Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef __i386_UACCESS_H |
| 2 | #define __i386_UACCESS_H |
| 3 | |
| 4 | /* |
| 5 | * User space memory access functions |
| 6 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | #include <linux/errno.h> |
| 8 | #include <linux/thread_info.h> |
| 9 | #include <linux/prefetch.h> |
| 10 | #include <linux/string.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 | |
| 24 | #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) |
| 25 | |
| 26 | |
| 27 | #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFUL) |
| 28 | #define USER_DS MAKE_MM_SEG(PAGE_OFFSET) |
| 29 | |
| 30 | #define get_ds() (KERNEL_DS) |
| 31 | #define get_fs() (current_thread_info()->addr_limit) |
| 32 | #define set_fs(x) (current_thread_info()->addr_limit = (x)) |
| 33 | |
| 34 | #define segment_eq(a,b) ((a).seg == (b).seg) |
| 35 | |
| 36 | /* |
| 37 | * movsl can be slow when source and dest are not both 8-byte aligned |
| 38 | */ |
| 39 | #ifdef CONFIG_X86_INTEL_USERCOPY |
| 40 | extern struct movsl_mask { |
| 41 | int mask; |
| 42 | } ____cacheline_aligned_in_smp movsl_mask; |
| 43 | #endif |
| 44 | |
| 45 | #define __addr_ok(addr) ((unsigned long __force)(addr) < (current_thread_info()->addr_limit.seg)) |
| 46 | |
| 47 | /* |
| 48 | * Test whether a block of memory is a valid user space address. |
| 49 | * Returns 0 if the range is valid, nonzero otherwise. |
| 50 | * |
| 51 | * This is equivalent to the following test: |
| 52 | * (u33)addr + (u33)size >= (u33)current->addr_limit.seg |
| 53 | * |
| 54 | * This needs 33-bit arithmetic. We have a carry... |
| 55 | */ |
| 56 | #define __range_ok(addr,size) ({ \ |
| 57 | unsigned long flag,sum; \ |
| 58 | __chk_user_ptr(addr); \ |
| 59 | asm("addl %3,%1 ; sbbl %0,%0; cmpl %1,%4; sbbl $0,%0" \ |
| 60 | :"=&r" (flag), "=r" (sum) \ |
Roman Zippel | 722f4f5 | 2006-06-23 02:04:31 -0700 | [diff] [blame] | 61 | :"1" (addr),"g" ((int)(size)),"rm" (current_thread_info()->addr_limit.seg)); \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | flag; }) |
| 63 | |
| 64 | /** |
| 65 | * access_ok: - Checks if a user space pointer is valid |
| 66 | * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that |
| 67 | * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe |
| 68 | * to write to a block, it is always safe to read from it. |
| 69 | * @addr: User space pointer to start of block to check |
| 70 | * @size: Size of block to check |
| 71 | * |
| 72 | * Context: User context only. This function may sleep. |
| 73 | * |
| 74 | * Checks if a pointer to a block of memory in user space is valid. |
| 75 | * |
| 76 | * Returns true (nonzero) if the memory block may be valid, false (zero) |
| 77 | * if it is definitely invalid. |
| 78 | * |
| 79 | * Note that, depending on architecture, this function probably just |
| 80 | * checks that the pointer is in the user space range - after calling |
| 81 | * this function, memory access functions may still return -EFAULT. |
| 82 | */ |
| 83 | #define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0)) |
| 84 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | /* |
| 86 | * The exception table consists of pairs of addresses: the first is the |
| 87 | * address of an instruction that is allowed to fault, and the second is |
| 88 | * the address at which the program should continue. No registers are |
| 89 | * modified, so it is entirely up to the continuation code to figure out |
| 90 | * what to do. |
| 91 | * |
| 92 | * All the routines below use bits of fixup code that are out of line |
| 93 | * with the main instruction path. This means when everything is well, |
| 94 | * we don't even have to jump over them. Further, they do not intrude |
| 95 | * on our cache or tlb entries. |
| 96 | */ |
| 97 | |
