?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
x86/mm/pat: Don't report PAT on CPUs that don't support it
[linux/fpc-iii.git] / arch / x86 / include / asm / uaccess.h
blobdead0f3921f33287b05f5cfbab8ef9af6f7c0968
1 #ifndef _ASM_X86_UACCESS_H
2 #define _ASM_X86_UACCESS_H
3 /*
4 * User space memory access functions
5 */
6 #include <linux/errno.h>
7 #include <linux/compiler.h>
8 #include <linux/kasan-checks.h>
9 #include <linux/thread_info.h>
10 #include <linux/string.h>
11 #include <asm/asm.h>
12 #include <asm/page.h>
13 #include <asm/smap.h>
14 #include <asm/extable.h>
15
16 #define VERIFY_READ 0
17 #define VERIFY_WRITE 1
18
19 /*
20 * The fs value determines whether argument validity checking should be
21 * performed or not. If get_fs() == USER_DS, checking is performed, with
22 * get_fs() == KERNEL_DS, checking is bypassed.
23 *
24 * For historical reasons, these macros are grossly misnamed.
25 */
26
27 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
28
29 #define KERNEL_DS MAKE_MM_SEG(-1UL)
30 #define USER_DS MAKE_MM_SEG(TASK_SIZE_MAX)
31
32 #define get_ds() (KERNEL_DS)
33 #define get_fs() (current->thread.addr_limit)
34 #define set_fs(x) (current->thread.addr_limit = (x))
35
36 #define segment_eq(a, b) ((a).seg == (b).seg)
37
38 #define user_addr_max() (current->thread.addr_limit.seg)
39 #define __addr_ok(addr) \
40 ((unsigned long __force)(addr) < user_addr_max())
41
42 /*
43 * Test whether a block of memory is a valid user space address.
44 * Returns 0 if the range is valid, nonzero otherwise.
45 */
46 static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit)
47 {
48 /*
49 * If we have used "sizeof()" for the size,
50 * we know it won't overflow the limit (but
51 * it might overflow the 'addr', so it's
52 * important to subtract the size from the
53 * limit, not add it to the address).
54 */
55 if (__builtin_constant_p(size))
56 return unlikely(addr > limit - size);
57
58 /* Arbitrary sizes? Be careful about overflow */
59 addr += size;
60 if (unlikely(addr < size))
61 return true;
62 return unlikely(addr > limit);
63 }
64
65 #define __range_not_ok(addr, size, limit) \
66 ({ \
67 __chk_user_ptr(addr); \
68 __chk_range_not_ok((unsigned long __force)(addr), size, limit); \
69 })
70
71 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
72 # define WARN_ON_IN_IRQ() WARN_ON_ONCE(!in_task())
73 #else
74 # define WARN_ON_IN_IRQ()
75 #endif
76
77 /**
78 * access_ok: - Checks if a user space pointer is valid
79 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
80 * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
81 * to write to a block, it is always safe to read from it.
82 * @addr: User space pointer to start of block to check
83 * @size: Size of block to check
84 *
85 * Context: User context only. This function may sleep if pagefaults are
86 * enabled.
87 *
88 * Checks if a pointer to a block of memory in user space is valid.
89 *
90 * Returns true (nonzero) if the memory block may be valid, false (zero)
91 * if it is definitely invalid.
92 *
93 * Note that, depending on architecture, this function probably just
94 * checks that the pointer is in the user space range - after calling
95 * this function, memory access functions may still return -EFAULT.
96 */
97 #define access_ok(type, addr, size) \
98 ({ \
99 WARN_ON_IN_IRQ(); \
100 likely(!__range_not_ok(addr, size, user_addr_max())); \
101 })
102
103 /*
104 * These are the main single-value transfer routines. They automatically
105 * use the right size if we just have the right pointer type.
