182 lines
		
	
	
		
			4.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			182 lines
		
	
	
		
			4.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef __M68KNOMMU_UACCESS_H
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| #define __M68KNOMMU_UACCESS_H
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| 
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| /*
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|  * User space memory access functions
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|  */
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| #include <linux/sched.h>
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| #include <linux/mm.h>
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| #include <linux/string.h>
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| 
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| #include <asm/segment.h>
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| 
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| #define VERIFY_READ	0
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| #define VERIFY_WRITE	1
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| 
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| #define access_ok(type,addr,size)	_access_ok((unsigned long)(addr),(size))
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| 
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| /*
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|  * It is not enough to just have access_ok check for a real RAM address.
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|  * This would disallow the case of code/ro-data running XIP in flash/rom.
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|  * Ideally we would check the possible flash ranges too, but that is
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|  * currently not so easy.
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|  */
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| static inline int _access_ok(unsigned long addr, unsigned long size)
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| {
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| 	return 1;
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| }
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| 
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| /*
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|  * The exception table consists of pairs of addresses: the first is the
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|  * address of an instruction that is allowed to fault, and the second is
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|  * the address at which the program should continue.  No registers are
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|  * modified, so it is entirely up to the continuation code to figure out
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|  * what to do.
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|  *
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|  * All the routines below use bits of fixup code that are out of line
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|  * with the main instruction path.  This means when everything is well,
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|  * we don't even have to jump over them.  Further, they do not intrude
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|  * on our cache or tlb entries.
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|  */
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| 
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| struct exception_table_entry
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| {
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| 	unsigned long insn, fixup;
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| };
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| 
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| /* Returns 0 if exception not found and fixup otherwise.  */
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| extern unsigned long search_exception_table(unsigned long);
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| 
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| 
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| /*
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|  * These are the main single-value transfer routines.  They automatically
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|  * use the right size if we just have the right pointer type.
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|  */
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| 
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| #define put_user(x, ptr)				\
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| ({							\
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|     int __pu_err = 0;					\
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|     typeof(*(ptr)) __pu_val = (x);			\
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|     switch (sizeof (*(ptr))) {				\
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|     case 1:						\
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| 	__put_user_asm(__pu_err, __pu_val, ptr, b);	\
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| 	break;						\
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|     case 2:						\
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| 	__put_user_asm(__pu_err, __pu_val, ptr, w);	\
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| 	break;						\
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|     case 4:						\
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| 	__put_user_asm(__pu_err, __pu_val, ptr, l);	\
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| 	break;						\
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|     case 8:						\
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| 	memcpy(ptr, &__pu_val, sizeof (*(ptr))); \
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| 	break;						\
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|     default:						\
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| 	__pu_err = __put_user_bad();			\
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| 	break;						\
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|     }							\
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|     __pu_err;						\
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| })
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| #define __put_user(x, ptr) put_user(x, ptr)
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| 
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| extern int __put_user_bad(void);
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| 
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| /*
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|  * Tell gcc we read from memory instead of writing: this is because
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|  * we do not write to any memory gcc knows about, so there are no
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|  * aliasing issues.
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|  */
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| 
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| #define __ptr(x) ((unsigned long *)(x))
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| 
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| #define __put_user_asm(err,x,ptr,bwl)				\
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| 	__asm__ ("move" #bwl " %0,%1"				\
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| 		: /* no outputs */						\
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| 		:"d" (x),"m" (*__ptr(ptr)) : "memory")
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| 
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| #define get_user(x, ptr)					\
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| ({								\
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|     int __gu_err = 0;						\
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|     typeof(x) __gu_val = 0;					\
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|     switch (sizeof(*(ptr))) {					\
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|     case 1:							\
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| 	__get_user_asm(__gu_err, __gu_val, ptr, b, "=d");	\
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| 	break;							\
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|     case 2:							\
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| 	__get_user_asm(__gu_err, __gu_val, ptr, w, "=r");	\
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| 	break;							\
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|     case 4:							\
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| 	__get_user_asm(__gu_err, __gu_val, ptr, l, "=r");	\
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| 	break;							\
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|     case 8:							\
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| 	memcpy((void *) &__gu_val, ptr, sizeof (*(ptr)));	\
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| 	break;							\
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|     default:							\
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| 	__gu_val = 0;						\
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| 	__gu_err = __get_user_bad();				\
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| 	break;							\
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|     }								\
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|     (x) = (typeof(*(ptr))) __gu_val;				\
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|     __gu_err;							\
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| })
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| #define __get_user(x, ptr) get_user(x, ptr)
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| 
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| extern int __get_user_bad(void);
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| 
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| #define __get_user_asm(err,x,ptr,bwl,reg)			\
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| 	__asm__ ("move" #bwl " %1,%0"				\
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| 		 : "=d" (x)					\
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| 		 : "m" (*__ptr(ptr)))
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| 
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| #define copy_from_user(to, from, n)		(memcpy(to, from, n), 0)
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| #define copy_to_user(to, from, n)		(memcpy(to, from, n), 0)
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| 
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| #define __copy_from_user(to, from, n) copy_from_user(to, from, n)
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| #define __copy_to_user(to, from, n) copy_to_user(to, from, n)
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| #define __copy_to_user_inatomic __copy_to_user
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| #define __copy_from_user_inatomic __copy_from_user
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| 
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| #define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
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| 
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| #define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
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| 
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| /*
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|  * Copy a null terminated string from userspace.
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|  */
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| 
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| static inline long
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| strncpy_from_user(char *dst, const char *src, long count)
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| {
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| 	char *tmp;
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| 	strncpy(dst, src, count);
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| 	for (tmp = dst; *tmp && count > 0; tmp++, count--)
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| 		;
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| 	return(tmp - dst); /* DAVIDM should we count a NUL ?  check getname */
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| }
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| 
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| /*
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|  * Return the size of a string (including the ending 0)
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|  *
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|  * Return 0 on exception, a value greater than N if too long
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|  */
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| static inline long strnlen_user(const char *src, long n)
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| {
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| 	return(strlen(src) + 1); /* DAVIDM make safer */
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| }
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| 
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| #define strlen_user(str) strnlen_user(str, 32767)
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| 
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| /*
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|  * Zero Userspace
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|  */
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| 
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| static inline unsigned long
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| __clear_user(void *to, unsigned long n)
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| {
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| 	memset(to, 0, n);
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| 	return 0;
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| }
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| 
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| #define	clear_user(to,n)	__clear_user(to,n)
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| 
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| #endif /* _M68KNOMMU_UACCESS_H */
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