Line data Source code
1 : /* SPDX-License-Identifier: GPL-2.0 */
2 : #ifndef _ASM_X86_UACCESS_H
3 : #define _ASM_X86_UACCESS_H
4 : /*
5 : * User space memory access functions
6 : */
7 : #include <linux/compiler.h>
8 : #include <linux/instrumented.h>
9 : #include <linux/kasan-checks.h>
10 : #include <linux/mm_types.h>
11 : #include <linux/string.h>
12 : #include <linux/mmap_lock.h>
13 : #include <asm/asm.h>
14 : #include <asm/page.h>
15 : #include <asm/smap.h>
16 : #include <asm/extable.h>
17 : #include <asm/tlbflush.h>
18 :
19 : #ifdef CONFIG_X86_32
20 : # include <asm/uaccess_32.h>
21 : #else
22 : # include <asm/uaccess_64.h>
23 : #endif
24 :
25 : #include <asm-generic/access_ok.h>
26 :
27 : extern int __get_user_1(void);
28 : extern int __get_user_2(void);
29 : extern int __get_user_4(void);
30 : extern int __get_user_8(void);
31 : extern int __get_user_nocheck_1(void);
32 : extern int __get_user_nocheck_2(void);
33 : extern int __get_user_nocheck_4(void);
34 : extern int __get_user_nocheck_8(void);
35 : extern int __get_user_bad(void);
36 :
37 : #define __uaccess_begin() stac()
38 : #define __uaccess_end() clac()
39 : #define __uaccess_begin_nospec() \
40 : ({ \
41 : stac(); \
42 : barrier_nospec(); \
43 : })
44 :
45 : /*
46 : * This is the smallest unsigned integer type that can fit a value
47 : * (up to 'long long')
48 : */
49 : #define __inttype(x) __typeof__( \
50 : __typefits(x,char, \
51 : __typefits(x,short, \
52 : __typefits(x,int, \
53 : __typefits(x,long,0ULL)))))
54 :
55 : #define __typefits(x,type,not) \
56 : __builtin_choose_expr(sizeof(x)<=sizeof(type),(unsigned type)0,not)
57 :
58 : /*
59 : * This is used for both get_user() and __get_user() to expand to
60 : * the proper special function call that has odd calling conventions
61 : * due to returning both a value and an error, and that depends on
62 : * the size of the pointer passed in.
63 : *
64 : * Careful: we have to cast the result to the type of the pointer
65 : * for sign reasons.
66 : *
67 : * The use of _ASM_DX as the register specifier is a bit of a
68 : * simplification, as gcc only cares about it as the starting point
69 : * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits
70 : * (%ecx being the next register in gcc's x86 register sequence), and
71 : * %rdx on 64 bits.
72 : *
73 : * Clang/LLVM cares about the size of the register, but still wants
74 : * the base register for something that ends up being a pair.
75 : */
76 : #define do_get_user_call(fn,x,ptr) \
77 : ({ \
78 : int __ret_gu; \
79 : register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \
80 : __chk_user_ptr(ptr); \
81 : asm volatile("call __" #fn "_%P4" \
82 : : "=a" (__ret_gu), "=r" (__val_gu), \
83 : ASM_CALL_CONSTRAINT \
84 : : "0" (ptr), "i" (sizeof(*(ptr)))); \
85 : instrument_get_user(__val_gu); \
86 : (x) = (__force __typeof__(*(ptr))) __val_gu; \
87 : __builtin_expect(__ret_gu, 0); \
88 : })
89 :
90 : /**
91 : * get_user - Get a simple variable from user space.
92 : * @x: Variable to store result.
93 : * @ptr: Source address, in user space.
94 : *
95 : * Context: User context only. This function may sleep if pagefaults are
96 : * enabled.
97 : *
98 : * This macro copies a single simple variable from user space to kernel
99 : * space. It supports simple types like char and int, but not larger
100 : * data types like structures or arrays.
