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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> | |
8 | #include <linux/thread_info.h> | |
ca233862 GC |
9 | #include <linux/string.h> |
10 | #include <asm/asm.h> | |
11 | #include <asm/page.h> | |
63bcff2a | 12 | #include <asm/smap.h> |
ca233862 GC |
13 | |
14 | #define VERIFY_READ 0 | |
15 | #define VERIFY_WRITE 1 | |
16 | ||
17 | /* | |
18 | * The fs value determines whether argument validity checking should be | |
19 | * performed or not. If get_fs() == USER_DS, checking is performed, with | |
20 | * get_fs() == KERNEL_DS, checking is bypassed. | |
21 | * | |
22 | * For historical reasons, these macros are grossly misnamed. | |
23 | */ | |
24 | ||
25 | #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) | |
26 | ||
27 | #define KERNEL_DS MAKE_MM_SEG(-1UL) | |
9063c61f | 28 | #define USER_DS MAKE_MM_SEG(TASK_SIZE_MAX) |
ca233862 GC |
29 | |
30 | #define get_ds() (KERNEL_DS) | |
31 | #define get_fs() (current_thread_info()->addr_limit) | |
32 | #define set_fs(x) (current_thread_info()->addr_limit = (x)) | |
33 | ||
34 | #define segment_eq(a, b) ((a).seg == (b).seg) | |
35 | ||
4ae73f2d | 36 | #define user_addr_max() (current_thread_info()->addr_limit.seg) |
bc6ca7b3 AS |
37 | #define __addr_ok(addr) \ |
38 | ((unsigned long __force)(addr) < user_addr_max()) | |
002ca169 | 39 | |
ca233862 GC |
40 | /* |
41 | * Test whether a block of memory is a valid user space address. | |
42 | * Returns 0 if the range is valid, nonzero otherwise. | |
ca233862 | 43 | */ |
a740576a | 44 | static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit) |
c5fe5d80 LT |
45 | { |
46 | /* | |
47 | * If we have used "sizeof()" for the size, | |
48 | * we know it won't overflow the limit (but | |
49 | * it might overflow the 'addr', so it's | |
50 | * important to subtract the size from the | |
51 | * limit, not add it to the address). | |
52 | */ | |
53 | if (__builtin_constant_p(size)) | |
7e0f51cb | 54 | return unlikely(addr > limit - size); |
c5fe5d80 LT |
55 | |
56 | /* Arbitrary sizes? Be careful about overflow */ | |
57 | addr += size; | |
7e0f51cb | 58 | if (unlikely(addr < size)) |
a740576a | 59 | return true; |
7e0f51cb | 60 | return unlikely(addr > limit); |
c5fe5d80 | 61 | } |
ca233862 | 62 | |
bc6ca7b3 | 63 | #define __range_not_ok(addr, size, limit) \ |
ca233862 | 64 | ({ \ |
ca233862 | 65 | __chk_user_ptr(addr); \ |
c5fe5d80 | 66 | __chk_range_not_ok((unsigned long __force)(addr), size, limit); \ |
ca233862 GC |
67 | }) |
68 | ||
69 | /** | |
70 | * access_ok: - Checks if a user space pointer is valid | |
71 | * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that | |
72 | * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe | |
73 | * to write to a block, it is always safe to read from it. | |
74 | * @addr: User space pointer to start of block to check | |
75 | * @size: Size of block to check | |
76 | * | |
b3c395ef DH |
77 | * Context: User context only. This function may sleep if pagefaults are |
78 | * enabled. | |
ca233862 GC |
79 | * |
80 | * Checks if a pointer to a block of memory in user space is valid. | |
81 | * | |
82 | * Returns true (nonzero) if the memory block may be valid, false (zero) | |
83 | * if it is definitely invalid. | |
84 | * | |
85 | * Note that, depending on architecture, this function probably just | |
86 | * checks that the pointer is in the user space range - after calling | |
87 | * this function, memory access functions may still return -EFAULT. | |
88 | */ | |
bc6ca7b3 | 89 | #define access_ok(type, addr, size) \ |
a740576a | 90 | likely(!__range_not_ok(addr, size, user_addr_max())) |
