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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1965aae3 PA |
2 | #ifndef _ASM_X86_UACCESS_H |
3 | #define _ASM_X86_UACCESS_H | |
ca233862 GC |
4 | /* |
5 | * User space memory access functions | |
6 | */ | |
ca233862 | 7 | #include <linux/compiler.h> |
1771c6e1 | 8 | #include <linux/kasan-checks.h> |
ca233862 GC |
9 | #include <linux/string.h> |
10 | #include <asm/asm.h> | |
11 | #include <asm/page.h> | |
63bcff2a | 12 | #include <asm/smap.h> |
45caf470 | 13 | #include <asm/extable.h> |
ca233862 | 14 | |
ca233862 GC |
15 | /* |
16 | * The fs value determines whether argument validity checking should be | |
17 | * performed or not. If get_fs() == USER_DS, checking is performed, with | |
18 | * get_fs() == KERNEL_DS, checking is bypassed. | |
19 | * | |
20 | * For historical reasons, these macros are grossly misnamed. | |
21 | */ | |
22 | ||
23 | #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) | |
24 | ||
25 | #define KERNEL_DS MAKE_MM_SEG(-1UL) | |
9063c61f | 26 | #define USER_DS MAKE_MM_SEG(TASK_SIZE_MAX) |
ca233862 GC |
27 | |
28 | #define get_ds() (KERNEL_DS) | |
13d4ea09 | 29 | #define get_fs() (current->thread.addr_limit) |
5ea0727b TG |
30 | static inline void set_fs(mm_segment_t fs) |
31 | { | |
32 | current->thread.addr_limit = fs; | |
33 | /* On user-mode return, check fs is correct */ | |
34 | set_thread_flag(TIF_FSCHECK); | |
35 | } | |
ca233862 GC |
36 | |
37 | #define segment_eq(a, b) ((a).seg == (b).seg) | |
38 | ||
13d4ea09 | 39 | #define user_addr_max() (current->thread.addr_limit.seg) |
bc6ca7b3 AS |
40 | #define __addr_ok(addr) \ |
41 | ((unsigned long __force)(addr) < user_addr_max()) | |
002ca169 | 42 | |
ca233862 GC |
43 | /* |
44 | * Test whether a block of memory is a valid user space address. | |
45 | * Returns 0 if the range is valid, nonzero otherwise. | |
ca233862 | 46 | */ |
a740576a | 47 | static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit) |
c5fe5d80 LT |
48 | { |
49 | /* | |
50 | * If we have used "sizeof()" for the size, | |
51 | * we know it won't overflow the limit (but | |
52 | * it might overflow the 'addr', so it's | |
53 | * important to subtract the size from the | |
54 | * limit, not add it to the address). | |
55 | */ | |
56 | if (__builtin_constant_p(size)) | |
7e0f51cb | 57 | return unlikely(addr > limit - size); |
c5fe5d80 LT |
58 | |
59 | /* Arbitrary sizes? Be careful about overflow */ | |
60 | addr += size; | |
7e0f51cb | 61 | if (unlikely(addr < size)) |
a740576a | 62 | return true; |
7e0f51cb | 63 | return unlikely(addr > limit); |
c5fe5d80 | 64 | } |
ca233862 | 65 | |
bc6ca7b3 | 66 | #define __range_not_ok(addr, size, limit) \ |
ca233862 | 67 | ({ \ |
ca233862 | 68 | __chk_user_ptr(addr); \ |
c5fe5d80 | 69 | __chk_range_not_ok((unsigned long __force)(addr), size, limit); \ |
ca233862 GC |
70 | }) |
71 | ||
7c478895 PZ |
72 | #ifdef CONFIG_DEBUG_ATOMIC_SLEEP |
73 | # define WARN_ON_IN_IRQ() WARN_ON_ONCE(!in_task()) | |
74 | #else | |
75 | # define WARN_ON_IN_IRQ() | |
76 | #endif | |
77 | ||
ca233862 GC |
78 | /** |
79 | * access_ok: - Checks if a user space pointer is valid | |
80 | * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that | |
81 | * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe | |
82 | * to write to a block, it is always safe to read from it. | |
83 | * @addr: User space pointer to start of block to check | |
84 | * @size: Size of block to check | |
85 | * | |
b3c395ef DH |
86 | * Context: User context only. This function may sleep if pagefaults are |
