1 /* $Id: uaccess.h,v 1.11 2003/10/13 07:21:20 lethal Exp $
3 * User space memory access functions
5 * Copyright (C) 1999, 2002 Niibe Yutaka
6 * Copyright (C) 2003 Paul Mundt
9 * MIPS implementation version 1.15 by
10 * Copyright (C) 1996, 1997, 1998 by Ralf Baechle
13 #ifndef __ASM_SH_UACCESS_H
14 #define __ASM_SH_UACCESS_H
16 #include <linux/errno.h>
17 #include <linux/sched.h>
20 * NOTE: Macro/functions in this file depends on threads_info.h implementation.
24 * USER_ADDR_LIMIT == 0x80000000
28 #define VERIFY_WRITE 1
31 unsigned int is_user_space;
35 * The fs value determines whether argument validity checking should be
36 * performed or not. If get_fs() == USER_DS, checking is performed, with
37 * get_fs() == KERNEL_DS, checking is bypassed.
39 * For historical reasons (Data Segment Register?), these macros are misnamed.
42 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
43 #define segment_eq(a,b) ((a).is_user_space == (b).is_user_space)
45 #define USER_ADDR_LIMIT 0x80000000
47 #define KERNEL_DS MAKE_MM_SEG(0)
48 #define USER_DS MAKE_MM_SEG(1)
50 #define get_ds() (KERNEL_DS)
52 #if !defined(CONFIG_MMU)
53 static inline mm_segment_t get_fs(void)
58 static inline void set_fs(mm_segment_t s)
63 * __access_ok: Check if address with size is OK or not.
65 * If we don't have an MMU (or if its disabled) the only thing we really have
66 * to look out for is if the address resides somewhere outside of what
67 * available RAM we have.
69 * TODO: This check could probably also stand to be restricted somewhat more..
70 * though it still does the Right Thing(tm) for the time being.
72 static inline int __access_ok(unsigned long addr, unsigned long size)
74 extern unsigned long memory_start, memory_end;
76 return ((addr >= memory_start) && ((addr + size) < memory_end));
78 #else /* CONFIG_MMU */
79 static inline mm_segment_t get_fs(void)
81 return MAKE_MM_SEG(test_thread_flag(TIF_USERSPACE));
84 static inline void set_fs(mm_segment_t s)
86 unsigned long ti, flag;
89 "mov.l @(8,%0), %1\n\t"
94 : "=&r" (ti), "=&r" (flag)
95 : "r" (s.is_user_space)
99 set_thread_flag(TIF_USERSPACE);
101 clear_thread_flag(TIF_USERSPACE);
106 * __access_ok: Check if address with size is OK or not.
108 * We do three checks:
109 * (1) is it user space?
110 * (2) addr + size --> carry?
111 * (3) addr + size >= 0x80000000 (USER_ADDR_LIMIT)
113 * (1) (2) (3) | RESULT
123 static inline int __access_ok(unsigned long addr, unsigned long size)
125 unsigned long flag, tmp;
127 __asm__("stc r7_bank, %0\n\t"
128 "mov.l @(8,%0), %0\n\t"
135 : "=&z" (flag), "=r" (tmp)
136 : "r" (addr), "1" (size)
141 #endif /* CONFIG_MMU */
143 static inline int access_ok(int type, const void __user *p, unsigned long size)
145 unsigned long addr = (unsigned long)p;
146 return __access_ok(addr, size);
149 static inline int verify_area(int type, const void __user * addr, unsigned long size)
151 return access_ok(type,addr,size) ? 0 : -EFAULT;
155 * Uh, these should become the main single-value transfer routines ...
156 * They automatically use the right size if we just have the right
159 * As SuperH uses the same address space for kernel and user data, we
160 * can just do these as direct assignments.
