1 /* MN10300 userspace access functions
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
11 #ifndef _ASM_UACCESS_H
12 #define _ASM_UACCESS_H
15 * User space memory access functions
17 #include <linux/thread_info.h>
18 #include <linux/kernel.h>
20 #include <asm/errno.h>
23 #define VERIFY_WRITE 1
26 * The fs value determines whether argument validity checking should be
27 * performed or not. If get_fs() == USER_DS, checking is performed, with
28 * get_fs() == KERNEL_DS, checking is bypassed.
30 * For historical reasons, these macros are grossly misnamed.
32 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
34 #define KERNEL_XDS MAKE_MM_SEG(0xBFFFFFFF)
35 #define KERNEL_DS MAKE_MM_SEG(0x9FFFFFFF)
36 #define USER_DS MAKE_MM_SEG(TASK_SIZE)
38 #define get_ds() (KERNEL_DS)
39 #define get_fs() (current_thread_info()->addr_limit)
40 #define set_fs(x) (current_thread_info()->addr_limit = (x))
41 #define __kernel_ds_p() (current_thread_info()->addr_limit.seg == 0x9FFFFFFF)
43 #define segment_eq(a, b) ((a).seg == (b).seg)
45 #define __addr_ok(addr) \
46 ((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
49 * check that a range of addresses falls within the current address limit
51 static inline int ___range_ok(unsigned long addr
, unsigned int size
)
55 asm(" add %3,%1 \n" /* set C-flag if addr + size > 4Gb */
57 " cmp %4,%1 \n" /* jump if addr+size>limit (error) */
59 " clr %0 \n" /* mark okay */
61 : "=r"(flag
), "=&r"(tmp
)
62 : "1"(addr
), "ir"(size
),
63 "r"(current_thread_info()->addr_limit
.seg
), "0"(flag
)
70 #define __range_ok(addr, size) ___range_ok((unsigned long)(addr), (u32)(size))
72 #define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
73 #define __access_ok(addr, size) (__range_ok((addr), (size)) == 0)
75 static inline int verify_area(int type
, const void *addr
, unsigned long size
)
77 return access_ok(type
, addr
, size
) ? 0 : -EFAULT
;
82 * The exception table consists of pairs of addresses: the first is the
83 * address of an instruction that is allowed to fault, and the second is
84 * the address at which the program should continue. No registers are
85 * modified, so it is entirely up to the continuation code to figure out
88 * All the routines below use bits of fixup code that are out of line
89 * with the main instruction path. This means when everything is well,
90 * we don't even have to jump over them. Further, they do not intrude
91 * on our cache or tlb entries.
94 struct exception_table_entry
96 unsigned long insn
, fixup
;
99 /* Returns 0 if exception not found and fixup otherwise. */
100 extern int fixup_exception(struct pt_regs
*regs
);
102 #define put_user(x, ptr) __put_user_check((x), (ptr), sizeof(*(ptr)))
103 #define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)))
106 * The "__xxx" versions do not do address space checking, useful when
107 * doing multiple accesses to the same area (the user has to do the
108 * checks by hand with "access_ok()")
110 #define __put_user(x, ptr) __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
111 #define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
114 * The "xxx_ret" versions return constant specified in third argument, if
115 * something bad happens. These macros can be optimized for the
116 * case of just returning from the function xxx_ret is used.
119 #define put_user_ret(x, ptr, ret) \
120 ({ if (put_user((x), (ptr))) return (ret); })
121 #define get_user_ret(x, ptr, ret) \
122 ({ if (get_user((x), (ptr))) return (ret); })
123 #define __put_user_ret(x, ptr, ret) \
124 ({ if (__put_user((x), (ptr))) return (ret); })
125 #define __get_user_ret(x, ptr, ret) \
126 ({ if (__get_user((x), (ptr))) return (ret); })
128 struct __large_struct
{ unsigned long buf
[100]; };
129 #define __m(x) (*(struct __large_struct *)(x))
131 #define __get_user_nocheck(x, ptr, size) \
133 unsigned long __gu_addr; \
135 __gu_addr = (unsigned long) (ptr); \
138 unsigned char __gu_val; \
139 __get_user_asm("bu"); \
140 (x) = *(__force __typeof__(*(ptr))*) &__gu_val; \
144 unsigned short __gu_val; \
145 __get_user_asm("hu"); \
146 (x) = *(__force __typeof__(*(ptr))*) &__gu_val; \
150 unsigned int __gu_val; \
151 __get_user_asm(""); \
152 (x) = *(__force __typeof__(*(ptr))*) &__gu_val; \
156 __get_user_unknown(); \
162 #define __get_user_check(x, ptr, size) \
164 const __typeof__(*(ptr))* __guc_ptr = (ptr); \
166 if (likely(__access_ok((unsigned long) __guc_ptr, (size)))) \
167 _e = __get_user_nocheck((x), __guc_ptr, (size)); \
170 (x) = (__typeof__(x))0; \
175 #define __get_user_asm(INSN) \
179 " mov"INSN" %2,%1\n" \
182 " .section .fixup,\"ax\"\n" \
187 " .section __ex_table,\"a\"\n" \
191 : "=&r" (__gu_err), "=&r" (__gu_val) \
192 : "m" (__m(__gu_addr)), "i" (-EFAULT)); \
195 extern int __get_user_unknown(void);
197 #define __put_user_nocheck(x, ptr, size) \
