- 根目录:
- arch
- metag
- include
- asm
- uaccess.h
#ifndef __METAG_UACCESS_H
#define __METAG_UACCESS_H
/*
* User space memory access functions
*/
#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, these macros are grossly misnamed.
*/
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
#define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
#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))
/*
* Explicitly allow NULL pointers here. Parts of the kernel such
* as readv/writev use access_ok to validate pointers, but want
* to allow NULL pointers for various reasons. NULL pointers are
* safe to allow through because the first page is not mappable on
* Meta.
*
* We also wish to avoid letting user code access the system area
* and the kernel half of the address space.
*/
#define __user_bad(addr, size) (((addr) > 0 && (addr) < META_MEMORY_BASE) || \
((addr) > PAGE_OFFSET && \
(addr) < LINCORE_BASE))
static inline int __access_ok(unsigned long addr, unsigned long size)
{
return __kernel_ok || !__user_bad(addr, size);
}
#define access_ok(type, addr, size) __access_ok((unsigned long)(addr), \
(unsigned long)(size))
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;
};
extern int fixup_exception(struct pt_regs *regs);
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*/
#define put_user(x, ptr) \
__put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
#define __put_user(x, ptr) \
__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
extern void __put_user_bad(void);
#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)) __user *__pu_addr = (ptr); \
if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
__put_user_size((x), __pu_addr, (size), __pu_err); \
__pu_err; \
})
extern long __put_user_asm_b(unsigned int x, void __user *addr);
extern long __put_user_asm_w(unsigned int x, void __user *addr);
extern long __put_user_asm_d(unsigned int x, void __user *addr);
extern long __put_user_asm_l(unsigned long long x, void __user *addr);
#define __put_user_size(x, ptr, size, retval) \
do { \
retval = 0; \
switch (size) { \
case 1: \
retval = __put_user_asm_b((unsigned int)x, ptr); break; \
case 2: \
retval = __put_user_asm_w((unsigned int)x, ptr); break; \
case 4: \
retval = __put_user_asm_d((unsigned int)x, ptr); break; \
case 8: \
retval = __put_user_asm_l((unsigned long long)x, ptr); break; \
default: \
__put_user_bad(); \
} \
} while (0)
#define get_user(x, ptr) \
__get_user_check((x), (ptr), sizeof(*(ptr)))
#define __get_user(x, ptr) \
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
extern long __get_user_bad(void);
#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)) __user *__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 unsigned char __get_user_asm_b(const void __user *addr, long *err);
extern unsigned short __get_user_asm_w(const void __user *addr, long *err);
extern unsigned int __get_user_asm_d(const void __user *addr, long *err);
#define __get_user_size(x, ptr, size, retval) \
do { \
retval = 0; \
switch (size) { \
case 1: \
x = __get_user_asm_b(ptr, &retval); break; \
case 2: \
x = __get_user_asm_w(ptr, &retval); break; \
case 4: \
x = __get_user_asm_d(ptr, &retval); break; \
default: \
(x) = __get_user_bad(); \
} \
} while (0)
/*
* Copy a null terminated string from userspace.
*
* Must return:
* -EFAULT for an exception
* count if we hit the buffer limit
* bytes copied if we hit a null byte
* (without the null byte)
*/
extern long __must_check __strncpy_from_user(char *dst, const char __user *src,
long count);
#define strncpy_from_user(dst, src, count) __strncpy_from_user(dst, src, count)
/*
* Return the size of a string (including the ending 0)
*
* Return 0 on exception, a value greater than N if too long
*/
extern long __must_check strnlen_user(const char __user *src, long count);
#define strlen_user(str) strnlen_user(str, 32767)
extern unsigned long __must_check __copy_user_zeroing(void *to,
const void __user *from,
unsigned long n);
static inline unsigned long
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;
}
#define __copy_from_user(to, from, n) __copy_user_zeroing(to, from, n)
#define __copy_from_user_inatomic __copy_from_user
extern unsigned long __must_check __copy_user(void __user *to,
const void *from,
unsigned long n);
static inline unsigned long 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;
}
#define __copy_to_user(to, from, n) __copy_user(to, from, n)
#define __copy_to_user_inatomic __copy_to_user
/*
* Zero Userspace
*/
extern unsigned long __must_check __do_clear_user(void __user *to,
unsigned long n);
static inline unsigned long clear_user(void __user *to, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
return __do_clear_user(to, n);
return n;
}
#define __clear_user(to, n) __do_clear_user(to, n)
#endif /* _METAG_UACCESS_H */