87 | * enabled. | |
ca233862 GC |
88 | * |
89 | * Checks if a pointer to a block of memory in user space is valid. | |
90 | * | |
91 | * Returns true (nonzero) if the memory block may be valid, false (zero) | |
92 | * if it is definitely invalid. | |
93 | * | |
94 | * Note that, depending on architecture, this function probably just | |
95 | * checks that the pointer is in the user space range - after calling | |
96 | * this function, memory access functions may still return -EFAULT. | |
97 | */ | |
7c478895 PZ |
98 | #define access_ok(type, addr, size) \ |
99 | ({ \ | |
100 | WARN_ON_IN_IRQ(); \ | |
101 | likely(!__range_not_ok(addr, size, user_addr_max())); \ | |
102 | }) | |
ca233862 | 103 | |
ca233862 GC |
104 | /* |
105 | * These are the main single-value transfer routines. They automatically | |
106 | * use the right size if we just have the right pointer type. | |
107 | * | |
108 | * This gets kind of ugly. We want to return _two_ values in "get_user()" | |
109 | * and yet we don't want to do any pointers, because that is too much | |
110 | * of a performance impact. Thus we have a few rather ugly macros here, | |
111 | * and hide all the ugliness from the user. | |
112 | * | |
113 | * The "__xxx" versions of the user access functions are versions that | |
114 | * do not verify the address space, that must have been done previously | |
115 | * with a separate "access_ok()" call (this is used when we do multiple | |
116 | * accesses to the same area of user memory). | |
117 | */ | |
118 | ||
119 | extern int __get_user_1(void); | |
120 | extern int __get_user_2(void); | |
121 | extern int __get_user_4(void); | |
122 | extern int __get_user_8(void); | |
123 | extern int __get_user_bad(void); | |
124 | ||
11f1a4b9 LT |
125 | #define __uaccess_begin() stac() |
126 | #define __uaccess_end() clac() | |
127 | ||
3578baae PA |
128 | /* |
129 | * This is a type: either unsigned long, if the argument fits into | |
130 | * that type, or otherwise unsigned long long. | |
131 | */ | |
132 | #define __inttype(x) \ | |
133 | __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) | |
865e5b76 GC |
134 | |
135 | /** | |
136 | * get_user: - Get a simple variable from user space. | |
137 | * @x: Variable to store result. | |
138 | * @ptr: Source address, in user space. | |
139 | * | |
b3c395ef DH |
140 | * Context: User context only. This function may sleep if pagefaults are |
141 | * enabled. | |
865e5b76 GC |
142 | * |
143 | * This macro copies a single simple variable from user space to kernel | |
144 | * space. It supports simple types like char and int, but not larger | |
145 | * data types like structures or arrays. | |
146 | * | |
147 | * @ptr must have pointer-to-simple-variable type, and the result of | |
148 | * dereferencing @ptr must be assignable to @x without a cast. | |
149 | * | |
150 | * Returns zero on success, or -EFAULT on error. | |
151 | * On error, the variable @x is set to zero. | |
ff52c3b0 PA |
152 | */ |
153 | /* | |
3578baae PA |
154 | * Careful: we have to cast the result to the type of the pointer |
155 | * for sign reasons. | |
ff52c3b0 | 156 | * |
f69fa9a9 | 157 | * The use of _ASM_DX as the register specifier is a bit of a |
ff52c3b0 PA |
158 | * simplification, as gcc only cares about it as the starting point |
159 | * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits | |
160 | * (%ecx being the next register in gcc's x86 register sequence), and | |
161 | * %rdx on 64 bits. | |
f69fa9a9 PA |
162 | * |