163 * (a) re-use the arguments for side effects (sizeof is ok)
164 * (b) require any knowledge of processes at this stage
166 #define put_user(x,ptr) __put_user_check((x),(ptr),sizeof(*(ptr)))
167 #define get_user(x,ptr) __get_user_check((x),(ptr),sizeof(*(ptr)))
170 * The "__xxx" versions do not do address space checking, useful when
171 * doing multiple accesses to the same area (the user has to do the
172 * checks by hand with "access_ok()")
174 #define __put_user(x,ptr) \
175 __put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
176 #define __get_user(x,ptr) \
177 __get_user_nocheck((x),(ptr),sizeof(*(ptr)))
179 struct __large_struct { unsigned long buf[100]; };
180 #define __m(x) (*(struct __large_struct *)(x))
182 #define __get_user_size(x,ptr,size,retval) \
187 __get_user_asm(x, ptr, retval, "b"); \
190 __get_user_asm(x, ptr, retval, "w"); \
193 __get_user_asm(x, ptr, retval, "l"); \
196 __get_user_unknown(); \
201 #define __get_user_nocheck(x,ptr,size) \
203 long __gu_err, __gu_val; \
204 __get_user_size(__gu_val, (ptr), (size), __gu_err); \
205 (x) = (__typeof__(*(ptr)))__gu_val; \
209 #define __get_user_check(x,ptr,size) \
211 long __gu_err, __gu_val; \
214 __get_user_1(__gu_val, (ptr), __gu_err); \
217 __get_user_2(__gu_val, (ptr), __gu_err); \
220 __get_user_4(__gu_val, (ptr), __gu_err); \
223 __get_user_unknown(); \
227 (x) = (__typeof__(*(ptr)))__gu_val; \
231 #define __get_user_1(x,addr,err) ({ \
232 __asm__("stc r7_bank, %1\n\t" \
233 "mov.l @(8,%1), %1\n\t" \
243 "mov.b @%2, %1\n\t" \
246 ".section __ex_table,\"a\"\n\t" \
249 : "=&r" (err), "=&r" (x) \
254 #define __get_user_2(x,addr,err) ({ \
255 __asm__("stc r7_bank, %1\n\t" \
256 "mov.l @(8,%1), %1\n\t" \
266 "mov.w @%2, %1\n\t" \
269 ".section __ex_table,\"a\"\n\t" \
272 : "=&r" (err), "=&r" (x) \
277 #define __get_user_4(x,addr,err) ({ \
278 __asm__("stc r7_bank, %1\n\t" \
279 "mov.l @(8,%1), %1\n\t" \
289 "mov.l @%2, %1\n\t" \
291 ".section __ex_table,\"a\"\n\t" \
294 : "=&r" (err), "=&r" (x) \
299 #define __get_user_asm(x, addr, err, insn) \
301 __asm__ __volatile__( \
303 "mov." insn " %2, %1\n\t" \
306 ".section .fixup,\"ax\"\n" \
314 ".section __ex_table,\"a\"\n\t" \
317 :"=&r" (err), "=&r" (x) \
318 :"m" (__m(addr)), "i" (-EFAULT)); })
320 extern void __get_user_unknown(void);
322 #define __put_user_size(x,ptr,size,retval) \
327 __put_user_asm(x, ptr, retval, "b"); \
330 __put_user_asm(x, ptr, retval, "w"); \
333 __put_user_asm(x, ptr, retval, "l"); \
336 __put_user_u64(x, ptr, retval); \
339 __put_user_unknown(); \
343 #define __put_user_nocheck(x,ptr,size) \
346 __put_user_size((x),(ptr),(size),__pu_err); \
350 #define __put_user_check(x,ptr,size) \
352 long __pu_err = -EFAULT; \
353 __typeof__(*(ptr)) *__pu_addr = (ptr); \
355 if (__access_ok((unsigned long)__pu_addr,size)) \
356 __put_user_size((x),__pu_addr,(size),__pu_err); \
360 #define __put_user_asm(x, addr, err, insn) \
362 __asm__ __volatile__( \
364 "mov." insn " %1, %2\n\t" \
367 ".section .fixup,\"ax\"\n" \
375 ".section __ex_table,\"a\"\n\t" \
379 :"r" (x), "m" (__m(addr)), "i" (-EFAULT) \
382 #if defined(__LITTLE_ENDIAN__)
383 #define __put_user_u64(val,addr,retval) \
385 __asm__ __volatile__( \
388 "mov.l %S1,%T2\n\t" \
391 ".section .fixup,\"ax\"\n" \
399 ".section __ex_table,\"a\"\n\t" \
403 : "r" (val), "m" (__m(addr)), "i" (-EFAULT) \
406 #define __put_user_u64(val,addr,retval) \
408 __asm__ __volatile__( \
411 "mov.l %R1,%T2\n\t" \
414 ".section .fixup,\"ax\"\n" \
422 ".section __ex_table,\"a\"\n\t" \
426 : "r" (val), "m" (__m(addr)), "i" (-EFAULT) \
