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1965aae3 PA |
1 | #ifndef _ASM_X86_UACCESS_H |
2 | #define _ASM_X86_UACCESS_H | |
ca233862 GC |
3 | /* |
4 | * User space memory access functions | |
5 | */ | |
6 | #include <linux/errno.h> | |
7 | #include <linux/compiler.h> | |
1771c6e1 | 8 | #include <linux/kasan-checks.h> |
ca233862 | 9 | #include <linux/thread_info.h> |
ca233862 GC |
10 | #include <linux/string.h> |
11 | #include <asm/asm.h> | |
12 | #include <asm/page.h> | |
63bcff2a | 13 | #include <asm/smap.h> |
ca233862 GC |
14 | |
15 | #define VERIFY_READ 0 | |
16 | #define VERIFY_WRITE 1 | |
17 | ||
18 | /* | |
19 | * The fs value determines whether argument validity checking should be | |
20 | * performed or not. If get_fs() == USER_DS, checking is performed, with | |
21 | * get_fs() == KERNEL_DS, checking is bypassed. | |
22 | * | |
23 | * For historical reasons, these macros are grossly misnamed. | |
24 | */ | |
25 | ||
26 | #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) | |
27 | ||
28 | #define KERNEL_DS MAKE_MM_SEG(-1UL) | |
9063c61f | 29 | #define USER_DS MAKE_MM_SEG(TASK_SIZE_MAX) |
ca233862 GC |
30 | |
31 | #define get_ds() (KERNEL_DS) | |
13d4ea09 AL |
32 | #define get_fs() (current->thread.addr_limit) |
33 | #define set_fs(x) (current->thread.addr_limit = (x)) | |
ca233862 GC |
34 | |
35 | #define segment_eq(a, b) ((a).seg == (b).seg) | |
36 | ||
13d4ea09 | 37 | #define user_addr_max() (current->thread.addr_limit.seg) |
bc6ca7b3 AS |
38 | #define __addr_ok(addr) \ |
39 | ((unsigned long __force)(addr) < user_addr_max()) | |
002ca169 | 40 | |
ca233862 GC |
41 | /* |
42 | * Test whether a block of memory is a valid user space address. | |
43 | * Returns 0 if the range is valid, nonzero otherwise. | |
ca233862 | 44 | */ |
a740576a | 45 | static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit) |
c5fe5d80 LT |
46 | { |
47 | /* | |
48 | * If we have used "sizeof()" for the size, | |
49 | * we know it won't overflow the limit (but | |
50 | * it might overflow the 'addr', so it's | |
51 | * important to subtract the size from the | |
52 | * limit, not add it to the address). | |
53 | */ | |
54 | if (__builtin_constant_p(size)) | |
7e0f51cb | 55 | return unlikely(addr > limit - size); |
c5fe5d80 LT |
56 | |
57 | /* Arbitrary sizes? Be careful about overflow */ | |
58 | addr += size; | |
7e0f51cb | 59 | if (unlikely(addr < size)) |
a740576a | 60 | return true; |
7e0f51cb | 61 | return unlikely(addr > limit); |
c5fe5d80 | 62 | } |
ca233862 | 63 | |
bc6ca7b3 | 64 | #define __range_not_ok(addr, size, limit) \ |
ca233862 | 65 | ({ \ |
ca233862 | 66 | __chk_user_ptr(addr); \ |
c5fe5d80 | 67 | __chk_range_not_ok((unsigned long __force)(addr), size, limit); \ |
ca233862 GC |
68 | }) |
69 | ||
70 | /** | |
71 | * access_ok: - Checks if a user space pointer is valid | |
72 | * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that | |
73 | * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe | |
74 | * to write to a block, it is always safe to read from it. | |
75 | * @addr: User space pointer to start of block to check | |
76 | * @size: Size of block to check | |
77 | * | |
b3c395ef DH |
78 | * Context: User context only. This function may sleep if pagefaults are |
79 | * enabled. | |
ca233862 GC |
80 | * |
81 | * Checks if a pointer to a block of memory in user space is valid. | |
82 | * | |
83 | * Returns true (nonzero) if the memory block may be valid, false (zero) | |
84 | * if it is definitely invalid. | |
85 | * | |
86 | * Note that, depending on architecture, this function probably just | |
87 | * checks that the pointer is in the user space range - after calling | |
88 | * this function, memory access functions may still return -EFAULT. | |
89 | */ | |
bc6ca7b3 | 90 | #define access_ok(type, addr, size) \ |
a740576a | 91 | likely(!__range_not_ok(addr, size, user_addr_max())) |
ca233862 GC |
