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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 | */ |
c5fe5d80 LT |
44 | static inline int __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit) |
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)) | |
54 | return addr > limit - size; | |
55 | ||
56 | /* Arbitrary sizes? Be careful about overflow */ | |
57 | addr += size; | |
58 | return (addr < size) || (addr > limit); | |
59 | } | |
ca233862 | 60 | |
bc6ca7b3 | 61 | #define __range_not_ok(addr, size, limit) \ |
ca233862 | 62 | ({ \ |
ca233862 | 63 | __chk_user_ptr(addr); \ |
c5fe5d80 | 64 | __chk_range_not_ok((unsigned long __force)(addr), size, limit); \ |
ca233862 GC |
65 | }) |
66 | ||
67 | /** | |
68 | * access_ok: - Checks if a user space pointer is valid | |
69 | * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that | |
70 | * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe | |
71 | * to write to a block, it is always safe to read from it. | |
72 | * @addr: User space pointer to start of block to check | |
73 | * @size: Size of block to check | |
74 | * | |
75 | * Context: User context only. This function may sleep. | |
76 | * | |
77 | * Checks if a pointer to a block of memory in user space is valid. | |
78 | * | |
79 | * Returns true (nonzero) if the memory block may be valid, false (zero) | |
80 | * if it is definitely invalid. | |
81 | * | |
82 | * Note that, depending on architecture, this function probably just | |
83 | * checks that the pointer is in the user space range - after calling | |
84 | * this function, memory access functions may still return -EFAULT. | |
85 | */ | |
bc6ca7b3 AS |
86 | #define access_ok(type, addr, size) \ |
87 | (likely(__range_not_ok(addr, size, user_addr_max()) == 0)) | |
ca233862 GC |
88 | |
89 | /* | |
70627654 PA |
90 | * The exception table consists of pairs of addresses relative to the |
91 | * exception table enty itself: the first is the address of an | |
92 | * instruction that is allowed to fault, and the second is the address | |
93 | * at which the program should continue. No registers are modified, | |
94 | * so it is entirely up to the continuation code to figure out what to | |
95 | * do. | |
ca233862 GC |
96 | * |
97 | * All the routines below use bits of fixup code that are out of line | |
98 | * with the main instruction path. This means when everything is well, | |
99 | * we don't even have to jump over them. Further, they do not intrude | |
100 | * on our cache or tlb entries. | |
101 | */ | |
102 | ||
103 | struct exception_table_entry { | |
70627654 | 104 | int insn, fixup; |
ca233862 | 105 | }; |
70627654 PA |
106 | /* This is not the generic standard exception_table_entry format */ |
107 | #define ARCH_HAS_SORT_EXTABLE | |
108 | #define ARCH_HAS_SEARCH_EXTABLE | |
ca233862 GC |
109 | |
110 | extern int fixup_exception(struct pt_regs *regs); | |
70627654 | 111 | extern int early_fixup_exception(unsigned long *ip); |
ca233862 GC |
112 | |
113 | /* | |
114 | * These are the main single-value transfer routines. They automatically | |
115 | * use the right size if we just have the right pointer type. | |
116 | * | |
117 | * This gets kind of ugly. We want to return _two_ values in "get_user()" | |
118 | * and yet we don't want to do any pointers, because that is too much | |
119 | * of a performance impact. Thus we have a few rather ugly macros here, | |
120 | * and hide all the ugliness from the user. | |
121 | * | |