106 *
107 * This gets kind of ugly. We want to return _two_ values in "get_user()"
108 * and yet we don't want to do any pointers, because that is too much
109 * of a performance impact. Thus we have a few rather ugly macros here,
110 * and hide all the ugliness from the user.
111 *
112 * The "__xxx" versions of the user access functions are versions that
113 * do not verify the address space, that must have been done previously
114 * with a separate "access_ok()" call (this is used when we do multiple
115 * accesses to the same area of user memory).
116 */
117
118 extern int __get_user_1(void);
119 extern int __get_user_2(void);
120 extern int __get_user_4(void);
121 extern int __get_user_8(void);
122 extern int __get_user_bad(void);
123
124 #define __uaccess_begin() stac()
125 #define __uaccess_end() clac()
126
127 /*
128 * This is a type: either unsigned long, if the argument fits into
129 * that type, or otherwise unsigned long long.
130 */
131 #define __inttype(x) \
132 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
133
134 /**
135 * get_user: - Get a simple variable from user space.
136 * @x: Variable to store result.
137 * @ptr: Source address, in user space.
138 *
139 * Context: User context only. This function may sleep if pagefaults are
140 * enabled.
141 *
142 * This macro copies a single simple variable from user space to kernel
143 * space. It supports simple types like char and int, but not larger
144 * data types like structures or arrays.
145 *
146 * @ptr must have pointer-to-simple-variable type, and the result of
147 * dereferencing @ptr must be assignable to @x without a cast.
148 *
149 * Returns zero on success, or -EFAULT on error.
150 * On error, the variable @x is set to zero.
151 */
152 /*
153 * Careful: we have to cast the result to the type of the pointer
154 * for sign reasons.
155 *
156 * The use of _ASM_DX as the register specifier is a bit of a
157 * simplification, as gcc only cares about it as the starting point
158 * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits
159 * (%ecx being the next register in gcc's x86 register sequence), and
160 * %rdx on 64 bits.
161 *
162 * Clang/LLVM cares about the size of the register, but still wants
163 * the base register for something that ends up being a pair.
164 */
165 #define get_user(x, ptr) \
166 ({ \
167 int __ret_gu; \
168 register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \
169 register void *__sp asm(_ASM_SP); \
170 __chk_user_ptr(ptr); \
171 might_fault(); \
172 asm volatile("call __get_user_%P4" \
173 : "=a" (__ret_gu), "=r" (__val_gu), "+r" (__sp) \
174 : "0" (ptr), "i" (sizeof(*(ptr)))); \
175 (x) = (__force __typeof__(*(ptr))) __val_gu; \
176 __builtin_expect(__ret_gu, 0); \
177 })
178
179 #define __put_user_x(size, x, ptr, __ret_pu) \
180 asm volatile("call __put_user_" #size : "=a" (__ret_pu) \
181 : "0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
182
183
184
185 #ifdef CONFIG_X86_32
186 #define __put_user_asm_u64(x, addr, err, errret) \
187 asm volatile("\n" \
188 "1: movl %%eax,0(%2)\n" \
189 "2: movl %%edx,4(%2)\n" \
190 "3:" \
191 ".section .fixup,\"ax\"\n" \
192 "4: movl %3,%0\n" \
193 " jmp 3b\n" \
194 ".previous\n" \
195 _ASM_EXTABLE(1b, 4b) \
196 _ASM_EXTABLE(2b, 4b) \
197 : "=r" (err) \
198 : "A" (x), "r" (addr), "i" (errret), "0" (err))
199
200 #define __put_user_asm_ex_u64(x, addr) \
201 asm volatile("\n" \
202 "1: movl %%eax,0(%1)\n" \
203 "2: movl %%edx,4(%1)\n" \
204 "3:" \
205 _ASM_EXTABLE_EX(1b, 2b) \
206 _ASM_EXTABLE_EX(2b, 3b) \
207 : : "A" (x), "r" (addr))
208
209 #define __put_user_x8(x, ptr, __ret_pu) \
210 asm volatile("call __put_user_8" : "=a" (__ret_pu) \
211 : "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
212 #else
213 #define __put_user_asm_u64(x, ptr, retval, errret) \
214 __put_user_asm(x, ptr, retval, "q", "", "er", errret)
215 #define __put_user_asm_ex_u64(x, addr) \
216 __put_user_asm_ex(x, addr, "q", "", "er")
217 #define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu)
218 #endif
219
220 extern void __put_user_bad(void);
221
222 /*
223 * Strange magic calling convention: pointer in %ecx,
224 * value in %eax(:%edx), return value in %eax. clobbers %rbx
225 */
226 extern void __put_user_1(void);
227 extern void __put_user_2(void);
228 extern void __put_user_4(void);
229 extern void __put_user_8(void);
230
231 /**
232 * put_user: - Write a simple value into user space.