| 98 | struct exception_table_entry |
| 99 | { |
| 100 | unsigned long insn, fixup; |
| 101 | }; |
| 102 | |
| 103 | extern int fixup_exception(struct pt_regs *regs); |
| 104 | |
| 105 | /* |
| 106 | * These are the main single-value transfer routines. They automatically |
| 107 | * use the right size if we just have the right pointer type. |
| 108 | * |
| 109 | * This gets kind of ugly. We want to return _two_ values in "get_user()" |
| 110 | * and yet we don't want to do any pointers, because that is too much |
| 111 | * of a performance impact. Thus we have a few rather ugly macros here, |
| 112 | * and hide all the ugliness from the user. |
| 113 | * |
| 114 | * The "__xxx" versions of the user access functions are versions that |
| 115 | * do not verify the address space, that must have been done previously |
| 116 | * with a separate "access_ok()" call (this is used when we do multiple |
| 117 | * accesses to the same area of user memory). |
| 118 | */ |
| 119 | |
| 120 | extern void __get_user_1(void); |
| 121 | extern void __get_user_2(void); |
| 122 | extern void __get_user_4(void); |
| 123 | |
| 124 | #define __get_user_x(size,ret,x,ptr) \ |
| 125 | __asm__ __volatile__("call __get_user_" #size \ |
| 126 | :"=a" (ret),"=d" (x) \ |
| 127 | :"0" (ptr)) |
| 128 | |
| 129 | |
| 130 | /* Careful: we have to cast the result to the type of the pointer for sign reasons */ |
| 131 | /** |
| 132 | * get_user: - Get a simple variable from user space. |
| 133 | * @x: Variable to store result. |
| 134 | * @ptr: Source address, in user space. |
| 135 | * |
| 136 | * Context: User context only. This function may sleep. |
| 137 | * |
| 138 | * This macro copies a single simple variable from user space to kernel |
| 139 | * space. It supports simple types like char and int, but not larger |
| 140 | * data types like structures or arrays. |
| 141 | * |
| 142 | * @ptr must have pointer-to-simple-variable type, and the result of |
| 143 | * dereferencing @ptr must be assignable to @x without a cast. |
| 144 | * |
| 145 | * Returns zero on success, or -EFAULT on error. |
| 146 | * On error, the variable @x is set to zero. |
| 147 | */ |
| 148 | #define get_user(x,ptr) \ |
| 149 | ({ int __ret_gu; \ |
| 150 | unsigned long __val_gu; \ |
| 151 | __chk_user_ptr(ptr); \ |
| 152 | switch(sizeof (*(ptr))) { \ |
| 153 | case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \ |
| 154 | case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \ |
| 155 | case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \ |
| 156 | default: __get_user_x(X,__ret_gu,__val_gu,ptr); break; \ |
| 157 | } \ |
| 158 | (x) = (__typeof__(*(ptr)))__val_gu; \ |
| 159 | __ret_gu; \ |
| 160 | }) |
| 161 | |
| 162 | extern void __put_user_bad(void); |
| 163 | |
| 164 | /* |
| 165 | * Strange magic calling convention: pointer in %ecx, |
| 166 | * value in %eax(:%edx), return value in %eax, no clobbers. |
| 167 | */ |
| 168 | extern void __put_user_1(void); |
| 169 | extern void __put_user_2(void); |
| 170 | extern void __put_user_4(void); |
| 171 | extern void __put_user_8(void); |
| 172 | |
| 173 | #define __put_user_1(x, ptr) __asm__ __volatile__("call __put_user_1":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr)) |
| 174 | #define __put_user_2(x, ptr) __asm__ __volatile__("call __put_user_2":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr)) |
| 175 | #define __put_user_4(x, ptr) __asm__ __volatile__("call __put_user_4":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr)) |
| 176 | #define __put_user_8(x, ptr) __asm__ __volatile__("call __put_user_8":"=a" (__ret_pu):"A" ((typeof(*(ptr)))(x)), "c" (ptr)) |
| 177 | #define __put_user_X(x, ptr) __asm__ __volatile__("call __put_user_X":"=a" (__ret_pu):"c" (ptr)) |
| 178 | |
| 179 | /** |
