Viewing file:  uaccess.h (11.3 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
/*
* Authors: Bjorn Wesen (bjornw@axis.com)
* Hans-Peter Nilsson (hp@axis.com)
*/
/* Asm:s have been tweaked (within the domain of correctness) to give
satisfactory results for "gcc version 2.96 20000427 (experimental)".
Check regularly...
Register $r9 is chosen for temporaries, being a call-clobbered register
first in line to be used (notably for local blocks), not colliding with
parameter registers. */
#ifndef _CRIS_UACCESS_H
#define _CRIS_UACCESS_H
#ifndef __ASSEMBLY__
#include <linux/sched.h>
#include <linux/errno.h>
#include <asm/processor.h>
#include <asm/page.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
/*
* The fs value determines whether argument validity checking should be
* performed or not. If get_fs() == USER_DS, checking is performed, with
* get_fs() == KERNEL_DS, checking is bypassed.
*
* For historical reasons, these macros are grossly misnamed.
*/
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
/* addr_limit is the maximum accessible address for the task. we misuse
* the KERNEL_DS and USER_DS values to both assign and compare the
* addr_limit values through the equally misnamed get/set_fs macros.
* (see above)
*/
#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
#define USER_DS MAKE_MM_SEG(TASK_SIZE)
#define get_ds() (KERNEL_DS)
#define get_fs() (current_thread_info()->addr_limit)
#define set_fs(x) (current_thread_info()->addr_limit = (x))
#define segment_eq(a,b) ((a).seg == (b).seg)
#define __kernel_ok (segment_eq(get_fs(), KERNEL_DS))
#define __user_ok(addr,size) (((size) <= TASK_SIZE)&&((addr) <= TASK_SIZE-(size)))
#define __access_ok(addr,size) (__kernel_ok || __user_ok((addr),(size)))
#define access_ok(type,addr,size) __access_ok((unsigned long)(addr),(size))
#include <arch/uaccess.h>
/*
* 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;
};
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*
* This gets kind of ugly. We want to return _two_ values in "get_user()"
* and yet we don't want to do any pointers, because that is too much
* of a performance impact. Thus we have a few rather ugly macros here,
* and hide all the ugliness from the user.
*
* The "__xxx" versions of the user access functions are versions that
* do not verify the address space, that must have been done previously
* with a separate "access_ok()" call (this is used when we do multiple
* accesses to the same area of user memory).
*
* As we use the same address space for kernel and user data on
* CRIS, we can just do these as direct assignments. (Of course, the
* exception handling means that it's no longer "just"...)
*/
#define get_user(x,ptr) \
__get_user_check((x),(ptr),sizeof(*(ptr)))
#define put_user(x,ptr) \
__put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
#define __get_user(x,ptr) \
__get_user_nocheck((x),(ptr),sizeof(*(ptr)))
#define __put_user(x,ptr) \
__put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
extern long __put_user_bad(void);
#define __put_user_size(x,ptr,size,retval) \
do { \
retval = 0; \
switch (size) { \
case 1: __put_user_asm(x,ptr,retval,"move.b"); break; \
case 2: __put_user_asm(x,ptr,retval,"move.w"); break; \
case 4: __put_user_asm(x,ptr,retval,"move.d"); break; \
case 8: __put_user_asm_64(x,ptr,retval); break; \
default: __put_user_bad(); \
} \
} while (0)
#define __get_user_size(x,ptr,size,retval) \
do { \
retval = 0; \
switch (size) { \
case 1: __get_user_asm(x,ptr,retval,"move.b"); break; \
case 2: __get_user_asm(x,ptr,retval,"move.w"); break; \
case 4: __get_user_asm(x,ptr,retval,"move.d"); break; \
case 8: __get_user_asm_64(x,ptr,retval); break; \
default: (x) = __get_user_bad(); \
} \
} while (0)
#define __put_user_nocheck(x,ptr,size) \
({ \
long __pu_err; \
__put_user_size((x),(ptr),(size),__pu_err); \
__pu_err; \
})
#define __put_user_check(x,ptr,size) \
({ \
long __pu_err = -EFAULT; \
__typeof__(*(ptr)) *__pu_addr = (ptr); \
if (access_ok(VERIFY_WRITE,__pu_addr,size)) \
__put_user_size((x),__pu_addr,(size),__pu_err); \
__pu_err; \
})
struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct *)(x))
#define __get_user_nocheck(x,ptr,size) \
({ \
long __gu_err, __gu_val; \
__get_user_size(__gu_val,(ptr),(size),__gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
#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)) \
__get_user_size(__gu_val,__gu_addr,(size),__gu_err); \
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
extern long __get_user_bad(void);
/* More complex functions. Most are inline, but some call functions that
live in lib/usercopy.c */
extern unsigned long __copy_user(void __user *to, const void *from, unsigned long n);
extern unsigned long __copy_user_zeroing(void *to, const void __user *from, unsigned long n);
extern unsigned long __do_clear_user(void __user *to, unsigned long n);
static inline unsigned long
__generic_copy_to_user(void __user *to, const void *from, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
return __copy_user(to,from,n);
return n;
}
static inline unsigned long
__generic_copy_from_user(void *to, const void __user *from, unsigned long n)
{