ca233862 GC |
91 | |
92 | /* | |
70627654 PA |
93 | * The exception table consists of pairs of addresses relative to the |
94 | * exception table enty itself: the first is the address of an | |
95 | * instruction that is allowed to fault, and the second is the address | |
96 | * at which the program should continue. No registers are modified, | |
97 | * so it is entirely up to the continuation code to figure out what to | |
98 | * do. | |
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 { | |
70627654 | 107 | int insn, fixup; |
ca233862 | 108 | }; |
70627654 PA |
109 | /* This is not the generic standard exception_table_entry format */ |
110 | #define ARCH_HAS_SORT_EXTABLE | |
111 | #define ARCH_HAS_SEARCH_EXTABLE | |
ca233862 GC |
112 | |
113 | extern int fixup_exception(struct pt_regs *regs); | |
70627654 | 114 | extern int early_fixup_exception(unsigned long *ip); |
ca233862 GC |
115 | |
116 | /* | |
117 | * These are the main single-value transfer routines. They automatically | |
118 | * use the right size if we just have the right pointer type. | |
119 | * | |
120 | * This gets kind of ugly. We want to return _two_ values in "get_user()" | |
121 | * and yet we don't want to do any pointers, because that is too much | |
122 | * of a performance impact. Thus we have a few rather ugly macros here, | |
123 | * and hide all the ugliness from the user. | |
124 | * | |
125 | * The "__xxx" versions of the user access functions are versions that | |
126 | * do not verify the address space, that must have been done previously | |
127 | * with a separate "access_ok()" call (this is used when we do multiple | |
128 | * accesses to the same area of user memory). | |
129 | */ | |
130 | ||
131 | extern int __get_user_1(void); | |
132 | extern int __get_user_2(void); | |
133 | extern int __get_user_4(void); | |
134 | extern int __get_user_8(void); | |
135 | extern int __get_user_bad(void); | |
136 | ||
3578baae PA |
137 | /* |
138 | * This is a type: either unsigned long, if the argument fits into | |
139 | * that type, or otherwise unsigned long long. | |
140 | */ | |
141 | #define __inttype(x) \ | |
142 | __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) | |
865e5b76 GC |
143 | |
144 | /** | |
145 | * get_user: - Get a simple variable from user space. | |
146 | * @x: Variable to store result. | |
147 | * @ptr: Source address, in user space. | |
148 | * | |
b3c395ef DH |
149 | * Context: User context only. This function may sleep if pagefaults are |
150 | * enabled. | |
865e5b76 GC |
151 | * |
152 | * This macro copies a single simple variable from user space to kernel | |
153 | * space. It supports simple types like char and int, but not larger | |
154 | * data types like structures or arrays. | |
155 | * | |
156 | * @ptr must have pointer-to-simple-variable type, and the result of | |
157 | * dereferencing @ptr must be assignable to @x without a cast. | |
158 | * | |
159 | * Returns zero on success, or -EFAULT on error. | |
160 | * On error, the variable @x is set to zero. | |
ff52c3b0 PA |
161 | */ |
162 | /* | |
3578baae PA |
163 | * Careful: we have to cast the result to the type of the pointer |
164 | * for sign reasons. | |
ff52c3b0 | 165 | * |
f69fa9a9 | 166 | * The use of _ASM_DX as the register specifier is a bit of a |
ff52c3b0 PA |
167 | * simplification, as gcc only cares about it as the starting point |
168 | * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits | |
169 | * (%ecx being the next register in gcc's x86 register sequence), and | |
170 | * %rdx on 64 bits. | |
f69fa9a9 PA |
171 | * |
