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1da177e4 LT |
1 | #ifndef __i386_UACCESS_H |
2 | #define __i386_UACCESS_H | |
3 | ||
4 | /* | |
5 | * User space memory access functions | |
6 | */ | |
1da177e4 LT |
7 | #include <linux/errno.h> |
8 | #include <linux/thread_info.h> | |
9 | #include <linux/prefetch.h> | |
10 | #include <linux/string.h> | |
11 | #include <asm/page.h> | |
12 | ||
13 | #define VERIFY_READ 0 | |
14 | #define VERIFY_WRITE 1 | |
15 | ||
16 | /* | |
17 | * The fs value determines whether argument validity checking should be | |
18 | * performed or not. If get_fs() == USER_DS, checking is performed, with | |
19 | * get_fs() == KERNEL_DS, checking is bypassed. | |
20 | * | |
21 | * For historical reasons, these macros are grossly misnamed. | |
22 | */ | |
23 | ||
24 | #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) }) | |
25 | ||
26 | ||
27 | #define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFUL) | |
28 | #define USER_DS MAKE_MM_SEG(PAGE_OFFSET) | |
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 | ||
36 | /* | |
37 | * movsl can be slow when source and dest are not both 8-byte aligned | |
38 | */ | |
39 | #ifdef CONFIG_X86_INTEL_USERCOPY | |
40 | extern struct movsl_mask { | |
41 | int mask; | |
42 | } ____cacheline_aligned_in_smp movsl_mask; | |
43 | #endif | |
44 | ||
45 | #define __addr_ok(addr) ((unsigned long __force)(addr) < (current_thread_info()->addr_limit.seg)) | |
46 | ||
47 | /* | |
48 | * Test whether a block of memory is a valid user space address. | |
49 | * Returns 0 if the range is valid, nonzero otherwise. | |
50 | * | |
51 | * This is equivalent to the following test: | |
52 | * (u33)addr + (u33)size >= (u33)current->addr_limit.seg | |
53 | * | |
54 | * This needs 33-bit arithmetic. We have a carry... | |
55 | */ | |
56 | #define __range_ok(addr,size) ({ \ | |
16cf5b39 | 57 | unsigned long flag,roksum; \ |
1da177e4 LT |
58 | __chk_user_ptr(addr); \ |
59 | asm("addl %3,%1 ; sbbl %0,%0; cmpl %1,%4; sbbl $0,%0" \ | |
16cf5b39 | 60 | :"=&r" (flag), "=r" (roksum) \ |
722f4f5b | 61 | :"1" (addr),"g" ((int)(size)),"rm" (current_thread_info()->addr_limit.seg)); \ |
1da177e4 LT |
62 | flag; }) |
63 | ||
64 | /** | |
65 | * access_ok: - Checks if a user space pointer is valid | |
66 | * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that | |
67 | * %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe | |
68 | * to write to a block, it is always safe to read from it. | |
69 | * @addr: User space pointer to start of block to check | |
70 | * @size: Size of block to check | |
71 | * | |
72 | * Context: User context only. This function may sleep. | |
73 | * | |
74 | * Checks if a pointer to a block of memory in user space is valid. | |
75 | * | |
76 | * Returns true (nonzero) if the memory block may be valid, false (zero) | |
77 | * if it is definitely invalid. | |
78 | * | |
79 | * Note that, depending on architecture, this function probably just | |
80 | * checks that the pointer is in the user space range - after calling | |
81 | * this function, memory access functions may still return -EFAULT. | |
82 | */ | |
83 | #define access_ok(type,addr,size) (likely(__range_ok(addr,size) == 0)) | |
84 | ||
1da177e4 LT |
85 | /* |
86 | * The exception table consists of pairs of addresses: the first is the | |
87 | * address of an instruction that is allowed to fault, and the second is | |