if (access_ok(VERIFY_READ, from, n))
return __copy_user_zeroing(to,from,n);
return n;
}
static inline unsigned long
__generic_clear_user(void __user *to, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
return __do_clear_user(to,n);
return n;
}
static inline long
__strncpy_from_user(char *dst, const char __user *src, long count)
{
return __do_strncpy_from_user(dst, src, count);
}
static inline long
strncpy_from_user(char *dst, const char __user *src, long count)
{
long res = -EFAULT;
if (access_ok(VERIFY_READ, src, 1))
res = __do_strncpy_from_user(dst, src, count);
return res;
}
/* Note that these expand awfully if made into switch constructs, so
don't do that. */
static inline unsigned long
__constant_copy_from_user(void *to, const void __user *from, unsigned long n)
{
unsigned long ret = 0;
if (n == 0)
;
else if (n == 1)
__asm_copy_from_user_1(to, from, ret);
else if (n == 2)
__asm_copy_from_user_2(to, from, ret);
else if (n == 3)
__asm_copy_from_user_3(to, from, ret);
else if (n == 4)
__asm_copy_from_user_4(to, from, ret);
else if (n == 5)
__asm_copy_from_user_5(to, from, ret);
else if (n == 6)
__asm_copy_from_user_6(to, from, ret);
else if (n == 7)
__asm_copy_from_user_7(to, from, ret);
else if (n == 8)
__asm_copy_from_user_8(to, from, ret);
else if (n == 9)
__asm_copy_from_user_9(to, from, ret);
else if (n == 10)
__asm_copy_from_user_10(to, from, ret);
else if (n == 11)
__asm_copy_from_user_11(to, from, ret);
else if (n == 12)
__asm_copy_from_user_12(to, from, ret);
else if (n == 13)
__asm_copy_from_user_13(to, from, ret);
else if (n == 14)
__asm_copy_from_user_14(to, from, ret);
else if (n == 15)
__asm_copy_from_user_15(to, from, ret);
else if (n == 16)
__asm_copy_from_user_16(to, from, ret);
else if (n == 20)
__asm_copy_from_user_20(to, from, ret);
else if (n == 24)
__asm_copy_from_user_24(to, from, ret);
else
ret = __generic_copy_from_user(to, from, n);
return ret;
}
/* Ditto, don't make a switch out of this. */
static inline unsigned long
__constant_copy_to_user(void __user *to, const void *from, unsigned long n)
{
unsigned long ret = 0;
if (n == 0)
;
else if (n == 1)
__asm_copy_to_user_1(to, from, ret);
else if (n == 2)
__asm_copy_to_user_2(to, from, ret);
else if (n == 3)
__asm_copy_to_user_3(to, from, ret);
else if (n == 4)
__asm_copy_to_user_4(to, from, ret);
else if (n == 5)
__asm_copy_to_user_5(to, from, ret);
else if (n == 6)
__asm_copy_to_user_6(to, from, ret);
else if (n == 7)
__asm_copy_to_user_7(to, from, ret);
else if (n == 8)
__asm_copy_to_user_8(to, from, ret);
else if (n == 9)
__asm_copy_to_user_9(to, from, ret);
else if (n == 10)
__asm_copy_to_user_10(to, from, ret);
else if (n == 11)
__asm_copy_to_user_11(to, from, ret);
else if (n == 12)
__asm_copy_to_user_12(to, from, ret);
else if (n == 13)
__asm_copy_to_user_13(to, from, ret);
else if (n == 14)
__asm_copy_to_user_14(to, from, ret);
else if (n == 15)
__asm_copy_to_user_15(to, from, ret);
else if (n == 16)
__asm_copy_to_user_16(to, from, ret);
else if (n == 20)
__asm_copy_to_user_20(to, from, ret);
else if (n == 24)
__asm_copy_to_user_24(to, from, ret);
else
ret = __generic_copy_to_user(to, from, n);
return ret;
}
/* No switch, please. */
static inline unsigned long
__constant_clear_user(void __user *to, unsigned long n)
{
unsigned long ret = 0;
if (n == 0)
;
else if (n == 1)
__asm_clear_1(to, ret);
else if (n == 2)
__asm_clear_2(to, ret);
else if (n == 3)
__asm_clear_3(to, ret);
else if (n == 4)
__asm_clear_4(to, ret);
else if (n == 8)
__asm_clear_8(to, ret);
else if (n == 12)
__asm_clear_12(to, ret);
else if (n == 16)
__asm_clear_16(to, ret);
else if (n == 20)
__asm_clear_20(to, ret);
else if (n == 24)
__asm_clear_24(to, ret);
else
ret = __generic_clear_user(to, n);
return ret;
}
#define clear_user(to, n) \
(__builtin_constant_p(n) ? \
__constant_clear_user(to, n) : \
__generic_clear_user(to, n))
#define copy_from_user(to, from, n) \
(__builtin_constant_p(n) ? \
__constant_copy_from_user(to, from, n) : \
__generic_copy_from_user(to, from, n))
#define copy_to_user(to, from, n) \
(__builtin_constant_p(n) ? \
__constant_copy_to_user(to, from, n) : \
__generic_copy_to_user(to, from, n))
/* We let the __ versions of copy_from/to_user inline, because they're often
* used in fast paths and have only a small space overhead.
*/
static inline unsigned long
__generic_copy_from_user_nocheck(void *to, const void __user *from,
unsigned long n)
{
return __copy_user_zeroing(to,from,n);
}
static inline unsigned long
__generic_copy_to_user_nocheck(void __user *to, const void *from,
unsigned long n)
{
return __copy_user(to,from,n);
}
static inline unsigned long
__generic_clear_user_nocheck(void __user *to, unsigned long n)
{
return __do_clear_user(to,n);
}
/* without checking */
#define __copy_to_user(to,from,n) __generic_copy_to_user_nocheck((to),(from),(n))
#define __copy_from_user(to,from,n) __generic_copy_from_user_nocheck((to),(from),(n))
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user
#define __clear_user(to,n) __generic_clear_user_nocheck((to),(n))
#define strlen_user(str) strnlen_user((str), 0x7ffffffe)
#endif /* __ASSEMBLY__ */
#endif /* _CRIS_UACCESS_H */
|