172 | * Clang/LLVM cares about the size of the register, but still wants | |
173 | * the base register for something that ends up being a pair. | |
865e5b76 | 174 | */ |
865e5b76 GC |
175 | #define get_user(x, ptr) \ |
176 | ({ \ | |
177 | int __ret_gu; \ | |
bdfc017e | 178 | register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \ |
865e5b76 | 179 | __chk_user_ptr(ptr); \ |
3ee1afa3 | 180 | might_fault(); \ |
3578baae PA |
181 | asm volatile("call __get_user_%P3" \ |
182 | : "=a" (__ret_gu), "=r" (__val_gu) \ | |
183 | : "0" (ptr), "i" (sizeof(*(ptr)))); \ | |
e182c570 | 184 | (x) = (__force __typeof__(*(ptr))) __val_gu; \ |
a76cf66e | 185 | __builtin_expect(__ret_gu, 0); \ |
865e5b76 GC |
186 | }) |
187 | ||
e30a44fd GC |
188 | #define __put_user_x(size, x, ptr, __ret_pu) \ |
189 | asm volatile("call __put_user_" #size : "=a" (__ret_pu) \ | |
4d5d7838 | 190 | : "0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx") |
e30a44fd GC |
191 | |
192 | ||
193 | ||
dc70ddf4 | 194 | #ifdef CONFIG_X86_32 |
18114f61 | 195 | #define __put_user_asm_u64(x, addr, err, errret) \ |
63bcff2a PA |
196 | asm volatile(ASM_STAC "\n" \ |
197 | "1: movl %%eax,0(%2)\n" \ | |
dc70ddf4 | 198 | "2: movl %%edx,4(%2)\n" \ |
63bcff2a | 199 | "3: " ASM_CLAC "\n" \ |
dc70ddf4 GC |
200 | ".section .fixup,\"ax\"\n" \ |
201 | "4: movl %3,%0\n" \ | |
202 | " jmp 3b\n" \ | |
203 | ".previous\n" \ | |
204 | _ASM_EXTABLE(1b, 4b) \ | |
205 | _ASM_EXTABLE(2b, 4b) \ | |
206 | : "=r" (err) \ | |
18114f61 | 207 | : "A" (x), "r" (addr), "i" (errret), "0" (err)) |
e30a44fd | 208 | |
fe40c0af | 209 | #define __put_user_asm_ex_u64(x, addr) \ |
63bcff2a PA |
210 | asm volatile(ASM_STAC "\n" \ |
211 | "1: movl %%eax,0(%1)\n" \ | |
fe40c0af | 212 | "2: movl %%edx,4(%1)\n" \ |
63bcff2a | 213 | "3: " ASM_CLAC "\n" \ |
535c0c34 PA |
214 | _ASM_EXTABLE_EX(1b, 2b) \ |
215 | _ASM_EXTABLE_EX(2b, 3b) \ | |
fe40c0af HS |
216 | : : "A" (x), "r" (addr)) |
217 | ||
e30a44fd GC |
218 | #define __put_user_x8(x, ptr, __ret_pu) \ |
219 | asm volatile("call __put_user_8" : "=a" (__ret_pu) \ | |
220 | : "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx") | |
dc70ddf4 | 221 | #else |
18114f61 | 222 | #define __put_user_asm_u64(x, ptr, retval, errret) \ |
ebe119cd | 223 | __put_user_asm(x, ptr, retval, "q", "", "er", errret) |
fe40c0af | 224 | #define __put_user_asm_ex_u64(x, addr) \ |
ebe119cd | 225 | __put_user_asm_ex(x, addr, "q", "", "er") |
e30a44fd | 226 | #define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu) |
dc70ddf4 GC |
227 | #endif |
228 | ||
e30a44fd GC |
229 | extern void __put_user_bad(void); |
230 | ||
231 | /* | |
232 | * Strange magic calling convention: pointer in %ecx, | |
233 | * value in %eax(:%edx), return value in %eax. clobbers %rbx | |
234 | */ | |
235 | extern void __put_user_1(void); | |
236 | extern void __put_user_2(void); | |
237 | extern void __put_user_4(void); | |
238 | extern void __put_user_8(void); | |
239 | ||
e30a44fd GC |
240 | /** |
241 | * put_user: - Write a simple value into user space. | |
242 | * @x: Value to copy to user space. | |
243 | * @ptr: Destination address, in user space. | |
244 | * | |
b3c395ef DH |
245 | * Context: User context only. This function may sleep if pagefaults are |
246 | * enabled. | |
e30a44fd GC |
247 | * |
248 | * This macro copies a single simple value from kernel space to user | |
249 | * space. It supports simple types like char and int, but not larger | |
250 | * data types like structures or arrays. | |
251 | * | |
252 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
253 | * to the result of dereferencing @ptr. | |
254 | * | |