122 | * The "__xxx" versions of the user access functions are versions that | |
123 | * do not verify the address space, that must have been done previously | |
124 | * with a separate "access_ok()" call (this is used when we do multiple | |
125 | * accesses to the same area of user memory). | |
126 | */ | |
127 | ||
128 | extern int __get_user_1(void); | |
129 | extern int __get_user_2(void); | |
130 | extern int __get_user_4(void); | |
131 | extern int __get_user_8(void); | |
132 | extern int __get_user_bad(void); | |
133 | ||
3578baae PA |
134 | /* |
135 | * This is a type: either unsigned long, if the argument fits into | |
136 | * that type, or otherwise unsigned long long. | |
137 | */ | |
138 | #define __inttype(x) \ | |
139 | __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) | |
865e5b76 GC |
140 | |
141 | /** | |
142 | * get_user: - Get a simple variable from user space. | |
143 | * @x: Variable to store result. | |
144 | * @ptr: Source address, in user space. | |
145 | * | |
146 | * Context: User context only. This function may sleep. | |
147 | * | |
148 | * This macro copies a single simple variable from user space to kernel | |
149 | * space. It supports simple types like char and int, but not larger | |
150 | * data types like structures or arrays. | |
151 | * | |
152 | * @ptr must have pointer-to-simple-variable type, and the result of | |
153 | * dereferencing @ptr must be assignable to @x without a cast. | |
154 | * | |
155 | * Returns zero on success, or -EFAULT on error. | |
156 | * On error, the variable @x is set to zero. | |
ff52c3b0 PA |
157 | */ |
158 | /* | |
3578baae PA |
159 | * Careful: we have to cast the result to the type of the pointer |
160 | * for sign reasons. | |
ff52c3b0 | 161 | * |
f69fa9a9 | 162 | * The use of _ASM_DX as the register specifier is a bit of a |
ff52c3b0 PA |
163 | * simplification, as gcc only cares about it as the starting point |
164 | * and not size: for a 64-bit value it will use %ecx:%edx on 32 bits | |
165 | * (%ecx being the next register in gcc's x86 register sequence), and | |
166 | * %rdx on 64 bits. | |
f69fa9a9 PA |
167 | * |
168 | * Clang/LLVM cares about the size of the register, but still wants | |
169 | * the base register for something that ends up being a pair. | |
865e5b76 | 170 | */ |
865e5b76 GC |
171 | #define get_user(x, ptr) \ |
172 | ({ \ | |
173 | int __ret_gu; \ | |
bdfc017e | 174 | register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \ |
865e5b76 | 175 | __chk_user_ptr(ptr); \ |
3ee1afa3 | 176 | might_fault(); \ |
3578baae PA |
177 | asm volatile("call __get_user_%P3" \ |
178 | : "=a" (__ret_gu), "=r" (__val_gu) \ | |
179 | : "0" (ptr), "i" (sizeof(*(ptr)))); \ | |
180 | (x) = (__typeof__(*(ptr))) __val_gu; \ | |
865e5b76 GC |
181 | __ret_gu; \ |
182 | }) | |
183 | ||
e30a44fd GC |
184 | #define __put_user_x(size, x, ptr, __ret_pu) \ |
185 | asm volatile("call __put_user_" #size : "=a" (__ret_pu) \ | |
4d5d7838 | 186 | : "0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx") |
e30a44fd GC |
187 | |
188 | ||
189 | ||
dc70ddf4 | 190 | #ifdef CONFIG_X86_32 |
18114f61 | 191 | #define __put_user_asm_u64(x, addr, err, errret) \ |
63bcff2a PA |
192 | asm volatile(ASM_STAC "\n" \ |
193 | "1: movl %%eax,0(%2)\n" \ | |
dc70ddf4 | 194 | "2: movl %%edx,4(%2)\n" \ |
63bcff2a | 195 | "3: " ASM_CLAC "\n" \ |
dc70ddf4 GC |
196 | ".section .fixup,\"ax\"\n" \ |
197 | "4: movl %3,%0\n" \ | |
198 | " jmp 3b\n" \ | |
199 | ".previous\n" \ | |