92 | |
93 | /* | |
548acf19 TL |
94 | * The exception table consists of triples of addresses relative to the |
95 | * exception table entry itself. The first address is of an instruction | |
96 | * that is allowed to fault, the second is the target at which the program | |
97 | * should continue. The third is a handler function to deal with the fault | |
98 | * caused by the instruction in the first field. | |
ca233862 GC |
99 | * |
100 | * All the routines below use bits of fixup code that are out of line | |
101 | * with the main instruction path. This means when everything is well, | |
102 | * we don't even have to jump over them. Further, they do not intrude | |
103 | * on our cache or tlb entries. | |
104 | */ | |
105 | ||
106 | struct exception_table_entry { | |
548acf19 | 107 | int insn, fixup, handler; |
ca233862 | 108 | }; |
29934b0f AB |
109 | |
110 | #define ARCH_HAS_RELATIVE_EXTABLE | |
ca233862 | 111 | |
67d7a982 MK |
112 | #define swap_ex_entry_fixup(a, b, tmp, delta) \ |
113 | do { \ | |
114 | (a)->fixup = (b)->fixup + (delta); \ | |
115 | (b)->fixup = (tmp).fixup - (delta); \ | |
116 | (a)->handler = (b)->handler + (delta); \ | |
117 | (b)->handler = (tmp).handler - (delta); \ | |
118 | } while (0) | |
119 | ||
548acf19 TL |
120 | extern int fixup_exception(struct pt_regs *regs, int trapnr); |
121 | extern bool ex_has_fault_handler(unsigned long ip); | |
0e861fbb | 122 | extern void early_fixup_exception(struct pt_regs *regs, int trapnr); |
ca233862 GC |
123 | |
124 | /* | |
125 | * These are the main single-value transfer routines. They automatically | |
126 | * use the right size if we just have the right pointer type. | |
127 | * | |
128 | * This gets kind of ugly. We want to return _two_ values in "get_user()" | |
129 | * and yet we don't want to do any pointers, because that is too much | |
130 | * of a performance impact. Thus we have a few rather ugly macros here, | |
131 | * and hide all the ugliness from the user. | |
132 | * | |
133 | * The "__xxx" versions of the user access functions are versions that | |
134 | * do not verify the address space, that must have been done previously | |
135 | * with a separate "access_ok()" call (this is used when we do multiple | |
136 | * accesses to the same area of user memory). | |
137 | */ | |
138 | ||
139 | extern int __get_user_1(void); | |
140 | extern int __get_user_2(void); | |
141 | extern int __get_user_4(void); | |
142 | extern int __get_user_8(void); | |
143 | extern int __get_user_bad(void); | |
144 | ||
11f1a4b9 LT |
145 | #define __uaccess_begin() stac() |
146 | #define __uaccess_end() clac() | |
147 | ||
3578baae PA |
148 | /* |
149 | * This is a type: either unsigned long, if the argument fits into | |
150 | * that type, or otherwise unsigned long long. | |
151 | */ | |
152 | #define __inttype(x) \ | |
153 | __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) | |
865e5b76 GC |
154 | |
155 | /** | |
156 | * get_user: - Get a simple variable from user space. | |
157 | * @x: Variable to store result. | |
158 | * @ptr: Source address, in user space. | |
159 | * | |
b3c395ef DH |
160 | * Context: User context only. This function may sleep if pagefaults are |
161 | * enabled. | |
865e5b76 GC |
162 | * |
163 | * This macro copies a single simple variable from user space to kernel | |
164 | * space. It supports simple types like char and int, but not larger | |
165 | * data types like structures or arrays. | |
166 | * | |
167 | * @ptr must have pointer-to-simple-variable type, and the result of | |
168 | * dereferencing @ptr must be assignable to @x without a cast. | |
169 | * | |
170 | * Returns zero on success, or -EFAULT on error. | |
171 | * On error, the variable @x is set to zero. | |
ff52c3b0 PA |
172 | */ |
173 | /* | |
3578baae PA |
174 | * Careful: we have to cast the result to the type of the pointer |
175 | * for sign reasons. | |
