#ifndef _PPC64_UACCESS_H
#define _PPC64_UACCESS_H
/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef __ASSEMBLY__
#include <linux/sched.h>
#include <linux/errno.h>
#include <asm/processor.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(0UL)
#define USER_DS MAKE_MM_SEG(0xf000000000000000UL)
#define get_ds() (KERNEL_DS)
#define get_fs() (current->thread.fs)
#define set_fs(val) (current->thread.fs = (val))
#define segment_eq(a,b) ((a).seg == (b).seg)
/*
* Use the alpha trick for checking ranges:
*
* Is a address valid? This does a straightforward calculation rather
* than tests.
*
* Address valid if:
* - "addr" doesn't have any high-bits set
* - AND "size" doesn't have any high-bits set
* - OR we are in kernel mode.
*
* We dont have to check for high bits in (addr+size) because the first
* two checks force the maximum result to be below the start of the
* kernel region.
*/
#define __access_ok(addr,size,segment) \
(((segment).seg & (addr | size )) == 0)
#define access_ok(type,addr,size) \
__access_ok(((__force unsigned long)(addr)),(size),get_fs())
/*
* 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 unsigned long search_exception_table(unsigned long);
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*
* This gets kind of ugly. We want to return _two_ values in "get_user()"
* and yet we don't want to do any pointers, because that is too much
* of a performance impact. Thus we have a few rather ugly macros here,
* and hide all the ugliness from the user.
*
* The "__xxx" versions of the user access functions are versions that
* do not verify the address space, that must have been done previously
* with a separate "access_ok()" call (this is used when we do multiple
* accesses to the same area of user memory).
*
* As we use the same address space for kernel and user data on the
* PowerPC, we can just do these as direct assignments. (Of course, the
* exception handling means that it's no longer "just"...)
*/
#define get_user(x,ptr) \
__get_user_check((x),(ptr),sizeof(*(ptr)))
#define put_user(x,ptr) \
__put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
#define __get_user(x,ptr) \
__get_user_nocheck((x),(ptr),sizeof(*(ptr)))
#define __put_user(x,ptr) \
__put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
#define __get_user_unaligned __get_user
#define __put_user_unaligned __put_user
extern long __put_user_bad(void);
#define __put_user_nocheck(x,ptr,size) \
({ \
long __pu_err; \
might_sleep(); \
__chk_user_ptr(ptr); \
__put_user_size((x),(ptr),(size),__pu_err,-EFAULT); \
__pu_err; \
})
#define __put_user_check(x,ptr,size) \
({ \
long __pu_err = -EFAULT; \
void __user *__pu_addr = (ptr); \
might_sleep(); \
if (access_ok(VERIFY_WRITE,__pu_addr,size)) \
__put_user_size((x),__pu_addr,(size),__pu_err,-EFAULT); \
__pu_err; \
})
#define __put_user_size(x,ptr,size,retval,errret) \
do { \
retval = 0; \
switch (size) { \
case 1: __put_user_asm(x,ptr,retval,"stb",errret); break; \
case 2: __put_user_asm(x,ptr,retval,"sth",errret); break; \
case 4: __put_user_asm(x,ptr,retval,"stw",errret); break; \
case 8: __put_user_asm(x,ptr,retval,"std",errret); break; \
default: __put_user_bad(); \
} \
} while (0)
/*
* We don't tell gcc that we are accessing memory, but this is OK
* because we do not write to any memory gcc knows about, so there
* are no aliasing issues.
