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[mirror_ubuntu-artful-kernel.git] / arch / x86 / include / asm / uaccess.h
1 #ifndef _ASM_X86_UACCESS_H
2 #define _ASM_X86_UACCESS_H
3 /*
4 * User space memory access functions
5 */
6 #include <linux/compiler.h>
7 #include <linux/kasan-checks.h>
8 #include <linux/string.h>
9 #include <asm/asm.h>
10 #include <asm/page.h>
11 #include <asm/smap.h>
12 #include <asm/extable.h>
13
14 /*
15 * The fs value determines whether argument validity checking should be
16 * performed or not. If get_fs() == USER_DS, checking is performed, with
17 * get_fs() == KERNEL_DS, checking is bypassed.
18 *
19 * For historical reasons, these macros are grossly misnamed.
20 */
21
22 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
23
24 #define KERNEL_DS MAKE_MM_SEG(-1UL)
25 #define USER_DS MAKE_MM_SEG(TASK_SIZE_MAX)
26
27 #define get_ds() (KERNEL_DS)
28 #define get_fs() (current->thread.addr_limit)
29 static inline void set_fs(mm_segment_t fs)
30 {
31 current->thread.addr_limit = fs;
32 /* On user-mode return, check fs is correct */
33 set_thread_flag(TIF_FSCHECK);
34 }
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 __chk_user_ptr(ptr); \
170 might_fault(); \
171 asm volatile("call __get_user_%P4" \
172 : "=a" (__ret_gu), "=r" (__val_gu), \
173 ASM_CALL_CONSTRAINT \
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 #define __get_user_asm_nozero(x, addr, err, itype, rtype, ltype, errret) \
388 asm volatile("\n" \
389 "1: mov"itype" %2,%"rtype"1\n" \
390 "2:\n" \
391 ".section .fixup,\"ax\"\n" \
392 "3: mov %3,%0\n" \
393 " jmp 2b\n" \
394 ".previous\n" \
395 _ASM_EXTABLE(1b, 3b) \
396 : "=r" (err), ltype(x) \
397 : "m" (__m(addr)), "i" (errret), "0" (err))
398
399 /*
400 * This doesn't do __uaccess_begin/end - the exception handling
401 * around it must do that.
402 */
403 #define __get_user_size_ex(x, ptr, size) \
404 do { \
405 __chk_user_ptr(ptr); \
406 switch (size) { \
407 case 1: \
408 __get_user_asm_ex(x, ptr, "b", "b", "=q"); \
409 break; \
410 case 2: \
411 __get_user_asm_ex(x, ptr, "w", "w", "=r"); \
412 break; \
413 case 4: \
414 __get_user_asm_ex(x, ptr, "l", "k", "=r"); \
415 break; \
416 case 8: \
417 __get_user_asm_ex_u64(x, ptr); \
418 break; \
419 default: \
420 (x) = __get_user_bad(); \
421 } \
422 } while (0)
423
424 #define __get_user_asm_ex(x, addr, itype, rtype, ltype) \
425 asm volatile("1: mov"itype" %1,%"rtype"0\n" \
426 "2:\n" \
427 ".section .fixup,\"ax\"\n" \
428 "3:xor"itype" %"rtype"0,%"rtype"0\n" \
429 " jmp 2b\n" \
430 ".previous\n" \
431 _ASM_EXTABLE_EX(1b, 3b) \
432 : ltype(x) : "m" (__m(addr)))
433
434 #define __put_user_nocheck(x, ptr, size) \
435 ({ \
436 int __pu_err; \
437 __uaccess_begin(); \
438 __put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \
439 __uaccess_end(); \
440 __builtin_expect(__pu_err, 0); \
441 })
442
443 #define __get_user_nocheck(x, ptr, size) \
444 ({ \
445 int __gu_err; \
446 __inttype(*(ptr)) __gu_val; \
447 __uaccess_begin(); \
448 __get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \
449 __uaccess_end(); \
450 (x) = (__force __typeof__(*(ptr)))__gu_val; \
451 __builtin_expect(__gu_err, 0); \
452 })
453
454 /* FIXME: this hack is definitely wrong -AK */
455 struct __large_struct { unsigned long buf[100]; };
456 #define __m(x) (*(struct __large_struct __user *)(x))
457
458 /*
459 * Tell gcc we read from memory instead of writing: this is because
460 * we do not write to any memory gcc knows about, so there are no
461 * aliasing issues.