255 | * Returns zero on success, or -EFAULT on error. | |
256 | */ | |
257 | #define put_user(x, ptr) \ | |
258 | ({ \ | |
259 | int __ret_pu; \ | |
260 | __typeof__(*(ptr)) __pu_val; \ | |
261 | __chk_user_ptr(ptr); \ | |
3ee1afa3 | 262 | might_fault(); \ |
e30a44fd GC |
263 | __pu_val = x; \ |
264 | switch (sizeof(*(ptr))) { \ | |
265 | case 1: \ | |
266 | __put_user_x(1, __pu_val, ptr, __ret_pu); \ | |
267 | break; \ | |
268 | case 2: \ | |
269 | __put_user_x(2, __pu_val, ptr, __ret_pu); \ | |
270 | break; \ | |
271 | case 4: \ | |
272 | __put_user_x(4, __pu_val, ptr, __ret_pu); \ | |
273 | break; \ | |
274 | case 8: \ | |
275 | __put_user_x8(__pu_val, ptr, __ret_pu); \ | |
276 | break; \ | |
277 | default: \ | |
278 | __put_user_x(X, __pu_val, ptr, __ret_pu); \ | |
279 | break; \ | |
280 | } \ | |
a76cf66e | 281 | __builtin_expect(__ret_pu, 0); \ |
e30a44fd GC |
282 | }) |
283 | ||
dc70ddf4 GC |
284 | #define __put_user_size(x, ptr, size, retval, errret) \ |
285 | do { \ | |
286 | retval = 0; \ | |
287 | __chk_user_ptr(ptr); \ | |
288 | switch (size) { \ | |
289 | case 1: \ | |
290 | __put_user_asm(x, ptr, retval, "b", "b", "iq", errret); \ | |
291 | break; \ | |
292 | case 2: \ | |
293 | __put_user_asm(x, ptr, retval, "w", "w", "ir", errret); \ | |
294 | break; \ | |
295 | case 4: \ | |
4d5d7838 | 296 | __put_user_asm(x, ptr, retval, "l", "k", "ir", errret); \ |
dc70ddf4 GC |
297 | break; \ |
298 | case 8: \ | |
18114f61 HS |
299 | __put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval, \ |
300 | errret); \ | |
dc70ddf4 GC |
301 | break; \ |
302 | default: \ | |
303 | __put_user_bad(); \ | |
304 | } \ | |
305 | } while (0) | |
306 | ||
fe40c0af HS |
307 | #define __put_user_size_ex(x, ptr, size) \ |
308 | do { \ | |
309 | __chk_user_ptr(ptr); \ | |
310 | switch (size) { \ | |
311 | case 1: \ | |
312 | __put_user_asm_ex(x, ptr, "b", "b", "iq"); \ | |
313 | break; \ | |
314 | case 2: \ | |
315 | __put_user_asm_ex(x, ptr, "w", "w", "ir"); \ | |
316 | break; \ | |
317 | case 4: \ | |
318 | __put_user_asm_ex(x, ptr, "l", "k", "ir"); \ | |
319 | break; \ | |
320 | case 8: \ | |
321 | __put_user_asm_ex_u64((__typeof__(*ptr))(x), ptr); \ | |
322 | break; \ | |
323 | default: \ | |
324 | __put_user_bad(); \ | |
325 | } \ | |
326 | } while (0) | |
327 | ||
3f168221 GC |
328 | #ifdef CONFIG_X86_32 |
329 | #define __get_user_asm_u64(x, ptr, retval, errret) (x) = __get_user_bad() | |
fe40c0af | 330 | #define __get_user_asm_ex_u64(x, ptr) (x) = __get_user_bad() |
3f168221 GC |
331 | #else |
332 | #define __get_user_asm_u64(x, ptr, retval, errret) \ | |
333 | __get_user_asm(x, ptr, retval, "q", "", "=r", errret) | |
fe40c0af HS |
334 | #define __get_user_asm_ex_u64(x, ptr) \ |
335 | __get_user_asm_ex(x, ptr, "q", "", "=r") | |
3f168221 GC |
336 | #endif |
337 | ||
338 | #define __get_user_size(x, ptr, size, retval, errret) \ | |
339 | do { \ | |
340 | retval = 0; \ | |
341 | __chk_user_ptr(ptr); \ | |
342 | switch (size) { \ | |
343 | case 1: \ | |
344 | __get_user_asm(x, ptr, retval, "b", "b", "=q", errret); \ | |
345 | break; \ | |
346 | case 2: \ | |
347 | __get_user_asm(x, ptr, retval, "w", "w", "=r", errret); \ | |
348 | break; \ | |
349 | case 4: \ | |
350 | __get_user_asm(x, ptr, retval, "l", "k", "=r", errret); \ | |
351 | break; \ | |
352 | case 8: \ | |
353 | __get_user_asm_u64(x, ptr, retval, errret); \ | |
354 | break; \ | |
355 | default: \ | |
356 | (x) = __get_user_bad(); \ | |
357 | } \ | |
358 | } while (0) | |
359 | ||
360 | #define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \ | |
63bcff2a PA |
361 | asm volatile(ASM_STAC "\n" \ |