88 | * the address at which the program should continue. No registers are | |
89 | * modified, so it is entirely up to the continuation code to figure out | |
90 | * what to do. | |
91 | * | |
92 | * All the routines below use bits of fixup code that are out of line | |
93 | * with the main instruction path. This means when everything is well, | |
94 | * we don't even have to jump over them. Further, they do not intrude | |
95 | * on our cache or tlb entries. | |
96 | */ | |
97 | ||
98 | struct exception_table_entry | |
99 | { | |
100 | unsigned long insn, fixup; | |
101 | }; | |
102 | ||
103 | extern int fixup_exception(struct pt_regs *regs); | |
104 | ||
105 | /* | |
106 | * These are the main single-value transfer routines. They automatically | |
107 | * use the right size if we just have the right pointer type. | |
108 | * | |
109 | * This gets kind of ugly. We want to return _two_ values in "get_user()" | |
110 | * and yet we don't want to do any pointers, because that is too much | |
111 | * of a performance impact. Thus we have a few rather ugly macros here, | |
112 | * and hide all the ugliness from the user. | |
113 | * | |
114 | * The "__xxx" versions of the user access functions are versions that | |
115 | * do not verify the address space, that must have been done previously | |
116 | * with a separate "access_ok()" call (this is used when we do multiple | |
117 | * accesses to the same area of user memory). | |
118 | */ | |
119 | ||
120 | extern void __get_user_1(void); | |
121 | extern void __get_user_2(void); | |
122 | extern void __get_user_4(void); | |
123 | ||
124 | #define __get_user_x(size,ret,x,ptr) \ | |
125 | __asm__ __volatile__("call __get_user_" #size \ | |
126 | :"=a" (ret),"=d" (x) \ | |
127 | :"0" (ptr)) | |
128 | ||
129 | ||
130 | /* Careful: we have to cast the result to the type of the pointer for sign reasons */ | |
131 | /** | |
132 | * get_user: - Get a simple variable from user space. | |
133 | * @x: Variable to store result. | |
134 | * @ptr: Source address, in user space. | |
135 | * | |
136 | * Context: User context only. This function may sleep. | |
137 | * | |
138 | * This macro copies a single simple variable from user space to kernel | |
139 | * space. It supports simple types like char and int, but not larger | |
140 | * data types like structures or arrays. | |
141 | * | |
142 | * @ptr must have pointer-to-simple-variable type, and the result of | |
143 | * dereferencing @ptr must be assignable to @x without a cast. | |
144 | * | |
145 | * Returns zero on success, or -EFAULT on error. | |
146 | * On error, the variable @x is set to zero. | |
147 | */ | |
148 | #define get_user(x,ptr) \ | |
149 | ({ int __ret_gu; \ | |
150 | unsigned long __val_gu; \ | |
151 | __chk_user_ptr(ptr); \ | |
152 | switch(sizeof (*(ptr))) { \ | |
153 | case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \ | |
154 | case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \ | |
155 | case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \ | |
156 | default: __get_user_x(X,__ret_gu,__val_gu,ptr); break; \ | |
157 | } \ | |
158 | (x) = (__typeof__(*(ptr)))__val_gu; \ | |
159 | __ret_gu; \ | |
160 | }) | |
161 | ||
162 | extern void __put_user_bad(void); | |
163 | ||
164 | /* | |
165 | * Strange magic calling convention: pointer in %ecx, | |
166 | * value in %eax(:%edx), return value in %eax, no clobbers. | |