462 */
463 #define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \
464 asm volatile("\n" \
465 "1: mov"itype" %"rtype"1,%2\n" \
466 "2:\n" \
467 ".section .fixup,\"ax\"\n" \
468 "3: mov %3,%0\n" \
469 " jmp 2b\n" \
470 ".previous\n" \
471 _ASM_EXTABLE(1b, 3b) \
472 : "=r"(err) \
473 : ltype(x), "m" (__m(addr)), "i" (errret), "0" (err))
474
475 #define __put_user_asm_ex(x, addr, itype, rtype, ltype) \
476 asm volatile("1: mov"itype" %"rtype"0,%1\n" \
477 "2:\n" \
478 _ASM_EXTABLE_EX(1b, 2b) \
479 : : ltype(x), "m" (__m(addr)))
480
481 /*
482 * uaccess_try and catch
483 */
484 #define uaccess_try do { \
485 current->thread.uaccess_err = 0; \
486 __uaccess_begin(); \
487 barrier();
488
489 #define uaccess_catch(err) \
490 __uaccess_end(); \
491 (err) |= (current->thread.uaccess_err ? -EFAULT : 0); \
492 } while (0)
493
494 /**
495 * __get_user: - Get a simple variable from user space, with less checking.
496 * @x: Variable to store result.
497 * @ptr: Source address, in user space.
498 *
499 * Context: User context only. This function may sleep if pagefaults are
500 * enabled.
501 *
502 * This macro copies a single simple variable from user space to kernel
503 * space. It supports simple types like char and int, but not larger
504 * data types like structures or arrays.
505 *
506 * @ptr must have pointer-to-simple-variable type, and the result of
507 * dereferencing @ptr must be assignable to @x without a cast.
508 *
509 * Caller must check the pointer with access_ok() before calling this
510 * function.
511 *
512 * Returns zero on success, or -EFAULT on error.
513 * On error, the variable @x is set to zero.
514 */
515
516 #define __get_user(x, ptr) \
517 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
518
519 /**
520 * __put_user: - Write a simple value into user space, with less checking.
521 * @x: Value to copy to user space.
522 * @ptr: Destination address, in user space.
523 *
524 * Context: User context only. This function may sleep if pagefaults are
525 * enabled.
526 *
527 * This macro copies a single simple value from kernel space to user
528 * space. It supports simple types like char and int, but not larger
529 * data types like structures or arrays.
530 *
531 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
532 * to the result of dereferencing @ptr.
533 *
534 * Caller must check the pointer with access_ok() before calling this
535 * function.
536 *
537 * Returns zero on success, or -EFAULT on error.
538 */
539
540 #define __put_user(x, ptr) \
541 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
542
543 /*
544 * {get|put}_user_try and catch
545 *
546 * get_user_try {
547 * get_user_ex(...);
548 * } get_user_catch(err)
549 */
550 #define get_user_try uaccess_try
551 #define get_user_catch(err) uaccess_catch(err)
552
553 #define get_user_ex(x, ptr) do { \
554 unsigned long __gue_val; \
555 __get_user_size_ex((__gue_val), (ptr), (sizeof(*(ptr)))); \
556 (x) = (__force __typeof__(*(ptr)))__gue_val; \
557 } while (0)
558
559 #define put_user_try uaccess_try
560 #define put_user_catch(err) uaccess_catch(err)
561
562 #define put_user_ex(x, ptr) \
563 __put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
564
565 extern unsigned long
566 copy_from_user_nmi(void *to, const void __user *from, unsigned long n);
567 extern __must_check long
568 strncpy_from_user(char *dst, const char __user *src, long count);
569
570 extern __must_check long strnlen_user(const char __user *str, long n);
571
572 unsigned long __must_check clear_user(void __user *mem, unsigned long len);
573 unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
574
575 extern void __cmpxchg_wrong_size(void)
576 __compiletime_error("Bad argument size for cmpxchg");
577
578 #define __user_atomic_cmpxchg_inatomic(uval, ptr, old, new, size) \
579 ({ \
580 int __ret = 0; \
581 __typeof__(ptr) __uval = (uval); \