| 180 | * put_user: - Write a simple value into user space. |
| 181 | * @x: Value to copy to user space. |
| 182 | * @ptr: Destination address, in user space. |
| 183 | * |
| 184 | * Context: User context only. This function may sleep. |
| 185 | * |
| 186 | * This macro copies a single simple value from kernel space to user |
| 187 | * space. It supports simple types like char and int, but not larger |
| 188 | * data types like structures or arrays. |
| 189 | * |
| 190 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable |
| 191 | * to the result of dereferencing @ptr. |
| 192 | * |
| 193 | * Returns zero on success, or -EFAULT on error. |
| 194 | */ |
| 195 | #ifdef CONFIG_X86_WP_WORKS_OK |
| 196 | |
| 197 | #define put_user(x,ptr) \ |
| 198 | ({ int __ret_pu; \ |
Eric W. Biederman | 30e931d | 2006-03-23 02:59:35 -0800 | [diff] [blame] | 199 | __typeof__(*(ptr)) __pu_val; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | __chk_user_ptr(ptr); \ |
Eric W. Biederman | 30e931d | 2006-03-23 02:59:35 -0800 | [diff] [blame] | 201 | __pu_val = x; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | switch(sizeof(*(ptr))) { \ |
Eric W. Biederman | 30e931d | 2006-03-23 02:59:35 -0800 | [diff] [blame] | 203 | case 1: __put_user_1(__pu_val, ptr); break; \ |
| 204 | case 2: __put_user_2(__pu_val, ptr); break; \ |
| 205 | case 4: __put_user_4(__pu_val, ptr); break; \ |
| 206 | case 8: __put_user_8(__pu_val, ptr); break; \ |
| 207 | default:__put_user_X(__pu_val, ptr); break; \ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 208 | } \ |
| 209 | __ret_pu; \ |
| 210 | }) |
| 211 | |
| 212 | #else |
| 213 | #define put_user(x,ptr) \ |
| 214 | ({ \ |
| 215 | int __ret_pu; \ |
| 216 | __typeof__(*(ptr)) __pus_tmp = x; \ |
| 217 | __ret_pu=0; \ |
| 218 | if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp, \ |
| 219 | sizeof(*(ptr))) != 0)) \ |
| 220 | __ret_pu=-EFAULT; \ |
| 221 | __ret_pu; \ |
| 222 | }) |
| 223 | |
| 224 | |
| 225 | #endif |
| 226 | |
| 227 | /** |
| 228 | * __get_user: - Get a simple variable from user space, with less checking. |
| 229 | * @x: Variable to store result. |
| 230 | * @ptr: Source address, in user space. |
| 231 | * |
| 232 | * Context: User context only. This function may sleep. |
| 233 | * |
| 234 | * This macro copies a single simple variable from user space to kernel |
| 235 | * space. It supports simple types like char and int, but not larger |
| 236 | * data types like structures or arrays. |
| 237 | * |
| 238 | * @ptr must have pointer-to-simple-variable type, and the result of |
| 239 | * dereferencing @ptr must be assignable to @x without a cast. |
| 240 | * |
| 241 | * Caller must check the pointer with access_ok() before calling this |
| 242 | * function. |
| 243 | * |
| 244 | * Returns zero on success, or -EFAULT on error. |
| 245 | * On error, the variable @x is set to zero. |
| 246 | */ |
| 247 | #define __get_user(x,ptr) \ |
| 248 | __get_user_nocheck((x),(ptr),sizeof(*(ptr))) |
| 249 | |
| 250 | |
| 251 | /** |
| 252 | * __put_user: - Write a simple value into user space, with less checking. |
| 253 | * @x: Value to copy to user space. |
| 254 | * @ptr: Destination address, in user space. |
| 255 | * |
| 256 | * Context: User context only. This function may sleep. |
| 257 | * |
| 258 | * This macro copies a single simple value from kernel space to user |
| 259 | * space. It supports simple types like char and int, but not larger |
| 260 | * data types like structures or arrays. |
| 261 | * |
| 262 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable |
| 263 | * to the result of dereferencing @ptr. |
| 264 | * |
| 265 | * Caller must check the pointer with access_ok() before calling this |
| 266 | * function. |
| 267 | * |
| 268 | * Returns zero on success, or -EFAULT on error. |
| 269 | */ |