362 | "1: mov"itype" %2,%"rtype"1\n" \ | |
363 | "2: " ASM_CLAC "\n" \ | |
3f168221 GC |
364 | ".section .fixup,\"ax\"\n" \ |
365 | "3: mov %3,%0\n" \ | |
366 | " xor"itype" %"rtype"1,%"rtype"1\n" \ | |
367 | " jmp 2b\n" \ | |
368 | ".previous\n" \ | |
369 | _ASM_EXTABLE(1b, 3b) \ | |
370 | : "=r" (err), ltype(x) \ | |
371 | : "m" (__m(addr)), "i" (errret), "0" (err)) | |
372 | ||
fe40c0af HS |
373 | #define __get_user_size_ex(x, ptr, size) \ |
374 | do { \ | |
375 | __chk_user_ptr(ptr); \ | |
376 | switch (size) { \ | |
377 | case 1: \ | |
378 | __get_user_asm_ex(x, ptr, "b", "b", "=q"); \ | |
379 | break; \ | |
380 | case 2: \ | |
381 | __get_user_asm_ex(x, ptr, "w", "w", "=r"); \ | |
382 | break; \ | |
383 | case 4: \ | |
384 | __get_user_asm_ex(x, ptr, "l", "k", "=r"); \ | |
385 | break; \ | |
386 | case 8: \ | |
387 | __get_user_asm_ex_u64(x, ptr); \ | |
388 | break; \ | |
389 | default: \ | |
390 | (x) = __get_user_bad(); \ | |
391 | } \ | |
392 | } while (0) | |
393 | ||
394 | #define __get_user_asm_ex(x, addr, itype, rtype, ltype) \ | |
5e88353d PA |
395 | asm volatile("1: mov"itype" %1,%"rtype"0\n" \ |
396 | "2:\n" \ | |
535c0c34 | 397 | _ASM_EXTABLE_EX(1b, 2b) \ |
fe40c0af HS |
398 | : ltype(x) : "m" (__m(addr))) |
399 | ||
dc70ddf4 GC |
400 | #define __put_user_nocheck(x, ptr, size) \ |
401 | ({ \ | |
16855f87 | 402 | int __pu_err; \ |
dc70ddf4 | 403 | __put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \ |
a76cf66e | 404 | __builtin_expect(__pu_err, 0); \ |
dc70ddf4 GC |
405 | }) |
406 | ||
3f168221 GC |
407 | #define __get_user_nocheck(x, ptr, size) \ |
408 | ({ \ | |
16855f87 | 409 | int __gu_err; \ |
3f168221 GC |
410 | unsigned long __gu_val; \ |
411 | __get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \ | |
412 | (x) = (__force __typeof__(*(ptr)))__gu_val; \ | |
a76cf66e | 413 | __builtin_expect(__gu_err, 0); \ |
3f168221 | 414 | }) |
dc70ddf4 GC |
415 | |
416 | /* FIXME: this hack is definitely wrong -AK */ | |
417 | struct __large_struct { unsigned long buf[100]; }; | |
418 | #define __m(x) (*(struct __large_struct __user *)(x)) | |
419 | ||
420 | /* | |
421 | * Tell gcc we read from memory instead of writing: this is because | |
422 | * we do not write to any memory gcc knows about, so there are no | |
423 | * aliasing issues. | |
424 | */ | |
425 | #define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \ | |
63bcff2a PA |
426 | asm volatile(ASM_STAC "\n" \ |
427 | "1: mov"itype" %"rtype"1,%2\n" \ | |
428 | "2: " ASM_CLAC "\n" \ | |
dc70ddf4 GC |
429 | ".section .fixup,\"ax\"\n" \ |
430 | "3: mov %3,%0\n" \ | |
431 | " jmp 2b\n" \ | |
432 | ".previous\n" \ | |
433 | _ASM_EXTABLE(1b, 3b) \ | |
434 | : "=r"(err) \ | |
435 | : ltype(x), "m" (__m(addr)), "i" (errret), "0" (err)) | |
fe40c0af HS |
436 | |
437 | #define __put_user_asm_ex(x, addr, itype, rtype, ltype) \ | |
5e88353d PA |
438 | asm volatile("1: mov"itype" %"rtype"0,%1\n" \ |
439 | "2:\n" \ | |
535c0c34 | 440 | _ASM_EXTABLE_EX(1b, 2b) \ |
fe40c0af HS |
441 | : : ltype(x), "m" (__m(addr))) |
442 | ||
443 | /* | |
444 | * uaccess_try and catch | |
445 | */ | |
446 | #define uaccess_try do { \ | |
fe40c0af | 447 | current_thread_info()->uaccess_err = 0; \ |
5e88353d | 448 | stac(); \ |
fe40c0af HS |
449 | barrier(); |
450 | ||
451 | #define uaccess_catch(err) \ | |
5e88353d | 452 | clac(); \ |
4fc34901 | 453 | (err) |= (current_thread_info()->uaccess_err ? -EFAULT : 0); \ |
fe40c0af HS |
454 | } while (0) |
455 | ||
8cb834e9 GC |
456 | /** |
457 | * __get_user: - Get a simple variable from user space, with less checking. | |
458 | * @x: Variable to store result. | |