101 : *
102 : * @ptr must have pointer-to-simple-variable type, and the result of
103 : * dereferencing @ptr must be assignable to @x without a cast.
104 : *
105 : * Return: zero on success, or -EFAULT on error.
106 : * On error, the variable @x is set to zero.
107 : */
108 : #define get_user(x,ptr) ({ might_fault(); do_get_user_call(get_user,x,ptr); })
109 :
110 : /**
111 : * __get_user - Get a simple variable from user space, with less checking.
112 : * @x: Variable to store result.
113 : * @ptr: Source address, in user space.
114 : *
115 : * Context: User context only. This function may sleep if pagefaults are
116 : * enabled.
117 : *
118 : * This macro copies a single simple variable from user space to kernel
119 : * space. It supports simple types like char and int, but not larger
120 : * data types like structures or arrays.
121 : *
122 : * @ptr must have pointer-to-simple-variable type, and the result of
123 : * dereferencing @ptr must be assignable to @x without a cast.
124 : *
125 : * Caller must check the pointer with access_ok() before calling this
126 : * function.
127 : *
128 : * Return: zero on success, or -EFAULT on error.
129 : * On error, the variable @x is set to zero.
130 : */
131 : #define __get_user(x,ptr) do_get_user_call(get_user_nocheck,x,ptr)
132 :
133 :
134 : #ifdef CONFIG_X86_32
135 : #define __put_user_goto_u64(x, addr, label) \
136 : asm_volatile_goto("\n" \
137 : "1: movl %%eax,0(%1)\n" \
138 : "2: movl %%edx,4(%1)\n" \
139 : _ASM_EXTABLE_UA(1b, %l2) \
140 : _ASM_EXTABLE_UA(2b, %l2) \
141 : : : "A" (x), "r" (addr) \
142 : : : label)
143 :
144 : #else
145 : #define __put_user_goto_u64(x, ptr, label) \
146 : __put_user_goto(x, ptr, "q", "er", label)
147 : #endif
148 :
149 : extern void __put_user_bad(void);
150 :
151 : /*
152 : * Strange magic calling convention: pointer in %ecx,
153 : * value in %eax(:%edx), return value in %ecx. clobbers %rbx
154 : */
155 : extern void __put_user_1(void);
156 : extern void __put_user_2(void);
157 : extern void __put_user_4(void);
158 : extern void __put_user_8(void);
159 : extern void __put_user_nocheck_1(void);
160 : extern void __put_user_nocheck_2(void);
161 : extern void __put_user_nocheck_4(void);
162 : extern void __put_user_nocheck_8(void);
163 :
164 : /*
165 : * ptr must be evaluated and assigned to the temporary __ptr_pu before
166 : * the assignment of x to __val_pu, to avoid any function calls
167 : * involved in the ptr expression (possibly implicitly generated due
168 : * to KASAN) from clobbering %ax.
169 : */
170 : #define do_put_user_call(fn,x,ptr) \
171 : ({ \
172 : int __ret_pu; \
173 : void __user *__ptr_pu; \
174 : register __typeof__(*(ptr)) __val_pu asm("%"_ASM_AX); \
175 : __typeof__(*(ptr)) __x = (x); /* eval x once */ \
176 : __typeof__(ptr) __ptr = (ptr); /* eval ptr once */ \
177 : __chk_user_ptr(__ptr); \
178 : __ptr_pu = __ptr; \
179 : __val_pu = __x; \
180 : asm volatile("call __" #fn "_%P[size]" \
181 : : "=c" (__ret_pu), \
182 : ASM_CALL_CONSTRAINT \
183 : : "0" (__ptr_pu), \
184 : "r" (__val_pu), \
185 : [size] "i" (sizeof(*(ptr))) \
186 : :"ebx"); \
187 : instrument_put_user(__x, __ptr, sizeof(*(ptr))); \
188 : __builtin_expect(__ret_pu, 0); \
189 : })
190 :
191 : /**
192 : * put_user - Write a simple value into user space.
