aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-i386/uaccess.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-i386/uaccess.h')
-rw-r--r--include/asm-i386/uaccess.h590
1 files changed, 0 insertions, 590 deletions
diff --git a/include/asm-i386/uaccess.h b/include/asm-i386/uaccess.h
deleted file mode 100644
index d2a4f7be9c2c..000000000000
--- a/include/asm-i386/uaccess.h
+++ /dev/null
@@ -1,590 +0,0 @@
1#ifndef __i386_UACCESS_H
2#define __i386_UACCESS_H
3
4/*
5 * User space memory access functions
6 */
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
40extern 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) ({ \
57 unsigned long flag,roksum; \
58 __chk_user_ptr(addr); \
59 asm("addl %3,%1 ; sbbl %0,%0; cmpl %1,%4; sbbl $0,%0" \
60 :"=&r" (flag), "=r" (roksum) \
61 :"1" (addr),"g" ((int)(size)),"rm" (current_thread_info()->addr_limit.seg)); \
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
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
98struct exception_table_entry
99{
100 unsigned long insn, fixup;
101};
102
103extern 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
120extern void __get_user_1(void);
121extern void __get_user_2(void);
122extern 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
162extern 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 */
168extern void __put_user_1(void);
169extern void __put_user_2(void);
170extern void __put_user_4(void);
171extern 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; \
199 __typeof__(*(ptr)) __pu_val; \
200 __chk_user_ptr(ptr); \
201 __pu_val = x; \
202 switch(sizeof(*(ptr))) { \
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; \
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) \
301do { \
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) \
316do { \
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
325struct __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
358extern long __get_user_bad(void);
359
360#define __get_user_size(x,ptr,size,retval,errret) \
361do { \
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
389unsigned long __must_check __copy_to_user_ll(void __user *to,
390 const void *from, unsigned long n);
391unsigned long __must_check __copy_from_user_ll(void *to,
392 const void __user *from, unsigned long n);
393unsigned long __must_check __copy_from_user_ll_nozero(void *to,
394 const void __user *from, unsigned long n);
395unsigned long __must_check __copy_from_user_ll_nocache(void *to,
396 const void __user *from, unsigned long n);
397unsigned long __must_check __copy_from_user_ll_nocache_nozero(void *to,
398 const void __user *from, unsigned long n);
399
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 *
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
419static __always_inline unsigned long __must_check
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
440/**
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.
444 * @n: Number of bytes to copy.
445 *
446 * Context: User context only. This function may sleep.
447 *
448 * Copy data from kernel space to user space. Caller must check
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.
453 */
454static __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
461static __always_inline unsigned long
462__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
463{
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}
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 */
509static __always_inline unsigned long
510__copy_from_user(void *to, const void __user *from, unsigned long n)
511{
512 might_sleep();
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
531#define ARCH_HAS_NOCACHE_UACCESS
532
533static __always_inline unsigned long __copy_from_user_nocache(void *to,
534 const void __user *from, unsigned long n)
535{
536 might_sleep();
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
555static __always_inline unsigned long
556__copy_from_user_inatomic_nocache(void *to, const void __user *from, unsigned long n)
557{
558 return __copy_from_user_ll_nocache_nozero(to, from, n);
559}
560
561unsigned long __must_check copy_to_user(void __user *to,
562 const void *from, unsigned long n);
563unsigned long __must_check copy_from_user(void *to,
564 const void __user *from, unsigned long n);
565long __must_check strncpy_from_user(char *dst, const char __user *src,
566 long count);
567long __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, LONG_MAX)
585
586long strnlen_user(const char __user *str, long n);
587unsigned long __must_check clear_user(void __user *mem, unsigned long len);
588unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
589
590#endif /* __i386_UACCESS_H */
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-17 08:21:36 -0500