163 | * Clang/LLVM cares about the size of the register, but still wants | |
164 | * the base register for something that ends up being a pair. | |
865e5b76 | 165 | */ |
865e5b76 GC |
166 | #define get_user(x, ptr) \ |
167 | ({ \ | |
168 | int __ret_gu; \ | |
bdfc017e | 169 | register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \ |
865e5b76 | 170 | __chk_user_ptr(ptr); \ |
3ee1afa3 | 171 | might_fault(); \ |
f05058c4 | 172 | asm volatile("call __get_user_%P4" \ |
f5caf621 JP |
173 | : "=a" (__ret_gu), "=r" (__val_gu), \ |
174 | ASM_CALL_CONSTRAINT \ | |
3578baae | 175 | : "0" (ptr), "i" (sizeof(*(ptr)))); \ |
e182c570 | 176 | (x) = (__force __typeof__(*(ptr))) __val_gu; \ |
a76cf66e | 177 | __builtin_expect(__ret_gu, 0); \ |
865e5b76 GC |
178 | }) |
179 | ||
e30a44fd GC |
180 | #define __put_user_x(size, x, ptr, __ret_pu) \ |
181 | asm volatile("call __put_user_" #size : "=a" (__ret_pu) \ | |
4d5d7838 | 182 | : "0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx") |
e30a44fd GC |
183 | |
184 | ||
185 | ||
dc70ddf4 | 186 | #ifdef CONFIG_X86_32 |
18114f61 | 187 | #define __put_user_asm_u64(x, addr, err, errret) \ |
11f1a4b9 | 188 | asm volatile("\n" \ |
63bcff2a | 189 | "1: movl %%eax,0(%2)\n" \ |
dc70ddf4 | 190 | "2: movl %%edx,4(%2)\n" \ |
11f1a4b9 | 191 | "3:" \ |
dc70ddf4 GC |
192 | ".section .fixup,\"ax\"\n" \ |
193 | "4: movl %3,%0\n" \ | |
194 | " jmp 3b\n" \ | |
195 | ".previous\n" \ | |
196 | _ASM_EXTABLE(1b, 4b) \ | |
197 | _ASM_EXTABLE(2b, 4b) \ | |
198 | : "=r" (err) \ | |
18114f61 | 199 | : "A" (x), "r" (addr), "i" (errret), "0" (err)) |
e30a44fd | 200 | |
fe40c0af | 201 | #define __put_user_asm_ex_u64(x, addr) \ |
11f1a4b9 | 202 | asm volatile("\n" \ |
63bcff2a | 203 | "1: movl %%eax,0(%1)\n" \ |
fe40c0af | 204 | "2: movl %%edx,4(%1)\n" \ |
11f1a4b9 | 205 | "3:" \ |
535c0c34 PA |
206 | _ASM_EXTABLE_EX(1b, 2b) \ |
207 | _ASM_EXTABLE_EX(2b, 3b) \ | |
fe40c0af HS |
208 | : : "A" (x), "r" (addr)) |
209 | ||
e30a44fd GC |
210 | #define __put_user_x8(x, ptr, __ret_pu) \ |
211 | asm volatile("call __put_user_8" : "=a" (__ret_pu) \ | |
212 | : "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx") | |
dc70ddf4 | 213 | #else |
18114f61 | 214 | #define __put_user_asm_u64(x, ptr, retval, errret) \ |
ebe119cd | 215 | __put_user_asm(x, ptr, retval, "q", "", "er", errret) |
fe40c0af | 216 | #define __put_user_asm_ex_u64(x, addr) \ |
ebe119cd | 217 | __put_user_asm_ex(x, addr, "q", "", "er") |
e30a44fd | 218 | #define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu) |
dc70ddf4 GC |
219 | #endif |
220 | ||
e30a44fd GC |
221 | extern void __put_user_bad(void); |
222 | ||
223 | /* | |
224 | * Strange magic calling convention: pointer in %ecx, | |
225 | * value in %eax(:%edx), return value in %eax. clobbers %rbx | |
226 | */ | |
227 | extern void __put_user_1(void); | |
228 | extern void __put_user_2(void); | |
229 | extern void __put_user_4(void); | |
230 | extern void __put_user_8(void); | |
231 | ||
e30a44fd GC |
232 | /** |
233 | * put_user: - Write a simple value into user space. | |
234 | * @x: Value to copy to user space. | |
235 | * @ptr: Destination address, in user space. | |
236 | * | |
b3c395ef DH |
237 | * Context: User context only. This function may sleep if pagefaults are |
238 | * enabled. | |
e30a44fd GC |
239 | * |
240 | * This macro copies a single simple value from kernel space to user | |
241 | * space. It supports simple types like char and int, but not larger | |
242 | * data types like structures or arrays. | |
243 | * | |
244 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
