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/*
* linux/include/asm-arm/uaccess.h
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef _ASMARM_UACCESS_H
#define _ASMARM_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/sched.h>
#include <asm/errno.h>
#include <asm/memory.h>
#include <asm/domain.h>
#include <asm/system.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;
};
extern int fixup_exception(struct pt_regs *regs);
/*
* These two are intentionally not defined anywhere - if the kernel
* code generates any references to them, that's a bug.
*/
extern int __get_user_bad(void);
extern int __put_user_bad(void);
/*
* Note that this is actually 0x1,0000,0000
*/
#define KERNEL_DS 0x00000000
#define get_ds() (KERNEL_DS)
#ifdef CONFIG_MMU
#define USER_DS TASK_SIZE
#define get_fs() (current_thread_info()->addr_limit)
static inline void set_fs(mm_segment_t fs)
{
current_thread_info()->addr_limit = fs;
modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
}
#define segment_eq(a,b) ((a) == (b))
#define __addr_ok(addr) ({ \
unsigned long flag; \
__asm__("cmp %2, %0; movlo %0, #0" \
: "=&r" (flag) \
: "0" (current_thread_info()->addr_limit), "r" (addr) \
: "cc"); \
(flag == 0); })
/* We use 33-bit arithmetic here... */
#define __range_ok(addr,size) ({ \
unsigned long flag, roksum; \
__chk_user_ptr(addr); \
__asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
: "=&r" (flag), "=&r" (roksum) \
: "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
: "cc"); \
flag; })
/*
* 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.
*/
extern int __get_user_1(void *);
extern int __get_user_2(void *);
extern int __get_user_4(void *);
#define __get_user_x(__r2,__p,__e,__s,__i...) \
__asm__ __volatile__ ( \
__asmeq("%0", "r0") __asmeq("%1", "r2") \
"bl __get_user_" #__s \
: "=&r" (__e), "=r" (__r2) \
: "0" (__p) \
: __i, "cc")
#define get_user(x,p) \
({ \
register const typeof(*(p)) __user *__p asm("r0") = (p);\
register unsigned long __r2 asm("r2"); \
register int __e asm("r0"); \
switch (sizeof(*(__p))) { \
case 1: \
__get_user_x(__r2, __p, __e, 1, "lr"); \
break; \
case 2: \
__get_user_x(__r2, __p, __e, 2, "r3", "lr"); \
break; \
case 4: \
__get_user_x(__r2, __p, __e, 4, "lr"); \
break; \
default: __e = __get_user_bad(); break; \
} \
x = (typeof(*(p))) __r2; \
__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);
#define __put_user_x(__r2,__p,__e,__s) \
__asm__ __volatile__ ( \
__asmeq("%0", "r0") __asmeq("%2", "r2") \
"bl __put_user_" #__s \
: "=&r" (__e) \
: "0" (__p), "r" (__r2) \
: "ip", "lr", "cc")
#define put_user(x,p) \
({ \
register const typeof(*(p)) __r2 asm("r2") = (x); \
register const typeof(*(p)) __user *__p asm("r0") = (p);\
register int __e asm("r0"); \
switch (sizeof(*(__p))) { \
case 1: \
__put_user_x(__r2, __p, __e, 1); \
break; \
case 2: \
__put_user_x(__r2, __p, __e, 2); \
break; \
case 4: \
__put_user_x(__r2, __p, __e, 4); \
break; \
case 8: \
__put_user_x(__r2, __p, __e, 8); \
break; \
default: __e = __put_user_bad(); break; \
} \
__e; \
})
#else /* CONFIG_MMU */
/*
* uClinux has only one addr space, so has simplified address limits.
*/
#define USER_DS KERNEL_DS
#define segment_eq(a,b) (1)
#define __addr_ok(addr) (1)
#define __range_ok(addr,size) (0)
#define get_fs() (KERNEL_DS)
static inline void set_fs(mm_segment_t fs)
{
}
#define get_user(x,p) __get_user(x,p)
#define put_user(x,p) __put_user(x,p)
#endif /* CONFIG_MMU */
#define access_ok(type,addr,size) (__range_ok(addr,size) == 0)
/*
* 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).