167 | */ | |
168 | extern void __put_user_1(void); | |
169 | extern void __put_user_2(void); | |
170 | extern void __put_user_4(void); | |
171 | extern void __put_user_8(void); | |
172 | ||
173 | #define __put_user_1(x, ptr) __asm__ __volatile__("call __put_user_1":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr)) | |
174 | #define __put_user_2(x, ptr) __asm__ __volatile__("call __put_user_2":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr)) | |
175 | #define __put_user_4(x, ptr) __asm__ __volatile__("call __put_user_4":"=a" (__ret_pu):"0" ((typeof(*(ptr)))(x)), "c" (ptr)) | |
176 | #define __put_user_8(x, ptr) __asm__ __volatile__("call __put_user_8":"=a" (__ret_pu):"A" ((typeof(*(ptr)))(x)), "c" (ptr)) | |
177 | #define __put_user_X(x, ptr) __asm__ __volatile__("call __put_user_X":"=a" (__ret_pu):"c" (ptr)) | |
178 | ||
179 | /** | |
180 | * put_user: - Write a simple value into user space. | |
181 | * @x: Value to copy to user space. | |
182 | * @ptr: Destination address, in user space. | |
183 | * | |
184 | * Context: User context only. This function may sleep. | |
185 | * | |
186 | * This macro copies a single simple value from kernel space to user | |
187 | * space. It supports simple types like char and int, but not larger | |
188 | * data types like structures or arrays. | |
189 | * | |
190 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
191 | * to the result of dereferencing @ptr. | |
192 | * | |
193 | * Returns zero on success, or -EFAULT on error. | |
194 | */ | |
195 | #ifdef CONFIG_X86_WP_WORKS_OK | |
196 | ||
197 | #define put_user(x,ptr) \ | |
198 | ({ int __ret_pu; \ | |
30e931d4 | 199 | __typeof__(*(ptr)) __pu_val; \ |
1da177e4 | 200 | __chk_user_ptr(ptr); \ |
30e931d4 | 201 | __pu_val = x; \ |
1da177e4 | 202 | switch(sizeof(*(ptr))) { \ |
30e931d4 EB |
203 | case 1: __put_user_1(__pu_val, ptr); break; \ |
204 | case 2: __put_user_2(__pu_val, ptr); break; \ | |
205 | case 4: __put_user_4(__pu_val, ptr); break; \ | |
206 | case 8: __put_user_8(__pu_val, ptr); break; \ | |
207 | default:__put_user_X(__pu_val, ptr); break; \ | |
1da177e4 LT |
208 | } \ |
209 | __ret_pu; \ | |
210 | }) | |
211 | ||
212 | #else | |
213 | #define put_user(x,ptr) \ | |
214 | ({ \ | |
215 | int __ret_pu; \ | |
216 | __typeof__(*(ptr)) __pus_tmp = x; \ | |
217 | __ret_pu=0; \ | |
218 | if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp, \ | |
219 | sizeof(*(ptr))) != 0)) \ | |
220 | __ret_pu=-EFAULT; \ | |
221 | __ret_pu; \ | |
222 | }) | |
223 | ||
224 | ||
225 | #endif | |
226 | ||
227 | /** | |
228 | * __get_user: - Get a simple variable from user space, with less checking. | |
229 | * @x: Variable to store result. | |
230 | * @ptr: Source address, in user space. | |
231 | * | |
232 | * Context: User context only. This function may sleep. | |
233 | * | |
234 | * This macro copies a single simple variable from user space to kernel | |
235 | * space. It supports simple types like char and int, but not larger | |
236 | * data types like structures or arrays. | |
237 | * | |
238 | * @ptr must have pointer-to-simple-variable type, and the result of | |
239 | * dereferencing @ptr must be assignable to @x without a cast. | |
240 | * | |
241 | * Caller must check the pointer with access_ok() before calling this | |
242 | * function. | |
243 | * | |
244 | * Returns zero on success, or -EFAULT on error. | |