245 | * to the result of dereferencing @ptr. | |
246 | * | |
247 | * Returns zero on success, or -EFAULT on error. | |
248 | */ | |
249 | #define put_user(x, ptr) \ | |
250 | ({ \ | |
251 | int __ret_pu; \ | |
252 | __typeof__(*(ptr)) __pu_val; \ | |
253 | __chk_user_ptr(ptr); \ | |
3ee1afa3 | 254 | might_fault(); \ |
e30a44fd GC |
255 | __pu_val = x; \ |
256 | switch (sizeof(*(ptr))) { \ | |
257 | case 1: \ | |
258 | __put_user_x(1, __pu_val, ptr, __ret_pu); \ | |
259 | break; \ | |
260 | case 2: \ | |
261 | __put_user_x(2, __pu_val, ptr, __ret_pu); \ | |
262 | break; \ | |
263 | case 4: \ | |
264 | __put_user_x(4, __pu_val, ptr, __ret_pu); \ | |
265 | break; \ | |
266 | case 8: \ | |
267 | __put_user_x8(__pu_val, ptr, __ret_pu); \ | |
268 | break; \ | |
269 | default: \ | |
270 | __put_user_x(X, __pu_val, ptr, __ret_pu); \ | |
271 | break; \ | |
272 | } \ | |
a76cf66e | 273 | __builtin_expect(__ret_pu, 0); \ |
e30a44fd GC |
274 | }) |
275 | ||
dc70ddf4 GC |
276 | #define __put_user_size(x, ptr, size, retval, errret) \ |
277 | do { \ | |
278 | retval = 0; \ | |
279 | __chk_user_ptr(ptr); \ | |
280 | switch (size) { \ | |
281 | case 1: \ | |
282 | __put_user_asm(x, ptr, retval, "b", "b", "iq", errret); \ | |
283 | break; \ | |
284 | case 2: \ | |
285 | __put_user_asm(x, ptr, retval, "w", "w", "ir", errret); \ | |
286 | break; \ | |
287 | case 4: \ | |
4d5d7838 | 288 | __put_user_asm(x, ptr, retval, "l", "k", "ir", errret); \ |
dc70ddf4 GC |
289 | break; \ |
290 | case 8: \ | |
18114f61 HS |
291 | __put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval, \ |
292 | errret); \ | |
dc70ddf4 GC |
293 | break; \ |
294 | default: \ | |
295 | __put_user_bad(); \ | |
296 | } \ | |
297 | } while (0) | |
298 | ||
11f1a4b9 LT |
299 | /* |
300 | * This doesn't do __uaccess_begin/end - the exception handling | |
301 | * around it must do that. | |
302 | */ | |
fe40c0af HS |
303 | #define __put_user_size_ex(x, ptr, size) \ |
304 | do { \ | |
305 | __chk_user_ptr(ptr); \ | |
306 | switch (size) { \ | |
307 | case 1: \ | |
308 | __put_user_asm_ex(x, ptr, "b", "b", "iq"); \ | |
309 | break; \ | |
310 | case 2: \ | |
311 | __put_user_asm_ex(x, ptr, "w", "w", "ir"); \ | |
312 | break; \ | |
313 | case 4: \ | |
314 | __put_user_asm_ex(x, ptr, "l", "k", "ir"); \ | |
315 | break; \ | |
316 | case 8: \ | |
317 | __put_user_asm_ex_u64((__typeof__(*ptr))(x), ptr); \ | |
318 | break; \ | |
319 | default: \ | |
320 | __put_user_bad(); \ | |
321 | } \ | |
322 | } while (0) | |
323 | ||
3f168221 | 324 | #ifdef CONFIG_X86_32 |
b2f68038 BL |
325 | #define __get_user_asm_u64(x, ptr, retval, errret) \ |
326 | ({ \ | |
327 | __typeof__(ptr) __ptr = (ptr); \ | |
33c9e972 | 328 | asm volatile("\n" \ |
b2f68038 BL |
329 | "1: movl %2,%%eax\n" \ |
330 | "2: movl %3,%%edx\n" \ | |
33c9e972 | 331 | "3:\n" \ |
b2f68038 BL |
332 | ".section .fixup,\"ax\"\n" \ |
333 | "4: mov %4,%0\n" \ | |
334 | " xorl %%eax,%%eax\n" \ | |
335 | " xorl %%edx,%%edx\n" \ | |
336 | " jmp 3b\n" \ | |
337 | ".previous\n" \ | |
338 | _ASM_EXTABLE(1b, 4b) \ | |
339 | _ASM_EXTABLE(2b, 4b) \ | |
33c9e972 | 340 | : "=r" (retval), "=&A"(x) \ |
5ac751d9 | 341 | : "m" (__m(__ptr)), "m" __m(((u32 __user *)(__ptr)) + 1), \ |
b2f68038 BL |
342 | "i" (errret), "0" (retval)); \ |
343 | }) | |
344 | ||
fe40c0af | 345 | #define __get_user_asm_ex_u64(x, ptr) (x) = __get_user_bad() |
3f168221 GC |
346 | #else |
347 | #define __get_user_asm_u64(x, ptr, retval, errret) \ | |
348 | __get_user_asm(x, ptr, retval, "q", "", "=r", errret) | |
fe40c0af HS |