*/
#define __get_user(x,ptr) \
({ \
long __gu_err = 0; \
__get_user_err((x),(ptr),__gu_err); \
__gu_err; \
})
#define __get_user_error(x,ptr,err) \
({ \
__get_user_err((x),(ptr),err); \
(void) 0; \
})
#define __get_user_err(x,ptr,err) \
do { \
unsigned long __gu_addr = (unsigned long)(ptr); \
unsigned long __gu_val; \
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \
case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \
case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \
default: (__gu_val) = __get_user_bad(); \
} \
(x) = (__typeof__(*(ptr)))__gu_val; \
} while (0)
#define __get_user_asm_byte(x,addr,err) \
__asm__ __volatile__( \
"1: ldrbt %1,[%2],#0\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"3: mov %0, %3\n" \
" mov %1, #0\n" \
" b 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 3b\n" \
" .previous" \
: "+r" (err), "=&r" (x) \
: "r" (addr), "i" (-EFAULT) \
: "cc")
#ifndef __ARMEB__
#define __get_user_asm_half(x,__gu_addr,err) \
({ \
unsigned long __b1, __b2; \
__get_user_asm_byte(__b1, __gu_addr, err); \
__get_user_asm_byte(__b2, __gu_addr + 1, err); \
(x) = __b1 | (__b2 << 8); \
})
#else
#define __get_user_asm_half(x,__gu_addr,err) \
({ \
unsigned long __b1, __b2; \
__get_user_asm_byte(__b1, __gu_addr, err); \
__get_user_asm_byte(__b2, __gu_addr + 1, err); \
(x) = (__b1 << 8) | __b2; \
})
#endif
#define __get_user_asm_word(x,addr,err) \
__asm__ __volatile__( \
"1: ldrt %1,[%2],#0\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"3: mov %0, %3\n" \
" mov %1, #0\n" \
" b 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 3b\n" \
" .previous" \
: "+r" (err), "=&r" (x) \
: "r" (addr), "i" (-EFAULT) \
: "cc")
#define __put_user(x,ptr) \
({ \
long __pu_err = 0; \
__put_user_err((x),(ptr),__pu_err); \
__pu_err; \
})
#define __put_user_error(x,ptr,err) \
({ \
__put_user_err((x),(ptr),err); \
(void) 0; \
})
#define __put_user_err(x,ptr,err) \
do { \
unsigned long __pu_addr = (unsigned long)(ptr); \
__typeof__(*(ptr)) __pu_val = (x); \
__chk_user_ptr(ptr); \
switch (sizeof(*(ptr))) { \
case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \
case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \
case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \
case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \
default: __put_user_bad(); \
} \
} while (0)
#define __put_user_asm_byte(x,__pu_addr,err) \
__asm__ __volatile__( \
"1: strbt %1,[%2],#0\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"3: mov %0, %3\n" \
" b 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 3b\n" \
" .previous" \
: "+r" (err) \
: "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
: "cc")
#ifndef __ARMEB__
#define __put_user_asm_half(x,__pu_addr,err) \
({ \
unsigned long __temp = (unsigned long)(x); \
__put_user_asm_byte(__temp, __pu_addr, err); \
__put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
})
#else
#define __put_user_asm_half(x,__pu_addr,err) \
({ \
unsigned long __temp = (unsigned long)(x); \
__put_user_asm_byte(__temp >> 8, __pu_addr, err); \
__put_user_asm_byte(__temp, __pu_addr + 1, err); \
})
#endif
#define __put_user_asm_word(x,__pu_addr,err) \
__asm__ __volatile__( \
"1: strt %1,[%2],#0\n" \
"2:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"3: mov %0, %3\n" \
" b 2b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 3b\n" \
" .previous" \
: "+r" (err) \
: "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
: "cc")
#ifndef __ARMEB__
#define __reg_oper0 "%R2"
#define __reg_oper1 "%Q2"
#else
#define __reg_oper0 "%Q2"
#define __reg_oper1 "%R2"
#endif
#define __put_user_asm_dword(x,__pu_addr,err) \
__asm__ __volatile__( \
"1: strt " __reg_oper1 ", [%1], #4\n" \
"2: strt " __reg_oper0 ", [%1], #0\n" \
"3:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"4: mov %0, %3\n" \
" b 3b\n" \
" .previous\n" \
" .section __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 4b\n" \
" .long 2b, 4b\n" \
" .previous" \
: "+r" (err), "+r" (__pu_addr) \
: "r" (x), "i" (-EFAULT) \
: "cc")
#ifdef CONFIG_MMU
extern unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n);
extern unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n);
extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
#else
#define __copy_from_user(to,from,n) (memcpy(to, (void __force *)from, n), 0)
#define __copy_to_user(to,from,n) (memcpy((void __force *)to, from, n), 0)
#define __clear_user(addr,n) (memset((void __force *)addr, 0, n), 0)
#endif
extern unsigned long __must_check __strncpy_from_user(char *to, const char __user *from, unsigned long count);
extern unsigned long __must_check __strnlen_user(const char __user *s, long n);
static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
{
if (access_ok(VERIFY_READ, from, n))
n = __copy_from_user(to, from, n);
else /* security hole - plug it */
memzero(to, n);
return n;
}
static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
n = __copy_to_user(to, from, n);
return n;
}
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user
static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
n = __clear_user(to, n);
return n;
}
static inline long __must_check strncpy_from_user(char *dst, const char __user *src, long count)
{
long res = -EFAULT;
if (access_ok(VERIFY_READ, src, 1))
res = __strncpy_from_user(dst, src, count);
return res;
}
#define strlen_user(s) strnlen_user(s, ~0UL >> 1)
static inline long __must_check strnlen_user(const char __user *s, long n)
{
unsigned long res = 0;
if (__addr_ok(s))
res = __strnlen_user(s, n);
return res;
}
#endif /* _ASMARM_UACCESS_H */
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