459 | * @ptr: Source address, in user space. | |
460 | * | |
b3c395ef DH |
461 | * Context: User context only. This function may sleep if pagefaults are |
462 | * enabled. | |
8cb834e9 GC |
463 | * |
464 | * This macro copies a single simple variable from user space to kernel | |
465 | * space. It supports simple types like char and int, but not larger | |
466 | * data types like structures or arrays. | |
467 | * | |
468 | * @ptr must have pointer-to-simple-variable type, and the result of | |
469 | * dereferencing @ptr must be assignable to @x without a cast. | |
470 | * | |
471 | * Caller must check the pointer with access_ok() before calling this | |
472 | * function. | |
473 | * | |
474 | * Returns zero on success, or -EFAULT on error. | |
475 | * On error, the variable @x is set to zero. | |
476 | */ | |
477 | ||
478 | #define __get_user(x, ptr) \ | |
479 | __get_user_nocheck((x), (ptr), sizeof(*(ptr))) | |
fe40c0af | 480 | |
8cb834e9 GC |
481 | /** |
482 | * __put_user: - Write a simple value into user space, with less checking. | |
483 | * @x: Value to copy to user space. | |
484 | * @ptr: Destination address, in user space. | |
485 | * | |
b3c395ef DH |
486 | * Context: User context only. This function may sleep if pagefaults are |
487 | * enabled. | |
8cb834e9 GC |
488 | * |
489 | * This macro copies a single simple value from kernel space to user | |
490 | * space. It supports simple types like char and int, but not larger | |
491 | * data types like structures or arrays. | |
492 | * | |
493 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
494 | * to the result of dereferencing @ptr. | |
495 | * | |
496 | * Caller must check the pointer with access_ok() before calling this | |
497 | * function. | |
498 | * | |
499 | * Returns zero on success, or -EFAULT on error. | |
500 | */ | |
501 | ||
502 | #define __put_user(x, ptr) \ | |
503 | __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
dc70ddf4 | 504 | |
8cb834e9 GC |
505 | #define __get_user_unaligned __get_user |
506 | #define __put_user_unaligned __put_user | |
865e5b76 | 507 | |
fe40c0af HS |
508 | /* |
509 | * {get|put}_user_try and catch | |
510 | * | |
511 | * get_user_try { | |
512 | * get_user_ex(...); | |
513 | * } get_user_catch(err) | |
514 | */ | |
515 | #define get_user_try uaccess_try | |
516 | #define get_user_catch(err) uaccess_catch(err) | |
fe40c0af HS |
517 | |
518 | #define get_user_ex(x, ptr) do { \ | |
519 | unsigned long __gue_val; \ | |
520 | __get_user_size_ex((__gue_val), (ptr), (sizeof(*(ptr)))); \ | |
521 | (x) = (__force __typeof__(*(ptr)))__gue_val; \ | |
522 | } while (0) | |
523 | ||
019a1369 HS |
524 | #define put_user_try uaccess_try |
525 | #define put_user_catch(err) uaccess_catch(err) | |
526 | ||
fe40c0af HS |
527 | #define put_user_ex(x, ptr) \ |
528 | __put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
529 | ||
1ac2e6ca RR |
530 | extern unsigned long |
531 | copy_from_user_nmi(void *to, const void __user *from, unsigned long n); | |
92ae03f2 LT |
532 | extern __must_check long |
533 | strncpy_from_user(char *dst, const char __user *src, long count); | |
1ac2e6ca | 534 | |
5723aa99 LT |
535 | extern __must_check long strlen_user(const char __user *str); |
536 | extern __must_check long strnlen_user(const char __user *str, long n); | |
537 | ||
a052858f PA |
538 | unsigned long __must_check clear_user(void __user *mem, unsigned long len); |
539 | unsigned long __must_check __clear_user(void __user *mem, unsigned long len); | |
540 | ||
f09174c5 QR |
541 | extern void __cmpxchg_wrong_size(void) |
542 | __compiletime_error("Bad argument size for cmpxchg"); | |