193 : * @x: Value to copy to user space.
194 : * @ptr: Destination address, in user space.
195 : *
196 : * Context: User context only. This function may sleep if pagefaults are
197 : * enabled.
198 : *
199 : * This macro copies a single simple value from kernel space to user
200 : * space. It supports simple types like char and int, but not larger
201 : * data types like structures or arrays.
202 : *
203 : * @ptr must have pointer-to-simple-variable type, and @x must be assignable
204 : * to the result of dereferencing @ptr.
205 : *
206 : * Return: zero on success, or -EFAULT on error.
207 : */
208 : #define put_user(x, ptr) ({ might_fault(); do_put_user_call(put_user,x,ptr); })
209 :
210 : /**
211 : * __put_user - Write a simple value into user space, with less checking.
212 : * @x: Value to copy to user space.
213 : * @ptr: Destination address, in user space.
214 : *
215 : * Context: User context only. This function may sleep if pagefaults are
216 : * enabled.
217 : *
218 : * This macro copies a single simple value from kernel space to user
219 : * space. It supports simple types like char and int, but not larger
220 : * data types like structures or arrays.
221 : *
222 : * @ptr must have pointer-to-simple-variable type, and @x must be assignable
223 : * to the result of dereferencing @ptr.
224 : *
225 : * Caller must check the pointer with access_ok() before calling this
226 : * function.
227 : *
228 : * Return: zero on success, or -EFAULT on error.
229 : */
230 : #define __put_user(x, ptr) do_put_user_call(put_user_nocheck,x,ptr)
231 :
232 : #define __put_user_size(x, ptr, size, label) \
233 : do { \
234 : __typeof__(*(ptr)) __x = (x); /* eval x once */ \
235 : __typeof__(ptr) __ptr = (ptr); /* eval ptr once */ \
236 : __chk_user_ptr(__ptr); \
237 : switch (size) { \
238 : case 1: \
239 : __put_user_goto(__x, __ptr, "b", "iq", label); \
240 : break; \
241 : case 2: \
242 : __put_user_goto(__x, __ptr, "w", "ir", label); \
243 : break; \
244 : case 4: \
245 : __put_user_goto(__x, __ptr, "l", "ir", label); \
246 : break; \
247 : case 8: \
248 : __put_user_goto_u64(__x, __ptr, label); \
249 : break; \
250 : default: \
251 : __put_user_bad(); \
252 : } \
253 : instrument_put_user(__x, __ptr, size); \
254 : } while (0)
255 :
256 : #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
257 :
258 : #ifdef CONFIG_X86_32
259 : #define __get_user_asm_u64(x, ptr, label) do { \
260 : unsigned int __gu_low, __gu_high; \
261 : const unsigned int __user *__gu_ptr; \
262 : __gu_ptr = (const void __user *)(ptr); \
263 : __get_user_asm(__gu_low, __gu_ptr, "l", "=r", label); \
264 : __get_user_asm(__gu_high, __gu_ptr+1, "l", "=r", label); \
265 : (x) = ((unsigned long long)__gu_high << 32) | __gu_low; \
266 : } while (0)
267 : #else
268 : #define __get_user_asm_u64(x, ptr, label) \
269 : __get_user_asm(x, ptr, "q", "=r", label)
270 : #endif
271 :
272 : #define __get_user_size(x, ptr, size, label) \
273 : do { \
274 : __chk_user_ptr(ptr); \
275 : switch (size) { \
276 : case 1: { \
277 : unsigned char x_u8__; \
278 : __get_user_asm(x_u8__, ptr, "b", "=q", label); \
279 : (x) = x_u8__; \
280 : break; \
281 : } \
282 : case 2: \