200 | _ASM_EXTABLE(1b, 4b) \ | |
201 | _ASM_EXTABLE(2b, 4b) \ | |
202 | : "=r" (err) \ | |
18114f61 | 203 | : "A" (x), "r" (addr), "i" (errret), "0" (err)) |
e30a44fd | 204 | |
fe40c0af | 205 | #define __put_user_asm_ex_u64(x, addr) \ |
63bcff2a PA |
206 | asm volatile(ASM_STAC "\n" \ |
207 | "1: movl %%eax,0(%1)\n" \ | |
fe40c0af | 208 | "2: movl %%edx,4(%1)\n" \ |
63bcff2a | 209 | "3: " ASM_CLAC "\n" \ |
535c0c34 PA |
210 | _ASM_EXTABLE_EX(1b, 2b) \ |
211 | _ASM_EXTABLE_EX(2b, 3b) \ | |
fe40c0af HS |
212 | : : "A" (x), "r" (addr)) |
213 | ||
e30a44fd GC |
214 | #define __put_user_x8(x, ptr, __ret_pu) \ |
215 | asm volatile("call __put_user_8" : "=a" (__ret_pu) \ | |
216 | : "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx") | |
dc70ddf4 | 217 | #else |
18114f61 | 218 | #define __put_user_asm_u64(x, ptr, retval, errret) \ |
ebe119cd | 219 | __put_user_asm(x, ptr, retval, "q", "", "er", errret) |
fe40c0af | 220 | #define __put_user_asm_ex_u64(x, addr) \ |
ebe119cd | 221 | __put_user_asm_ex(x, addr, "q", "", "er") |
e30a44fd | 222 | #define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu) |
dc70ddf4 GC |
223 | #endif |
224 | ||
e30a44fd GC |
225 | extern void __put_user_bad(void); |
226 | ||
227 | /* | |
228 | * Strange magic calling convention: pointer in %ecx, | |
229 | * value in %eax(:%edx), return value in %eax. clobbers %rbx | |
230 | */ | |
231 | extern void __put_user_1(void); | |
232 | extern void __put_user_2(void); | |
233 | extern void __put_user_4(void); | |
234 | extern void __put_user_8(void); | |
235 | ||
e30a44fd GC |
236 | /** |
237 | * put_user: - Write a simple value into user space. | |
238 | * @x: Value to copy to user space. | |
239 | * @ptr: Destination address, in user space. | |
240 | * | |
241 | * Context: User context only. This function may sleep. | |
242 | * | |
243 | * This macro copies a single simple value from kernel space to user | |
244 | * space. It supports simple types like char and int, but not larger | |
245 | * data types like structures or arrays. | |
246 | * | |
247 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
248 | * to the result of dereferencing @ptr. | |
249 | * | |
250 | * Returns zero on success, or -EFAULT on error. | |
251 | */ | |
252 | #define put_user(x, ptr) \ | |
253 | ({ \ | |
254 | int __ret_pu; \ | |
255 | __typeof__(*(ptr)) __pu_val; \ | |
256 | __chk_user_ptr(ptr); \ | |
3ee1afa3 | 257 | might_fault(); \ |
e30a44fd GC |
258 | __pu_val = x; \ |
259 | switch (sizeof(*(ptr))) { \ | |
260 | case 1: \ | |
261 | __put_user_x(1, __pu_val, ptr, __ret_pu); \ | |
262 | break; \ | |
263 | case 2: \ | |
264 | __put_user_x(2, __pu_val, ptr, __ret_pu); \ | |
265 | break; \ | |
266 | case 4: \ | |
267 | __put_user_x(4, __pu_val, ptr, __ret_pu); \ | |
268 | break; \ | |
269 | case 8: \ | |
270 | __put_user_x8(__pu_val, ptr, __ret_pu); \ | |
271 | break; \ | |
272 | default: \ | |
273 | __put_user_x(X, __pu_val, ptr, __ret_pu); \ | |
274 | break; \ | |
275 | } \ | |
276 | __ret_pu; \ | |
277 | }) | |
278 | ||
dc70ddf4 GC |
279 | #define __put_user_size(x, ptr, size, retval, errret) \ |
280 | do { \ | |
281 | retval = 0; \ | |
282 | __chk_user_ptr(ptr); \ | |
283 | switch (size) { \ | |
284 | case 1: \ | |
285 | __put_user_asm(x, ptr, retval, "b", "b", "iq", errret); \ | |
286 | break; \ | |
287 | case 2: \ | |
288 | __put_user_asm(x, ptr, retval, "w", "w", "ir", errret); \ | |
289 | break; \ | |
290 | case 4: \ | |