582 __typeof__(*(ptr)) __old = (old); \
583 __typeof__(*(ptr)) __new = (new); \
584 __uaccess_begin(); \
585 switch (size) { \
586 case 1: \
587 { \
588 asm volatile("\n" \
589 "1:\t" LOCK_PREFIX "cmpxchgb %4, %2\n" \
590 "2:\n" \
591 "\t.section .fixup, \"ax\"\n" \
592 "3:\tmov %3, %0\n" \
593 "\tjmp 2b\n" \
594 "\t.previous\n" \
595 _ASM_EXTABLE(1b, 3b) \
596 : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
597 : "i" (-EFAULT), "q" (__new), "1" (__old) \
598 : "memory" \
599 ); \
600 break; \
601 } \
602 case 2: \
603 { \
604 asm volatile("\n" \
605 "1:\t" LOCK_PREFIX "cmpxchgw %4, %2\n" \
606 "2:\n" \
607 "\t.section .fixup, \"ax\"\n" \
608 "3:\tmov %3, %0\n" \
609 "\tjmp 2b\n" \
610 "\t.previous\n" \
611 _ASM_EXTABLE(1b, 3b) \
612 : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
613 : "i" (-EFAULT), "r" (__new), "1" (__old) \
614 : "memory" \
615 ); \
616 break; \
617 } \
618 case 4: \
619 { \
620 asm volatile("\n" \
621 "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n" \
622 "2:\n" \
623 "\t.section .fixup, \"ax\"\n" \
624 "3:\tmov %3, %0\n" \
625 "\tjmp 2b\n" \
626 "\t.previous\n" \
627 _ASM_EXTABLE(1b, 3b) \
628 : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
629 : "i" (-EFAULT), "r" (__new), "1" (__old) \
630 : "memory" \
631 ); \
632 break; \
633 } \
634 case 8: \
635 { \
636 if (!IS_ENABLED(CONFIG_X86_64)) \
637 __cmpxchg_wrong_size(); \
638 \
639 asm volatile("\n" \
640 "1:\t" LOCK_PREFIX "cmpxchgq %4, %2\n" \
641 "2:\n" \
642 "\t.section .fixup, \"ax\"\n" \
643 "3:\tmov %3, %0\n" \
644 "\tjmp 2b\n" \
645 "\t.previous\n" \
646 _ASM_EXTABLE(1b, 3b) \
647 : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
648 : "i" (-EFAULT), "r" (__new), "1" (__old) \
649 : "memory" \
650 ); \
651 break; \
652 } \
653 default: \
654 __cmpxchg_wrong_size(); \
655 } \
656 __uaccess_end(); \
657 *__uval = __old; \
658 __ret; \
659 })
660
661 #define user_atomic_cmpxchg_inatomic(uval, ptr, old, new) \
662 ({ \
663 access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \
664 __user_atomic_cmpxchg_inatomic((uval), (ptr), \
665 (old), (new), sizeof(*(ptr))) : \
666 -EFAULT; \
667 })
668
669 /*
670 * movsl can be slow when source and dest are not both 8-byte aligned
671 */
672 #ifdef CONFIG_X86_INTEL_USERCOPY
673 extern struct movsl_mask {
674 int mask;
675 } ____cacheline_aligned_in_smp movsl_mask;
676 #endif
677
678 #define ARCH_HAS_NOCACHE_UACCESS 1
679
680 #ifdef CONFIG_X86_32
681 # include <asm/uaccess_32.h>
682 #else
683 # include <asm/uaccess_64.h>
684 #endif
685
686 /*
687 * We rely on the nested NMI work to allow atomic faults from the NMI path; the
688 * nested NMI paths are careful to preserve CR2.
689 *
690 * Caller must use pagefault_enable/disable, or run in interrupt context,
691 * and also do a uaccess_ok() check
692 */
693 #define __copy_from_user_nmi __copy_from_user_inatomic
694
695 /*
696 * The "unsafe" user accesses aren't really "unsafe", but the naming
697 * is a big fat warning: you have to not only do the access_ok()
698 * checking before using them, but you have to surround them with the
699 * user_access_begin/end() pair.
700 */
701 #define user_access_begin() __uaccess_begin()
702 #define user_access_end() __uaccess_end()
703
704 #define unsafe_put_user(x, ptr, err_label) \
705 do { \
706 int __pu_err; \
707 __typeof__(*(ptr)) __pu_val = (x); \
708 __put_user_size(__pu_val, (ptr), sizeof(*(ptr)), __pu_err, -EFAULT); \
709 if (unlikely(__pu_err)) goto err_label; \
710 } while (0)
711
712 #define unsafe_get_user(x, ptr, err_label) \
713 do { \
714 int __gu_err; \
715 __inttype(*(ptr)) __gu_val; \
716 __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), __gu_err, -EFAULT); \
717 (x) = (__force __typeof__(*(ptr)))__gu_val; \
718 if (unlikely(__gu_err)) goto err_label; \
719 } while (0)
720
721 #endif /* _ASM_X86_UACCESS_H */
722
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