blob: bc6853b221770dd1b10a3e2038200bea4b66ddea [file] [log] [blame]
#ifndef _ASMARM_UACCESS_H
#define _ASMARM_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/sched.h>
#include <asm/errno.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
/*
* The exception table consists of pairs of addresses: the first is the
* address of an instruction that is allowed to fault, and the second is
* the address at which the program should continue. No registers are
* modified, so it is entirely up to the continuation code to figure out
* what to do.
*
* All the routines below use bits of fixup code that are out of line
* with the main instruction path. This means when everything is well,
* we don't even have to jump over them. Further, they do not intrude
* on our cache or tlb entries.
*/
struct exception_table_entry
{
unsigned long insn, fixup;
};
/* Returns 0 if exception not found and fixup otherwise. */
extern unsigned long search_exception_table(unsigned long);
#define get_ds() (KERNEL_DS)
#define get_fs() (current_thread_info()->addr_limit)
#define segment_eq(a,b) ((a) == (b))
#include <asm/proc/uaccess.h>
#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
static inline int verify_area(int type, const void * addr, unsigned long size)
{
return access_ok(type, addr, size) ? 0 : -EFAULT;
}
/*
* Single-value transfer routines. They automatically use the right
* size if we just have the right pointer type. Note that the functions
* which read from user space (*get_*) need to take care not to leak
* kernel data even if the calling code is buggy and fails to check
* the return value. This means zeroing out the destination variable
* or buffer on error. Normally this is done out of line by the
* fixup code, but there are a few places where it intrudes on the
* main code path. When we only write to user space, there is no
* problem.
*
* The "__xxx" versions of the user access functions do not verify the
* address space - it must have been done previously with a separate
* "access_ok()" call.
*
* The "xxx_error" versions set the third argument to EFAULT if an
* error occurs, and leave it unchanged on success. Note that these
* versions are void (ie, don't return a value as such).
*/
extern int __get_user_1(void *);
extern int __get_user_2(void *);
extern int __get_user_4(void *);
extern int __get_user_8(void *);
extern int __get_user_bad(void);
#define __get_user_x(__r1,__p,__e,__s,__i...) \
__asm__ __volatile__ ("bl __get_user_" #__s \
: "=&r" (__e), "=r" (__r1) \
: "0" (__p) \
: __i)
#define get_user(x,p) \
({ \
const register typeof(*(p)) *__p asm("r0") = (p); \
register typeof(*(p)) __r1 asm("r1"); \
register int __e asm("r0"); \
switch (sizeof(*(p))) { \
case 1: \
__get_user_x(__r1, __p, __e, 1, "lr"); \
break; \
case 2: \
__get_user_x(__r1, __p, __e, 2, "r2", "lr"); \
break; \
case 4: \
__get_user_x(__r1, __p, __e, 4, "lr"); \
break; \
case 8: \
__get_user_x(__r1, __p, __e, 8, "lr"); \
break; \
default: __e = __get_user_bad(); break; \
} \
x = __r1; \
__e; \
})
#define __get_user(x,p) __get_user_nocheck((x),(p),sizeof(*(p)))
#define __get_user_error(x,p,e) __get_user_nocheck_error((x),(p),sizeof(*(p)),(e))
extern int __put_user_1(void *, unsigned int);
extern int __put_user_2(void *, unsigned int);
extern int __put_user_4(void *, unsigned int);
extern int __put_user_8(void *, unsigned long long);
extern int __put_user_bad(void);
#define __put_user_x(__r1,__p,__e,__s,__i...) \
__asm__ __volatile__ ("bl __put_user_" #__s \
: "=&r" (__e) \
: "0" (__p), "r" (__r1) \
: __i)
#define put_user(x,p) \
({ \
const register typeof(*(p)) __r1 asm("r1") = (x); \
const register typeof(*(p)) *__p asm("r0") = (p); \
register int __e asm("r0"); \
switch (sizeof(*(p))) { \
case 1: \
__put_user_x(__r1, __p, __e, 1, "r2", "lr"); \
break; \