543 | ||
544 | #define __user_atomic_cmpxchg_inatomic(uval, ptr, old, new, size) \ | |
545 | ({ \ | |
546 | int __ret = 0; \ | |
547 | __typeof__(ptr) __uval = (uval); \ | |
548 | __typeof__(*(ptr)) __old = (old); \ | |
549 | __typeof__(*(ptr)) __new = (new); \ | |
550 | switch (size) { \ | |
551 | case 1: \ | |
552 | { \ | |
553 | asm volatile("\t" ASM_STAC "\n" \ | |
554 | "1:\t" LOCK_PREFIX "cmpxchgb %4, %2\n" \ | |
555 | "2:\t" ASM_CLAC "\n" \ | |
556 | "\t.section .fixup, \"ax\"\n" \ | |
557 | "3:\tmov %3, %0\n" \ | |
558 | "\tjmp 2b\n" \ | |
559 | "\t.previous\n" \ | |
560 | _ASM_EXTABLE(1b, 3b) \ | |
561 | : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ | |
562 | : "i" (-EFAULT), "q" (__new), "1" (__old) \ | |
563 | : "memory" \ | |
564 | ); \ | |
565 | break; \ | |
566 | } \ | |
567 | case 2: \ | |
568 | { \ | |
569 | asm volatile("\t" ASM_STAC "\n" \ | |
570 | "1:\t" LOCK_PREFIX "cmpxchgw %4, %2\n" \ | |
571 | "2:\t" ASM_CLAC "\n" \ | |
572 | "\t.section .fixup, \"ax\"\n" \ | |
573 | "3:\tmov %3, %0\n" \ | |
574 | "\tjmp 2b\n" \ | |
575 | "\t.previous\n" \ | |
576 | _ASM_EXTABLE(1b, 3b) \ | |
577 | : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ | |
578 | : "i" (-EFAULT), "r" (__new), "1" (__old) \ | |
579 | : "memory" \ | |
580 | ); \ | |
581 | break; \ | |
582 | } \ | |
583 | case 4: \ | |
584 | { \ | |
585 | asm volatile("\t" ASM_STAC "\n" \ | |
586 | "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n" \ | |
587 | "2:\t" ASM_CLAC "\n" \ | |
588 | "\t.section .fixup, \"ax\"\n" \ | |
589 | "3:\tmov %3, %0\n" \ | |
590 | "\tjmp 2b\n" \ | |
591 | "\t.previous\n" \ | |
592 | _ASM_EXTABLE(1b, 3b) \ | |
593 | : "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \ | |
594 | : "i" (-EFAULT), "r" (__new), "1" (__old) \ | |
595 | : "memory" \ | |
596 | ); \ | |
597 | break; \ | |
598 | } \ | |
599 | case 8: \ | |
600 | { \ | |
601 | if (!IS_ENABLED(CONFIG_X86_64)) \ | |
602 | __cmpxchg_wrong_size(); \ | |
603 | \ | |
604 | asm volatile("\t" ASM_STAC "\n" \ | |
605 | "1:\t" LOCK_PREFIX "cmpxchgq %4, %2\n" \ | |
606 | "2:\t" ASM_CLAC "\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 | default: \ | |
619 | __cmpxchg_wrong_size(); \ | |
620 | } \ | |
621 | *__uval = __old; \ | |
622 | __ret; \ | |
623 | }) | |
624 | ||
625 | #define user_atomic_cmpxchg_inatomic(uval, ptr, old, new) \ | |
626 | ({ \ | |
627 | access_ok(VERIFY_WRITE, (ptr), sizeof(*(ptr))) ? \ | |
628 | __user_atomic_cmpxchg_inatomic((uval), (ptr), \ | |
629 | (old), (new), sizeof(*(ptr))) : \ | |
630 | -EFAULT; \ | |
631 | }) | |
632 | ||
8bc7de0c GC |
633 | /* |
634 | * movsl can be slow when source and dest are not both 8-byte aligned | |
635 | */ | |
636 | #ifdef CONFIG_X86_INTEL_USERCOPY | |
637 | extern struct movsl_mask { | |
638 | int mask; | |
639 | } ____cacheline_aligned_in_smp movsl_mask; | |
640 | #endif | |
641 | ||
22cac167 GC |
642 | #define ARCH_HAS_NOCACHE_UACCESS 1 |
643 | ||
96a388de | 644 | #ifdef CONFIG_X86_32 |
a1ce3928 | 645 | # include <asm/uaccess_32.h> |
96a388de | 646 | #else |
a1ce3928 | 647 | # include <asm/uaccess_64.h> |
96a388de | 648 | #endif |
ca233862 | 649 | |
3df7b41a JB |
650 | unsigned long __must_check _copy_from_user(void *to, const void __user *from, |
651 | unsigned n); | |
7a3d9b0f JB |
652 | unsigned long __must_check _copy_to_user(void __user *to, const void *from, |
653 | unsigned n); | |
3df7b41a JB |
654 | |
655 | #ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS | |
656 | # define copy_user_diag __compiletime_error | |
657 | #else | |
658 | # define copy_user_diag __compiletime_warning | |
659 | #endif | |
