/* MN10300 userspace access functions
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_UACCESS_H
#define _ASM_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/thread_info.h>
#include <linux/kernel.h>
#include <asm/page.h>
#include <asm/errno.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) })
#define KERNEL_XDS MAKE_MM_SEG(0xBFFFFFFF)
#define KERNEL_DS MAKE_MM_SEG(0x9FFFFFFF)
#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 __kernel_ds_p() (current_thread_info()->addr_limit.seg == 0x9FFFFFFF)
#define segment_eq(a, b) ((a).seg == (b).seg)
#define __addr_ok(addr) \
((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
/*
* check that a range of addresses falls within the current address limit
*/
static inline int ___range_ok(unsigned long addr, unsigned int size)
{
int flag = 1, tmp;
asm(" add %3,%1 \n" /* set C-flag if addr + size > 4Gb */
" bcs 0f \n"
" cmp %4,%1 \n" /* jump if addr+size>limit (error) */
" bhi 0f \n"
" clr %0 \n" /* mark okay */
"0: \n"
: "=r"(flag), "=&r"(tmp)
: "1"(addr), "ir"(size),
"r"(current_thread_info()->addr_limit.seg), "0"(flag)
: "cc"
);
return flag;
}
#define __range_ok(addr, size) ___range_ok((unsigned long)(addr), (u32)(size))
#define access_ok(type, addr, size) (__range_ok((addr), (size)) == 0)
#define __access_ok(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;
}
/*
* 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 int fixup_exception(struct pt_regs *regs);
#define put_user(x, ptr) __put_user_check((x), (ptr), sizeof(*(ptr)))
#define get_user(x, ptr) __get_user_check((x), (ptr), sizeof(*(ptr)))
/*
* The "__xxx" versions do not do address space checking, useful when
* doing multiple accesses to the same area (the user has to do the
* checks by hand with "access_ok()")
*/
#define __put_user(x, ptr) __put_user_nocheck((x), (ptr), sizeof(*(ptr)))
#define __get_user(x, ptr) __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
/*
* The "xxx_ret" versions return constant specified in third argument, if
* something bad happens. These macros can be optimized for the
* case of just returning from the function xxx_ret is used.
*/
#define put_user_ret(x, ptr, ret) \
({ if (put_user((x), (ptr))) return (ret); })
#define get_user_ret(x, ptr, ret) \
({ if (get_user((x), (ptr))) return (ret); })
#define __put_user_ret(x, ptr, ret) \
({ if (__put_user((x), (ptr))) return (ret); })
#define __get_user_ret(x, ptr, ret) \
({ if (__get_user((x), (ptr))) return (ret); })
struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct *)(x))
#define __get_user_nocheck(x, ptr, size) \
({ \
unsigned long __gu_addr; \
int __gu_err; \
__gu_addr = (unsigned long) (ptr); \
switch (size) { \
case 1: { \
unsigned char __gu_val; \
__get_user_asm("bu"); \
(x) = *(__force __typeof__(*(ptr))*) &__gu_val; \
break; \
} \
case 2: { \
unsigned short __gu_val; \
__get_user_asm("hu"); \
(x) = *(__force __typeof__(*(ptr))*) &__gu_val; \
break; \
} \
case 4: { \
unsigned int __gu_val; \
__get_user_asm(""); \
(x) = *(__force __typeof__(*(ptr))*) &__gu_val; \
break; \
} \
default: \
__get_user_unknown(); \
break; \
} \
__gu_err; \
})
#define __get_user_check(x, ptr, size) \
({ \
const __typeof__(*(ptr))* __guc_ptr = (ptr); \
int _e; \
if (likely(__access_ok((unsigned long) __guc_ptr, (size)))) \
_e = __get_user_nocheck((x), __guc_ptr, (size)); \
else { \
_e = -EFAULT; \
