You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
510 lines
13 KiB
510 lines
13 KiB
/* $Id: uaccess.h,v 1.11 2003/10/13 07:21:20 lethal Exp $
|
|
*
|
|
* User space memory access functions
|
|
*
|
|
* Copyright (C) 1999, 2002 Niibe Yutaka
|
|
* Copyright (C) 2003 Paul Mundt
|
|
*
|
|
* Based on:
|
|
* MIPS implementation version 1.15 by
|
|
* Copyright (C) 1996, 1997, 1998 by Ralf Baechle
|
|
* and i386 version.
|
|
*/
|
|
#ifndef __ASM_SH_UACCESS_H
|
|
#define __ASM_SH_UACCESS_H
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/sched.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 (Data Segment Register?), these macros are misnamed.
|
|
*/
|
|
|
|
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
|
|
|
|
#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFFUL)
|
|
#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
|
|
|
|
#define segment_eq(a,b) ((a).seg == (b).seg)
|
|
|
|
#define get_ds() (KERNEL_DS)
|
|
|
|
#if !defined(CONFIG_MMU)
|
|
/* NOMMU is always true */
|
|
#define __addr_ok(addr) (1)
|
|
|
|
static inline mm_segment_t get_fs(void)
|
|
{
|
|
return USER_DS;
|
|
}
|
|
|
|
static inline void set_fs(mm_segment_t s)
|
|
{
|
|
}
|
|
|
|
/*
|
|
* __access_ok: Check if address with size is OK or not.
|
|
*
|
|
* If we don't have an MMU (or if its disabled) the only thing we really have
|
|
* to look out for is if the address resides somewhere outside of what
|
|
* available RAM we have.
|
|
*
|
|
* TODO: This check could probably also stand to be restricted somewhat more..
|
|
* though it still does the Right Thing(tm) for the time being.
|
|
*/
|
|
static inline int __access_ok(unsigned long addr, unsigned long size)
|
|
{
|
|
return ((addr >= memory_start) && ((addr + size) < memory_end));
|
|
}
|
|
#else /* CONFIG_MMU */
|
|
#define __addr_ok(addr) \
|
|
((unsigned long)(addr) < (current_thread_info()->addr_limit.seg))
|
|
|
|
#define get_fs() (current_thread_info()->addr_limit)
|
|
#define set_fs(x) (current_thread_info()->addr_limit = (x))
|
|
|
|
/*
|
|
* __access_ok: Check if address with size is OK or not.
|
|
*
|
|
* Uhhuh, this needs 33-bit arithmetic. We have a carry..
|
|
*
|
|
* sum := addr + size; carry? --> flag = true;
|
|
* if (sum >= addr_limit) flag = true;
|
|
*/
|
|
static inline int __access_ok(unsigned long addr, unsigned long size)
|
|
{
|
|
unsigned long flag, sum;
|
|
|
|
__asm__("clrt\n\t"
|
|
"addc %3, %1\n\t"
|
|
"movt %0\n\t"
|
|
"cmp/hi %4, %1\n\t"
|
|
"rotcl %0"
|
|
:"=&r" (flag), "=r" (sum)
|
|
:"1" (addr), "r" (size),
|
|
"r" (current_thread_info()->addr_limit.seg)
|
|
:"t");
|
|
return flag == 0;
|
|
}
|
|
#endif /* CONFIG_MMU */
|
|
|
|
#define access_ok(type, addr, size) \
|
|
(__chk_user_ptr(addr), \
|
|
__access_ok((unsigned long __force)(addr), (size)))
|
|
|
|
/*
|
|
* Uh, these should become the main single-value transfer routines ...
|
|
* They automatically use the right size if we just have the right
|
|
* pointer type ...
|
|
*
|
|
* As SuperH uses the same address space for kernel and user data, we
|
|
* can just do these as direct assignments.
