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-rw-r--r--include/asm-x86/uaccess_64.h384
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diff --git a/include/asm-x86/uaccess_64.h b/include/asm-x86/uaccess_64.h
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1#ifndef __X86_64_UACCESS_H
2#define __X86_64_UACCESS_H
3
4/*
5 * User space memory access functions
6 */
7#include <linux/compiler.h>
8#include <linux/errno.h>
9#include <linux/prefetch.h>
10#include <asm/page.h>
11
12#define VERIFY_READ 0
13#define VERIFY_WRITE 1
14
15/*
16 * The fs value determines whether argument validity checking should be
17 * performed or not. If get_fs() == USER_DS, checking is performed, with
18 * get_fs() == KERNEL_DS, checking is bypassed.
19 *
20 * For historical reasons, these macros are grossly misnamed.
21 */
22
23#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
24
25#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFFFFFFFFFUL)
26#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
27
28#define get_ds() (KERNEL_DS)
29#define get_fs() (current_thread_info()->addr_limit)
30#define set_fs(x) (current_thread_info()->addr_limit = (x))
31
32#define segment_eq(a,b) ((a).seg == (b).seg)
33
34#define __addr_ok(addr) (!((unsigned long)(addr) & (current_thread_info()->addr_limit.seg)))
35
36/*
37 * Uhhuh, this needs 65-bit arithmetic. We have a carry..
38 */
39#define __range_not_ok(addr,size) ({ \
40 unsigned long flag,roksum; \
41 __chk_user_ptr(addr); \
42 asm("# range_ok\n\r" \
43 "addq %3,%1 ; sbbq %0,%0 ; cmpq %1,%4 ; sbbq $0,%0" \
44 :"=&r" (flag), "=r" (roksum) \
45 :"1" (addr),"g" ((long)(size)),"g" (current_thread_info()->addr_limit.seg)); \
46 flag; })
47
48#define access_ok(type, addr, size) (__range_not_ok(addr,size) == 0)
49
50/*
51 * The exception table consists of pairs of addresses: the first is the
52 * address of an instruction that is allowed to fault, and the second is
53 * the address at which the program should continue. No registers are
54 * modified, so it is entirely up to the continuation code to figure out
55 * what to do.
56 *
57 * All the routines below use bits of fixup code that are out of line
58 * with the main instruction path. This means when everything is well,
59 * we don't even have to jump over them. Further, they do not intrude
60 * on our cache or tlb entries.
61 */
62
63struct exception_table_entry
64{
65 unsigned long insn, fixup;
66};
67
68#define ARCH_HAS_SEARCH_EXTABLE
69
70/*
71 * These are the main single-value transfer routines. They automatically
72 * use the right size if we just have the right pointer type.
73 *
74 * This gets kind of ugly. We want to return _two_ values in "get_user()"
75 * and yet we don't want to do any pointers, because that is too much
76 * of a performance impact. Thus we have a few rather ugly macros here,
77 * and hide all the ugliness from the user.
78 *
79 * The "__xxx" versions of the user access functions are versions that
80 * do not verify the address space, that must have been done previously
81 * with a separate "access_ok()" call (this is used when we do multiple
82 * accesses to the same area of user memory).
83 */
84
85#define __get_user_x(size,ret,x,ptr) \
86 asm volatile("call __get_user_" #size \
87 :"=a" (ret),"=d" (x) \
88 :"c" (ptr) \
89 :"r8")
90
91/* Careful: we have to cast the result to the type of the pointer for sign reasons */
92#define get_user(x,ptr) \
93({ unsigned long __val_gu; \
94 int __ret_gu; \
95 __chk_user_ptr(ptr); \
96 switch(sizeof (*(ptr))) { \
97 case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \
98 case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \
99 case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \
100 case 8: __get_user_x(8,__ret_gu,__val_gu,ptr); break; \
101 default: __get_user_bad(); break; \
102 } \
103 (x) = (__force typeof(*(ptr)))__val_gu; \
104 __ret_gu; \
105})
106
107extern void __put_user_1(void);
108extern void __put_user_2(void);
109extern void __put_user_4(void);
110extern void __put_user_8(void);
111extern void __put_user_bad(void);
112
113#define __put_user_x(size,ret,x,ptr) \
114 asm volatile("call __put_user_" #size \
115 :"=a" (ret) \
116 :"c" (ptr),"d" (x) \
117 :"r8")
118
119#define put_user(x,ptr) \
120 __put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
121
122#define __get_user(x,ptr) \
123 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
124#define __put_user(x,ptr) \
125 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
126
127#define __get_user_unaligned __get_user
128#define __put_user_unaligned __put_user
129
130#define __put_user_nocheck(x,ptr,size) \
131({ \
132 int __pu_err; \
133 __put_user_size((x),(ptr),(size),__pu_err); \
134 __pu_err; \
135})
136
137
138#define __put_user_check(x,ptr,size) \
139({ \
140 int __pu_err; \
141 typeof(*(ptr)) __user *__pu_addr = (ptr); \
142 switch (size) { \
143 case 1: __put_user_x(1,__pu_err,x,__pu_addr); break; \
144 case 2: __put_user_x(2,__pu_err,x,__pu_addr); break; \
145 case 4: __put_user_x(4,__pu_err,x,__pu_addr); break; \
146 case 8: __put_user_x(8,__pu_err,x,__pu_addr); break; \
147 default: __put_user_bad(); \
148 } \
149 __pu_err; \
150})
151
152#define __put_user_size(x,ptr,size,retval) \
153do { \
154 retval = 0; \
155 __chk_user_ptr(ptr); \
156 switch (size) { \
157 case 1: __put_user_asm(x,ptr,retval,"b","b","iq",-EFAULT); break;\
158 case 2: __put_user_asm(x,ptr,retval,"w","w","ir",-EFAULT); break;\
159 case 4: __put_user_asm(x,ptr,retval,"l","k","ir",-EFAULT); break;\
160 case 8: __put_user_asm(x,ptr,retval,"q","","Zr",-EFAULT); break;\
161 default: __put_user_bad(); \
162 } \
163} while (0)
164
165/* FIXME: this hack is definitely wrong -AK */
166struct __large_struct { unsigned long buf[100]; };
167#define __m(x) (*(struct __large_struct __user *)(x))
168
169/*
170 * Tell gcc we read from memory instead of writing: this is because
171 * we do not write to any memory gcc knows about, so there are no
172 * aliasing issues.