ff52c3b0 | 176 | * |
f69fa9a9 | 177 | * The use of _ASM_DX as the register specifier is a bit of a |
ff52c3b0 PA |
178 | * simplification, as gcc only cares about it as the starting point |
179 | * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits | |
180 | * (%ecx being the next register in gcc's x86 register sequence), and | |
181 | * %rdx on 64 bits. | |
f69fa9a9 PA |
182 | * |
183 | * Clang/LLVM cares about the size of the register, but still wants | |
184 | * the base register for something that ends up being a pair. | |
865e5b76 | 185 | */ |
865e5b76 GC |
186 | #define get_user(x, ptr) \ |
187 | ({ \ | |
188 | int __ret_gu; \ | |
bdfc017e | 189 | register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \ |
f05058c4 | 190 | register void *__sp asm(_ASM_SP); \ |
865e5b76 | 191 | __chk_user_ptr(ptr); \ |
3ee1afa3 | 192 | might_fault(); \ |
f05058c4 CA |
193 | asm volatile("call __get_user_%P4" \ |
194 | : "=a" (__ret_gu), "=r" (__val_gu), "+r" (__sp) \ | |
3578baae | 195 | : "0" (ptr), "i" (sizeof(*(ptr)))); \ |
e182c570 | 196 | (x) = (__force __typeof__(*(ptr))) __val_gu; \ |
a76cf66e | 197 | __builtin_expect(__ret_gu, 0); \ |
865e5b76 GC |
198 | }) |
199 | ||
e30a44fd GC |
200 | #define __put_user_x(size, x, ptr, __ret_pu) \ |
201 | asm volatile("call __put_user_" #size : "=a" (__ret_pu) \ | |
4d5d7838 | 202 | : "0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx") |
e30a44fd GC |
203 | |
204 | ||
205 | ||
dc70ddf4 | 206 | #ifdef CONFIG_X86_32 |
18114f61 | 207 | #define __put_user_asm_u64(x, addr, err, errret) \ |
11f1a4b9 | 208 | asm volatile("\n" \ |
63bcff2a | 209 | "1: movl %%eax,0(%2)\n" \ |
dc70ddf4 | 210 | "2: movl %%edx,4(%2)\n" \ |
11f1a4b9 | 211 | "3:" \ |
dc70ddf4 GC |
212 | ".section .fixup,\"ax\"\n" \ |
213 | "4: movl %3,%0\n" \ | |
214 | " jmp 3b\n" \ | |
215 | ".previous\n" \ | |
216 | _ASM_EXTABLE(1b, 4b) \ | |
217 | _ASM_EXTABLE(2b, 4b) \ | |
218 | : "=r" (err) \ | |
18114f61 | 219 | : "A" (x), "r" (addr), "i" (errret), "0" (err)) |
e30a44fd | 220 | |
fe40c0af | 221 | #define __put_user_asm_ex_u64(x, addr) \ |
11f1a4b9 | 222 | asm volatile("\n" \ |
63bcff2a | 223 | "1: movl %%eax,0(%1)\n" \ |
fe40c0af | 224 | "2: movl %%edx,4(%1)\n" \ |
11f1a4b9 | 225 | "3:" \ |
535c0c34 PA |
226 | _ASM_EXTABLE_EX(1b, 2b) \ |
227 | _ASM_EXTABLE_EX(2b, 3b) \ | |
fe40c0af HS |
228 | : : "A" (x), "r" (addr)) |
229 | ||
e30a44fd GC |
230 | #define __put_user_x8(x, ptr, __ret_pu) \ |
231 | asm volatile("call __put_user_8" : "=a" (__ret_pu) \ | |
232 | : "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx") | |
dc70ddf4 | 233 | #else |
18114f61 | 234 | #define __put_user_asm_u64(x, ptr, retval, errret) \ |
ebe119cd | 235 | __put_user_asm(x, ptr, retval, "q", "", "er", errret) |
fe40c0af | 236 | #define __put_user_asm_ex_u64(x, addr) \ |
ebe119cd | 237 | __put_user_asm_ex(x, addr, "q", "", "er") |
e30a44fd | 238 | #define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu) |
dc70ddf4 GC |
239 | #endif |
240 | ||
e30a44fd GC |
241 | extern void __put_user_bad(void); |
242 | ||
243 | /* | |
244 | * Strange magic calling convention: pointer in %ecx, | |
245 | * value in %eax(:%edx), return value in %eax. clobbers %rbx | |
246 | */ | |
247 | extern void __put_user_1(void); | |
248 | extern void __put_user_2(void); | |
249 | extern void __put_user_4(void); | |
250 | extern void __put_user_8(void); | |
251 | ||
e30a44fd GC |
252 | /** |
253 | * put_user: - Write a simple value into user space. | |
254 | * @x: Value to copy to user space. | |
255 | * @ptr: Destination address, in user space. | |
256 | * | |
b3c395ef DH |
257 | * Context: User context only. This function may sleep if pagefaults are |
258 | * enabled. | |
e30a44fd GC |
259 | * |
260 | * This macro copies a single simple value from kernel space to user | |
261 | * space. It supports simple types like char and int, but not larger | |
