const void *from, unsigned long n) |
| 274 | { |
| 275 | return __copy_to_user_asm(from, n, to); |
| 276 | } |
| 277 | |
| 278 | #define __copy_to_user_inatomic __copy_to_user |
| 279 | #define __copy_from_user_inatomic __copy_from_user |
| 280 | |
| 281 | /** |
| 282 | * copy_to_user: - Copy a block of data into user space. |
| 283 | * @to: Destination address, in user space. |
| 284 | * @from: Source address, in kernel space. |
| 285 | * @n: Number of bytes to copy. |
| 286 | * |
| 287 | * Context: User context only. This function may sleep. |
| 288 | * |
| 289 | * Copy data from kernel space to user space. |
| 290 | * |
| 291 | * Returns number of bytes that could not be copied. |
| 292 | * On success, this will be zero. |
| 293 | */ |
| 294 | static inline unsigned long |
| 295 | copy_to_user(void __user *to, const void *from, unsigned long n) |
| 296 | { |
| 297 | might_sleep(); |
| 298 | if (access_ok(VERIFY_WRITE, to, n)) |
| 299 | n = __copy_to_user(to, from, n); |
| 300 | return n; |
| 301 | } |
| 302 | |
| 303 | extern long __copy_from_user_asm(void *to, long n, const void __user *from); |
| 304 | |
| 305 | /** |
| 306 | * __copy_from_user: - Copy a block of data from user space, with less checking. |
| 307 | * @to: Destination address, in kernel space. |
| 308 | * @from: Source address, in user space. |
| 309 | * @n: Number of bytes to copy. |
| 310 | * |
| 311 | * Context: User context only. This function may sleep. |
| 312 | * |
| 313 | * Copy data from user space to kernel space. Caller must check |
| 314 | * the specified block with access_ok() before calling this function. |
| 315 | * |
| 316 | * Returns number of bytes that could not be copied. |
| 317 | * On success, this will be zero. |
| 318 | * |
| 319 | * If some data could not be copied, this function will pad the copied |
| 320 | * data to the requested size using zero bytes. |
| 321 | */ |
| 322 | static inline unsigned long |
| 323 | __copy_from_user(void *to, const void __user *from, unsigned long n) |
| 324 | { |
| 325 | return __copy_from_user_asm(to, n, from); |
| 326 | } |
| 327 | |
| 328 | /** |
| 329 | * copy_from_user: - Copy a block of data from user space. |
| 330 | * @to: Destination address, in kernel space. |
| 331 | * @from: Source address, in user space. |
| 332 | * @n: Number of bytes to copy. |
| 333 | * |
| 334 | * Context: User context only. This function may sleep. |
| 335 | * |
| 336 | * Copy data from user space to kernel space. |
| 337 | * |
| 338 | * Returns number of bytes that could not be copied. |
| 339 | * On success, this will be zero. |
| 340 | * |
| 341 | * If some data could not be copied, this function will pad the copied |
| 342 | * data to the requested size using zero bytes. |
| 343 | */ |
| 344 | static inline unsigned long |
| 345 | copy_from_user(void *to, const void __user *from, unsigned long n) |
| 346 | { |
| 347 | might_sleep(); |
| 348 | if (access_ok(VERIFY_READ, from, n)) |
| 349 | n = __copy_from_user(to, from, n); |
| 350 | else |
| 351 | memset(to, 0, n); |
| 352 | return n; |
| 353 | } |
| 354 | |
| 355 | extern unsigned long __copy_in_user_asm(const void __user *from, long n, |
| 356 | void __user *to); |
| 357 | |
| 358 | static inline unsigned long |
| 359 | __copy_in_user(void __user *to, const void __user *from, unsigned long n) |
| 360 | { |
| 361 | return __copy_in_user_asm(from, n, to); |
| 362 | } |
| 363 | |
| 364 | static inline unsigned long |
| 365 | copy_in_user(void __user *to, const void __user *from, unsigned long n) |
| 366 | { |
| 367 | might_sleep(); |
| 368 | if (__access_ok(from,n) && __access_ok(to,n)) |
| 369 | n = __copy_in_user_asm(from, n, to); |
| 370 | return n; |
| 371 | } |
| 372 | |
| 373 | /* |
| 374 | * Copy a null terminated string from userspace. |
| 375 | */ |
| 376 | extern long __strncpy_from_user_asm(long count, char *dst, |
| 377 | const char __user *src); |
| 378 | |
| 379 | static inline long |
| 380 | strncpy_from_user(char *dst, const char __user *src, long count) |
| 381 | { |
| 382 | long res = -EFAULT; |
| 383 | might_sleep(); |
| 384 | if (access_ok(VERIFY_READ, src, 1)) |
| 385 | res = __strncpy_from_user_asm(count, dst, src); |
| 386 | return res; |
| 387 | } |
| 388 | |
| 389 | |
| 390 | extern long __strnlen_user_asm(long count, const char __user *src); |
| 391 | |
| 392 | static inline unsigned long |
| 393 | strnlen_user(const char __user * src, unsigned long n) |
| 394 | { |
| 395 | might_sleep(); |
| 396 | return __strnlen_user_asm(n, src); |
| 397 | } |
| 398 | |
| 399 | /** |
| 400 | * strlen_user: - Get the size of a string in user space. |
| 401 | * @str: The string to measure. |
| 402 | * |
| 403 | * Context: User context only. This function may sleep. |
| 404 | * |
| 405 | * Get the size of a NUL-terminated string in user space. |
| 406 | * |
| 407 | * Returns the size of the string INCLUDING the terminating NUL. |
| 408 | * On exception, returns 0. |
| 409 | * |
| 410 | * If there is a limit on the length of a valid string, you may wish to |
| 411 | * consider using strnlen_user() instead. |
| 412 | */ |
| 413 | #define strlen_user(str) strnlen_user(str, ~0UL) |
| 414 | |
| 415 | /* |
| 416 | * Zero Userspace |
| 417 | */ |
| 418 | |
| 419 | extern long __clear_user_asm(void __user *to, long n); |
| 420 | |
| 421 | static inline unsigned long |
| 422 | __clear_user(void __user *to, unsigned long n) |
| 423 | { |
| 424 | return __clear_user_asm(to, n); |
| 425 | } |
| 426 | |
| 427 | static inline unsigned long |
| 428 | clear_user(void __user *to, unsigned long n) |
| 429 | { |
| 430 | might_sleep(); |
| 431 | if (access_ok(VERIFY_WRITE, to, n)) |
| 432 | n = __clear_user_asm(to, n); |
| 433 | return n; |
| 434 | } |
| 435 | |
| 436 | #endif /* __S390_UACCESS_H */ |