| 270 | #define __put_user(x,ptr) \ |
| 271 | __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) |
| 272 | |
| 273 | #define __put_user_nocheck(x,ptr,size) \ |
| 274 | ({ \ |
| 275 | long __pu_err; \ |
| 276 | __put_user_size((x),(ptr),(size),__pu_err,-EFAULT); \ |
| 277 | __pu_err; \ |
| 278 | }) |
| 279 | |
| 280 | |
| 281 | #define __put_user_u64(x, addr, err) \ |
| 282 | __asm__ __volatile__( \ |
| 283 | "1: movl %%eax,0(%2)\n" \ |
| 284 | "2: movl %%edx,4(%2)\n" \ |
| 285 | "3:\n" \ |
| 286 | ".section .fixup,\"ax\"\n" \ |
| 287 | "4: movl %3,%0\n" \ |
| 288 | " jmp 3b\n" \ |
| 289 | ".previous\n" \ |
| 290 | ".section __ex_table,\"a\"\n" \ |
| 291 | " .align 4\n" \ |
| 292 | " .long 1b,4b\n" \ |
| 293 | " .long 2b,4b\n" \ |
| 294 | ".previous" \ |
| 295 | : "=r"(err) \ |
| 296 | : "A" (x), "r" (addr), "i"(-EFAULT), "0"(err)) |
| 297 | |
| 298 | #ifdef CONFIG_X86_WP_WORKS_OK |
| 299 | |
| 300 | #define __put_user_size(x,ptr,size,retval,errret) \ |
| 301 | do { \ |
| 302 | retval = 0; \ |
| 303 | __chk_user_ptr(ptr); \ |
| 304 | switch (size) { \ |
| 305 | case 1: __put_user_asm(x,ptr,retval,"b","b","iq",errret);break; \ |
| 306 | case 2: __put_user_asm(x,ptr,retval,"w","w","ir",errret);break; \ |
| 307 | case 4: __put_user_asm(x,ptr,retval,"l","","ir",errret); break; \ |
| 308 | case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\ |
| 309 | default: __put_user_bad(); \ |
| 310 | } \ |
| 311 | } while (0) |
| 312 | |
| 313 | #else |
| 314 | |
| 315 | #define __put_user_size(x,ptr,size,retval,errret) \ |
| 316 | do { \ |
| 317 | __typeof__(*(ptr)) __pus_tmp = x; \ |
| 318 | retval = 0; \ |
| 319 | \ |
| 320 | if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp, size) != 0)) \ |
| 321 | retval = errret; \ |
| 322 | } while (0) |
| 323 | |
| 324 | #endif |
| 325 | struct __large_struct { unsigned long buf[100]; }; |
| 326 | #define __m(x) (*(struct __large_struct __user *)(x)) |
| 327 | |
| 328 | /* |
| 329 | * Tell gcc we read from memory instead of writing: this is because |
| 330 | * we do not write to any memory gcc knows about, so there are no |
| 331 | * aliasing issues. |
| 332 | */ |
| 333 | #define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \ |
| 334 | __asm__ __volatile__( \ |
| 335 | "1: mov"itype" %"rtype"1,%2\n" \ |
| 336 | "2:\n" \ |
| 337 | ".section .fixup,\"ax\"\n" \ |
| 338 | "3: movl %3,%0\n" \ |
| 339 | " jmp 2b\n" \ |
| 340 | ".previous\n" \ |
| 341 | ".section __ex_table,\"a\"\n" \ |
| 342 | " .align 4\n" \ |
| 343 | " .long 1b,3b\n" \ |
| 344 | ".previous" \ |
| 345 | : "=r"(err) \ |
| 346 | : ltype (x), "m"(__m(addr)), "i"(errret), "0"(err)) |
| 347 | |
| 348 | |
| 349 | #define __get_user_nocheck(x,ptr,size) \ |
| 350 | ({ \ |
| 351 | long __gu_err; \ |
| 352 | unsigned long __gu_val; \ |
| 353 | __get_user_size(__gu_val,(ptr),(size),__gu_err,-EFAULT);\ |
| 354 | (x) = (__typeof__(*(ptr)))__gu_val; \ |
| 355 | __gu_err; \ |
| 356 | }) |
| 357 | |
| 358 | extern long __get_user_bad(void); |
| 359 | |
| 360 | #define __get_user_size(x,ptr,size,retval,errret) \ |
| 361 | do { \ |
| 362 | retval = 0; \ |
| 363 | __chk_user_ptr(ptr); \ |
| 364 | switch (size) { \ |
| 365 | case 1: __get_user_asm(x,ptr,retval,"b","b","=q",errret);break; \ |
| 366 | case 2: __get_user_asm(x,ptr,retval,"w","w","=r",errret);break; \ |
| 367 | case 4: __get_user_asm(x,ptr,retval,"l","","=r",errret);break; \ |
| 368 | default: (x) = __get_user_bad(); \ |
| 369 | } \ |
| 370 | } while (0) |
| 371 | |
| 372 | #define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \ |
| 373 | __asm__ __volatile__( \ |
| 374 | "1: mov"itype" %2,%"rtype"1\n" \ |
| 375 | "2:\n" \ |
| 376 | ".section .fixup,\"ax\"\n" \ |
| 377 | "3: movl %3,%0\n" \ |
| 378 | " xor"itype" %"rtype"1,%"rtype"1\n" \ |
| 379 | " jmp 2b\n" \ |
| 380 | ".previous\n" \ |