|
|
*
|
|
* Careful to not
|
|
* (a) re-use the arguments for side effects (sizeof is ok)
|
|
* (b) require any knowledge of processes at this stage
|
|
*/
|
|
#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)))
|
|
|
|
struct __large_struct { unsigned long buf[100]; };
|
|
#define __m(x) (*(struct __large_struct __user *)(x))
|
|
|
|
#define __get_user_size(x,ptr,size,retval) \
|
|
do { \
|
|
retval = 0; \
|
|
switch (size) { \
|
|
case 1: \
|
|
__get_user_asm(x, ptr, retval, "b"); \
|
|
break; \
|
|
case 2: \
|
|
__get_user_asm(x, ptr, retval, "w"); \
|
|
break; \
|
|
case 4: \
|
|
__get_user_asm(x, ptr, retval, "l"); \
|
|
break; \
|
|
default: \
|
|
__get_user_unknown(); \
|
|
break; \
|
|
} \
|
|
} while (0)
|
|
|
|
#define __get_user_nocheck(x,ptr,size) \
|
|
({ \
|
|
long __gu_err; \
|
|
unsigned long __gu_val; \
|
|
const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
|
|
__chk_user_ptr(ptr); \
|
|
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
|
|
(x) = (__typeof__(*(ptr)))__gu_val; \
|
|
__gu_err; \
|
|
})
|
|
|
|
#define __get_user_check(x,ptr,size) \
|
|
({ \
|
|
long __gu_err = -EFAULT; \
|
|
unsigned long __gu_val = 0; \
|
|
const __typeof__(*(ptr)) *__gu_addr = (ptr); \
|
|
if (likely(access_ok(VERIFY_READ, __gu_addr, (size)))) \
|
|
__get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
|
|
(x) = (__typeof__(*(ptr)))__gu_val; \
|
|
__gu_err; \
|
|
})
|
|
|
|
#define __get_user_asm(x, addr, err, insn) \
|
|
({ \
|
|
__asm__ __volatile__( \
|
|
"1:\n\t" \
|
|
"mov." insn " %2, %1\n\t" \
|
|
"2:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"3:\n\t" \
|
|
"mov #0, %1\n\t" \
|
|
"mov.l 4f, %0\n\t" \
|
|
"jmp @%0\n\t" \
|
|
" mov %3, %0\n\t" \
|
|
".balign 4\n" \
|
|
"4: .long 2b\n\t" \
|
|
".previous\n" \
|
|
".section __ex_table,\"a\"\n\t" \
|
|
".long 1b, 3b\n\t" \
|
|
".previous" \
|
|
:"=&r" (err), "=&r" (x) \
|
|
:"m" (__m(addr)), "i" (-EFAULT), "0" (err)); })
|
|
|
|
extern void __get_user_unknown(void);
|
|
|
|
#define __put_user_size(x,ptr,size,retval) \
|
|
do { \
|
|
retval = 0; \
|
|
switch (size) { \
|
|
case 1: \
|
|
__put_user_asm(x, ptr, retval, "b"); \
|
|
break; \
|
|
case 2: \
|
|
__put_user_asm(x, ptr, retval, "w"); \
|
|
break; \
|
|
case 4: \
|
|
__put_user_asm(x, ptr, retval, "l"); \
|
|
break; \
|
|
case 8: \
|
|
__put_user_u64(x, ptr, retval); \
|
|
break; \
|
|
default: \
|
|
__put_user_unknown(); \
|
|
} \
|
|
} while (0)
|
|
|
|
#define __put_user_nocheck(x,ptr,size) \
|
|
({ \
|
|
long __pu_err; \
|
|
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
|
|
__chk_user_ptr(ptr); \
|
|
__put_user_size((x), __pu_addr, (size), __pu_err); \
|
|
__pu_err; \
|
|
})
|
|
|
|
#define __put_user_check(x,ptr,size) \
|
|
({ \
|
|
long __pu_err = -EFAULT; \
|
|
__typeof__(*(ptr)) __user *__pu_addr = (ptr); \
|
|
if (likely(access_ok(VERIFY_WRITE, __pu_addr, size))) \
|
|
__put_user_size((x), __pu_addr, (size), \
|
|
__pu_err); \
|
|
__pu_err; \
|
|
})
|
|
|
|
#define __put_user_asm(x, addr, err, insn) \
|
|
({ \
|
|
__asm__ __volatile__( \
|
|
"1:\n\t" \
|
|
"mov." insn " %1, %2\n\t" \
|
|
"2:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"3:\n\t" \
|
|
"mov.l 4f, %0\n\t" \
|
|
"jmp @%0\n\t" \
|
|
" mov %3, %0\n\t" \
|
|
".balign 4\n" \
|
|
"4: .long 2b\n\t" \
|
|
".previous\n" \
|
|
".section __ex_table,\"a\"\n\t" \
|
|
".long 1b, 3b\n\t" \
|
|
".previous" \
|
|
:"=&r" (err) \
|
|
:"r" (x), "m" (__m(addr)), "i" (-EFAULT), "0" (err) \
|
|
:"memory"); })
|
|
|
|
#if defined(CONFIG_CPU_LITTLE_ENDIAN)
|
|
#define __put_user_u64(val,addr,retval) \
|
|
({ \
|
|
__asm__ __volatile__( \
|
|
"1:\n\t" \
|
|
"mov.l %R1,%2\n\t" \
|
|
"mov.l %S1,%T2\n\t" \
|
|
"2:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"3:\n\t" \
|
|
"mov.l 4f,%0\n\t" \