283 : __get_user_asm(x, ptr, "w", "=r", label); \
284 : break; \
285 : case 4: \
286 : __get_user_asm(x, ptr, "l", "=r", label); \
287 : break; \
288 : case 8: \
289 : __get_user_asm_u64(x, ptr, label); \
290 : break; \
291 : default: \
292 : (x) = __get_user_bad(); \
293 : } \
294 : instrument_get_user(x); \
295 : } while (0)
296 :
297 : #define __get_user_asm(x, addr, itype, ltype, label) \
298 : asm_volatile_goto("\n" \
299 : "1: mov"itype" %[umem],%[output]\n" \
300 : _ASM_EXTABLE_UA(1b, %l2) \
301 : : [output] ltype(x) \
302 : : [umem] "m" (__m(addr)) \
303 : : : label)
304 :
305 : #else // !CONFIG_CC_HAS_ASM_GOTO_OUTPUT
306 :
307 : #ifdef CONFIG_X86_32
308 : #define __get_user_asm_u64(x, ptr, retval) \
309 : ({ \
310 : __typeof__(ptr) __ptr = (ptr); \
311 : asm volatile("\n" \
312 : "1: movl %[lowbits],%%eax\n" \
313 : "2: movl %[highbits],%%edx\n" \
314 : "3:\n" \
315 : _ASM_EXTABLE_TYPE_REG(1b, 3b, EX_TYPE_EFAULT_REG | \
316 : EX_FLAG_CLEAR_AX_DX, \
317 : %[errout]) \
318 : _ASM_EXTABLE_TYPE_REG(2b, 3b, EX_TYPE_EFAULT_REG | \
319 : EX_FLAG_CLEAR_AX_DX, \
320 : %[errout]) \
321 : : [errout] "=r" (retval), \
322 : [output] "=&A"(x) \
323 : : [lowbits] "m" (__m(__ptr)), \
324 : [highbits] "m" __m(((u32 __user *)(__ptr)) + 1), \
325 : "0" (retval)); \
326 : })
327 :
328 : #else
329 : #define __get_user_asm_u64(x, ptr, retval) \
330 : __get_user_asm(x, ptr, retval, "q")
331 : #endif
332 :
333 : #define __get_user_size(x, ptr, size, retval) \
334 : do { \
335 : unsigned char x_u8__; \
336 : \
337 : retval = 0; \
338 : __chk_user_ptr(ptr); \
339 : switch (size) { \
340 : case 1: \
341 : __get_user_asm(x_u8__, ptr, retval, "b"); \
342 : (x) = x_u8__; \
343 : break; \
344 : case 2: \
345 : __get_user_asm(x, ptr, retval, "w"); \
346 : break; \
347 : case 4: \
348 : __get_user_asm(x, ptr, retval, "l"); \
349 : break; \
350 : case 8: \
351 : __get_user_asm_u64(x, ptr, retval); \
352 : break; \
353 : default: \
354 : (x) = __get_user_bad(); \
355 : } \
356 : } while (0)
357 :
358 : #define __get_user_asm(x, addr, err, itype) \
359 : asm volatile("\n" \
360 : "1: mov"itype" %[umem],%[output]\n" \
361 : "2:\n" \
362 : _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG | \
363 : EX_FLAG_CLEAR_AX, \
364 : %[errout]) \
365 : : [errout] "=r" (err), \
366 : [output] "=a" (x) \
367 : : [umem] "m" (__m(addr)), \
368 : "0" (err))
369 :
370 : #endif // CONFIG_CC_HAS_ASM_GOTO_OUTPUT
371 :
372 : #ifdef CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT
373 : #define __try_cmpxchg_user_asm(itype, ltype, _ptr, _pold, _new, label) ({ \
374 : bool success; \
375 : __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \
376 : __typeof__(*(_ptr)) __old = *_old; \
377 : __typeof__(*(_ptr)) __new = (_new); \
378 : asm_volatile_goto("\n" \
379 : "1: " LOCK_PREFIX "cmpxchg"itype" %[new], %[ptr]\n"\
380 : _ASM_EXTABLE_UA(1b, %l[label]) \
381 : : CC_OUT(z) (success), \
382 : [ptr] "+m" (*_ptr), \
383 : [old] "+a" (__old) \
384 : : [new] ltype (__new) \
385 : : "memory" \
386 : : label); \
387 : if (unlikely(!success)) \
388 : *_old = __old; \
389 : likely(success); })
390 :
391 : #ifdef CONFIG_X86_32