*/
#define __put_user_asm(x, addr, err, op, errret) \
__asm__ __volatile__( \
"1: "op" %1,0(%2) # put_user\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: li %0,%3\n" \
" b 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 3\n" \
" .llong 1b,3b\n" \
".previous" \
: "=r"(err) \
: "r"(x), "b"(addr), "i"(errret), "0"(err))
#define __get_user_nocheck(x,ptr,size) \
({ \
long __gu_err; \
unsigned long __gu_val; \
might_sleep(); \
__get_user_size(__gu_val,(ptr),(size),__gu_err,-EFAULT);\
(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)) __user *__gu_addr = (ptr); \
might_sleep(); \
if (access_ok(VERIFY_READ,__gu_addr,size)) \
__get_user_size(__gu_val,__gu_addr,(size),__gu_err,-EFAULT);\
(x) = (__typeof__(*(ptr)))__gu_val; \
__gu_err; \
})
extern long __get_user_bad(void);
#define __get_user_size(x,ptr,size,retval,errret) \
do { \
retval = 0; \
__chk_user_ptr(ptr); \
switch (size) { \
case 1: __get_user_asm(x,ptr,retval,"lbz",errret); break; \
case 2: __get_user_asm(x,ptr,retval,"lhz",errret); break; \
case 4: __get_user_asm(x,ptr,retval,"lwz",errret); break; \
case 8: __get_user_asm(x,ptr,retval,"ld",errret); break; \
default: (x) = __get_user_bad(); \
} \
} while (0)
#define __get_user_asm(x, addr, err, op, errret) \
__asm__ __volatile__( \
"1: "op" %1,0(%2) # get_user\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: li %0,%3\n" \
" li %1,0\n" \
" b 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 3\n" \
" .llong 1b,3b\n" \
".previous" \
: "=r"(err), "=r"(x) \
: "b"(addr), "i"(errret), "0"(err))
/* more complex routines */
extern unsigned long __copy_tofrom_user(void __user *to, const void __user *from,
unsigned long size);
static inline unsigned long
__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
{
if (__builtin_constant_p(n)) {
unsigned long ret;
switch (n) {
case 1:
__get_user_size(*(u8 *)to, from, 1, ret, 1);
return ret;
case 2:
__get_user_size(*(u16 *)to, from, 2, ret, 2);
return ret;
case 4:
__get_user_size(*(u32 *)to, from, 4, ret, 4);
return ret;
case 8:
__get_user_size(*(u64 *)to, from, 8, ret, 8);
return ret;
}
}
return __copy_tofrom_user((__force void __user *) to, from, n);
}
static inline unsigned long
__copy_from_user(void *to, const void __user *from, unsigned long n)
{
might_sleep();
return __copy_from_user_inatomic(to, from, n);
}
static inline unsigned long
__copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
{
if (__builtin_constant_p(n)) {
unsigned long ret;
switch (n) {
case 1:
__put_user_size(*(u8 *)from, (u8 __user *)to, 1, ret, 1);
return ret;
case 2:
__put_user_size(*(u16 *)from, (u16 __user *)to, 2, ret, 2);
return ret;
case 4:
__put_user_size(*(u32 *)from, (u32 __user *)to, 4, ret, 4);
return ret;
case 8:
__put_user_size(*(u64 *)from, (u64 __user *)to, 8, ret, 8);
return ret;
}
}
return __copy_tofrom_user(to, (__force const void __user *) from, n);
}
static inline unsigned long
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
might_sleep();
return __copy_to_user_inatomic(to, from, n);
}
#define __copy_in_user(to, from, size) \
__copy_tofrom_user((to), (from), (size))
extern unsigned long copy_from_user(void *to, const void __user *from,
unsigned long n);
extern unsigned long copy_to_user(void __user *to, const void *from,
unsigned long n);
extern unsigned long copy_in_user(void __user *to, const void __user *from,
unsigned long n);
extern unsigned long __clear_user(void __user *addr, unsigned long size);
static inline unsigned long
clear_user(void __user *addr, unsigned long size)
{
might_sleep();
if (likely(access_ok(VERIFY_WRITE, addr, size)))
size = __clear_user(addr, size);
return size;
}
extern int __strncpy_from_user(char *dst, const char __user *src, long count);
static inline long
strncpy_from_user(char *dst, const char __user *src, long count)
{
might_sleep();
if (likely(access_ok(VERIFY_READ, src, 1)))
return __strncpy_from_user(dst, src, count);
return -EFAULT;
}
/*
* Return the size of a string (including the ending 0)
*
* Return 0 for error
*/
extern int __strnlen_user(const char __user *str, long len);
/*
* Returns the length of the string at str (including the null byte),
* or 0 if we hit a page we can't access,
* or something > len if we didn't find a null byte.
*/
static inline int strnlen_user(const char __user *str, long len)
{
might_sleep();
if (likely(access_ok(VERIFY_READ, str, 1)))
return __strnlen_user(str, len);
return 0;
}
#define strlen_user(str) strnlen_user((str), 0x7ffffffe)
#endif /* __ASSEMBLY__ */
#endif /* _PPC64_UACCESS_H */