262 | * data types like structures or arrays. | |
263 | * | |
264 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
265 | * to the result of dereferencing @ptr. | |
266 | * | |
267 | * Returns zero on success, or -EFAULT on error. | |
268 | */ | |
269 | #define put_user(x, ptr) \ | |
270 | ({ \ | |
271 | int __ret_pu; \ | |
272 | __typeof__(*(ptr)) __pu_val; \ | |
273 | __chk_user_ptr(ptr); \ | |
3ee1afa3 | 274 | might_fault(); \ |
e30a44fd GC |
275 | __pu_val = x; \ |
276 | switch (sizeof(*(ptr))) { \ | |
277 | case 1: \ | |
278 | __put_user_x(1, __pu_val, ptr, __ret_pu); \ | |
279 | break; \ | |
280 | case 2: \ | |
281 | __put_user_x(2, __pu_val, ptr, __ret_pu); \ | |
282 | break; \ | |
283 | case 4: \ | |
284 | __put_user_x(4, __pu_val, ptr, __ret_pu); \ | |
285 | break; \ | |
286 | case 8: \ | |
287 | __put_user_x8(__pu_val, ptr, __ret_pu); \ | |
288 | break; \ | |
289 | default: \ | |
290 | __put_user_x(X, __pu_val, ptr, __ret_pu); \ | |
291 | break; \ | |
292 | } \ | |
a76cf66e | 293 | __builtin_expect(__ret_pu, 0); \ |
e30a44fd GC |
294 | }) |
295 | ||
dc70ddf4 GC |
296 | #define __put_user_size(x, ptr, size, retval, errret) \ |
297 | do { \ | |
298 | retval = 0; \ | |
299 | __chk_user_ptr(ptr); \ | |
300 | switch (size) { \ | |
301 | case 1: \ | |
302 | __put_user_asm(x, ptr, retval, "b", "b", "iq", errret); \ | |
303 | break; \ | |
304 | case 2: \ | |
305 | __put_user_asm(x, ptr, retval, "w", "w", "ir", errret); \ | |
306 | break; \ | |
307 | case 4: \ | |
4d5d7838 | 308 | __put_user_asm(x, ptr, retval, "l", "k", "ir", errret); \ |
dc70ddf4 GC |
309 | break; \ |
310 | case 8: \ | |
18114f61 HS |
311 | __put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval, \ |
312 | errret); \ | |
dc70ddf4 GC |
313 | break; \ |
314 | default: \ | |
315 | __put_user_bad(); \ | |
316 | } \ | |
317 | } while (0) | |
318 | ||
11f1a4b9 LT |
319 | /* |
320 | * This doesn't do __uaccess_begin/end - the exception handling | |
321 | * around it must do that. | |
322 | */ | |
fe40c0af HS |
323 | #define __put_user_size_ex(x, ptr, size) \ |
324 | do { \ | |
325 | __chk_user_ptr(ptr); \ | |
326 | switch (size) { \ | |
327 | case 1: \ | |
328 | __put_user_asm_ex(x, ptr, "b", "b", "iq"); \ | |
329 | break; \ | |
330 | case 2: \ | |
331 | __put_user_asm_ex(x, ptr, "w", "w", "ir"); \ | |
332 | break; \ | |
333 | case 4: \ | |
334 | __put_user_asm_ex(x, ptr, "l", "k", "ir"); \ | |
335 | break; \ | |
336 | case 8: \ | |
337 | __put_user_asm_ex_u64((__typeof__(*ptr))(x), ptr); \ | |
338 | break; \ | |
339 | default: \ | |
340 | __put_user_bad(); \ | |
341 | } \ | |
342 | } while (0) | |
343 | ||
3f168221 | 344 | #ifdef CONFIG_X86_32 |
b2f68038 BL |
345 | #define __get_user_asm_u64(x, ptr, retval, errret) \ |
346 | ({ \ | |
347 | __typeof__(ptr) __ptr = (ptr); \ | |
348 | asm volatile(ASM_STAC "\n" \ | |
349 | "1: movl %2,%%eax\n" \ | |
350 | "2: movl %3,%%edx\n" \ | |
351 | "3: " ASM_CLAC "\n" \ | |
352 | ".section .fixup,\"ax\"\n" \ | |
353 | "4: mov %4,%0\n" \ | |
354 | " xorl %%eax,%%eax\n" \ | |
355 | " xorl %%edx,%%edx\n" \ | |
356 | " jmp 3b\n" \ | |
357 | ".previous\n" \ | |
358 | _ASM_EXTABLE(1b, 4b) \ | |
359 | _ASM_EXTABLE(2b, 4b) \ | |
360 | : "=r" (retval), "=A"(x) \ | |
361 | : "m" (__m(__ptr)), "m" __m(((u32 *)(__ptr)) + 1), \ | |
362 | "i" (errret), "0" (retval)); \ | |
363 | }) | |
364 | ||
fe40c0af | 365 | #define __get_user_asm_ex_u64(x, ptr) (x) = __get_user_bad() |
3f168221 GC |
366 | #else |
367 | #define __get_user_asm_u64(x, ptr, retval, errret) \ | |
368 | __get_user_asm(x, ptr, retval, "q", "", "=r", errret) | |
fe40c0af HS |
369 | #define __get_user_asm_ex_u64(x, ptr) \ |
370 | __get_user_asm_ex(x, ptr, "q", "", "=r") | |
3f168221 GC |
371 | #endif |
372 | ||
373 | #define __get_user_size(x, ptr, size, retval, errret) \ | |
374 | do { \ | |
375 | retval = 0; \ | |
376 | __chk_user_ptr(ptr); \ | |
377 | switch (size) { \ | |