4d5d7838 | 291 | __put_user_asm(x, ptr, retval, "l", "k", "ir", errret); \ |
dc70ddf4 GC |
292 | break; \ |
293 | case 8: \ | |
18114f61 HS |
294 | __put_user_asm_u64((__typeof__(*ptr))(x), ptr, retval, \ |
295 | errret); \ | |
dc70ddf4 GC |
296 | break; \ |
297 | default: \ | |
298 | __put_user_bad(); \ | |
299 | } \ | |
300 | } while (0) | |
301 | ||
fe40c0af HS |
302 | #define __put_user_size_ex(x, ptr, size) \ |
303 | do { \ | |
304 | __chk_user_ptr(ptr); \ | |
305 | switch (size) { \ | |
306 | case 1: \ | |
307 | __put_user_asm_ex(x, ptr, "b", "b", "iq"); \ | |
308 | break; \ | |
309 | case 2: \ | |
310 | __put_user_asm_ex(x, ptr, "w", "w", "ir"); \ | |
311 | break; \ | |
312 | case 4: \ | |
313 | __put_user_asm_ex(x, ptr, "l", "k", "ir"); \ | |
314 | break; \ | |
315 | case 8: \ | |
316 | __put_user_asm_ex_u64((__typeof__(*ptr))(x), ptr); \ | |
317 | break; \ | |
318 | default: \ | |
319 | __put_user_bad(); \ | |
320 | } \ | |
321 | } while (0) | |
322 | ||
3f168221 GC |
323 | #ifdef CONFIG_X86_32 |
324 | #define __get_user_asm_u64(x, ptr, retval, errret) (x) = __get_user_bad() | |
fe40c0af | 325 | #define __get_user_asm_ex_u64(x, ptr) (x) = __get_user_bad() |
3f168221 GC |
326 | #else |
327 | #define __get_user_asm_u64(x, ptr, retval, errret) \ | |
328 | __get_user_asm(x, ptr, retval, "q", "", "=r", errret) | |
fe40c0af HS |
329 | #define __get_user_asm_ex_u64(x, ptr) \ |
330 | __get_user_asm_ex(x, ptr, "q", "", "=r") | |
3f168221 GC |
331 | #endif |
332 | ||
333 | #define __get_user_size(x, ptr, size, retval, errret) \ | |
334 | do { \ | |
335 | retval = 0; \ | |
336 | __chk_user_ptr(ptr); \ | |
337 | switch (size) { \ | |
338 | case 1: \ | |
339 | __get_user_asm(x, ptr, retval, "b", "b", "=q", errret); \ | |
340 | break; \ | |
341 | case 2: \ | |
342 | __get_user_asm(x, ptr, retval, "w", "w", "=r", errret); \ | |
343 | break; \ | |
344 | case 4: \ | |
345 | __get_user_asm(x, ptr, retval, "l", "k", "=r", errret); \ | |
346 | break; \ | |
347 | case 8: \ | |
348 | __get_user_asm_u64(x, ptr, retval, errret); \ | |
349 | break; \ | |
350 | default: \ | |
351 | (x) = __get_user_bad(); \ | |
352 | } \ | |
353 | } while (0) | |
354 | ||
355 | #define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \ | |
63bcff2a PA |
356 | asm volatile(ASM_STAC "\n" \ |
357 | "1: mov"itype" %2,%"rtype"1\n" \ | |
358 | "2: " ASM_CLAC "\n" \ | |
3f168221 GC |
359 | ".section .fixup,\"ax\"\n" \ |
360 | "3: mov %3,%0\n" \ | |
361 | " xor"itype" %"rtype"1,%"rtype"1\n" \ | |
362 | " jmp 2b\n" \ | |
363 | ".previous\n" \ | |
364 | _ASM_EXTABLE(1b, 3b) \ | |
365 | : "=r" (err), ltype(x) \ | |
366 | : "m" (__m(addr)), "i" (errret), "0" (err)) | |
367 | ||
fe40c0af HS |
368 | #define __get_user_size_ex(x, ptr, size) \ |
369 | do { \ | |
370 | __chk_user_ptr(ptr); \ | |
371 | switch (size) { \ | |
372 | case 1: \ | |
373 | __get_user_asm_ex(x, ptr, "b", "b", "=q"); \ | |
374 | break; \ | |
375 | case 2: \ | |
376 | __get_user_asm_ex(x, ptr, "w", "w", "=r"); \ | |
377 | break; \ | |
378 | case 4: \ | |
379 | __get_user_asm_ex(x, ptr, "l", "k", "=r"); \ | |
380 | break; \ | |
381 | case 8: \ | |
382 | __get_user_asm_ex_u64(x, ptr); \ | |
383 | break; \ | |
384 | default: \ | |
385 | (x) = __get_user_bad(); \ | |
386 | } \ | |
387 | } while (0) | |
388 | ||
389 | #define __get_user_asm_ex(x, addr, itype, rtype, ltype) \ | |
5e88353d PA |
390 | asm volatile("1: mov"itype" %1,%"rtype"0\n" \ |
391 | "2:\n" \ | |
535c0c34 | 392 | _ASM_EXTABLE_EX(1b, 2b) \ |