245 | * On error, the variable @x is set to zero. | |
246 | */ | |
247 | #define __get_user(x,ptr) \ | |
248 | __get_user_nocheck((x),(ptr),sizeof(*(ptr))) | |
249 | ||
250 | ||
251 | /** | |
252 | * __put_user: - Write a simple value into user space, with less checking. | |
253 | * @x: Value to copy to user space. | |
254 | * @ptr: Destination address, in user space. | |
255 | * | |
256 | * Context: User context only. This function may sleep. | |
257 | * | |
258 | * This macro copies a single simple value from kernel space to user | |
259 | * space. It supports simple types like char and int, but not larger | |
260 | * data types like structures or arrays. | |
261 | * | |
262 | * @ptr must have pointer-to-simple-variable type, and @x must be assignable | |
263 | * to the result of dereferencing @ptr. | |
264 | * | |
265 | * Caller must check the pointer with access_ok() before calling this | |
266 | * function. | |
267 | * | |
268 | * Returns zero on success, or -EFAULT on error. | |
269 | */ | |
270 | #define __put_user(x,ptr) \ | |
271 | __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr))) | |
272 | ||
273 | #define __put_user_nocheck(x,ptr,size) \ | |
274 | ({ \ | |
275 | long __pu_err; \ | |
276 | __put_user_size((x),(ptr),(size),__pu_err,-EFAULT); \ | |
277 | __pu_err; \ | |
278 | }) | |
279 | ||
280 | ||
281 | #define __put_user_u64(x, addr, err) \ | |
282 | __asm__ __volatile__( \ | |
283 | "1: movl %%eax,0(%2)\n" \ | |
284 | "2: movl %%edx,4(%2)\n" \ | |
285 | "3:\n" \ | |
286 | ".section .fixup,\"ax\"\n" \ | |
287 | "4: movl %3,%0\n" \ | |
288 | " jmp 3b\n" \ | |
289 | ".previous\n" \ | |
290 | ".section __ex_table,\"a\"\n" \ | |
291 | " .align 4\n" \ | |
292 | " .long 1b,4b\n" \ | |
293 | " .long 2b,4b\n" \ | |
294 | ".previous" \ | |
295 | : "=r"(err) \ | |
296 | : "A" (x), "r" (addr), "i"(-EFAULT), "0"(err)) | |
297 | ||
298 | #ifdef CONFIG_X86_WP_WORKS_OK | |
299 | ||
300 | #define __put_user_size(x,ptr,size,retval,errret) \ | |
301 | do { \ | |
302 | retval = 0; \ | |
303 | __chk_user_ptr(ptr); \ | |
304 | switch (size) { \ | |
305 | case 1: __put_user_asm(x,ptr,retval,"b","b","iq",errret);break; \ | |
306 | case 2: __put_user_asm(x,ptr,retval,"w","w","ir",errret);break; \ | |
307 | case 4: __put_user_asm(x,ptr,retval,"l","","ir",errret); break; \ | |
308 | case 8: __put_user_u64((__typeof__(*ptr))(x),ptr,retval); break;\ | |
309 | default: __put_user_bad(); \ | |
310 | } \ | |
311 | } while (0) | |
312 | ||
313 | #else | |
314 | ||
315 | #define __put_user_size(x,ptr,size,retval,errret) \ | |
316 | do { \ | |
317 | __typeof__(*(ptr)) __pus_tmp = x; \ | |
318 | retval = 0; \ | |
319 | \ | |
320 | if(unlikely(__copy_to_user_ll(ptr, &__pus_tmp, size) != 0)) \ | |
321 | retval = errret; \ | |
322 | } while (0) | |
323 | ||
324 | #endif | |
325 | struct __large_struct { unsigned long buf[100]; }; | |
326 | #define __m(x) (*(struct __large_struct __user *)(x)) | |
327 | ||
328 | /* | |
329 | * Tell gcc we read from memory instead of writing: this is because | |
330 | * we do not write to any memory gcc knows about, so there are no | |
331 | * aliasing issues. | |
332 | */ | |
333 | #define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \ | |
334 | __asm__ __volatile__( \ | |
335 | "1: mov"itype" %"rtype"1,%2\n" \ | |
336 | "2:\n" \ | |
337 | ".section .fixup,\"ax\"\n" \ | |