200 __typeof__(*(ptr)) val; \
203 unsigned long __pu_addr; \
205 __pu_val.val = (x); \
206 __pu_addr = (unsigned long) (ptr); \
208 case 1: __put_user_asm("bu"); break; \
209 case 2: __put_user_asm("hu"); break; \
210 case 4: __put_user_asm("" ); break; \
211 case 8: __put_user_asm8(); break; \
212 default: __pu_err = __put_user_unknown(); break; \
217 #define __put_user_check(x, ptr, size) \
220 __typeof__(*(ptr)) val; \
223 unsigned long __pu_addr; \
225 __pu_val.val = (x); \
226 __pu_addr = (unsigned long) (ptr); \
227 if (likely(__access_ok(__pu_addr, size))) { \
229 case 1: __put_user_asm("bu"); break; \
230 case 2: __put_user_asm("hu"); break; \
231 case 4: __put_user_asm("" ); break; \
232 case 8: __put_user_asm8(); break; \
233 default: __pu_err = __put_user_unknown(); break; \
237 __pu_err = -EFAULT; \
242 #define __put_user_asm(INSN) \
246 " mov"INSN" %1,%2\n" \
249 " .section .fixup,\"ax\"\n" \
254 " .section __ex_table,\"a\"\n" \
259 : "r" (__pu_val.val), "m" (__m(__pu_addr)), \
264 #define __put_user_asm8() \
271 " .section .fixup,\"ax\" \n" \
276 " .section __ex_table,\"a\"\n" \
282 : "r" (__pu_val.bits[0]), "r" (__pu_val.bits[1]), \
283 "m" (__m(__pu_addr)), "m" (__m(__pu_addr+4)), \
288 extern int __put_user_unknown(void);
292 * Copy To/From Userspace
294 /* Generic arbitrary sized copy. */
295 #define __copy_user(to, from, size) \
299 const void *__from = from; \
302 "0: movbu (%0),%3;\n" \
303 "1: movbu %3,(%1);\n" \
309 " .section .fixup,\"ax\"\n" \
312 " .section __ex_table,\"a\"\n" \
317 : "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
318 : "0"(__from), "1"(__to), "2"(size) \
323 #define __copy_user_zeroing(to, from, size) \
327 const void *__from = from; \
330 "0: movbu (%0),%3;\n" \
331 "1: movbu %3,(%1);\n" \
337 " .section .fixup,\"ax\"\n" \
341 "4: movbu %3,(%1);\n" \
348 " .section __ex_table,\"a\"\n" \
353 : "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
354 : "0"(__from), "1"(__to), "2"(size) \
359 /* We let the __ versions of copy_from/to_user inline, because they're often
360 * used in fast paths and have only a small space overhead.
363 unsigned long __generic_copy_from_user_nocheck(void *to
, const void *from
,
366 __copy_user_zeroing(to
, from
, n
);
371 unsigned long __generic_copy_to_user_nocheck(void *to
, const void *from
,
374 __copy_user(to
, from
, n
);
380 #error "don't use - these macros don't increment to & from pointers"
381 /* Optimize just a little bit when we know the size of the move. */
382 #define __constant_copy_user(to, from, size) \
386 "0: movbu (%1),d3;\n" \
387 "1: movbu d3,(%2);\n" \
391 ".section .fixup,\"ax\"\n" \
394 ".section __ex_table,\"a\"\n" \
400 : "d"(size), "d"(to), "d"(from) \
404 /* Optimize just a little bit when we know the size of the move. */
405 #define __constant_copy_user_zeroing(to, from, size) \
409 "0: movbu (%1),d3;\n" \
410 "1: movbu d3,(%2);\n" \
414 ".section .fixup,\"ax\"\n" \
417 ".section __ex_table,\"a\"\n" \
423 : "d"(size), "d"(to), "d"(from) \
428 unsigned long __constant_copy_to_user(void *to
, const void *from
,
431 if (access_ok(VERIFY_WRITE
, to
, n
))
432 __constant_copy_user(to
, from
, n
);
437 unsigned long __constant_copy_from_user(void *to
, const void *from
,
440 if (access_ok(VERIFY_READ
, from
, n
))
441 __constant_copy_user_zeroing(to
, from
, n
);
446 unsigned long __constant_copy_to_user_nocheck(void *to
, const void *from
,
449 __constant_copy_user(to
, from
, n
);
454 unsigned long __constant_copy_from_user_nocheck(void *to
, const void *from
,
457 __constant_copy_user_zeroing(to
, from
, n
);
462 extern unsigned long __generic_copy_to_user(void __user
*, const void *,
464 extern unsigned long __generic_copy_from_user(void *, const void __user
*,
467 #define __copy_to_user_inatomic(to, from, n) \
468 __generic_copy_to_user_nocheck((to), (from), (n))
469 #define __copy_from_user_inatomic(to, from, n) \
470 __generic_copy_from_user_nocheck((to), (from), (n))
472 #define __copy_to_user(to, from, n) \
475 __copy_to_user_inatomic((to), (from), (n)); \
478 #define __copy_from_user(to, from, n) \
481 __copy_from_user_inatomic((to), (from), (n)); \
485 #define copy_to_user(to, from, n) __generic_copy_to_user((to), (from), (n))
486 #define copy_from_user(to, from, n) __generic_copy_from_user((to), (from), (n))
488 extern long strncpy_from_user(char *dst
, const char __user
*src
, long count
);
489 extern long __strncpy_from_user(char *dst
, const char __user
*src
, long count
);
490 extern long strnlen_user(const char __user
*str
, long n
);
491 #define strlen_user(str) strnlen_user(str, ~0UL >> 1)
492 extern unsigned long clear_user(void __user
*mem
, unsigned long len
);
493 extern unsigned long __clear_user(void __user
*mem
, unsigned long len
);
495 #endif /* _ASM_UACCESS_H */