173 */
174#define __put_user_asm(x, addr, err, itype, rtype, ltype, errno) \
175 asm volatile( \
176 "1: mov"itype" %"rtype"1,%2\n" \
177 "2:\n" \
178 ".section .fixup,\"ax\"\n" \
179 "3: mov %3,%0\n" \
180 " jmp 2b\n" \
181 ".previous\n" \
182 ".section __ex_table,\"a\"\n" \
183 " .align 8\n" \
184 " .quad 1b,3b\n" \
185 ".previous" \
186 : "=r"(err) \
187 : ltype (x), "m"(__m(addr)), "i"(errno), "0"(err))
188
189
190#define __get_user_nocheck(x,ptr,size) \
191({ \
192 int __gu_err; \
193 unsigned long __gu_val; \
194 __get_user_size(__gu_val,(ptr),(size),__gu_err); \
195 (x) = (__force typeof(*(ptr)))__gu_val; \
196 __gu_err; \
197})
198
199extern int __get_user_1(void);
200extern int __get_user_2(void);
201extern int __get_user_4(void);
202extern int __get_user_8(void);
203extern int __get_user_bad(void);
204
205#define __get_user_size(x,ptr,size,retval) \
206do { \
207 retval = 0; \
208 __chk_user_ptr(ptr); \
209 switch (size) { \
210 case 1: __get_user_asm(x,ptr,retval,"b","b","=q",-EFAULT); break;\
211 case 2: __get_user_asm(x,ptr,retval,"w","w","=r",-EFAULT); break;\
212 case 4: __get_user_asm(x,ptr,retval,"l","k","=r",-EFAULT); break;\
213 case 8: __get_user_asm(x,ptr,retval,"q","","=r",-EFAULT); break;\
214 default: (x) = __get_user_bad(); \
215 } \
216} while (0)
217
218#define __get_user_asm(x, addr, err, itype, rtype, ltype, errno) \
219 asm volatile( \
220 "1: mov"itype" %2,%"rtype"1\n" \
221 "2:\n" \
222 ".section .fixup,\"ax\"\n" \
223 "3: mov %3,%0\n" \
224 " xor"itype" %"rtype"1,%"rtype"1\n" \
225 " jmp 2b\n" \
226 ".previous\n" \
227 ".section __ex_table,\"a\"\n" \
228 " .align 8\n" \
229 " .quad 1b,3b\n" \
230 ".previous" \
231 : "=r"(err), ltype (x) \
232 : "m"(__m(addr)), "i"(errno), "0"(err))
233
234/*
235 * Copy To/From Userspace
236 */
237
238/* Handles exceptions in both to and from, but doesn't do access_ok */
239__must_check unsigned long
240copy_user_generic(void *to, const void *from, unsigned len);
241
242__must_check unsigned long
243copy_to_user(void __user *to, const void *from, unsigned len);
244__must_check unsigned long
245copy_from_user(void *to, const void __user *from, unsigned len);
246__must_check unsigned long
247copy_in_user(void __user *to, const void __user *from, unsigned len);
248
249static __always_inline __must_check
250int __copy_from_user(void *dst, const void __user *src, unsigned size)
251{
252 int ret = 0;
253 if (!__builtin_constant_p(size))
254 return copy_user_generic(dst,(__force void *)src,size);
255 switch (size) {
256 case 1:__get_user_asm(*(u8*)dst,(u8 __user *)src,ret,"b","b","=q",1);
257 return ret;
258 case 2:__get_user_asm(*(u16*)dst,(u16 __user *)src,ret,"w","w","=r",2);
259 return ret;
260 case 4:__get_user_asm(*(u32*)dst,(u32 __user *)src,ret,"l","k","=r",4);
261 return ret;
262 case 8:__get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",8);
263 return ret;
264 case 10:
265 __get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",16);
266 if (unlikely(ret)) return ret;
267 __get_user_asm(*(u16*)(8+(char*)dst),(u16 __user *)(8+(char __user *)src),ret,"w","w","=r",2);
268 return ret;
269 case 16:
270 __get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",16);
271 if (unlikely(ret)) return ret;
272 __get_user_asm(*(u64*)(8+(char*)dst),(u64 __user *)(8+(char __user *)src),ret,"q","","=r",8);
273 return ret;
274 default:
275 return copy_user_generic(dst,(__force void *)src,size);
276 }
277}
278
279static __always_inline __must_check
280int __copy_to_user(void __user *dst, const void *src, unsigned size)
281{
282 int ret = 0;