fe40c0af HS |
393 | : ltype(x) : "m" (__m(addr))) |
394 | ||
dc70ddf4 GC |
395 | #define __put_user_nocheck(x, ptr, size) \ |
396 | ({ \ | |
16855f87 | 397 | int __pu_err; \ |
dc70ddf4 GC |
398 | __put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \ |
399 | __pu_err; \ | |
400 | }) | |
401 | ||
3f168221 GC |
402 | #define __get_user_nocheck(x, ptr, size) \ |
403 | ({ \ | |
16855f87 | 404 | int __gu_err; \ |
3f168221 GC |
405 | unsigned long __gu_val; \ |
406 | __get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \ | |
407 | (x) = (__force __typeof__(*(ptr)))__gu_val; \ | |
408 | __gu_err; \ | |
409 | }) | |
dc70ddf4 GC |
410 | |
411 | /* FIXME: this hack is definitely wrong -AK */ | |
412 | struct __large_struct { unsigned long buf[100]; }; | |
413 | #define __m(x) (*(struct __large_struct __user *)(x)) | |
414 | ||
415 | /* | |
416 | * Tell gcc we read from memory instead of writing: this is because | |
417 | * we do not write to any memory gcc knows about, so there are no | |
418 | * aliasing issues. | |
419 | */ | |
420 | #define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \ | |
63bcff2a PA |
421 | asm volatile(ASM_STAC "\n" \ |
422 | "1: mov"itype" %"rtype"1,%2\n" \ | |
423 | "2: " ASM_CLAC "\n" \ | |
dc70ddf4 GC |
424 | ".section .fixup,\"ax\"\n" \ |
425 | "3: mov %3,%0\n" \ | |
426 | " jmp 2b\n" \ | |
427 | ".previous\n" \ | |
428 | _ASM_EXTABLE(1b, 3b) \ | |
429 | : "=r"(err) \ | |
430 | : ltype(x), "m" (__m(addr)), "i" (errret), "0" (err)) | |
fe40c0af HS |
431 | |
432 | #define __put_user_asm_ex(x, addr, itype, rtype, ltype) \ | |
5e88353d PA |
433 | asm volatile("1: mov"itype" %"rtype"0,%1\n" \ |
434 | "2:\n" \ | |
535c0c34 | 435 | _ASM_EXTABLE_EX(1b, 2b) \ |
fe40c0af HS |
436 | : : ltype(x), "m" (__m(addr))) |
437 | ||
438 | /* | |
439 | * uaccess_try and catch | |
440 | */ | |
441 | #define uaccess_try do { \ | |
fe40c0af | 442 | current_thread_info()->uaccess_err = 0; \ |
5e88353d | 443 | stac(); \ |
fe40c0af HS |
444 | barrier(); |
445 | ||
446 | #define uaccess_catch(err) \ | |
5e88353d | 447 | clac(); \ |
4fc34901 | 448 | (err) |= (current_thread_info()->uaccess_err ? -EFAULT : 0); \ |
fe40c0af HS |
449 | } while (0) |
450 | ||
8cb834e9 GC |
451 | /** |
452 | * __get_user: - Get a simple variable from user space, with less checking. | |
453 | * @x: Variable to store result. | |
454 | * @ptr: Source address, in user space. | |
455 | * | |
456 | * Context: User context only. This function may sleep. | |
457 | * | |
458 | * This macro copies a single simple variable from user space to kernel | |
459 | * space. It supports simple types like char and int, but not larger | |
460 | * data types like structures or arrays. | |
461 | * | |
462 | * @ptr must have pointer-to-simple-variable type, and the result of | |
463 | * dereferencing @ptr must be assignable to @x without a cast. | |
464 | * | |
465 | * Caller must check the pointer with access_ok() before calling this | |
466 | * function. | |
467 | * | |
468 | * Returns zero on success, or -EFAULT on error. | |
469 | * On error, the variable @x is set to zero. | |
470 | */ | |
471 | ||
472 | #define __get_user(x, ptr) \ | |
473 | __get_user_nocheck((x), (ptr), sizeof(*(ptr))) | |
fe40c0af | 474 | |
8cb834e9 GC |
475 | /** |
476 | * __put_user: - Write a simple value into user space, with less checking. | |
477 | * @x: Value to copy to user space. | |
478 | * @ptr: Destination address, in user space. | |
479 | * | |