338 | "3: movl %3,%0\n" \ | |
339 | " jmp 2b\n" \ | |
340 | ".previous\n" \ | |
341 | ".section __ex_table,\"a\"\n" \ | |
342 | " .align 4\n" \ | |
343 | " .long 1b,3b\n" \ | |
344 | ".previous" \ | |
345 | : "=r"(err) \ | |
346 | : ltype (x), "m"(__m(addr)), "i"(errret), "0"(err)) | |
347 | ||
348 | ||
349 | #define __get_user_nocheck(x,ptr,size) \ | |
350 | ({ \ | |
351 | long __gu_err; \ | |
352 | unsigned long __gu_val; \ | |
353 | __get_user_size(__gu_val,(ptr),(size),__gu_err,-EFAULT);\ | |
354 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
355 | __gu_err; \ | |
356 | }) | |
357 | ||
358 | extern long __get_user_bad(void); | |
359 | ||
360 | #define __get_user_size(x,ptr,size,retval,errret) \ | |
361 | do { \ | |
362 | retval = 0; \ | |
363 | __chk_user_ptr(ptr); \ | |
364 | switch (size) { \ | |
365 | case 1: __get_user_asm(x,ptr,retval,"b","b","=q",errret);break; \ | |
366 | case 2: __get_user_asm(x,ptr,retval,"w","w","=r",errret);break; \ | |
367 | case 4: __get_user_asm(x,ptr,retval,"l","","=r",errret);break; \ | |
368 | default: (x) = __get_user_bad(); \ | |
369 | } \ | |
370 | } while (0) | |
371 | ||
372 | #define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \ | |
373 | __asm__ __volatile__( \ | |
374 | "1: mov"itype" %2,%"rtype"1\n" \ | |
375 | "2:\n" \ | |
376 | ".section .fixup,\"ax\"\n" \ | |
377 | "3: movl %3,%0\n" \ | |
378 | " xor"itype" %"rtype"1,%"rtype"1\n" \ | |
379 | " jmp 2b\n" \ | |
380 | ".previous\n" \ | |
381 | ".section __ex_table,\"a\"\n" \ | |
382 | " .align 4\n" \ | |
383 | " .long 1b,3b\n" \ | |
384 | ".previous" \ | |
385 | : "=r"(err), ltype (x) \ | |
386 | : "m"(__m(addr)), "i"(errret), "0"(err)) | |
387 | ||
388 | ||
389 | unsigned long __must_check __copy_to_user_ll(void __user *to, | |
390 | const void *from, unsigned long n); | |
391 | unsigned long __must_check __copy_from_user_ll(void *to, | |
392 | const void __user *from, unsigned long n); | |
7c12d811 N |
393 | unsigned long __must_check __copy_from_user_ll_nozero(void *to, |
394 | const void __user *from, unsigned long n); | |
c22ce143 HY |
395 | unsigned long __must_check __copy_from_user_ll_nocache(void *to, |
396 | const void __user *from, unsigned long n); | |
7c12d811 N |
397 | unsigned long __must_check __copy_from_user_ll_nocache_nozero(void *to, |
398 | const void __user *from, unsigned long n); | |
1da177e4 | 399 | |
6d1c4261 AK |
400 | /** |
401 | * __copy_to_user_inatomic: - Copy a block of data into user space, with less checking. | |
402 | * @to: Destination address, in user space. | |
403 | * @from: Source address, in kernel space. | |
404 | * @n: Number of bytes to copy. | |
405 | * | |
406 | * Context: User context only. | |
407 | * | |
408 | * Copy data from kernel space to user space. Caller must check | |
409 | * the specified block with access_ok() before calling this function. | |
410 | * The caller should also make sure he pins the user space address | |
411 | * so that the we don't result in page fault and sleep. | |
412 | * | |
1da177e4 LT |
413 | * Here we special-case 1, 2 and 4-byte copy_*_user invocations. On a fault |
414 | * we return the initial request size (1, 2 or 4), as copy_*_user should do. | |
415 | * If a store crosses a page boundary and gets a fault, the x86 will not write | |
416 | * anything, so this is accurate. | |
417 | */ | |
418 | ||