378 | case 1: \ | |
379 | __get_user_asm(x, ptr, retval, "b", "b", "=q", errret); \ | |
380 | break; \ | |
381 | case 2: \ | |
382 | __get_user_asm(x, ptr, retval, "w", "w", "=r", errret); \ | |
383 | break; \ | |
384 | case 4: \ | |
385 | __get_user_asm(x, ptr, retval, "l", "k", "=r", errret); \ | |
386 | break; \ | |
387 | case 8: \ | |
388 | __get_user_asm_u64(x, ptr, retval, errret); \ | |
389 | break; \ | |
390 | default: \ | |
391 | (x) = __get_user_bad(); \ | |
392 | } \ | |
393 | } while (0) | |
394 | ||
395 | #define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \ | |
11f1a4b9 | 396 | asm volatile("\n" \ |
63bcff2a | 397 | "1: mov"itype" %2,%"rtype"1\n" \ |
11f1a4b9 | 398 | "2:\n" \ |
3f168221 GC |
399 | ".section .fixup,\"ax\"\n" \ |
400 | "3: mov %3,%0\n" \ | |
401 | " xor"itype" %"rtype"1,%"rtype"1\n" \ | |
402 | " jmp 2b\n" \ | |
403 | ".previous\n" \ | |
404 | _ASM_EXTABLE(1b, 3b) \ | |
405 | : "=r" (err), ltype(x) \ | |
406 | : "m" (__m(addr)), "i" (errret), "0" (err)) | |
407 | ||
11f1a4b9 LT |
408 | /* |
409 | * This doesn't do __uaccess_begin/end - the exception handling | |
410 | * around it must do that. | |
411 | */ | |
fe40c0af HS |
412 | #define __get_user_size_ex(x, ptr, size) \ |
413 | do { \ | |
414 | __chk_user_ptr(ptr); \ | |
415 | switch (size) { \ | |
416 | case 1: \ | |
417 | __get_user_asm_ex(x, ptr, "b", "b", "=q"); \ | |
418 | break; \ | |
419 | case 2: \ | |
420 | __get_user_asm_ex(x, ptr, "w", "w", "=r"); \ | |
421 | break; \ | |
422 | case 4: \ | |
423 | __get_user_asm_ex(x, ptr, "l", "k", "=r"); \ | |
424 | break; \ | |
425 | case 8: \ | |
426 | __get_user_asm_ex_u64(x, ptr); \ | |
427 | break; \ | |
428 | default: \ | |
429 | (x) = __get_user_bad(); \ | |
430 | } \ | |
431 | } while (0) | |
432 | ||
433 | #define __get_user_asm_ex(x, addr, itype, rtype, ltype) \ | |
5e88353d PA |
434 | asm volatile("1: mov"itype" %1,%"rtype"0\n" \ |
435 | "2:\n" \ | |
1c109fab AV |
436 | ".section .fixup,\"ax\"\n" \ |
437 | "3:xor"itype" %"rtype"0,%"rtype"0\n" \ | |
438 | " jmp 2b\n" \ | |
439 | ".previous\n" \ | |
440 | _ASM_EXTABLE_EX(1b, 3b) \ | |
fe40c0af HS |
441 | : ltype(x) : "m" (__m(addr))) |
442 | ||
dc70ddf4 GC |
443 | #define __put_user_nocheck(x, ptr, size) \ |
444 | ({ \ | |
16855f87 | 445 | int __pu_err; \ |
11f1a4b9 | 446 | __uaccess_begin(); \ |
dc70ddf4 | 447 | __put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \ |
11f1a4b9 | 448 | __uaccess_end(); \ |
a76cf66e | 449 | __builtin_expect(__pu_err, 0); \ |
dc70ddf4 GC |
450 | }) |
451 | ||
3f168221 GC |
452 | #define __get_user_nocheck(x, ptr, size) \ |
453 | ({ \ | |
16855f87 | 454 | int __gu_err; \ |
b2f68038 | 455 | __inttype(*(ptr)) __gu_val; \ |
11f1a4b9 | 456 | __uaccess_begin(); \ |
3f168221 | 457 | __get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \ |
11f1a4b9 | 458 | __uaccess_end(); \ |
3f168221 | 459 | (x) = (__force __typeof__(*(ptr)))__gu_val; \ |
a76cf66e | 460 | __builtin_expect(__gu_err, 0); \ |
3f168221 | 461 | }) |
dc70ddf4 GC |
462 | |
463 | /* FIXME: this hack is definitely wrong -AK */ | |
464 | struct __large_struct { unsigned long buf[100]; }; | |
465 | #define __m(x) (*(struct __large_struct __user *)(x)) | |
466 | ||
467 | /* | |
468 | * Tell gcc we read from memory instead of writing: this is because | |
469 | * we do not write to any memory gcc knows about, so there are no | |
470 | * aliasing issues. | |
471 | */ | |
472 | #define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \ | |
11f1a4b9 | 473 | asm volatile("\n" \ |
63bcff2a | 474 | "1: mov"itype" %"rtype"1,%2\n" \ |
11f1a4b9 | 475 | "2:\n" \ |
dc70ddf4 GC |
476 | ".section .fixup,\"ax\"\n" \ |
477 | "3: mov %3,%0\n" \ | |
478 | " jmp 2b\n" \ | |
479 | ".previous\n" \ | |
480 | _ASM_EXTABLE(1b, 3b) \ | |
481 | : "=r"(err) \ | |
482 | : ltype(x), "m" (__m(addr)), "i" (errret), "0" (err)) | |
fe40c0af HS |
483 | |