233 * @x: Value to copy to user space.
234 * @ptr: Destination address, in user space.
235 *
236 * Context: User context only. This function may sleep if pagefaults are
237 * enabled.
238 *
239 * This macro copies a single simple value from kernel space to user
240 * space. It supports simple types like char and int, but not larger
241 * data types like structures or arrays.
242 *
243 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
244 * to the result of dereferencing @ptr.
245 *
246 * Returns zero on success, or -EFAULT on error.
247 */
248 #define put_user(x, ptr) \
249 ({ \
250 int __ret_pu; \
251 __typeof__(*(ptr)) __pu_val; \
252 __chk_user_ptr(ptr); \
253 might_fault(); \
254 __pu_val = x; \
255 switch (sizeof(*(ptr))) { \
256 case 1: \
257 __put_user_x(1, __pu_val, ptr, __ret_pu); \
258 break; \
259 case 2: \
260 __put_user_x(2, __pu_val, ptr, __ret_pu); \
261 break; \
262 case 4: \
263 __put_user_x(4, __pu_val, ptr, __ret_pu); \
264 break; \
265 case 8: \
266 __put_user_x8(__pu_val, ptr, __ret_pu); \
267 break; \
268 default: \
269 __put_user_x(X, __pu_val, ptr, __ret_pu); \
270 break; \
271 } \
272 __builtin_expect(__ret_pu, 0); \
273 })
274
275 #define __put_user_size(x, ptr, size, retval, errret) \
276 do { \
277 retval = 0; \
278 __chk_user_ptr(ptr); \
279 switch (size) { \
280 case 1: \
281 __put_user_asm(x, ptr, retval, "b", "b", "iq", errret); \
282 break; \
283 case 2: \
284 __put_user_asm(x, ptr, retval, "w", "w", "ir", errret); \
285 break; \
286 case 4: \
287 __put_user_asm(x, ptr, retval, "l", "k", "ir", errret); \
288 break; \
289 case 8: \
290 __put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval, \
291 errret); \
292 break; \
293 default: \
294 __put_user_bad(); \
295 } \
296 } while (0)
297
298 /*
299 * This doesn't do __uaccess_begin/end - the exception handling
300 * around it must do that.