(x) = (__typeof__(x))0; \
} \
_e; \
})
#define __get_user_asm(INSN) \
({ \
asm volatile( \
"1:\n" \
" mov"INSN" %2,%1\n" \
" mov 0,%0\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
"3:\n\t" \
" mov %3,%0\n" \
" jmp 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 1b, 3b\n" \
" .previous" \
: "=&r" (__gu_err), "=&r" (__gu_val) \
: "m" (__m(__gu_addr)), "i" (-EFAULT)); \
})
extern int __get_user_unknown(void);
#define __put_user_nocheck(x, ptr, size) \
({ \
union { \
__typeof__(*(ptr)) val; \
u32 bits[2]; \
} __pu_val; \
unsigned long __pu_addr; \
int __pu_err; \
__pu_val.val = (x); \
__pu_addr = (unsigned long) (ptr); \
switch (size) { \
case 1: __put_user_asm("bu"); break; \
case 2: __put_user_asm("hu"); break; \
case 4: __put_user_asm("" ); break; \
case 8: __put_user_asm8(); break; \
default: __pu_err = __put_user_unknown(); break; \
} \
__pu_err; \
})
#define __put_user_check(x, ptr, size) \
({ \
union { \
__typeof__(*(ptr)) val; \
u32 bits[2]; \
} __pu_val; \
unsigned long __pu_addr; \
int __pu_err; \
__pu_val.val = (x); \
__pu_addr = (unsigned long) (ptr); \
if (likely(__access_ok(__pu_addr, size))) { \
switch (size) { \
case 1: __put_user_asm("bu"); break; \
case 2: __put_user_asm("hu"); break; \
case 4: __put_user_asm("" ); break; \
case 8: __put_user_asm8(); break; \
default: __pu_err = __put_user_unknown(); break; \
} \
} \
else { \
__pu_err = -EFAULT; \
} \
__pu_err; \
})
#define __put_user_asm(INSN) \
({ \
asm volatile( \
"1:\n" \
" mov"INSN" %1,%2\n" \
" mov 0,%0\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
"3:\n" \
" mov %3,%0\n" \
" jmp 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 1b, 3b\n" \
" .previous" \
: "=&r" (__pu_err) \
: "r" (__pu_val.val), "m" (__m(__pu_addr)), \
"i" (-EFAULT) \
); \
})
#define __put_user_asm8() \
({ \
asm volatile( \
"1: mov %1,%3 \n" \
"2: mov %2,%4 \n" \
" mov 0,%0 \n" \
"3: \n" \
" .section .fixup,\"ax\" \n" \
"4: \n" \
" mov %5,%0 \n" \
" jmp 3b \n" \
" .previous \n" \
" .section __ex_table,\"a\"\n" \
" .balign 4 \n" \
" .long 1b, 4b \n" \
" .long 2b, 4b \n" \
" .previous \n" \
: "=&r" (__pu_err) \
: "r" (__pu_val.bits[0]), "r" (__pu_val.bits[1]), \
"m" (__m(__pu_addr)), "m" (__m(__pu_addr+4)), \
"i" (-EFAULT) \
); \
})
extern int __put_user_unknown(void);
/*
* Copy To/From Userspace
*/
/* Generic arbitrary sized copy. */
#define __copy_user(to, from, size) \
do { \
if (size) { \
void *__to = to; \
const void *__from = from; \
int w; \
asm volatile( \
"0: movbu (%0),%3;\n" \
"1: movbu %3,(%1);\n" \
" inc %0;\n" \
" inc %1;\n" \
" add -1,%2;\n" \
" bne 0b;\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
"3: jmp 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 0b,3b\n" \
" .long 1b,3b\n" \
" .previous\n" \
: "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
: "0"(__from), "1"(__to), "2"(size) \
: "cc", "memory"); \
} \
} while (0)
#define __copy_user_zeroing(to, from, size) \
do { \
if (size) { \
void *__to = to; \
const void *__from = from; \
int w; \
asm volatile( \
"0: movbu (%0),%3;\n" \
"1: movbu %3,(%1);\n" \
" inc %0;\n" \
" inc %1;\n" \
" add -1,%2;\n" \
" bne 0b;\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
"3:\n" \
" mov %2,%0\n" \
" clr %3\n" \
"4: movbu %3,(%1);\n" \
" inc %1;\n" \
" add -1,%2;\n" \
" bne 4b;\n" \
" mov %0,%2\n" \
" jmp 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 0b,3b\n" \