392 : #define __try_cmpxchg64_user_asm(_ptr, _pold, _new, label) ({ \
393 : bool success; \
394 : __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \
395 : __typeof__(*(_ptr)) __old = *_old; \
396 : __typeof__(*(_ptr)) __new = (_new); \
397 : asm_volatile_goto("\n" \
398 : "1: " LOCK_PREFIX "cmpxchg8b %[ptr]\n" \
399 : _ASM_EXTABLE_UA(1b, %l[label]) \
400 : : CC_OUT(z) (success), \
401 : "+A" (__old), \
402 : [ptr] "+m" (*_ptr) \
403 : : "b" ((u32)__new), \
404 : "c" ((u32)((u64)__new >> 32)) \
405 : : "memory" \
406 : : label); \
407 : if (unlikely(!success)) \
408 : *_old = __old; \
409 : likely(success); })
410 : #endif // CONFIG_X86_32
411 : #else // !CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT
412 : #define __try_cmpxchg_user_asm(itype, ltype, _ptr, _pold, _new, label) ({ \
413 : int __err = 0; \
414 : bool success; \
415 : __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \
416 : __typeof__(*(_ptr)) __old = *_old; \
417 : __typeof__(*(_ptr)) __new = (_new); \
418 : asm volatile("\n" \
419 : "1: " LOCK_PREFIX "cmpxchg"itype" %[new], %[ptr]\n"\
420 : CC_SET(z) \
421 : "2:\n" \
422 : _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, \
423 : %[errout]) \
424 : : CC_OUT(z) (success), \
425 : [errout] "+r" (__err), \
426 : [ptr] "+m" (*_ptr), \
427 : [old] "+a" (__old) \
428 : : [new] ltype (__new) \
429 : : "memory"); \
430 : if (unlikely(__err)) \
431 : goto label; \
432 : if (unlikely(!success)) \
433 : *_old = __old; \
434 : likely(success); })
435 :
436 : #ifdef CONFIG_X86_32
437 : /*
438 : * Unlike the normal CMPXCHG, use output GPR for both success/fail and error.
439 : * There are only six GPRs available and four (EAX, EBX, ECX, and EDX) are
440 : * hardcoded by CMPXCHG8B, leaving only ESI and EDI. If the compiler uses
441 : * both ESI and EDI for the memory operand, compilation will fail if the error
442 : * is an input+output as there will be no register available for input.
443 : */
444 : #define __try_cmpxchg64_user_asm(_ptr, _pold, _new, label) ({ \
445 : int __result; \
446 : __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \
447 : __typeof__(*(_ptr)) __old = *_old; \
448 : __typeof__(*(_ptr)) __new = (_new); \
449 : asm volatile("\n" \
450 : "1: " LOCK_PREFIX "cmpxchg8b %[ptr]\n" \
451 : "mov $0, %[result]\n\t" \
452 : "setz %b[result]\n" \
453 : "2:\n" \
454 : _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, \
455 : %[result]) \
456 : : [result] "=q" (__result), \
457 : "+A" (__old), \
458 : [ptr] "+m" (*_ptr) \
459 : : "b" ((u32)__new), \
460 : "c" ((u32)((u64)__new >> 32)) \
461 : : "memory", "cc"); \
462 : if (unlikely(__result < 0)) \
463 : goto label; \
464 : if (unlikely(!__result)) \
465 : *_old = __old; \
466 : likely(__result); })
467 : #endif // CONFIG_X86_32
468 : #endif // CONFIG_CC_HAS_ASM_GOTO_TIED_OUTPUT
469 :
470 : /* FIXME: this hack is definitely wrong -AK */
471 : struct __large_struct { unsigned long buf[100]; };
472 : #define __m(x) (*(struct __large_struct __user *)(x))
473 :
474 : /*
475 : * Tell gcc we read from memory instead of writing: this is because
476 : * we do not write to any memory gcc knows about, so there are no
477 : * aliasing issues.