301 */
302 #define __put_user_size_ex(x, ptr, size) \
303 do { \
304 __chk_user_ptr(ptr); \
305 switch (size) { \
306 case 1: \
307 __put_user_asm_ex(x, ptr, "b", "b", "iq"); \
308 break; \
309 case 2: \
310 __put_user_asm_ex(x, ptr, "w", "w", "ir"); \
311 break; \
312 case 4: \
313 __put_user_asm_ex(x, ptr, "l", "k", "ir"); \
314 break; \
315 case 8: \
316 __put_user_asm_ex_u64((__typeof__(*ptr))(x), ptr); \
317 break; \
318 default: \
319 __put_user_bad(); \
320 } \
321 } while (0)
322
323 #ifdef CONFIG_X86_32
324 #define __get_user_asm_u64(x, ptr, retval, errret) \
325 ({ \
326 __typeof__(ptr) __ptr = (ptr); \
327 asm volatile("\n" \
328 "1: movl %2,%%eax\n" \
329 "2: movl %3,%%edx\n" \
330 "3:\n" \
331 ".section .fixup,\"ax\"\n" \
332 "4: mov %4,%0\n" \
333 " xorl %%eax,%%eax\n" \
334 " xorl %%edx,%%edx\n" \
335 " jmp 3b\n" \
336 ".previous\n" \
337 _ASM_EXTABLE(1b, 4b) \
338 _ASM_EXTABLE(2b, 4b) \
339 : "=r" (retval), "=&A"(x) \
340 : "m" (__m(__ptr)), "m" __m(((u32 *)(__ptr)) + 1), \
341 "i" (errret), "0" (retval)); \
342 })
343
344 #define __get_user_asm_ex_u64(x, ptr) (x) = __get_user_bad()
345 #else
346 #define __get_user_asm_u64(x, ptr, retval, errret) \
347 __get_user_asm(x, ptr, retval, "q", "", "=r", errret)
348 #define __get_user_asm_ex_u64(x, ptr) \
349 __get_user_asm_ex(x, ptr, "q", "", "=r")
350 #endif
351
352 #define __get_user_size(x, ptr, size, retval, errret) \
353 do { \
354 retval = 0; \
355 __chk_user_ptr(ptr); \
356 switch (size) { \
357 case 1: \
358 __get_user_asm(x, ptr, retval, "b", "b", "=q", errret); \
359 break; \
360 case 2: \
361 __get_user_asm(x, ptr, retval, "w", "w", "=r", errret); \
362 break; \
363 case 4: \
364 __get_user_asm(x, ptr, retval, "l", "k", "=r", errret); \
365 break; \
366 case 8: \
367 __get_user_asm_u64(x, ptr, retval, errret); \
368 break; \
369 default: \
370 (x) = __get_user_bad(); \
371 } \
372 } while (0)
373
374 #define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \
375 asm volatile("\n" \
376 "1: mov"itype" %2,%"rtype"1\n" \
377 "2:\n" \
378 ".section .fixup,\"ax\"\n" \
379 "3: mov %3,%0\n" \
380 " xor"itype" %"rtype"1,%"rtype"1\n" \
381 " jmp 2b\n" \
382 ".previous\n" \
383 _ASM_EXTABLE(1b, 3b) \
384 : "=r" (err), ltype(x) \
385 : "m" (__m(addr)), "i" (errret), "0" (err))
386
387 /*
388 * This doesn't do __uaccess_begin/end - the exception handling
389 * around it must do that.
390 */
391 #define __get_user_size_ex(x, ptr, size) \
392 do { \
393 __chk_user_ptr(ptr); \
394 switch (size) { \
395 case 1: \
396 __get_user_asm_ex(x, ptr, "b", "b", "=q"); \
397 break; \
398 case 2: \
399 __get_user_asm_ex(x, ptr, "w", "w", "=r"); \
400 break; \
401 case 4: \
402 __get_user_asm_ex(x, ptr, "l", "k", "=r"); \
403 break; \
404 case 8: \
405 __get_user_asm_ex_u64(x, ptr); \
406 break; \
407 default: \
408 (x) = __get_user_bad(); \
409 } \
410 } while (0)
411
412 #define __get_user_asm_ex(x, addr, itype, rtype, ltype) \
413 asm volatile("1: mov"itype" %1,%"rtype"0\n" \
414 "2:\n" \
415 ".section .fixup,\"ax\"\n" \
416 "3:xor"itype" %"rtype"0,%"rtype"0\n" \
417 " jmp 2b\n" \
418 ".previous\n" \
419 _ASM_EXTABLE_EX(1b, 3b) \
420 : ltype(x) : "m" (__m(addr)))
421
422 #define __put_user_nocheck(x, ptr, size) \
423 ({ \
424 int __pu_err; \
425 __uaccess_begin(); \
426 __put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \
427 __uaccess_end(); \
428 __builtin_expect(__pu_err, 0); \
429 })
430
431 #define __get_user_nocheck(x, ptr, size) \
432 ({ \
433 int __gu_err; \
434 __inttype(*(ptr)) __gu_val; \
435 __uaccess_begin(); \
436 __get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \
437 __uaccess_end(); \
438 (x) = (__force __typeof__(*(ptr)))__gu_val; \
439 __builtin_expect(__gu_err, 0); \
440 })
441
442 /* FIXME: this hack is definitely wrong -AK */
443 struct __large_struct { unsigned long buf[100]; };
444 #define __m(x) (*(struct __large_struct __user *)(x))
445
446 /*
447 * Tell gcc we read from memory instead of writing: this is because
448 * we do not write to any memory gcc knows about, so there are no
449 * aliasing issues.
