blob: 3f47889883b734c57c83232caa8bfc6ed91bb1ff [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* $Id: uaccess.h,v 1.24 2001/10/30 04:32:24 davem Exp $
2 * uaccess.h: User space memore access functions.
3 *
4 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
6 */
7#ifndef _ASM_UACCESS_H
8#define _ASM_UACCESS_H
9
10#ifdef __KERNEL__
11#include <linux/compiler.h>
12#include <linux/sched.h>
13#include <linux/string.h>
14#include <linux/errno.h>
15#include <asm/vac-ops.h>
16#include <asm/a.out.h>
17#endif
18
19#ifndef __ASSEMBLY__
20
21/* Sparc is not segmented, however we need to be able to fool verify_area()
22 * when doing system calls from kernel mode legitimately.
23 *
24 * "For historical reasons, these macros are grossly misnamed." -Linus
25 */
26
27#define KERNEL_DS ((mm_segment_t) { 0 })
28#define USER_DS ((mm_segment_t) { -1 })
29
30#define VERIFY_READ 0
31#define VERIFY_WRITE 1
32
33#define get_ds() (KERNEL_DS)
34#define get_fs() (current->thread.current_ds)
35#define set_fs(val) ((current->thread.current_ds) = (val))
36
37#define segment_eq(a,b) ((a).seg == (b).seg)
38
39/* We have there a nice not-mapped page at PAGE_OFFSET - PAGE_SIZE, so that this test
40 * can be fairly lightweight.
41 * No one can read/write anything from userland in the kernel space by setting
42 * large size and address near to PAGE_OFFSET - a fault will break his intentions.
43 */
44#define __user_ok(addr,size) ((addr) < STACK_TOP)
45#define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
46#define __access_ok(addr,size) (__user_ok((addr) & get_fs().seg,(size)))
47#define access_ok(type,addr,size) __access_ok((unsigned long)(addr),(size))
48
49/* this function will go away soon - use access_ok() instead */
50static inline int __deprecated verify_area(int type, const void __user * addr, unsigned long size)
51{
52 return access_ok(type,addr,size) ? 0 : -EFAULT;
53}
54
55/*
56 * The exception table consists of pairs of addresses: the first is the
57 * address of an instruction that is allowed to fault, and the second is
58 * the address at which the program should continue. No registers are
59 * modified, so it is entirely up to the continuation code to figure out
60 * what to do.
61 *
62 * All the routines below use bits of fixup code that are out of line
63 * with the main instruction path. This means when everything is well,
64 * we don't even have to jump over them. Further, they do not intrude
65 * on our cache or tlb entries.
66 *
67 * There is a special way how to put a range of potentially faulting
68 * insns (like twenty ldd/std's with now intervening other instructions)
69 * You specify address of first in insn and 0 in fixup and in the next
70 * exception_table_entry you specify last potentially faulting insn + 1
71 * and in fixup the routine which should handle the fault.
72 * That fixup code will get
73 * (faulting_insn_address - first_insn_in_the_range_address)/4
74 * in %g2 (ie. index of the faulting instruction in the range).
75 */
76
77struct exception_table_entry
78{
79 unsigned long insn, fixup;
80};
81
82/* Returns 0 if exception not found and fixup otherwise. */
83extern unsigned long search_extables_range(unsigned long addr, unsigned long *g2);
84
85extern void __ret_efault(void);
86
87/* Uh, these should become the main single-value transfer routines..
88 * They automatically use the right size if we just have the right
89 * pointer type..
90 *
91 * This gets kind of ugly. We want to return _two_ values in "get_user()"
92 * and yet we don't want to do any pointers, because that is too much
93 * of a performance impact. Thus we have a few rather ugly macros here,
94 * and hide all the ugliness from the user.