478 : */
479 : #define __put_user_goto(x, addr, itype, ltype, label) \
480 : asm_volatile_goto("\n" \
481 : "1: mov"itype" %0,%1\n" \
482 : _ASM_EXTABLE_UA(1b, %l2) \
483 : : : ltype(x), "m" (__m(addr)) \
484 : : : label)
485 :
486 : extern unsigned long
487 : copy_from_user_nmi(void *to, const void __user *from, unsigned long n);
488 : extern __must_check long
489 : strncpy_from_user(char *dst, const char __user *src, long count);
490 :
491 : extern __must_check long strnlen_user(const char __user *str, long n);
492 :
493 : #ifdef CONFIG_ARCH_HAS_COPY_MC
494 : unsigned long __must_check
495 : copy_mc_to_kernel(void *to, const void *from, unsigned len);
496 : #define copy_mc_to_kernel copy_mc_to_kernel
497 :
498 : unsigned long __must_check
499 : copy_mc_to_user(void *to, const void *from, unsigned len);
500 : #endif
501 :
502 : /*
503 : * movsl can be slow when source and dest are not both 8-byte aligned
504 : */
505 : #ifdef CONFIG_X86_INTEL_USERCOPY
506 : extern struct movsl_mask {
507 : int mask;
508 : } ____cacheline_aligned_in_smp movsl_mask;
509 : #endif
510 :
511 : #define ARCH_HAS_NOCACHE_UACCESS 1
512 :
513 : /*
514 : * The "unsafe" user accesses aren't really "unsafe", but the naming
515 : * is a big fat warning: you have to not only do the access_ok()
516 : * checking before using them, but you have to surround them with the
517 : * user_access_begin/end() pair.
518 : */
519 : static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len)
520 : {
521 56563241545 : if (unlikely(!access_ok(ptr,len)))
522 : return 0;
523 28281621218 : __uaccess_begin_nospec();
524 29186505522 : return 1;
525 : }
526 : #define user_access_begin(a,b) user_access_begin(a,b)
527 : #define user_access_end() __uaccess_end()
528 :
529 : #define user_access_save() smap_save()
530 : #define user_access_restore(x) smap_restore(x)
531 :
532 : #define unsafe_put_user(x, ptr, label) \
533 : __put_user_size((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), label)
534 :
535 : #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
536 : #define unsafe_get_user(x, ptr, err_label) \
537 : do { \
538 : __inttype(*(ptr)) __gu_val; \
539 : __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), err_label); \
540 : (x) = (__force __typeof__(*(ptr)))__gu_val; \
541 : } while (0)
542 : #else // !CONFIG_CC_HAS_ASM_GOTO_OUTPUT
543 : #define unsafe_get_user(x, ptr, err_label) \
544 : do { \
545 : int __gu_err; \
546 : __inttype(*(ptr)) __gu_val; \
547 : __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), __gu_err); \
548 : (x) = (__force __typeof__(*(ptr)))__gu_val; \
549 : if (unlikely(__gu_err)) goto err_label; \
550 : } while (0)
551 : #endif // CONFIG_CC_HAS_ASM_GOTO_OUTPUT
552 :
553 : extern void __try_cmpxchg_user_wrong_size(void);
554 :
555 : #ifndef CONFIG_X86_32
556 : #define __try_cmpxchg64_user_asm(_ptr, _oldp, _nval, _label) \
557 : __try_cmpxchg_user_asm("q", "r", (_ptr), (_oldp), (_nval), _label)
558 : #endif
559 :
560 : /*
561 : * Force the pointer to u<size> to match the size expected by the asm helper.