652050ae | 419 | static __always_inline unsigned long __must_check |
1da177e4 LT |
420 | __copy_to_user_inatomic(void __user *to, const void *from, unsigned long n) |
421 | { | |
422 | if (__builtin_constant_p(n)) { | |
423 | unsigned long ret; | |
424 | ||
425 | switch (n) { | |
426 | case 1: | |
427 | __put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret, 1); | |
428 | return ret; | |
429 | case 2: | |
430 | __put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret, 2); | |
431 | return ret; | |
432 | case 4: | |
433 | __put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret, 4); | |
434 | return ret; | |
435 | } | |
436 | } | |
437 | return __copy_to_user_ll(to, from, n); | |
438 | } | |
439 | ||
1da177e4 | 440 | /** |
9c7fff6e RD |
441 | * __copy_to_user: - Copy a block of data into user space, with less checking. |
442 | * @to: Destination address, in user space. | |
443 | * @from: Source address, in kernel space. | |
1da177e4 LT |
444 | * @n: Number of bytes to copy. |
445 | * | |
446 | * Context: User context only. This function may sleep. | |
447 | * | |
9c7fff6e | 448 | * Copy data from kernel space to user space. Caller must check |
1da177e4 LT |
449 | * the specified block with access_ok() before calling this function. |
450 | * | |
451 | * Returns number of bytes that could not be copied. | |
452 | * On success, this will be zero. | |
1da177e4 | 453 | */ |
9c7fff6e RD |
454 | static __always_inline unsigned long __must_check |
455 | __copy_to_user(void __user *to, const void *from, unsigned long n) | |
456 | { | |
457 | might_sleep(); | |
458 | return __copy_to_user_inatomic(to, from, n); | |
459 | } | |
460 | ||
652050ae | 461 | static __always_inline unsigned long |
1da177e4 LT |
462 | __copy_from_user_inatomic(void *to, const void __user *from, unsigned long n) |
463 | { | |
7c12d811 N |
464 | /* Avoid zeroing the tail if the copy fails.. |
465 | * If 'n' is constant and 1, 2, or 4, we do still zero on a failure, | |
466 | * but as the zeroing behaviour is only significant when n is not | |
467 | * constant, that shouldn't be a problem. | |
468 | */ | |
469 | if (__builtin_constant_p(n)) { | |
470 | unsigned long ret; | |
471 | ||
472 | switch (n) { | |
473 | case 1: | |
474 | __get_user_size(*(u8 *)to, from, 1, ret, 1); | |
475 | return ret; | |
476 | case 2: | |
477 | __get_user_size(*(u16 *)to, from, 2, ret, 2); | |
478 | return ret; | |
479 | case 4: | |
480 | __get_user_size(*(u32 *)to, from, 4, ret, 4); | |
481 | return ret; | |
482 | } | |
483 | } | |
484 | return __copy_from_user_ll_nozero(to, from, n); | |
485 | } | |
9c7fff6e RD |
486 | |
487 | /** | |
488 | * __copy_from_user: - Copy a block of data from user space, with less checking. | |
489 | * @to: Destination address, in kernel space. | |
490 | * @from: Source address, in user space. | |
491 | * @n: Number of bytes to copy. | |
492 | * | |
493 | * Context: User context only. This function may sleep. | |
494 | * | |
495 | * Copy data from user space to kernel space. Caller must check | |
496 | * the specified block with access_ok() before calling this function. | |
497 | * | |
498 | * Returns number of bytes that could not be copied. | |
499 | * On success, this will be zero. | |
500 | * | |
501 | * If some data could not be copied, this function will pad the copied | |
502 | * data to the requested size using zero bytes. | |
503 | * | |