95 */
96#define put_user(x,ptr) ({ \
97unsigned long __pu_addr = (unsigned long)(ptr); \
98__chk_user_ptr(ptr); \
99__put_user_check((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
100
101#define get_user(x,ptr) ({ \
102unsigned long __gu_addr = (unsigned long)(ptr); \
103__chk_user_ptr(ptr); \
104__get_user_check((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
105
106/*
107 * The "__xxx" versions do not do address space checking, useful when
108 * doing multiple accesses to the same area (the user has to do the
109 * checks by hand with "access_ok()")
110 */
111#define __put_user(x,ptr) __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
112#define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr)),__typeof__(*(ptr)))
113
114struct __large_struct { unsigned long buf[100]; };
115#define __m(x) ((struct __large_struct __user *)(x))
116
117#define __put_user_check(x,addr,size) ({ \
118register int __pu_ret; \
119if (__access_ok(addr,size)) { \
120switch (size) { \
121case 1: __put_user_asm(x,b,addr,__pu_ret); break; \
122case 2: __put_user_asm(x,h,addr,__pu_ret); break; \
123case 4: __put_user_asm(x,,addr,__pu_ret); break; \
124case 8: __put_user_asm(x,d,addr,__pu_ret); break; \
125default: __pu_ret = __put_user_bad(); break; \
126} } else { __pu_ret = -EFAULT; } __pu_ret; })
127
128#define __put_user_check_ret(x,addr,size,retval) ({ \
129register int __foo __asm__ ("l1"); \
130if (__access_ok(addr,size)) { \
131switch (size) { \
132case 1: __put_user_asm_ret(x,b,addr,retval,__foo); break; \
133case 2: __put_user_asm_ret(x,h,addr,retval,__foo); break; \
134case 4: __put_user_asm_ret(x,,addr,retval,__foo); break; \
135case 8: __put_user_asm_ret(x,d,addr,retval,__foo); break; \
136default: if (__put_user_bad()) return retval; break; \
137} } else return retval; })
138
139#define __put_user_nocheck(x,addr,size) ({ \
140register int __pu_ret; \
141switch (size) { \
142case 1: __put_user_asm(x,b,addr,__pu_ret); break; \
143case 2: __put_user_asm(x,h,addr,__pu_ret); break; \
144case 4: __put_user_asm(x,,addr,__pu_ret); break; \
145case 8: __put_user_asm(x,d,addr,__pu_ret); break; \
146default: __pu_ret = __put_user_bad(); break; \
147} __pu_ret; })
148
149#define __put_user_nocheck_ret(x,addr,size,retval) ({ \
150register int __foo __asm__ ("l1"); \
151switch (size) { \
152case 1: __put_user_asm_ret(x,b,addr,retval,__foo); break; \
153case 2: __put_user_asm_ret(x,h,addr,retval,__foo); break; \
154case 4: __put_user_asm_ret(x,,addr,retval,__foo); break; \
155case 8: __put_user_asm_ret(x,d,addr,retval,__foo); break; \
156default: if (__put_user_bad()) return retval; break; \
157} })
158
159#define __put_user_asm(x,size,addr,ret) \
160__asm__ __volatile__( \
161 "/* Put user asm, inline. */\n" \
162"1:\t" "st"#size " %1, %2\n\t" \
163 "clr %0\n" \
164"2:\n\n\t" \
165 ".section .fixup,#alloc,#execinstr\n\t" \
166 ".align 4\n" \
167"3:\n\t" \
168 "b 2b\n\t" \
169 " mov %3, %0\n\t" \
170 ".previous\n\n\t" \
171 ".section __ex_table,#alloc\n\t" \
172 ".align 4\n\t" \
173 ".word 1b, 3b\n\t" \
174 ".previous\n\n\t" \
175 : "=&r" (ret) : "r" (x), "m" (*__m(addr)), \
176 "i" (-EFAULT))
177
178#define __put_user_asm_ret(x,size,addr,ret,foo) \
179if (__builtin_constant_p(ret) && ret == -EFAULT) \
180__asm__ __volatile__( \
181 "/* Put user asm ret, inline. */\n" \
182"1:\t" "st"#size " %1, %2\n\n\t" \
183 ".section __ex_table,#alloc\n\t" \
184 ".align 4\n\t" \
185 ".word 1b, __ret_efault\n\n\t" \
186 ".previous\n\n\t" \
187 : "=r" (foo) : "r" (x), "m" (*__m(addr))); \
188else \
189__asm__ __volatile( \
190 "/* Put user asm ret, inline. */\n" \
191"1:\t" "st"#size " %1, %2\n\n\t" \
192 ".section .fixup,#alloc,#execinstr\n\t" \
193 ".align 4\n" \
194"3:\n\t" \
195 "ret\n\t" \
196 " restore %%g0, %3, %%o0\n\t" \
197 ".previous\n\n\t" \
198 ".section __ex_table,#alloc\n\t" \
199 ".align 4\n\t" \
200 ".word 1b, 3b\n\n\t" \
201 ".previous\n\n\t" \
202 : "=r" (foo) : "r" (x), "m" (*__m(addr)), "i" (ret))
203
204extern int __put_user_bad(void);
205
206#define __get_user_check(x,addr,size,type) ({ \
207register int __gu_ret; \
208register unsigned long __gu_val; \
209if (__access_ok(addr,size)) { \
210switch (size) { \
211case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
212case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
213case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \
214case 8: __get_user_asm(__gu_val,d,addr,__gu_ret); break; \
215default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
216} } else { __gu_val = 0; __gu_ret = -EFAULT; } x = (type) __gu_val; __gu_ret; })
217
218#define __get_user_check_ret(x,addr,size,type,retval) ({ \
219register unsigned long __gu_val __asm__ ("l1"); \
220if (__access_ok(addr,size)) { \
221switch (size) { \
222case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
223case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
224case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \
225case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \
226default: if (__get_user_bad()) return retval; \
227} x = (type) __gu_val; } else return retval; })
228
229#define __get_user_nocheck(x,addr,size,type) ({ \
230register int __gu_ret; \
231register unsigned long __gu_val; \
232switch (size) { \
233case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
234case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
235case 4: __get_user_asm(__gu_val,,addr,__gu_ret); break; \
236case 8: __get_user_asm(__gu_val,d,addr,__gu_ret); break; \
237default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
238} x = (type) __gu_val; __gu_ret; })
239
240#define __get_user_nocheck_ret(x,addr,size,type,retval) ({ \
241register unsigned long __gu_val __asm__ ("l1"); \
242switch (size) { \
243case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
244case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
245case 4: __get_user_asm_ret(__gu_val,,addr,retval); break; \
246case 8: __get_user_asm_ret(__gu_val,d,addr,retval); break; \
247default: if (__get_user_bad()) return retval; \
248} x = (type) __gu_val; })
249
250#define __get_user_asm(x,size,addr,ret) \
251__asm__ __volatile__( \
252 "/* Get user asm, inline. */\n" \
253"1:\t" "ld"#size " %2, %1\n\t" \
254 "clr %0\n" \
255"2:\n\n\t" \
256 ".section .fixup,#alloc,#execinstr\n\t" \
257 ".align 4\n" \
258"3:\n\t" \
259 "clr %1\n\t" \
260 "b 2b\n\t" \
261 " mov %3, %0\n\n\t" \
262 ".previous\n\t" \
263 ".section __ex_table,#alloc\n\t" \
264 ".align 4\n\t" \
265 ".word 1b, 3b\n\n\t" \
266 ".previous\n\t" \
267 : "=&r" (ret), "=&r" (x) : "m" (*__m(addr)), \
268 "i" (-EFAULT))
269
270#define __get_user_asm_ret(x,size,addr,retval) \
271if (__builtin_constant_p(retval) && retval == -EFAULT) \
272__asm__ __volatile__( \
273 "/* Get user asm ret, inline. */\n" \
274"1:\t" "ld"#size " %1, %0\n\n\t" \
275 ".section __ex_table,#alloc\n\t" \
276 ".align 4\n\t" \
277 ".word 1b,__ret_efault\n\n\t" \
278 ".previous\n\t" \
279 : "=&r" (x) : "m" (*__m(addr))); \
280else \
281__asm__ __volatile__( \
282 "/* Get user asm ret, inline. */\n" \
283"1:\t" "ld"#size " %1, %0\n\n\t" \
284 ".section .fixup,#alloc,#execinstr\n\t" \
285 ".align 4\n" \
286"3:\n\t" \
287 "ret\n\t" \
288 " restore %%g0, %2, %%o0\n\n\t" \
289 ".previous\n\t" \
290 ".section __ex_table,#alloc\n\t" \
291 ".align 4\n\t" \
292 ".word 1b, 3b\n\n\t" \
293 ".previous\n\t" \
294 : "=&r" (x) : "m" (*__m(addr)), "i" (retval))
295
296extern int __get_user_bad(void);
297
298extern unsigned long __copy_user(void __user *to, const void __user *from, unsigned long size);
299
300static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n)
301{
302 if (n && __access_ok((unsigned long) to, n))
303 return __copy_user(to, (__force void __user *) from, n);
304 else
305 return n;
306}
307
308static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
309{
310 return __copy_user(to, (__force void __user *) from, n);
311}
312
313static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
314{
315 if (n && __access_ok((unsigned long) from, n))
316 return __copy_user((__force void __user *) to, from, n);
317 else
318 return n;
319}
320
321static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n)
322{
323 return __copy_user((__force void __user *) to, from, n);
324}
325
326#define __copy_to_user_inatomic __copy_to_user
327#define __copy_from_user_inatomic __copy_from_user
328
329static inline unsigned long __clear_user(void __user *addr, unsigned long size)
330{
331 unsigned long ret;
332
333 __asm__ __volatile__ (
334 ".section __ex_table,#alloc\n\t"
335 ".align 4\n\t"
336 ".word 1f,3\n\t"
337 ".previous\n\t"
338 "mov %2, %%o1\n"
339 "1:\n\t"
340 "call __bzero\n\t"
341 " mov %1, %%o0\n\t"
342 "mov %%o0, %0\n"
343 : "=r" (ret) : "r" (addr), "r" (size) :
344 "o0", "o1", "o2", "o3", "o4", "o5", "o7",
345 "g1", "g2", "g3", "g4", "g5", "g7", "cc");
346
347 return ret;
348}
349
350static inline unsigned long clear_user(void __user *addr, unsigned long n)
351{
352 if (n && __access_ok((unsigned long) addr, n))
353 return __clear_user(addr, n);
354 else
355 return n;
356}
357
358extern long __strncpy_from_user(char *dest, const char __user *src, long count);
359
360static inline long strncpy_from_user(char *dest, const char __user *src, long count)
361{
362 if (__access_ok((unsigned long) src, count))
363 return __strncpy_from_user(dest, src, count);
364 else
365 return -EFAULT;
366}
367
368extern long __strlen_user(const char __user *);
369extern long __strnlen_user(const char __user *, long len);
370
371static inline long strlen_user(const char __user *str)
372{
373 if (!access_ok(VERIFY_READ, str, 0))
374 return 0;
375 else
376 return __strlen_user(str);
377}
378
379static inline long strnlen_user(const char __user *str, long len)
380{
381 if (!access_ok(VERIFY_READ, str, 0))
382 return 0;
383 else
384 return __strnlen_user(str, len);
385}
386
387#endif /* __ASSEMBLY__ */
388
389#endif /* _ASM_UACCESS_H */