480 | * Context: User context only. This function may sleep. | |
481 | * | |
482 | * This macro copies a single simple value from kernel space to user | |
483 | * space. It supports simple types like char and int, but not larger | |
484 | * data types like structures or arrays. | |
485 | * | |
486 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
487 | * to the result of dereferencing @ptr. | |
488 | * | |
489 | * Caller must check the pointer with access_ok() before calling this | |
490 | * function. | |
491 | * | |
492 | * Returns zero on success, or -EFAULT on error. | |
493 | */ | |
494 | ||
495 | #define __put_user(x, ptr) \ | |
496 | __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
dc70ddf4 | 497 | |
8cb834e9 GC |
498 | #define __get_user_unaligned __get_user |
499 | #define __put_user_unaligned __put_user | |
865e5b76 | 500 | |
fe40c0af HS |
501 | /* |
502 | * {get|put}_user_try and catch | |
503 | * | |
504 | * get_user_try { | |
505 | * get_user_ex(...); | |
506 | * } get_user_catch(err) | |
507 | */ | |
508 | #define get_user_try uaccess_try | |
509 | #define get_user_catch(err) uaccess_catch(err) | |
fe40c0af HS |
510 | |
511 | #define get_user_ex(x, ptr) do { \ | |
512 | unsigned long __gue_val; \ | |
513 | __get_user_size_ex((__gue_val), (ptr), (sizeof(*(ptr)))); \ | |
514 | (x) = (__force __typeof__(*(ptr)))__gue_val; \ | |
515 | } while (0) | |
516 | ||
019a1369 HS |
517 | #define put_user_try uaccess_try |
518 | #define put_user_catch(err) uaccess_catch(err) | |
519 | ||
fe40c0af HS |
520 | #define put_user_ex(x, ptr) \ |
521 | __put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) | |
522 | ||
1ac2e6ca RR |
523 | extern unsigned long |
524 | copy_from_user_nmi(void *to, const void __user *from, unsigned long n); | |
92ae03f2 LT |
525 | extern __must_check long |
526 | strncpy_from_user(char *dst, const char __user *src, long count); | |
1ac2e6ca | 527 | |
5723aa99 LT |
528 | extern __must_check long strlen_user(const char __user *str); |
529 | extern __must_check long strnlen_user(const char __user *str, long n); | |
530 | ||
a052858f PA |
531 | unsigned long __must_check clear_user(void __user *mem, unsigned long len); |
532 | unsigned long __must_check __clear_user(void __user *mem, unsigned long len); | |
533 | ||
8bc7de0c GC |
534 | /* |
535 | * movsl can be slow when source and dest are not both 8-byte aligned | |
536 | */ | |
537 | #ifdef CONFIG_X86_INTEL_USERCOPY | |
538 | extern struct movsl_mask { | |
539 | int mask; | |
540 | } ____cacheline_aligned_in_smp movsl_mask; | |
541 | #endif | |
542 | ||
22cac167 GC |
543 | #define ARCH_HAS_NOCACHE_UACCESS 1 |
544 | ||
96a388de | 545 | #ifdef CONFIG_X86_32 |
a1ce3928 | 546 | # include <asm/uaccess_32.h> |
96a388de | 547 | #else |
a1ce3928 | 548 | # include <asm/uaccess_64.h> |
96a388de | 549 | #endif |
ca233862 | 550 | |
3df7b41a JB |
551 | unsigned long __must_check _copy_from_user(void *to, const void __user *from, |
552 | unsigned n); | |
7a3d9b0f JB |
553 | unsigned long __must_check _copy_to_user(void __user *to, const void *from, |
554 | unsigned n); | |
3df7b41a JB |
555 | |
556 | #ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS | |
557 | # define copy_user_diag __compiletime_error | |
558 | #else | |
559 | # define copy_user_diag __compiletime_warning | |
560 | #endif | |
561 | ||
562 | extern void copy_user_diag("copy_from_user() buffer size is too small") | |
563 | copy_from_user_overflow(void); | |
7a3d9b0f JB |