484 | #define __put_user_asm_ex(x, addr, itype, rtype, ltype) \ | |
5e88353d PA |
485 | asm volatile("1: mov"itype" %"rtype"0,%1\n" \ |
486 | "2:\n" \ | |
535c0c34 | 487 | _ASM_EXTABLE_EX(1b, 2b) \ |
fe40c0af HS |
488 | : : ltype(x), "m" (__m(addr))) |
489 | ||
490 | /* | |
491 | * uaccess_try and catch | |
492 | */ | |
493 | #define uaccess_try do { \ | |
dfa9a942 | 494 | current->thread.uaccess_err = 0; \ |
11f1a4b9 | 495 | __uaccess_begin(); \ |
fe40c0af HS |
496 | barrier(); |
497 | ||
498 | #define uaccess_catch(err) \ | |
11f1a4b9 | 499 | __uaccess_end(); \ |
dfa9a942 | 500 | (err) |= (current->thread.uaccess_err ? -EFAULT : 0); \ |
fe40c0af HS |
501 | } while (0) |
502 | ||
8cb834e9 GC |
503 | /** |
504 | * __get_user: - Get a simple variable from user space, with less checking. | |
505 | * @x: Variable to store result. | |
506 | * @ptr: Source address, in user space. | |
507 | * | |
b3c395ef DH |
508 | * Context: User context only. This function may sleep if pagefaults are |
509 | * enabled. | |
8cb834e9 GC |
510 | * |
511 | * This macro copies a single simple variable from user space to kernel | |
512 | * space. It supports simple types like char and int, but not larger | |
513 | * data types like structures or arrays. | |
514 | * | |
515 | * @ptr must have pointer-to-simple-variable type, and the result of | |
516 | * dereferencing @ptr must be assignable to @x without a cast. | |
517 | * | |
518 | * Caller must check the pointer with access_ok() before calling this | |
519 | * function. | |
520 | * | |
521 | * Returns zero on success, or -EFAULT on error. | |
522 | * On error, the variable @x is set to zero. | |
523 | */ | |
524 | ||
525 | #define __get_user(x, ptr) \ | |
526 | __get_user_nocheck((x), (ptr), sizeof(*(ptr))) | |
fe40c0af | 527 | |
8cb834e9 GC |
528 | /** |
529 | * __put_user: - Write a simple value into user space, with less checking. | |
530 | * @x: Value to copy to user space. | |
531 | * @ptr: Destination address, in user space. | |
532 | * | |
b3c395ef DH |
533 | * Context: User context only. This function may sleep if pagefaults are |
534 | * enabled. | |
8cb834e9 GC |
535 | * |
536 | * This macro copies a single simple value from kernel space to user | |
537 | * space. It supports simple types like char and int, but not larger | |
538 | * data types like structures or arrays. | |
539 | * | |
540 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
541 | * to the result of dereferencing @ptr. | |
542 | * | |
543 | * Caller must check the pointer with access_ok() before calling this | |
544 | * function. | |
545 | * | |
546 | * Returns zero on success, or -EFAULT on error. | |
547 | */ | |
548 | ||
549 | #define __put_user(x, ptr) \ | |
550 | __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
dc70ddf4 | 551 | |
8cb834e9 GC |
552 | #define __get_user_unaligned __get_user |
553 | #define __put_user_unaligned __put_user | |
865e5b76 | 554 | |
fe40c0af HS |
555 | /* |
556 | * {get|put}_user_try and catch | |
557 | * | |
558 | * get_user_try { | |
559 | * get_user_ex(...); | |
560 | * } get_user_catch(err) | |
561 | */ | |
562 | #define get_user_try uaccess_try | |
563 | #define get_user_catch(err) uaccess_catch(err) | |
fe40c0af HS |
564 | |
565 | #define get_user_ex(x, ptr) do { \ | |
566 | unsigned long __gue_val; \ | |
567 | __get_user_size_ex((__gue_val), (ptr), (sizeof(*(ptr)))); \ | |
568 | (x) = (__force __typeof__(*(ptr)))__gue_val; \ | |
569 | } while (0) | |
570 | ||
019a1369 HS |
571 | #define put_user_try uaccess_try |
572 | #define put_user_catch(err) uaccess_catch(err) | |
573 | ||
fe40c0af HS |
574 | #define put_user_ex(x, ptr) \ |
575 | __put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
576 | ||
1ac2e6ca RR |
577 | extern unsigned long |
578 | copy_from_user_nmi(void *to, const void __user *from, unsigned long n); | |
92ae03f2 LT |
579 | extern __must_check long |