450 */
451 #define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \
452 asm volatile("\n" \
453 "1: mov"itype" %"rtype"1,%2\n" \
454 "2:\n" \
455 ".section .fixup,\"ax\"\n" \
456 "3: mov %3,%0\n" \
457 " jmp 2b\n" \
458 ".previous\n" \
459 _ASM_EXTABLE(1b, 3b) \
460 : "=r"(err) \
461 : ltype(x), "m" (__m(addr)), "i" (errret), "0" (err))
462
463 #define __put_user_asm_ex(x, addr, itype, rtype, ltype) \
464 asm volatile("1: mov"itype" %"rtype"0,%1\n" \
465 "2:\n" \
466 _ASM_EXTABLE_EX(1b, 2b) \
467 : : ltype(x), "m" (__m(addr)))
468
469 /*
470 * uaccess_try and catch
471 */
472 #define uaccess_try do { \
473 current->thread.uaccess_err = 0; \
474 __uaccess_begin(); \
475 barrier();
476
477 #define uaccess_catch(err) \
478 __uaccess_end(); \
479 (err) |= (current->thread.uaccess_err ? -EFAULT : 0); \
480 } while (0)
481
482 /**
483 * __get_user: - Get a simple variable from user space, with less checking.
484 * @x: Variable to store result.
485 * @ptr: Source address, in user space.
486 *
487 * Context: User context only. This function may sleep if pagefaults are
488 * enabled.
489 *
490 * This macro copies a single simple variable from user space to kernel
491 * space. It supports simple types like char and int, but not larger
492 * data types like structures or arrays.
493 *
494 * @ptr must have pointer-to-simple-variable type, and the result of
495 * dereferencing @ptr must be assignable to @x without a cast.
496 *
497 * Caller must check the pointer with access_ok() before calling this
498 * function.
499 *
500 * Returns zero on success, or -EFAULT on error.
501 * On error, the variable @x is set to zero.
502 */
503
504 #define __get_user(x, ptr) \
505 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
506
507 /**
508 * __put_user: - Write a simple value into user space, with less checking.
509 * @x: Value to copy to user space.
510 * @ptr: Destination address, in user space.
511 *
512 * Context: User context only. This function may sleep if pagefaults are
513 * enabled.
514 *
515 * This macro copies a single simple value from kernel space to user
516 * space. It supports simple types like char and int, but not larger
517 * data types like structures or arrays.
518 *
519 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
520 * to the result of dereferencing @ptr.
521 *
522 * Caller must check the pointer with access_ok() before calling this
523 * function.
524 *
525 * Returns zero on success, or -EFAULT on error.