430 extern void __put_user_unknown(void);
432 /* Generic arbitrary sized copy. */
433 /* Return the number of bytes NOT copied */
434 extern __kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
436 #define copy_to_user(to,from,n) ({ \
437 void *__copy_to = (void *) (to); \
438 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
439 __kernel_size_t __copy_res; \
440 if(__copy_size && __access_ok((unsigned long)__copy_to, __copy_size)) { \
441 __copy_res = __copy_user(__copy_to, (void *) (from), __copy_size); \
442 } else __copy_res = __copy_size; \
445 #define __copy_to_user(to,from,n) \
446 __copy_user((void *)(to), \
449 #define copy_from_user(to,from,n) ({ \
450 void *__copy_to = (void *) (to); \
451 void *__copy_from = (void *) (from); \
452 __kernel_size_t __copy_size = (__kernel_size_t) (n); \
453 __kernel_size_t __copy_res; \
454 if(__copy_size && __access_ok((unsigned long)__copy_from, __copy_size)) { \
455 __copy_res = __copy_user(__copy_to, __copy_from, __copy_size); \
456 } else __copy_res = __copy_size; \
459 #define __copy_from_user(to,from,n) \
460 __copy_user((void *)(to), \
464 * Clear the area and return remaining number of bytes
465 * (on failure. Usually it's 0.)
467 extern __kernel_size_t __clear_user(void *addr, __kernel_size_t size);
469 #define clear_user(addr,n) ({ \
470 void * __cl_addr = (addr); \
471 unsigned long __cl_size = (n); \
472 if (__cl_size && __access_ok(((unsigned long)(__cl_addr)), __cl_size)) \
473 __cl_size = __clear_user(__cl_addr, __cl_size); \
476 static __inline__ int
477 __strncpy_from_user(unsigned long __dest, unsigned long __user __src, int __count)
480 unsigned long __dummy, _d, _s;
482 __asm__ __volatile__(
495 ".section .fixup,\"ax\"\n"
503 ".section __ex_table,\"a\"\n"
507 : "=r" (res), "=&z" (__dummy), "=r" (_s), "=r" (_d)
508 : "0" (__count), "2" (__src), "3" (__dest), "r" (__count),
515 #define strncpy_from_user(dest,src,count) ({ \
516 unsigned long __sfu_src = (unsigned long) (src); \
517 int __sfu_count = (int) (count); \
518 long __sfu_res = -EFAULT; \
519 if(__access_ok(__sfu_src, __sfu_count)) { \
520 __sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \
524 * Return the size of a string (including the ending 0!)
526 static __inline__ long __strnlen_user(const char __user *__s, long __n)
529 unsigned long __dummy;
531 __asm__ __volatile__(
536 "mov.b @(%0,%3), %1\n\t"
541 ".section .fixup,\"ax\"\n"
549 ".section __ex_table,\"a\"\n"
553 : "=z" (res), "=&r" (__dummy)
554 : "0" (0), "r" (__s), "r" (__n), "i" (-EFAULT)
559 static __inline__ long strnlen_user(const char __user *s, long n)
561 if (!access_ok(VERIFY_READ, s, n))
564 return __strnlen_user(s, n);
567 static __inline__ long strlen_user(const char __user *s)
569 if (!access_ok(VERIFY_READ, s, 0))
572 return __strnlen_user(s, ~0UL >> 1);
576 * The exception table consists of pairs of addresses: the first is the
577 * address of an instruction that is allowed to fault, and the second is
578 * the address at which the program should continue. No registers are
579 * modified, so it is entirely up to the continuation code to figure out
582 * All the routines below use bits of fixup code that are out of line
583 * with the main instruction path. This means when everything is well,
584 * we don't even have to jump over them. Further, they do not intrude
585 * on our cache or tlb entries.
588 struct exception_table_entry
590 unsigned long insn, fixup;
593 extern int fixup_exception(struct pt_regs *regs);
595 #endif /* __ASM_SH_UACCESS_H */