580 | strncpy_from_user(char *dst, const char __user *src, long count); | |
1ac2e6ca | 581 | |
5723aa99 LT |
582 | extern __must_check long strlen_user(const char __user *str); |
583 | extern __must_check long strnlen_user(const char __user *str, long n); | |
584 | ||
a052858f PA |
585 | unsigned long __must_check clear_user(void __user *mem, unsigned long len); |
586 | unsigned long __must_check __clear_user(void __user *mem, unsigned long len); | |
587 | ||
f09174c5 QR |
588 | extern void __cmpxchg_wrong_size(void) |
589 | __compiletime_error("Bad argument size for cmpxchg"); | |
590 | ||
591 | #define __user_atomic_cmpxchg_inatomic(uval, ptr, old, new, size) \ | |
592 | ({ \ | |
593 | int __ret = 0; \ | |
594 | __typeof__(ptr) __uval = (uval); \ | |
595 | __typeof__(*(ptr)) __old = (old); \ | |
596 | __typeof__(*(ptr)) __new = (new); \ | |
11f1a4b9 | 597 | __uaccess_begin(); \ |
f09174c5 QR |
598 | switch (size) { \ |
599 | case 1: \ | |
600 | { \ | |
11f1a4b9 | 601 | asm volatile("\n" \ |
f09174c5 | 602 | "1:\t" LOCK_PREFIX "cmpxchgb %4, %2\n" \ |
11f1a4b9 | 603 | "2:\n" \ |
f09174c5 QR |
604 | "\t.section .fixup, \"ax\"\n" \ |
605 | "3:\tmov %3, %0\n" \ | |
606 | "\tjmp 2b\n" \ | |
607 | "\t.previous\n" \ | |
608 | _ASM_EXTABLE(1b, 3b) \ | |
609 | : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ | |
610 | : "i" (-EFAULT), "q" (__new), "1" (__old) \ | |
611 | : "memory" \ | |
612 | ); \ | |
613 | break; \ | |
614 | } \ | |
615 | case 2: \ | |
616 | { \ | |
11f1a4b9 | 617 | asm volatile("\n" \ |
f09174c5 | 618 | "1:\t" LOCK_PREFIX "cmpxchgw %4, %2\n" \ |
11f1a4b9 | 619 | "2:\n" \ |
f09174c5 QR |
620 | "\t.section .fixup, \"ax\"\n" \ |
621 | "3:\tmov %3, %0\n" \ | |
622 | "\tjmp 2b\n" \ | |
623 | "\t.previous\n" \ | |
624 | _ASM_EXTABLE(1b, 3b) \ | |
625 | : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ | |
626 | : "i" (-EFAULT), "r" (__new), "1" (__old) \ | |
627 | : "memory" \ | |
628 | ); \ | |
629 | break; \ | |
630 | } \ | |
631 | case 4: \ | |
632 | { \ | |
11f1a4b9 | 633 | asm volatile("\n" \ |
f09174c5 | 634 | "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n" \ |
11f1a4b9 | 635 | "2:\n" \ |
f09174c5 QR |
636 | "\t.section .fixup, \"ax\"\n" \ |
637 | "3:\tmov %3, %0\n" \ | |
638 | "\tjmp 2b\n" \ | |
639 | "\t.previous\n" \ | |
640 | _ASM_EXTABLE(1b, 3b) \ | |
641 | : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ | |
642 | : "i" (-EFAULT), "r" (__new), "1" (__old) \ | |
643 | : "memory" \ | |
644 | ); \ | |
645 | break; \ | |
646 | } \ | |
647 | case 8: \ | |
648 | { \ | |
649 | if (!IS_ENABLED(CONFIG_X86_64)) \ | |
650 | __cmpxchg_wrong_size(); \ | |
651 | \ | |
11f1a4b9 | 652 | asm volatile("\n" \ |
f09174c5 | 653 | "1:\t" LOCK_PREFIX "cmpxchgq %4, %2\n" \ |
11f1a4b9 | 654 | "2:\n" \ |
f09174c5 QR |
655 | "\t.section .fixup, \"ax\"\n" \ |
656 | "3:\tmov %3, %0\n" \ | |
657 | "\tjmp 2b\n" \ | |
658 | "\t.previous\n" \ | |
659 | _ASM_EXTABLE(1b, 3b) \ | |
660 | : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ | |
661 | : "i" (-EFAULT), "r" (__new), "1" (__old) \ | |
662 | : "memory" \ | |
663 | ); \ | |
664 | break; \ | |
665 | } \ | |
666 | default: \ | |
667 | __cmpxchg_wrong_size(); \ | |
668 | } \ | |
11f1a4b9 | 669 | __uaccess_end(); \ |
f09174c5 QR |
670 | *__uval = __old; \ |
671 | __ret; \ | |
672 | }) | |
673 | ||
674 | #define user_atomic_cmpxchg_inatomic(uval, ptr, old, new) \ | |
675 | ({ \ | |
676 | access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \ | |
677 | __user_atomic_cmpxchg_inatomic((uval), (ptr), \ | |
678 | (old), (new), sizeof(*(ptr))) : \ | |
679 | -EFAULT; \ | |
680 | }) | |
681 | ||
8bc7de0c GC |
682 | /* |
683 | * movsl can be slow when source and dest are not both 8-byte aligned | |
684 | */ | |
685 | #ifdef CONFIG_X86_INTEL_USERCOPY | |
686 | extern struct movsl_mask { | |
687 | int mask; | |
688 | } ____cacheline_aligned_in_smp movsl_mask; | |