660 | ||
661 | extern void copy_user_diag("copy_from_user() buffer size is too small") | |
662 | copy_from_user_overflow(void); | |
7a3d9b0f JB |
663 | extern void copy_user_diag("copy_to_user() buffer size is too small") |
664 | copy_to_user_overflow(void) __asm__("copy_from_user_overflow"); | |
3df7b41a JB |
665 | |
666 | #undef copy_user_diag | |
667 | ||
668 | #ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS | |
669 | ||
670 | extern void | |
671 | __compiletime_warning("copy_from_user() buffer size is not provably correct") | |
672 | __copy_from_user_overflow(void) __asm__("copy_from_user_overflow"); | |
673 | #define __copy_from_user_overflow(size, count) __copy_from_user_overflow() | |
674 | ||
7a3d9b0f JB |
675 | extern void |
676 | __compiletime_warning("copy_to_user() buffer size is not provably correct") | |
677 | __copy_to_user_overflow(void) __asm__("copy_from_user_overflow"); | |
678 | #define __copy_to_user_overflow(size, count) __copy_to_user_overflow() | |
679 | ||
3df7b41a JB |
680 | #else |
681 | ||
682 | static inline void | |
683 | __copy_from_user_overflow(int size, unsigned long count) | |
684 | { | |
685 | WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); | |
686 | } | |
687 | ||
7a3d9b0f JB |
688 | #define __copy_to_user_overflow __copy_from_user_overflow |
689 | ||
3df7b41a JB |
690 | #endif |
691 | ||
692 | static inline unsigned long __must_check | |
693 | copy_from_user(void *to, const void __user *from, unsigned long n) | |
694 | { | |
695 | int sz = __compiletime_object_size(to); | |
696 | ||
697 | might_fault(); | |
698 | ||
699 | /* | |
700 | * While we would like to have the compiler do the checking for us | |
701 | * even in the non-constant size case, any false positives there are | |
702 | * a problem (especially when DEBUG_STRICT_USER_COPY_CHECKS, but even | |
703 | * without - the [hopefully] dangerous looking nature of the warning | |
704 | * would make people go look at the respecitive call sites over and | |
705 | * over again just to find that there's no problem). | |
706 | * | |
707 | * And there are cases where it's just not realistic for the compiler | |
708 | * to prove the count to be in range. For example when multiple call | |
709 | * sites of a helper function - perhaps in different source files - | |
710 | * all doing proper range checking, yet the helper function not doing | |
711 | * so again. | |
712 | * | |
713 | * Therefore limit the compile time checking to the constant size | |
714 | * case, and do only runtime checking for non-constant sizes. | |
715 | */ | |
716 | ||
717 | if (likely(sz < 0 || sz >= n)) | |
718 | n = _copy_from_user(to, from, n); | |
719 | else if(__builtin_constant_p(n)) | |
720 | copy_from_user_overflow(); | |
721 | else | |
722 | __copy_from_user_overflow(sz, n); | |
723 | ||
724 | return n; | |
725 | } | |
726 | ||
7a3d9b0f JB |
727 | static inline unsigned long __must_check |
728 | copy_to_user(void __user *to, const void *from, unsigned long n) | |
729 | { | |
730 | int sz = __compiletime_object_size(from); | |
731 | ||
732 | might_fault(); | |
733 | ||
734 | /* See the comment in copy_from_user() above. */ | |
735 | if (likely(sz < 0 || sz >= n)) | |
736 | n = _copy_to_user(to, from, n); | |
737 | else if(__builtin_constant_p(n)) | |
738 | copy_to_user_overflow(); | |
739 | else | |
740 | __copy_to_user_overflow(sz, n); | |
741 | ||
742 | return n; | |
743 | } | |
744 | ||
3df7b41a | 745 | #undef __copy_from_user_overflow |
7a3d9b0f | 746 | #undef __copy_to_user_overflow |
3df7b41a | 747 | |
1965aae3 | 748 | #endif /* _ASM_X86_UACCESS_H */ |
8174c430 | 749 |