564 | extern void copy_user_diag("copy_to_user() buffer size is too small") |
565 | copy_to_user_overflow(void) __asm__("copy_from_user_overflow"); | |
3df7b41a JB |
566 | |
567 | #undef copy_user_diag | |
568 | ||
569 | #ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS | |
570 | ||
571 | extern void | |
572 | __compiletime_warning("copy_from_user() buffer size is not provably correct") | |
573 | __copy_from_user_overflow(void) __asm__("copy_from_user_overflow"); | |
574 | #define __copy_from_user_overflow(size, count) __copy_from_user_overflow() | |
575 | ||
7a3d9b0f JB |
576 | extern void |
577 | __compiletime_warning("copy_to_user() buffer size is not provably correct") | |
578 | __copy_to_user_overflow(void) __asm__("copy_from_user_overflow"); | |
579 | #define __copy_to_user_overflow(size, count) __copy_to_user_overflow() | |
580 | ||
3df7b41a JB |
581 | #else |
582 | ||
583 | static inline void | |
584 | __copy_from_user_overflow(int size, unsigned long count) | |
585 | { | |
586 | WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count); | |
587 | } | |
588 | ||
7a3d9b0f JB |
589 | #define __copy_to_user_overflow __copy_from_user_overflow |
590 | ||
3df7b41a JB |
591 | #endif |
592 | ||
593 | static inline unsigned long __must_check | |
594 | copy_from_user(void *to, const void __user *from, unsigned long n) | |
595 | { | |
596 | int sz = __compiletime_object_size(to); | |
597 | ||
598 | might_fault(); | |
599 | ||
600 | /* | |
601 | * While we would like to have the compiler do the checking for us | |
602 | * even in the non-constant size case, any false positives there are | |
603 | * a problem (especially when DEBUG_STRICT_USER_COPY_CHECKS, but even | |
604 | * without - the [hopefully] dangerous looking nature of the warning | |
605 | * would make people go look at the respecitive call sites over and | |
606 | * over again just to find that there's no problem). | |
607 | * | |
608 | * And there are cases where it's just not realistic for the compiler | |
609 | * to prove the count to be in range. For example when multiple call | |
610 | * sites of a helper function - perhaps in different source files - | |
611 | * all doing proper range checking, yet the helper function not doing | |
612 | * so again. | |
613 | * | |
614 | * Therefore limit the compile time checking to the constant size | |
615 | * case, and do only runtime checking for non-constant sizes. | |
616 | */ | |
617 | ||
618 | if (likely(sz < 0 || sz >= n)) | |
619 | n = _copy_from_user(to, from, n); | |
620 | else if(__builtin_constant_p(n)) | |
621 | copy_from_user_overflow(); | |
622 | else | |
623 | __copy_from_user_overflow(sz, n); | |
624 | ||
625 | return n; | |
626 | } | |
627 | ||
7a3d9b0f JB |
628 | static inline unsigned long __must_check |
629 | copy_to_user(void __user *to, const void *from, unsigned long n) | |
630 | { | |
631 | int sz = __compiletime_object_size(from); | |
632 | ||
633 | might_fault(); | |
634 | ||
635 | /* See the comment in copy_from_user() above. */ | |
636 | if (likely(sz < 0 || sz >= n)) | |
637 | n = _copy_to_user(to, from, n); | |
638 | else if(__builtin_constant_p(n)) | |
639 | copy_to_user_overflow(); | |
640 | else | |
641 | __copy_to_user_overflow(sz, n); | |
642 | ||
643 | return n; | |
644 | } | |
645 | ||
3df7b41a | 646 | #undef __copy_from_user_overflow |
7a3d9b0f | 647 | #undef __copy_to_user_overflow |
3df7b41a | 648 | |
1965aae3 | 649 | #endif /* _ASM_X86_UACCESS_H */ |
8174c430 | 650 |