/* $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_32_H
#define __ASM_SH_UACCESS_32_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);
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_32_H */