" .long 1b,3b\n" \
" .previous\n" \
: "=a"(__from), "=a"(__to), "=r"(size), "=&r"(w)\
: "0"(__from), "1"(__to), "2"(size) \
: "cc", "memory"); \
} \
} while (0)
/* 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 *from,
unsigned long n)
{
__copy_user_zeroing(to, from, n);
return n;
}
static inline
unsigned long __generic_copy_to_user_nocheck(void *to, const void *from,
unsigned long n)
{
__copy_user(to, from, n);
return n;
}
#if 0
#error "don't use - these macros don't increment to & from pointers"
/* Optimize just a little bit when we know the size of the move. */
#define __constant_copy_user(to, from, size) \
do { \
asm volatile( \
" mov %0,a0;\n" \
"0: movbu (%1),d3;\n" \
"1: movbu d3,(%2);\n" \
" add -1,a0;\n" \
" bne 0b;\n" \
"2:;" \
".section .fixup,\"ax\"\n" \
"3: jmp 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 0b,3b\n" \
" .long 1b,3b\n" \
".previous" \
: \
: "d"(size), "d"(to), "d"(from) \
: "d3", "a0"); \
} while (0)
/* Optimize just a little bit when we know the size of the move. */
#define __constant_copy_user_zeroing(to, from, size) \
do { \
asm volatile( \
" mov %0,a0;\n" \
"0: movbu (%1),d3;\n" \
"1: movbu d3,(%2);\n" \
" add -1,a0;\n" \
" bne 0b;\n" \
"2:;" \
".section .fixup,\"ax\"\n" \
"3: jmp 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .balign 4\n" \
" .long 0b,3b\n" \
" .long 1b,3b\n" \
".previous" \
: \
: "d"(size), "d"(to), "d"(from) \
: "d3", "a0"); \
} while (0)
static inline
unsigned long __constant_copy_to_user(void *to, const void *from,
unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
__constant_copy_user(to, from, n);
return n;
}
static inline
unsigned long __constant_copy_from_user(void *to, const void *from,
unsigned long n)
{
if (access_ok(VERIFY_READ, from, n))
__constant_copy_user_zeroing(to, from, n);
return n;
}
static inline
unsigned long __constant_copy_to_user_nocheck(void *to, const void *from,
unsigned long n)
{
__constant_copy_user(to, from, n);
return n;
}
static inline
unsigned long __constant_copy_from_user_nocheck(void *to, const void *from,
unsigned long n)
{
__constant_copy_user_zeroing(to, from, n);
return n;
}
#endif
extern unsigned long __generic_copy_to_user(void __user *, const void *,
unsigned long);
extern unsigned long __generic_copy_from_user(void *, const void __user *,
unsigned long);
#define __copy_to_user_inatomic(to, from, n) \
__generic_copy_to_user_nocheck((to), (from), (n))
#define __copy_from_user_inatomic(to, from, n) \
__generic_copy_from_user_nocheck((to), (from), (n))
#define __copy_to_user(to, from, n) \
({ \
might_fault(); \
__copy_to_user_inatomic((to), (from), (n)); \
})
#define __copy_from_user(to, from, n) \
({ \
might_fault(); \
__copy_from_user_inatomic((to), (from), (n)); \
})
#define copy_to_user(to, from, n) __generic_copy_to_user((to), (from), (n))
#define copy_from_user(to, from, n) __generic_copy_from_user((to), (from), (n))
extern long strncpy_from_user(char *dst, const char __user *src, long count);
extern long __strncpy_from_user(char *dst, const char __user *src, long count);
extern long strnlen_user(const char __user *str, long n);
#define strlen_user(str) strnlen_user(str, ~0UL >> 1)
extern unsigned long clear_user(void __user *mem, unsigned long len);
extern unsigned long __clear_user(void __user *mem, unsigned long len);
#endif /* _ASM_UACCESS_H */