|
|
"jmp @%0\n\t" \
|
|
" mov %3,%0\n\t" \
|
|
".balign 4\n" \
|
|
"4: .long 2b\n\t" \
|
|
".previous\n" \
|
|
".section __ex_table,\"a\"\n\t" \
|
|
".long 1b, 3b\n\t" \
|
|
".previous" \
|
|
: "=r" (retval) \
|
|
: "r" (val), "m" (__m(addr)), "i" (-EFAULT), "0" (retval) \
|
|
: "memory"); })
|
|
#else
|
|
#define __put_user_u64(val,addr,retval) \
|
|
({ \
|
|
__asm__ __volatile__( \
|
|
"1:\n\t" \
|
|
"mov.l %S1,%2\n\t" \
|
|
"mov.l %R1,%T2\n\t" \
|
|
"2:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"3:\n\t" \
|
|
"mov.l 4f,%0\n\t" \
|
|
"jmp @%0\n\t" \
|
|
" mov %3,%0\n\t" \
|
|
".balign 4\n" \
|
|
"4: .long 2b\n\t" \
|
|
".previous\n" \
|
|
".section __ex_table,\"a\"\n\t" \
|
|
".long 1b, 3b\n\t" \
|
|
".previous" \
|
|
: "=r" (retval) \
|
|
: "r" (val), "m" (__m(addr)), "i" (-EFAULT), "0" (retval) \
|
|
: "memory"); })
|
|
#endif
|
|
|
|
extern void __put_user_unknown(void);
|
|
|
|
/* Generic arbitrary sized copy. */
|
|
/* Return the number of bytes NOT copied */
|
|
__kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
|
|
|
|
#define copy_to_user(to,from,n) ({ \
|
|
void *__copy_to = (void *) (to); \
|
|
__kernel_size_t __copy_size = (__kernel_size_t) (n); \
|
|
__kernel_size_t __copy_res; \
|
|
if(__copy_size && __access_ok((unsigned long)__copy_to, __copy_size)) { \
|
|
__copy_res = __copy_user(__copy_to, (void *) (from), __copy_size); \
|
|
} else __copy_res = __copy_size; \
|
|
__copy_res; })
|
|
|
|
#define copy_from_user(to,from,n) ({ \
|
|
void *__copy_to = (void *) (to); \
|
|
void *__copy_from = (void *) (from); \
|
|
__kernel_size_t __copy_size = (__kernel_size_t) (n); \
|
|
__kernel_size_t __copy_res; \
|
|
if(__copy_size && __access_ok((unsigned long)__copy_from, __copy_size)) { \
|
|
__copy_res = __copy_user(__copy_to, __copy_from, __copy_size); \
|
|
} else __copy_res = __copy_size; \
|
|
__copy_res; })
|
|
|
|
static __always_inline unsigned long
|
|
__copy_from_user(void *to, const void __user *from, unsigned long n)
|
|
{
|
|
return __copy_user(to, (__force void *)from, n);
|
|
}
|
|
|
|
static __always_inline unsigned long __must_check
|
|
__copy_to_user(void __user *to, const void *from, unsigned long n)
|
|
{
|
|
return __copy_user((__force void *)to, from, n);
|
|
}
|
|
|
|
#define __copy_to_user_inatomic __copy_to_user
|
|
#define __copy_from_user_inatomic __copy_from_user
|
|
|
|
/*
|
|
* Clear the area and return remaining number of bytes
|
|
* (on failure. Usually it's 0.)
|
|
*/
|
|
extern __kernel_size_t __clear_user(void *addr, __kernel_size_t size);
|
|
|
|
#define clear_user(addr,n) ({ \
|
|
void * __cl_addr = (addr); \
|
|
unsigned long __cl_size = (n); \
|
|
if (__cl_size && __access_ok(((unsigned long)(__cl_addr)), __cl_size)) \
|
|
__cl_size = __clear_user(__cl_addr, __cl_size); \
|
|
__cl_size; })
|
|
|
|
static __inline__ int
|
|
__strncpy_from_user(unsigned long __dest, unsigned long __user __src, int __count)
|
|
{
|
|
__kernel_size_t res;
|
|
unsigned long __dummy, _d, _s, _c;
|
|
|
|
__asm__ __volatile__(
|
|
"9:\n"
|
|
"mov.b @%2+, %1\n\t"
|
|
"cmp/eq #0, %1\n\t"
|
|
"bt/s 2f\n"
|
|
"1:\n"
|
|
"mov.b %1, @%3\n\t"
|
|
"dt %4\n\t"
|
|
"bf/s 9b\n\t"
|
|
" add #1, %3\n\t"
|
|
"2:\n\t"
|
|
"sub %4, %0\n"
|
|
"3:\n"
|
|
".section .fixup,\"ax\"\n"
|
|
"4:\n\t"
|
|
"mov.l 5f, %1\n\t"
|
|
"jmp @%1\n\t"
|
|
" mov %9, %0\n\t"
|
|
".balign 4\n"
|
|
"5: .long 3b\n"
|
|
".previous\n"
|
|
".section __ex_table,\"a\"\n"
|
|
" .balign 4\n"
|
|
" .long 9b,4b\n"
|
|
".previous"
|
|
: "=r" (res), "=&z" (__dummy), "=r" (_s), "=r" (_d), "=r"(_c)
|
|
: "0" (__count), "2" (__src), "3" (__dest), "4" (__count),
|
|
"i" (-EFAULT)
|
|
: "memory", "t");
|
|
|
|
return res;
|
|
}
|
|
|
|
/**
|
|
* strncpy_from_user: - Copy a NUL terminated string from userspace.