283 if (!__builtin_constant_p(size))
284 return copy_user_generic((__force void *)dst,src,size);
285 switch (size) {
286 case 1:__put_user_asm(*(u8*)src,(u8 __user *)dst,ret,"b","b","iq",1);
287 return ret;
288 case 2:__put_user_asm(*(u16*)src,(u16 __user *)dst,ret,"w","w","ir",2);
289 return ret;
290 case 4:__put_user_asm(*(u32*)src,(u32 __user *)dst,ret,"l","k","ir",4);
291 return ret;
292 case 8:__put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",8);
293 return ret;
294 case 10:
295 __put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",10);
296 if (unlikely(ret)) return ret;
297 asm("":::"memory");
298 __put_user_asm(4[(u16*)src],4+(u16 __user *)dst,ret,"w","w","ir",2);
299 return ret;
300 case 16:
301 __put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",16);
302 if (unlikely(ret)) return ret;
303 asm("":::"memory");
304 __put_user_asm(1[(u64*)src],1+(u64 __user *)dst,ret,"q","","ir",8);
305 return ret;
306 default:
307 return copy_user_generic((__force void *)dst,src,size);
308 }
309}
310
311static __always_inline __must_check
312int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
313{
314 int ret = 0;
315 if (!__builtin_constant_p(size))
316 return copy_user_generic((__force void *)dst,(__force void *)src,size);
317 switch (size) {
318 case 1: {
319 u8 tmp;
320 __get_user_asm(tmp,(u8 __user *)src,ret,"b","b","=q",1);
321 if (likely(!ret))
322 __put_user_asm(tmp,(u8 __user *)dst,ret,"b","b","iq",1);
323 return ret;
324 }
325 case 2: {
326 u16 tmp;
327 __get_user_asm(tmp,(u16 __user *)src,ret,"w","w","=r",2);
328 if (likely(!ret))
329 __put_user_asm(tmp,(u16 __user *)dst,ret,"w","w","ir",2);
330 return ret;
331 }
332
333 case 4: {
334 u32 tmp;
335 __get_user_asm(tmp,(u32 __user *)src,ret,"l","k","=r",4);
336 if (likely(!ret))
337 __put_user_asm(tmp,(u32 __user *)dst,ret,"l","k","ir",4);
338 return ret;
339 }
340 case 8: {
341 u64 tmp;
342 __get_user_asm(tmp,(u64 __user *)src,ret,"q","","=r",8);
343 if (likely(!ret))
344 __put_user_asm(tmp,(u64 __user *)dst,ret,"q","","ir",8);
345 return ret;
346 }
347 default:
348 return copy_user_generic((__force void *)dst,(__force void *)src,size);
349 }
350}
351
352__must_check long
353strncpy_from_user(char *dst, const char __user *src, long count);
354__must_check long
355__strncpy_from_user(char *dst, const char __user *src, long count);
356__must_check long strnlen_user(const char __user *str, long n);
357__must_check long __strnlen_user(const char __user *str, long n);
358__must_check long strlen_user(const char __user *str);
359__must_check unsigned long clear_user(void __user *mem, unsigned long len);
360__must_check unsigned long __clear_user(void __user *mem, unsigned long len);
361
362__must_check long __copy_from_user_inatomic(void *dst, const void __user *src, unsigned size);
363
364static __must_check __always_inline int
365__copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
366{
367 return copy_user_generic((__force void *)dst, src, size);
368}
369
370#define ARCH_HAS_NOCACHE_UACCESS 1
371extern long __copy_user_nocache(void *dst, const void __user *src, unsigned size, int zerorest);
372
373static inline int __copy_from_user_nocache(void *dst, const void __user *src, unsigned size)
374{
375 might_sleep();
376 return __copy_user_nocache(dst, src, size, 1);
377}
378
379static inline int __copy_from_user_inatomic_nocache(void *dst, const void __user *src, unsigned size)
380{
381 return __copy_user_nocache(dst, src, size, 0);
382}
383
384#endif /* __X86_64_UACCESS_H */
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-30 21:15:57 -0500