526 */
527
528 #define __put_user(x, ptr) \
529 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
530
531 #define __get_user_unaligned __get_user
532 #define __put_user_unaligned __put_user
533
534 /*
535 * {get|put}_user_try and catch
536 *
537 * get_user_try {
538 * get_user_ex(...);
539 * } get_user_catch(err)
540 */
541 #define get_user_try uaccess_try
542 #define get_user_catch(err) uaccess_catch(err)
543
544 #define get_user_ex(x, ptr) do { \
545 unsigned long __gue_val; \
546 __get_user_size_ex((__gue_val), (ptr), (sizeof(*(ptr)))); \
547 (x) = (__force __typeof__(*(ptr)))__gue_val; \
548 } while (0)
549
550 #define put_user_try uaccess_try
551 #define put_user_catch(err) uaccess_catch(err)
552
553 #define put_user_ex(x, ptr) \
554 __put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
555
556 extern unsigned long
557 copy_from_user_nmi(void *to, const void __user *from, unsigned long n);
558 extern __must_check long
559 strncpy_from_user(char *dst, const char __user *src, long count);
560
561 extern __must_check long strlen_user(const char __user *str);
562 extern __must_check long strnlen_user(const char __user *str, long n);
563
564 unsigned long __must_check clear_user(void __user *mem, unsigned long len);
565 unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
566
567 extern void __cmpxchg_wrong_size(void)
568 __compiletime_error("Bad argument size for cmpxchg");
569
570 #define __user_atomic_cmpxchg_inatomic(uval, ptr, old, new, size) \
571 ({ \
572 int __ret = 0; \
573 __typeof__(ptr) __uval = (uval); \
574 __typeof__(*(ptr)) __old = (old); \
575 __typeof__(*(ptr)) __new = (new); \
576 __uaccess_begin(); \
577 switch (size) { \
578 case 1: \
579 { \
580 asm volatile("\n" \
581 "1:\t" LOCK_PREFIX "cmpxchgb %4, %2\n" \
582 "2:\n" \
583 "\t.section .fixup, \"ax\"\n" \
584 "3:\tmov %3, %0\n" \
585 "\tjmp 2b\n" \
586 "\t.previous\n" \
587 _ASM_EXTABLE(1b, 3b) \
588 : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
589 : "i" (-EFAULT), "q" (__new), "1" (__old) \
590 : "memory" \
591 ); \
592 break; \
593 } \
594 case 2: \
595 { \
596 asm volatile("\n" \
597 "1:\t" LOCK_PREFIX "cmpxchgw %4, %2\n" \
598 "2:\n" \
599 "\t.section .fixup, \"ax\"\n" \
600 "3:\tmov %3, %0\n" \
601 "\tjmp 2b\n" \
602 "\t.previous\n" \
603 _ASM_EXTABLE(1b, 3b) \
604 : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
605 : "i" (-EFAULT), "r" (__new), "1" (__old) \
606 : "memory" \
607 ); \
608 break; \
609 } \
610 case 4: \
611 { \
612 asm volatile("\n" \
613 "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n" \
614 "2:\n" \
615 "\t.section .fixup, \"ax\"\n" \
616 "3:\tmov %3, %0\n" \
617 "\tjmp 2b\n" \
618 "\t.previous\n" \
619 _ASM_EXTABLE(1b, 3b) \
620 : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
621 : "i" (-EFAULT), "r" (__new), "1" (__old) \
622 : "memory" \
623 ); \
624 break; \
625 } \
626 case 8: \
627 { \
628 if (!IS_ENABLED(CONFIG_X86_64)) \
629 __cmpxchg_wrong_size(); \
630 \
631 asm volatile("\n" \
632 "1:\t" LOCK_PREFIX "cmpxchgq %4, %2\n" \
633 "2:\n" \
634 "\t.section .fixup, \"ax\"\n" \
635 "3:\tmov %3, %0\n" \
636 "\tjmp 2b\n" \
637 "\t.previous\n" \
638 _ASM_EXTABLE(1b, 3b) \
639 : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
640 : "i" (-EFAULT), "r" (__new), "1" (__old) \
641 : "memory" \
642 ); \
643 break; \
644 } \
645 default: \
646 __cmpxchg_wrong_size(); \
647 } \
648 __uaccess_end(); \