562 : * clang/LLVM compiles all cases and only discards the unused paths after
563 : * processing errors, which breaks i386 if the pointer is an 8-byte value.
564 : */
565 : #define unsafe_try_cmpxchg_user(_ptr, _oldp, _nval, _label) ({ \
566 : bool __ret; \
567 : __chk_user_ptr(_ptr); \
568 : switch (sizeof(*(_ptr))) { \
569 : case 1: __ret = __try_cmpxchg_user_asm("b", "q", \
570 : (__force u8 *)(_ptr), (_oldp), \
571 : (_nval), _label); \
572 : break; \
573 : case 2: __ret = __try_cmpxchg_user_asm("w", "r", \
574 : (__force u16 *)(_ptr), (_oldp), \
575 : (_nval), _label); \
576 : break; \
577 : case 4: __ret = __try_cmpxchg_user_asm("l", "r", \
578 : (__force u32 *)(_ptr), (_oldp), \
579 : (_nval), _label); \
580 : break; \
581 : case 8: __ret = __try_cmpxchg64_user_asm((__force u64 *)(_ptr), (_oldp),\
582 : (_nval), _label); \
583 : break; \
584 : default: __try_cmpxchg_user_wrong_size(); \
585 : } \
586 : __ret; })
587 :
588 : /* "Returns" 0 on success, 1 on failure, -EFAULT if the access faults. */
589 : #define __try_cmpxchg_user(_ptr, _oldp, _nval, _label) ({ \
590 : int __ret = -EFAULT; \
591 : __uaccess_begin_nospec(); \
592 : __ret = !unsafe_try_cmpxchg_user(_ptr, _oldp, _nval, _label); \
593 : _label: \
594 : __uaccess_end(); \
595 : __ret; \
596 : })
597 :
598 : /*
599 : * We want the unsafe accessors to always be inlined and use
600 : * the error labels - thus the macro games.
601 : */
602 : #define unsafe_copy_loop(dst, src, len, type, label) \
603 : while (len >= sizeof(type)) { \
604 : unsafe_put_user(*(type *)(src),(type __user *)(dst),label); \
605 : dst += sizeof(type); \
606 : src += sizeof(type); \
607 : len -= sizeof(type); \
608 : }
609 :
610 : #define unsafe_copy_to_user(_dst,_src,_len,label) \
611 : do { \
612 : char __user *__ucu_dst = (_dst); \
613 : const char *__ucu_src = (_src); \
614 : size_t __ucu_len = (_len); \
615 : unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u64, label); \
616 : unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u32, label); \
617 : unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u16, label); \
618 : unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u8, label); \
619 : } while (0)
620 :
621 : #ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT
622 : #define __get_kernel_nofault(dst, src, type, err_label) \
623 : __get_user_size(*((type *)(dst)), (__force type __user *)(src), \
624 : sizeof(type), err_label)
625 : #else // !CONFIG_CC_HAS_ASM_GOTO_OUTPUT
626 : #define __get_kernel_nofault(dst, src, type, err_label) \
627 : do { \
628 : int __kr_err; \
629 : \
630 : __get_user_size(*((type *)(dst)), (__force type __user *)(src), \
631 : sizeof(type), __kr_err); \
632 : if (unlikely(__kr_err)) \
633 : goto err_label; \
634 : } while (0)
635 : #endif // CONFIG_CC_HAS_ASM_GOTO_OUTPUT
636 :
637 : #define __put_kernel_nofault(dst, src, type, err_label) \
638 : __put_user_size(*((type *)(src)), (__force type __user *)(dst), \
639 : sizeof(type), err_label)
640 :
641 : #endif /* _ASM_X86_UACCESS_H */
642 :
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