| 381 | ".section __ex_table,\"a\"\n" \ |
| 382 | " .align 4\n" \ |
| 383 | " .long 1b,3b\n" \ |
| 384 | ".previous" \ |
| 385 | : "=r"(err), ltype (x) \ |
| 386 | : "m"(__m(addr)), "i"(errret), "0"(err)) |
| 387 | |
| 388 | |
| 389 | unsigned long __must_check __copy_to_user_ll(void __user *to, |
| 390 | const void *from, unsigned long n); |
| 391 | unsigned long __must_check __copy_from_user_ll(void *to, |
| 392 | const void __user *from, unsigned long n); |
Hiro Yoshioka | c22ce14 | 2006-06-23 02:04:16 -0700 | [diff] [blame] | 393 | unsigned long __must_check __copy_from_user_ll_nocache(void *to, |
| 394 | const void __user *from, unsigned long n); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | |
| 396 | /* |
| 397 | * Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault |
| 398 | * we return the initial request size (1, 2 or 4), as copy_*_user should do. |
| 399 | * If a store crosses a page boundary and gets a fault, the x86 will not write |
| 400 | * anything, so this is accurate. |
| 401 | */ |
| 402 | |
| 403 | /** |
| 404 | * __copy_to_user: - Copy a block of data into user space, with less checking. |
| 405 | * @to: Destination address, in user space. |
| 406 | * @from: Source address, in kernel space. |
| 407 | * @n: Number of bytes to copy. |
| 408 | * |
| 409 | * Context: User context only. This function may sleep. |
| 410 | * |
| 411 | * Copy data from kernel space to user space. Caller must check |
| 412 | * the specified block with access_ok() before calling this function. |
| 413 | * |
| 414 | * Returns number of bytes that could not be copied. |
| 415 | * On success, this will be zero. |
| 416 | */ |
Ingo Molnar | 652050a | 2006-01-14 13:21:30 -0800 | [diff] [blame] | 417 | static __always_inline unsigned long __must_check |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) |
| 419 | { |
| 420 | if (__builtin_constant_p(n)) { |
| 421 | unsigned long ret; |
| 422 | |
| 423 | switch (n) { |
| 424 | case 1: |
| 425 | __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret, 1); |
| 426 | return ret; |
| 427 | case 2: |
| 428 | __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret, 2); |
| 429 | return ret; |
| 430 | case 4: |
| 431 | __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret, 4); |
| 432 | return ret; |
| 433 | } |
| 434 | } |
| 435 | return __copy_to_user_ll(to, from, n); |
| 436 | } |
| 437 | |
Ingo Molnar | 652050a | 2006-01-14 13:21:30 -0800 | [diff] [blame] | 438 | static __always_inline unsigned long __must_check |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | __copy_to_user(void __user *to, const void *from, unsigned long n) |
| 440 | { |
| 441 | might_sleep(); |
| 442 | return __copy_to_user_inatomic(to, from, n); |
| 443 | } |
| 444 | |
| 445 | /** |
| 446 | * __copy_from_user: - Copy a block of data from user space, with less checking. |
| 447 | * @to: Destination address, in kernel space. |
| 448 | * @from: Source address, in user space. |
| 449 | * @n: Number of bytes to copy. |
| 450 | * |
| 451 | * Context: User context only. This function may sleep. |
| 452 | * |
| 453 | * Copy data from user space to kernel space. Caller must check |
| 454 | * the specified block with access_ok() before calling this function. |
| 455 | * |
| 456 | * Returns number of bytes that could not be copied. |
| 457 | * On success, this will be zero. |
| 458 | * |
| 459 | * If some data could not be copied, this function will pad the copied |
| 460 | * data to the requested size using zero bytes. |
NeilBrown | 01408c4 | 2006-06-25 05:47:58 -0700 | [diff] [blame^] | 461 | * |
| 462 | * An alternate version - __copy_from_user_inatomic() - may be called from |
| 463 | * atomic context and will fail rather than sleep. In this case the |