649 *__uval = __old; \
650 __ret; \
651 })
652
653 #define user_atomic_cmpxchg_inatomic(uval, ptr, old, new) \
654 ({ \
655 access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \
656 __user_atomic_cmpxchg_inatomic((uval), (ptr), \
657 (old), (new), sizeof(*(ptr))) : \
658 -EFAULT; \
659 })
660
661 /*
662 * movsl can be slow when source and dest are not both 8-byte aligned
663 */
664 #ifdef CONFIG_X86_INTEL_USERCOPY
665 extern struct movsl_mask {
666 int mask;
667 } ____cacheline_aligned_in_smp movsl_mask;
668 #endif
669
670 #define ARCH_HAS_NOCACHE_UACCESS 1
671
672 #ifdef CONFIG_X86_32
673 # include <asm/uaccess_32.h>
674 #else
675 # include <asm/uaccess_64.h>
676 #endif
677
678 unsigned long __must_check _copy_from_user(void *to, const void __user *from,
679 unsigned n);
680 unsigned long __must_check _copy_to_user(void __user *to, const void *from,
681 unsigned n);
682
683 extern void __compiletime_error("usercopy buffer size is too small")
684 __bad_copy_user(void);
685
686 static inline void copy_user_overflow(int size, unsigned long count)
687 {
688 WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
689 }
690
691 static __always_inline unsigned long __must_check
692 copy_from_user(void *to, const void __user *from, unsigned long n)
693 {
694 int sz = __compiletime_object_size(to);
695
696 might_fault();
697
698 kasan_check_write(to, n);
699
700 if (likely(sz < 0 || sz >= n)) {
701 check_object_size(to, n, false);
702 n = _copy_from_user(to, from, n);
703 } else if (!__builtin_constant_p(n))
704 copy_user_overflow(sz, n);
705 else
706 __bad_copy_user();
707
708 return n;
709 }
710
711 static __always_inline unsigned long __must_check
712 copy_to_user(void __user *to, const void *from, unsigned long n)
713 {
714 int sz = __compiletime_object_size(from);
715
716 kasan_check_read(from, n);
717
718 might_fault();
719
720 if (likely(sz < 0 || sz >= n)) {
721 check_object_size(from, n, true);
722 n = _copy_to_user(to, from, n);
723 } else if (!__builtin_constant_p(n))
724 copy_user_overflow(sz, n);
725 else
726 __bad_copy_user();
727
728 return n;
729 }
730
731 /*
732 * We rely on the nested NMI work to allow atomic faults from the NMI path; the
733 * nested NMI paths are careful to preserve CR2.
734 *
735 * Caller must use pagefault_enable/disable, or run in interrupt context,
736 * and also do a uaccess_ok() check
737 */
738 #define __copy_from_user_nmi __copy_from_user_inatomic
739
740 /*
741 * The "unsafe" user accesses aren't really "unsafe", but the naming
742 * is a big fat warning: you have to not only do the access_ok()
743 * checking before using them, but you have to surround them with the
744 * user_access_begin/end() pair.
745 */
746 #define user_access_begin() __uaccess_begin()
747 #define user_access_end() __uaccess_end()
748
749 #define unsafe_put_user(x, ptr, err_label) \
750 do { \
751 int __pu_err; \
752 __put_user_size((x), (ptr), sizeof(*(ptr)), __pu_err, -EFAULT); \
753 if (unlikely(__pu_err)) goto err_label; \
754 } while (0)
755
756 #define unsafe_get_user(x, ptr, err_label) \
757 do { \
758 int __gu_err; \
759 unsigned long __gu_val; \
760 __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), __gu_err, -EFAULT); \
761 (x) = (__force __typeof__(*(ptr)))__gu_val; \
762 if (unlikely(__gu_err)) goto err_label; \
763 } while (0)
764
765 #endif /* _ASM_X86_UACCESS_H */
766
Linux with added FPC-III support