689 | #endif | |
690 | ||
22cac167 GC |
691 | #define ARCH_HAS_NOCACHE_UACCESS 1 |
692 | ||
96a388de | 693 | #ifdef CONFIG_X86_32 |
a1ce3928 | 694 | # include <asm/uaccess_32.h> |
96a388de | 695 | #else |
a1ce3928 | 696 | # include <asm/uaccess_64.h> |
96a388de | 697 | #endif |
ca233862 | 698 | |
3df7b41a JB |
699 | unsigned long __must_check _copy_from_user(void *to, const void __user *from, |
700 | unsigned n); | |
7a3d9b0f JB |
701 | unsigned long __must_check _copy_to_user(void __user *to, const void *from, |
702 | unsigned n); | |
3df7b41a | 703 | |
0d025d27 JP |
704 | extern void __compiletime_error("usercopy buffer size is too small") |
705 | __bad_copy_user(void); | |
3df7b41a | 706 | |
0d025d27 | 707 | static inline void copy_user_overflow(int size, unsigned long count) |
3df7b41a JB |
708 | { |
709 | WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); | |
710 | } | |
711 | ||
e6971009 | 712 | static __always_inline unsigned long __must_check |
3df7b41a JB |
713 | copy_from_user(void *to, const void __user *from, unsigned long n) |
714 | { | |
715 | int sz = __compiletime_object_size(to); | |
716 | ||
717 | might_fault(); | |
718 | ||
1771c6e1 AR |
719 | kasan_check_write(to, n); |
720 | ||
5b710f34 KC |
721 | if (likely(sz < 0 || sz >= n)) { |
722 | check_object_size(to, n, false); | |
3df7b41a | 723 | n = _copy_from_user(to, from, n); |
0d025d27 JP |
724 | } else if (!__builtin_constant_p(n)) |
725 | copy_user_overflow(sz, n); | |
3df7b41a | 726 | else |
0d025d27 | 727 | __bad_copy_user(); |
3df7b41a JB |
728 | |
729 | return n; | |
730 | } | |
731 | ||
e6971009 | 732 | static __always_inline unsigned long __must_check |
7a3d9b0f JB |
733 | copy_to_user(void __user *to, const void *from, unsigned long n) |
734 | { | |
735 | int sz = __compiletime_object_size(from); | |
736 | ||
1771c6e1 AR |
737 | kasan_check_read(from, n); |
738 | ||
7a3d9b0f JB |
739 | might_fault(); |
740 | ||
5b710f34 KC |
741 | if (likely(sz < 0 || sz >= n)) { |
742 | check_object_size(from, n, true); | |
7a3d9b0f | 743 | n = _copy_to_user(to, from, n); |
0d025d27 JP |
744 | } else if (!__builtin_constant_p(n)) |
745 | copy_user_overflow(sz, n); | |
7a3d9b0f | 746 | else |
0d025d27 | 747 | __bad_copy_user(); |
7a3d9b0f JB |
748 | |
749 | return n; | |
750 | } | |
751 | ||
10013ebb AK |
752 | /* |
753 | * We rely on the nested NMI work to allow atomic faults from the NMI path; the | |
754 | * nested NMI paths are careful to preserve CR2. | |
755 | * | |
756 | * Caller must use pagefault_enable/disable, or run in interrupt context, | |
757 | * and also do a uaccess_ok() check | |
758 | */ | |
759 | #define __copy_from_user_nmi __copy_from_user_inatomic | |
760 | ||
5b24a7a2 LT |
761 | /* |
762 | * The "unsafe" user accesses aren't really "unsafe", but the naming | |
763 | * is a big fat warning: you have to not only do the access_ok() | |
764 | * checking before using them, but you have to surround them with the | |
765 | * user_access_begin/end() pair. | |
766 | */ | |
767 | #define user_access_begin() __uaccess_begin() | |
768 | #define user_access_end() __uaccess_end() | |
769 | ||
1bd4403d LT |
770 | #define unsafe_put_user(x, ptr, err_label) \ |
771 | do { \ | |
5b24a7a2 LT |
772 | int __pu_err; \ |
773 | __put_user_size((x), (ptr), sizeof(*(ptr)), __pu_err, -EFAULT); \ | |
1bd4403d LT |
774 | if (unlikely(__pu_err)) goto err_label; \ |
775 | } while (0) | |
5b24a7a2 | 776 | |
1bd4403d LT |
777 | #define unsafe_get_user(x, ptr, err_label) \ |
778 | do { \ | |
5b24a7a2 LT |
779 | int __gu_err; \ |
780 | unsigned long __gu_val; \ | |
781 | __get_user_size(__gu_val, (ptr), sizeof(*(ptr)), __gu_err, -EFAULT); \ | |
782 | (x) = (__force __typeof__(*(ptr)))__gu_val; \ | |
1bd4403d LT |
783 | if (unlikely(__gu_err)) goto err_label; \ |
784 | } while (0) | |
5b24a7a2 | 785 | |
1965aae3 | 786 | #endif /* _ASM_X86_UACCESS_H */ |
8174c430 | 787 |