504 | * An alternate version - __copy_from_user_inatomic() - may be called from | |
505 | * atomic context and will fail rather than sleep. In this case the | |
506 | * uncopied bytes will *NOT* be padded with zeros. See fs/filemap.h | |
507 | * for explanation of why this is needed. | |
508 | */ | |
7c12d811 N |
509 | static __always_inline unsigned long |
510 | __copy_from_user(void *to, const void __user *from, unsigned long n) | |
511 | { | |
512 | might_sleep(); | |
1da177e4 LT |
513 | if (__builtin_constant_p(n)) { |
514 | unsigned long ret; | |
515 | ||
516 | switch (n) { | |
517 | case 1: | |
518 | __get_user_size(*(u8 *)to, from, 1, ret, 1); | |
519 | return ret; | |
520 | case 2: | |
521 | __get_user_size(*(u16 *)to, from, 2, ret, 2); | |
522 | return ret; | |
523 | case 4: | |
524 | __get_user_size(*(u32 *)to, from, 4, ret, 4); | |
525 | return ret; | |
526 | } | |
527 | } | |
528 | return __copy_from_user_ll(to, from, n); | |
529 | } | |
530 | ||
c22ce143 HY |
531 | #define ARCH_HAS_NOCACHE_UACCESS |
532 | ||
7c12d811 | 533 | static __always_inline unsigned long __copy_from_user_nocache(void *to, |
c22ce143 HY |
534 | const void __user *from, unsigned long n) |
535 | { | |
7c12d811 | 536 | might_sleep(); |
c22ce143 HY |
537 | if (__builtin_constant_p(n)) { |
538 | unsigned long ret; | |
539 | ||
540 | switch (n) { | |
541 | case 1: | |
542 | __get_user_size(*(u8 *)to, from, 1, ret, 1); | |
543 | return ret; | |
544 | case 2: | |
545 | __get_user_size(*(u16 *)to, from, 2, ret, 2); | |
546 | return ret; | |
547 | case 4: | |
548 | __get_user_size(*(u32 *)to, from, 4, ret, 4); | |
549 | return ret; | |
550 | } | |
551 | } | |
552 | return __copy_from_user_ll_nocache(to, from, n); | |
553 | } | |
554 | ||
652050ae | 555 | static __always_inline unsigned long |
7c12d811 | 556 | __copy_from_user_inatomic_nocache(void *to, const void __user *from, unsigned long n) |
1da177e4 | 557 | { |
7c12d811 | 558 | return __copy_from_user_ll_nocache_nozero(to, from, n); |
c22ce143 HY |
559 | } |
560 | ||
1da177e4 LT |
561 | unsigned long __must_check copy_to_user(void __user *to, |
562 | const void *from, unsigned long n); | |
563 | unsigned long __must_check copy_from_user(void *to, | |
564 | const void __user *from, unsigned long n); | |
565 | long __must_check strncpy_from_user(char *dst, const char __user *src, | |
566 | long count); | |
567 | long __must_check __strncpy_from_user(char *dst, | |
568 | const char __user *src, long count); | |
569 | ||
570 | /** | |
571 | * strlen_user: - Get the size of a string in user space. | |
572 | * @str: The string to measure. | |
573 | * | |
574 | * Context: User context only. This function may sleep. | |
575 | * | |
576 | * Get the size of a NUL-terminated string in user space. | |
577 | * | |
578 | * Returns the size of the string INCLUDING the terminating NUL. | |
579 | * On exception, returns 0. | |
580 | * | |
581 | * If there is a limit on the length of a valid string, you may wish to | |
582 | * consider using strnlen_user() instead. | |
583 | */ | |
584 | #define strlen_user(str) strnlen_user(str, ~0UL >> 1) | |
585 | ||
586 | long strnlen_user(const char __user *str, long n); | |
587 | unsigned long __must_check clear_user(void __user *mem, unsigned long len); | |
588 | unsigned long __must_check __clear_user(void __user *mem, unsigned long len); | |
589 | ||
590 | #endif /* __i386_UACCESS_H */ |