|
|
* @dst: Destination address, in kernel space. This buffer must be at
|
|
* least @count bytes long.
|
|
* @src: Source address, in user space.
|
|
* @count: Maximum number of bytes to copy, including the trailing NUL.
|
|
*
|
|
* Copies a NUL-terminated string from userspace to kernel space.
|
|
*
|
|
* On success, returns the length of the string (not including the trailing
|
|
* NUL).
|
|
*
|
|
* If access to userspace fails, returns -EFAULT (some data may have been
|
|
* copied).
|
|
*
|
|
* If @count is smaller than the length of the string, copies @count bytes
|
|
* and returns @count.
|
|
*/
|
|
#define strncpy_from_user(dest,src,count) ({ \
|
|
unsigned long __sfu_src = (unsigned long) (src); \
|
|
int __sfu_count = (int) (count); \
|
|
long __sfu_res = -EFAULT; \
|
|
if(__access_ok(__sfu_src, __sfu_count)) { \
|
|
__sfu_res = __strncpy_from_user((unsigned long) (dest), __sfu_src, __sfu_count); \
|
|
} __sfu_res; })
|
|
|
|
/*
|
|
* Return the size of a string (including the ending 0 even when we have
|
|
* exceeded the maximum string length).
|
|
*/
|
|
static __inline__ long __strnlen_user(const char __user *__s, long __n)
|
|
{
|
|
unsigned long res;
|
|
unsigned long __dummy;
|
|
|
|
__asm__ __volatile__(
|
|
"1:\t"
|
|
"mov.b @(%0,%3), %1\n\t"
|
|
"cmp/eq %4, %0\n\t"
|
|
"bt/s 2f\n\t"
|
|
" add #1, %0\n\t"
|
|
"tst %1, %1\n\t"
|
|
"bf 1b\n\t"
|
|
"2:\n"
|
|
".section .fixup,\"ax\"\n"
|
|
"3:\n\t"
|
|
"mov.l 4f, %1\n\t"
|
|
"jmp @%1\n\t"
|
|
" mov #0, %0\n"
|
|
".balign 4\n"
|
|
"4: .long 2b\n"
|
|
".previous\n"
|
|
".section __ex_table,\"a\"\n"
|
|
" .balign 4\n"
|
|
" .long 1b,3b\n"
|
|
".previous"
|
|
: "=z" (res), "=&r" (__dummy)
|
|
: "0" (0), "r" (__s), "r" (__n)
|
|
: "t");
|
|
return res;
|
|
}
|
|
|
|
/**
|
|
* strnlen_user: - Get the size of a string in user space.
|
|
* @s: The string to measure.
|
|
* @n: The maximum valid length
|
|
*
|
|
* Context: User context only. This function may sleep.
|
|
*
|
|
* Get the size of a NUL-terminated string in user space.
|
|
*
|
|
* Returns the size of the string INCLUDING the terminating NUL.
|
|
* On exception, returns 0.
|
|
* If the string is too long, returns a value greater than @n.
|
|
*/
|
|
static __inline__ long strnlen_user(const char __user *s, long n)
|
|
{
|
|
if (!__addr_ok(s))
|
|
return 0;
|
|
else
|
|
return __strnlen_user(s, n);
|
|
}
|
|
|
|
/**
|
|
* strlen_user: - Get the size of a string in user space.
|
|
* @str: The string to measure.
|
|
*
|
|
* Context: User context only. This function may sleep.
|
|
*
|
|
* Get the size of a NUL-terminated string in user space.
|
|
*
|
|
* Returns the size of the string INCLUDING the terminating NUL.
|
|
* On exception, returns 0.
|
|
*
|
|
* If there is a limit on the length of a valid string, you may wish to
|
|
* consider using strnlen_user() instead.
|
|
*/
|
|
#define strlen_user(str) strnlen_user(str, ~0UL >> 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);
|
|
|
|
#endif /* __ASM_SH_UACCESS_H */
|
|
|