349 | #define __get_user_asm_ex_u64(x, ptr) \ |
350 | __get_user_asm_ex(x, ptr, "q", "", "=r") | |
3f168221 GC |
351 | #endif |
352 | ||
353 | #define __get_user_size(x, ptr, size, retval, errret) \ | |
354 | do { \ | |
355 | retval = 0; \ | |
356 | __chk_user_ptr(ptr); \ | |
357 | switch (size) { \ | |
358 | case 1: \ | |
359 | __get_user_asm(x, ptr, retval, "b", "b", "=q", errret); \ | |
360 | break; \ | |
361 | case 2: \ | |
362 | __get_user_asm(x, ptr, retval, "w", "w", "=r", errret); \ | |
363 | break; \ | |
364 | case 4: \ | |
365 | __get_user_asm(x, ptr, retval, "l", "k", "=r", errret); \ | |
366 | break; \ | |
367 | case 8: \ | |
368 | __get_user_asm_u64(x, ptr, retval, errret); \ | |
369 | break; \ | |
370 | default: \ | |
371 | (x) = __get_user_bad(); \ | |
372 | } \ | |
373 | } while (0) | |
374 | ||
375 | #define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \ | |
11f1a4b9 | 376 | asm volatile("\n" \ |
63bcff2a | 377 | "1: mov"itype" %2,%"rtype"1\n" \ |
11f1a4b9 | 378 | "2:\n" \ |
3f168221 GC |
379 | ".section .fixup,\"ax\"\n" \ |
380 | "3: mov %3,%0\n" \ | |
381 | " xor"itype" %"rtype"1,%"rtype"1\n" \ | |
382 | " jmp 2b\n" \ | |
383 | ".previous\n" \ | |
384 | _ASM_EXTABLE(1b, 3b) \ | |
385 | : "=r" (err), ltype(x) \ | |
386 | : "m" (__m(addr)), "i" (errret), "0" (err)) | |
387 | ||
122b05dd AV |
388 | #define __get_user_asm_nozero(x, addr, err, itype, rtype, ltype, errret) \ |
389 | asm volatile("\n" \ | |
390 | "1: mov"itype" %2,%"rtype"1\n" \ | |
391 | "2:\n" \ | |
392 | ".section .fixup,\"ax\"\n" \ | |
393 | "3: mov %3,%0\n" \ | |
394 | " jmp 2b\n" \ | |
395 | ".previous\n" \ | |
396 | _ASM_EXTABLE(1b, 3b) \ | |
397 | : "=r" (err), ltype(x) \ | |
398 | : "m" (__m(addr)), "i" (errret), "0" (err)) | |
399 | ||
11f1a4b9 LT |
400 | /* |
401 | * This doesn't do __uaccess_begin/end - the exception handling | |
402 | * around it must do that. | |
403 | */ | |
fe40c0af HS |
404 | #define __get_user_size_ex(x, ptr, size) \ |
405 | do { \ | |
406 | __chk_user_ptr(ptr); \ | |
407 | switch (size) { \ | |
408 | case 1: \ | |
409 | __get_user_asm_ex(x, ptr, "b", "b", "=q"); \ | |
410 | break; \ | |
411 | case 2: \ | |
412 | __get_user_asm_ex(x, ptr, "w", "w", "=r"); \ | |
413 | break; \ | |
414 | case 4: \ | |
415 | __get_user_asm_ex(x, ptr, "l", "k", "=r"); \ | |
416 | break; \ | |
417 | case 8: \ | |
418 | __get_user_asm_ex_u64(x, ptr); \ | |
419 | break; \ | |
420 | default: \ | |
421 | (x) = __get_user_bad(); \ | |
422 | } \ | |
423 | } while (0) | |
424 | ||
425 | #define __get_user_asm_ex(x, addr, itype, rtype, ltype) \ | |
5e88353d PA |
426 | asm volatile("1: mov"itype" %1,%"rtype"0\n" \ |
427 | "2:\n" \ | |
1c109fab AV |
428 | ".section .fixup,\"ax\"\n" \ |
429 | "3:xor"itype" %"rtype"0,%"rtype"0\n" \ | |
430 | " jmp 2b\n" \ | |
431 | ".previous\n" \ | |
432 | _ASM_EXTABLE_EX(1b, 3b) \ | |
fe40c0af HS |
433 | : ltype(x) : "m" (__m(addr))) |
434 | ||
dc70ddf4 GC |
435 | #define __put_user_nocheck(x, ptr, size) \ |
436 | ({ \ | |
16855f87 | 437 | int __pu_err; \ |
11f1a4b9 | 438 | __uaccess_begin(); \ |
dc70ddf4 | 439 | __put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \ |
11f1a4b9 | 440 | __uaccess_end(); \ |
a76cf66e | 441 | __builtin_expect(__pu_err, 0); \ |
dc70ddf4 GC |
442 | }) |
443 | ||
3f168221 GC |
444 | #define __get_user_nocheck(x, ptr, size) \ |
445 | ({ \ | |
16855f87 | 446 | int __gu_err; \ |
b2f68038 | 447 | __inttype(*(ptr)) __gu_val; \ |
11f1a4b9 | 448 | __uaccess_begin(); \ |
3f168221 | 449 | __get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \ |
11f1a4b9 | 450 | __uaccess_end(); \ |
3f168221 | 451 | (x) = (__force __typeof__(*(ptr)))__gu_val; \ |
a76cf66e | 452 | __builtin_expect(__gu_err, 0); \ |
3f168221 | 453 | }) |
dc70ddf4 GC |
454 | |
455 | /* FIXME: this hack is definitely wrong -AK */ | |
456 | struct __large_struct { unsigned long buf[100]; }; | |
457 | #define __m(x) (*(struct __large_struct __user *)(x)) | |
458 | ||
459 | /* | |
460 | * Tell gcc we read from memory instead of writing: this is because | |
461 | * we do not write to any memory gcc knows about, so there are no | |
462 | * aliasing issues. | |
463 | */ | |
464 | #define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \ | |
11f1a4b9 | 465 | asm volatile("\n" \ |
63bcff2a | 466 | "1: mov"itype" %"rtype"1,%2\n" \ |
11f1a4b9 | 467 | "2:\n" \ |
dc70ddf4 GC |
468 | ".section .fixup,\"ax\"\n" \ |
469 | "3: mov %3,%0\n" \ | |
470 | " jmp 2b\n" \ | |
471 | ".previous\n" \ | |
472 | _ASM_EXTABLE(1b, 3b) \ | |
473 | : "=r"(err) \ | |
474 | : ltype(x), "m" (__m(addr)), "i" (errret), "0" (err)) | |
fe40c0af HS |
475 | |
476 | #define __put_user_asm_ex(x, addr, itype, rtype, ltype) \ | |
5e88353d PA |
477 | asm volatile("1: mov"itype" %"rtype"0,%1\n" \ |
478 | "2:\n" \ | |
535c0c34 | 479 | _ASM_EXTABLE_EX(1b, 2b) \ |
fe40c0af HS |
480 | : : ltype(x), "m" (__m(addr))) |
481 | ||
482 | /* | |
483 | * uaccess_try and catch | |
484 | */ | |
485 | #define uaccess_try do { \ | |
dfa9a942 | 486 | current->thread.uaccess_err = 0; \ |
11f1a4b9 | 487 | __uaccess_begin(); \ |
fe40c0af HS |
488 | barrier(); |
489 | ||
490 | #define uaccess_catch(err) \ | |
11f1a4b9 | 491 | __uaccess_end(); \ |
dfa9a942 | 492 | (err) |= (current->thread.uaccess_err ? -EFAULT : 0); \ |
fe40c0af HS |
493 | } while (0) |
494 | ||
8cb834e9 GC |
495 | /** |
496 | * __get_user: - Get a simple variable from user space, with less checking. | |
497 | * @x: Variable to store result. | |
498 | * @ptr: Source address, in user space. | |
499 | * | |
b3c395ef DH |
500 | * Context: User context only. This function may sleep if pagefaults are |
501 | * enabled. | |
8cb834e9 GC |
502 | * |
503 | * This macro copies a single simple variable from user space to kernel | |
504 | * space. It supports simple types like char and int, but not larger | |
505 | * data types like structures or arrays. | |
506 | * | |
507 | * @ptr must have pointer-to-simple-variable type, and the result of | |
508 | * dereferencing @ptr must be assignable to @x without a cast. | |
509 | * | |
510 | * Caller must check the pointer with access_ok() before calling this | |
511 | * function. | |
512 | * | |
513 | * Returns zero on success, or -EFAULT on error. | |
514 | * On error, the variable @x is set to zero. | |
515 | */ | |
516 | ||
517 | #define __get_user(x, ptr) \ | |
518 | __get_user_nocheck((x), (ptr), sizeof(*(ptr))) | |
fe40c0af | 519 | |
8cb834e9 GC |
520 | /** |
521 | * __put_user: - Write a simple value into user space, with less checking. | |
522 | * @x: Value to copy to user space. | |
523 | * @ptr: Destination address, in user space. | |
524 | * | |
b3c395ef DH |
525 | * Context: User context only. This function may sleep if pagefaults are |
526 | * enabled. | |
8cb834e9 GC |
527 | * |
528 | * This macro copies a single simple value from kernel space to user | |
529 | * space. It supports simple types like char and int, but not larger | |
530 | * data types like structures or arrays. | |
531 | * | |
532 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
533 | * to the result of dereferencing @ptr. | |