| 464 | * uncopied bytes will *NOT* be padded with zeros. See fs/filemap.h |
| 465 | * for explanation of why this is needed. |
| 466 | * FIXME this isn't implimented yet EMXIF |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | */ |
Ingo Molnar | 652050a | 2006-01-14 13:21:30 -0800 | [diff] [blame] | 468 | static __always_inline unsigned long |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 469 | __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) |
| 470 | { |
| 471 | if (__builtin_constant_p(n)) { |
| 472 | unsigned long ret; |
| 473 | |
| 474 | switch (n) { |
| 475 | case 1: |
| 476 | __get_user_size(*(u8 *)to, from, 1, ret, 1); |
| 477 | return ret; |
| 478 | case 2: |
| 479 | __get_user_size(*(u16 *)to, from, 2, ret, 2); |
| 480 | return ret; |
| 481 | case 4: |
| 482 | __get_user_size(*(u32 *)to, from, 4, ret, 4); |
| 483 | return ret; |
| 484 | } |
| 485 | } |
| 486 | return __copy_from_user_ll(to, from, n); |
| 487 | } |
| 488 | |
Hiro Yoshioka | c22ce14 | 2006-06-23 02:04:16 -0700 | [diff] [blame] | 489 | #define ARCH_HAS_NOCACHE_UACCESS |
| 490 | |
| 491 | static __always_inline unsigned long __copy_from_user_inatomic_nocache(void *to, |
| 492 | const void __user *from, unsigned long n) |
| 493 | { |
| 494 | if (__builtin_constant_p(n)) { |
| 495 | unsigned long ret; |
| 496 | |
| 497 | switch (n) { |
| 498 | case 1: |
| 499 | __get_user_size(*(u8 *)to, from, 1, ret, 1); |
| 500 | return ret; |
| 501 | case 2: |
| 502 | __get_user_size(*(u16 *)to, from, 2, ret, 2); |
| 503 | return ret; |
| 504 | case 4: |
| 505 | __get_user_size(*(u32 *)to, from, 4, ret, 4); |
| 506 | return ret; |
| 507 | } |
| 508 | } |
| 509 | return __copy_from_user_ll_nocache(to, from, n); |
| 510 | } |
| 511 | |
Ingo Molnar | 652050a | 2006-01-14 13:21:30 -0800 | [diff] [blame] | 512 | static __always_inline unsigned long |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 513 | __copy_from_user(void *to, const void __user *from, unsigned long n) |
| 514 | { |
| 515 | might_sleep(); |
| 516 | return __copy_from_user_inatomic(to, from, n); |
| 517 | } |
Hiro Yoshioka | c22ce14 | 2006-06-23 02:04:16 -0700 | [diff] [blame] | 518 | |
| 519 | static __always_inline unsigned long |
| 520 | __copy_from_user_nocache(void *to, const void __user *from, unsigned long n) |
| 521 | { |
| 522 | might_sleep(); |
| 523 | return __copy_from_user_inatomic_nocache(to, from, n); |
| 524 | } |
| 525 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | unsigned long __must_check copy_to_user(void __user *to, |
| 527 | const void *from, unsigned long n); |
| 528 | unsigned long __must_check copy_from_user(void *to, |
| 529 | const void __user *from, unsigned long n); |
| 530 | long __must_check strncpy_from_user(char *dst, const char __user *src, |
| 531 | long count); |
| 532 | long __must_check __strncpy_from_user(char *dst, |
| 533 | const char __user *src, long count); |
| 534 | |
| 535 | /** |
| 536 | * strlen_user: - Get the size of a string in user space. |
| 537 | * @str: The string to measure. |
| 538 | * |
| 539 | * Context: User context only. This function may sleep. |
| 540 | * |
| 541 | * Get the size of a NUL-terminated string in user space. |
| 542 | * |
| 543 | * Returns the size of the string INCLUDING the terminating NUL. |
| 544 | * On exception, returns 0. |
| 545 | * |
| 546 | * If there is a limit on the length of a valid string, you may wish to |
| 547 | * consider using strnlen_user() instead. |
| 548 | */ |
| 549 | #define strlen_user(str) strnlen_user(str, ~0UL >> 1) |
| 550 | |
| 551 | long strnlen_user(const char __user *str, long n); |
| 552 | unsigned long __must_check clear_user(void __user *mem, unsigned long len); |
| 553 | unsigned long __must_check __clear_user(void __user *mem, unsigned long len); |
| 554 | |
| 555 | #endif /* __i386_UACCESS_H */ |