case 2: \
__put_user_x(__r1, __p, __e, 2, "r2", "lr"); \
break; \
case 4: \
__put_user_x(__r1, __p, __e, 4, "r2", "lr"); \
break; \
case 8: \
__put_user_x(__r1, __p, __e, 8, "ip", "lr"); \
break; \
default: __e = __put_user_bad(); break; \
} \
__e; \
})
#define __put_user(x,p) __put_user_nocheck((__typeof(*(p)))(x),(p),sizeof(*(p)))
#define __put_user_error(x,p,e) __put_user_nocheck_error((x),(p),sizeof(*(p)),(e))
static __inline__ unsigned long copy_from_user(void *to, const void *from, unsigned long n)
{
if (access_ok(VERIFY_READ, from, n))
__do_copy_from_user(to, from, n);
else /* security hole - plug it */
memzero(to, n);
return n;
}
static __inline__ unsigned long __copy_from_user(void *to, const void *from, unsigned long n)
{
__do_copy_from_user(to, from, n);
return n;
}
static __inline__ unsigned long copy_to_user(void *to, const void *from, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
__do_copy_to_user(to, from, n);
return n;
}
static __inline__ unsigned long __copy_to_user(void *to, const void *from, unsigned long n)
{
__do_copy_to_user(to, from, n);
return n;
}
static __inline__ unsigned long clear_user (void *to, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
__do_clear_user(to, n);
return n;
}
static __inline__ unsigned long __clear_user (void *to, unsigned long n)
{
__do_clear_user(to, n);
return n;
}
static __inline__ long strncpy_from_user (char *dst, const char *src, long count)
{
long res = -EFAULT;
if (access_ok(VERIFY_READ, src, 1))
__do_strncpy_from_user(dst, src, count, res);
return res;
}
static __inline__ long __strncpy_from_user (char *dst, const char *src, long count)
{
long res;
__do_strncpy_from_user(dst, src, count, res);
return res;
}
#define strlen_user(s) strnlen_user(s, ~0UL >> 1)
static inline long strnlen_user(const char *s, long n)
{
unsigned long res = 0;
if (__addr_ok(s))
__do_strnlen_user(s, n, res);
return res;
}
/*
* These are the work horses of the get/put_user functions
*/
#if 0
#define __get_user_check(x,ptr,size) \
({ \
long __gu_err = -EFAULT, __gu_val = 0; \
const __typeof__(*(ptr)) *__gu_addr = (ptr); \
if (access_ok(VERIFY_READ,__gu_addr,size)) { \
__gu_err = 0; \
__get_user_size(__gu_val,__gu_addr,(size),__gu_err); \
} \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
#endif
#define __get_user_nocheck(x,ptr,size) \
({ \
long __gu_err = 0, __gu_val; \
__get_user_size(__gu_val,(ptr),(size),__gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
#define __get_user_nocheck_error(x,ptr,size,err) \
({ \
long __gu_val; \
__get_user_size(__gu_val,(ptr),(size),(err)); \
(x) = (__typeof__(*(ptr)))__gu_val; \
(void) 0; \
})
#define __put_user_check(x,ptr,size) \
({ \
long __pu_err = -EFAULT; \
__typeof__(*(ptr)) *__pu_addr = (ptr); \
if (access_ok(VERIFY_WRITE,__pu_addr,size)) { \
__pu_err = 0; \
__put_user_size((x),__pu_addr,(size),__pu_err); \
} \
__pu_err; \
})
#define __put_user_nocheck(x,ptr,size) \
({ \
long __pu_err = 0; \
__typeof__(*(ptr)) *__pu_addr = (ptr); \
__put_user_size((x),__pu_addr,(size),__pu_err); \
__pu_err; \
})
#define __put_user_nocheck_error(x,ptr,size,err) \
({ \
__put_user_size((x),(ptr),(size),err); \
(void) 0; \
})
#define __get_user_size(x,ptr,size,retval) \
do { \
switch (size) { \
case 1: __get_user_asm_byte(x,ptr,retval); break; \
case 2: __get_user_asm_half(x,ptr,retval); break; \
case 4: __get_user_asm_word(x,ptr,retval); break; \
default: (x) = __get_user_bad(); \
} \
} while (0)
#define __put_user_size(x,ptr,size,retval) \
do { \
switch (size) { \
case 1: __put_user_asm_byte(x,ptr,retval); break; \
case 2: __put_user_asm_half(x,ptr,retval); break; \
case 4: __put_user_asm_word(x,ptr,retval); break; \
default: __put_user_bad(); \
} \
} while (0)
#endif /* _ASMARM_UACCESS_H */