534 | * | |
535 | * Caller must check the pointer with access_ok() before calling this | |
536 | * function. | |
537 | * | |
538 | * Returns zero on success, or -EFAULT on error. | |
539 | */ | |
540 | ||
541 | #define __put_user(x, ptr) \ | |
542 | __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
dc70ddf4 | 543 | |
fe40c0af HS |
544 | /* |
545 | * {get|put}_user_try and catch | |
546 | * | |
547 | * get_user_try { | |
548 | * get_user_ex(...); | |
549 | * } get_user_catch(err) | |
550 | */ | |
551 | #define get_user_try uaccess_try | |
552 | #define get_user_catch(err) uaccess_catch(err) | |
fe40c0af HS |
553 | |
554 | #define get_user_ex(x, ptr) do { \ | |
555 | unsigned long __gue_val; \ | |
556 | __get_user_size_ex((__gue_val), (ptr), (sizeof(*(ptr)))); \ | |
557 | (x) = (__force __typeof__(*(ptr)))__gue_val; \ | |
558 | } while (0) | |
559 | ||
019a1369 HS |
560 | #define put_user_try uaccess_try |
561 | #define put_user_catch(err) uaccess_catch(err) | |
562 | ||
fe40c0af HS |
563 | #define put_user_ex(x, ptr) \ |
564 | __put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
565 | ||
1ac2e6ca RR |
566 | extern unsigned long |
567 | copy_from_user_nmi(void *to, const void __user *from, unsigned long n); | |
92ae03f2 LT |
568 | extern __must_check long |
569 | strncpy_from_user(char *dst, const char __user *src, long count); | |
1ac2e6ca | 570 | |
5723aa99 LT |
571 | extern __must_check long strnlen_user(const char __user *str, long n); |
572 | ||
a052858f PA |
573 | unsigned long __must_check clear_user(void __user *mem, unsigned long len); |
574 | unsigned long __must_check __clear_user(void __user *mem, unsigned long len); | |
575 | ||
f09174c5 QR |
576 | extern void __cmpxchg_wrong_size(void) |
577 | __compiletime_error("Bad argument size for cmpxchg"); | |
578 | ||
579 | #define __user_atomic_cmpxchg_inatomic(uval, ptr, old, new, size) \ | |
580 | ({ \ | |
581 | int __ret = 0; \ | |
582 | __typeof__(ptr) __uval = (uval); \ | |
583 | __typeof__(*(ptr)) __old = (old); \ | |
584 | __typeof__(*(ptr)) __new = (new); \ | |
11f1a4b9 | 585 | __uaccess_begin(); \ |
f09174c5 QR |
586 | switch (size) { \ |
587 | case 1: \ | |
588 | { \ | |
11f1a4b9 | 589 | asm volatile("\n" \ |
f09174c5 | 590 | "1:\t" LOCK_PREFIX "cmpxchgb %4, %2\n" \ |
11f1a4b9 | 591 | "2:\n" \ |
f09174c5 QR |
592 | "\t.section .fixup, \"ax\"\n" \ |
593 | "3:\tmov %3, %0\n" \ | |
594 | "\tjmp 2b\n" \ | |
595 | "\t.previous\n" \ | |
596 | _ASM_EXTABLE(1b, 3b) \ | |
597 | : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ | |
598 | : "i" (-EFAULT), "q" (__new), "1" (__old) \ | |
599 | : "memory" \ | |
600 | ); \ | |
601 | break; \ | |
602 | } \ | |
603 | case 2: \ | |
604 | { \ | |
11f1a4b9 | 605 | asm volatile("\n" \ |
f09174c5 | 606 | "1:\t" LOCK_PREFIX "cmpxchgw %4, %2\n" \ |
11f1a4b9 | 607 | "2:\n" \ |
f09174c5 QR |
608 | "\t.section .fixup, \"ax\"\n" \ |
609 | "3:\tmov %3, %0\n" \ | |
610 | "\tjmp 2b\n" \ | |
611 | "\t.previous\n" \ | |
612 | _ASM_EXTABLE(1b, 3b) \ | |
613 | : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ | |
614 | : "i" (-EFAULT), "r" (__new), "1" (__old) \ | |
615 | : "memory" \ | |
616 | ); \ | |
617 | break; \ | |
618 | } \ | |
619 | case 4: \ | |
620 | { \ | |
11f1a4b9 | 621 | asm volatile("\n" \ |
f09174c5 | 622 | "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n" \ |
11f1a4b9 | 623 | "2:\n" \ |
f09174c5 QR |
624 | "\t.section .fixup, \"ax\"\n" \ |
625 | "3:\tmov %3, %0\n" \ | |
626 | "\tjmp 2b\n" \ | |
627 | "\t.previous\n" \ | |
628 | _ASM_EXTABLE(1b, 3b) \ | |
629 | : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ | |
630 | : "i" (-EFAULT), "r" (__new), "1" (__old) \ | |
631 | : "memory" \ | |
632 | ); \ | |
633 | break; \ | |
634 | } \ | |
635 | case 8: \ | |
636 | { \ | |
637 | if (!IS_ENABLED(CONFIG_X86_64)) \ | |
638 | __cmpxchg_wrong_size(); \ | |
639 | \ | |
11f1a4b9 | 640 | asm volatile("\n" \ |
f09174c5 | 641 | "1:\t" LOCK_PREFIX "cmpxchgq %4, %2\n" \ |
11f1a4b9 | 642 | "2:\n" \ |
f09174c5 QR |
643 | "\t.section .fixup, \"ax\"\n" \ |
644 | "3:\tmov %3, %0\n" \ | |
645 | "\tjmp 2b\n" \ | |
646 | "\t.previous\n" \ | |
647 | _ASM_EXTABLE(1b, 3b) \ | |
648 | : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ | |
649 | : "i" (-EFAULT), "r" (__new), "1" (__old) \ | |
650 | : "memory" \ | |
651 | ); \ | |
652 | break; \ | |
653 | } \ | |
654 | default: \ | |
655 | __cmpxchg_wrong_size(); \ | |
656 | } \ | |
11f1a4b9 | 657 | __uaccess_end(); \ |
f09174c5 QR |
658 | *__uval = __old; \ |
659 | __ret; \ | |
660 | }) | |
661 | ||
662 | #define user_atomic_cmpxchg_inatomic(uval, ptr, old, new) \ | |
663 | ({ \ | |
664 | access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \ | |
665 | __user_atomic_cmpxchg_inatomic((uval), (ptr), \ | |
666 | (old), (new), sizeof(*(ptr))) : \ | |
667 | -EFAULT; \ | |
668 | }) | |
669 | ||
8bc7de0c GC |
670 | /* |
671 | * movsl can be slow when source and dest are not both 8-byte aligned | |
672 | */ | |
673 | #ifdef CONFIG_X86_INTEL_USERCOPY | |
674 | extern struct movsl_mask { | |
675 | int mask; | |
676 | } ____cacheline_aligned_in_smp movsl_mask; | |
677 | #endif | |
678 | ||
22cac167 GC |
679 | #define ARCH_HAS_NOCACHE_UACCESS 1 |
680 | ||
96a388de | 681 | #ifdef CONFIG_X86_32 |
a1ce3928 | 682 | # include <asm/uaccess_32.h> |
96a388de | 683 | #else |
a1ce3928 | 684 | # include <asm/uaccess_64.h> |
96a388de | 685 | #endif |
ca233862 | 686 | |
10013ebb AK |
687 | /* |
688 | * We rely on the nested NMI work to allow atomic faults from the NMI path; the | |
689 | * nested NMI paths are careful to preserve CR2. | |
690 | * | |
691 | * Caller must use pagefault_enable/disable, or run in interrupt context, | |
692 | * and also do a uaccess_ok() check | |
693 | */ | |
694 | #define __copy_from_user_nmi __copy_from_user_inatomic | |
695 | ||
5b24a7a2 LT |
696 | /* |
697 | * The "unsafe" user accesses aren't really "unsafe", but the naming | |
698 | * is a big fat warning: you have to not only do the access_ok() | |
699 | * checking before using them, but you have to surround them with the | |
700 | * user_access_begin/end() pair. | |
701 | */ | |
702 | #define user_access_begin() __uaccess_begin() | |
703 | #define user_access_end() __uaccess_end() | |
704 | ||
1bd4403d LT |
705 | #define unsafe_put_user(x, ptr, err_label) \ |
706 | do { \ | |
5b24a7a2 | 707 | int __pu_err; \ |
334a023e LT |
708 | __typeof__(*(ptr)) __pu_val = (x); \ |
709 | __put_user_size(__pu_val, (ptr), sizeof(*(ptr)), __pu_err, -EFAULT); \ | |
1bd4403d LT |
710 | if (unlikely(__pu_err)) goto err_label; \ |
711 | } while (0) | |
5b24a7a2 | 712 | |
1bd4403d LT |
713 | #define unsafe_get_user(x, ptr, err_label) \ |
714 | do { \ | |
5b24a7a2 | 715 | int __gu_err; \ |
334a023e | 716 | __inttype(*(ptr)) __gu_val; \ |
5b24a7a2 LT |
717 | __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), __gu_err, -EFAULT); \ |
718 | (x) = (__force __typeof__(*(ptr)))__gu_val; \ | |
1bd4403d LT |
719 | if (unlikely(__gu_err)) goto err_label; \ |
720 | } while (0) | |
5b24a7a2 | 721 | |
1965aae3 | 722 | #endif /* _ASM_X86_UACCESS_H */ |
8174c430 | 723 |