#ifndef __X86_64_UACCESS_H
#define __X86_64_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/compiler.h>
#include <linux/errno.h>
#include <linux/prefetch.h>
#include <asm/page.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(0xFFFFFFFFFFFFFFFFUL)
#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 __addr_ok(addr) (!((unsigned long)(addr) & (current_thread_info()->addr_limit.seg)))
/*
* Uhhuh, this needs 65-bit arithmetic. We have a carry..
*/
#define __range_not_ok(addr,size) ({ \
unsigned long flag,roksum; \
__chk_user_ptr(addr); \
asm("# range_ok\n\r" \
"addq %3,%1 ; sbbq %0,%0 ; cmpq %1,%4 ; sbbq $0,%0" \
:"=&r" (flag), "=r" (roksum) \
:"1" (addr),"g" ((long)(size)),"g" (current_thread_info()->addr_limit.seg)); \
flag; })
#define access_ok(type, addr, size) (__range_not_ok(addr,size) == 0)
/*
* 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;
};
#define ARCH_HAS_SEARCH_EXTABLE
/*
* 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).
*/
#define __get_user_x(size,ret,x,ptr) \
asm volatile("call __get_user_" #size \
:"=a" (ret),"=d" (x) \
:"c" (ptr) \
:"r8")
/* Careful: we have to cast the result to the type of the pointer for sign reasons */
#define get_user(x,ptr) \
({ unsigned long __val_gu; \
int __ret_gu; \
__chk_user_ptr(ptr); \
switch(sizeof (*(ptr))) { \
case 1: __get_user_x(1,__ret_gu,__val_gu,ptr); break; \
case 2: __get_user_x(2,__ret_gu,__val_gu,ptr); break; \
case 4: __get_user_x(4,__ret_gu,__val_gu,ptr); break; \
case 8: __get_user_x(8,__ret_gu,__val_gu,ptr); break; \
default: __get_user_bad(); break; \
} \
(x) = (__force typeof(*(ptr)))__val_gu; \
__ret_gu; \
})
extern void __put_user_1(void);
extern void __put_user_2(void);
extern void __put_user_4(void);
extern void __put_user_8(void);
extern void __put_user_bad(void);
#define __put_user_x(size,ret,x,ptr) \
asm volatile("call __put_user_" #size \
:"=a" (ret) \
:"c" (ptr),"d" (x) \
:"r8")
#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
#define __put_user_nocheck(x,ptr,size) \
({ \
int __pu_err; \
__put_user_size((x),(ptr),(size),__pu_err); \
__pu_err; \
})
#define __put_user_check(x,ptr,size) \
({ \
int __pu_err; \
typeof(*(ptr)) __user *__pu_addr = (ptr); \
switch (size) { \
case 1: __put_user_x(1,__pu_err,x,__pu_addr); break; \
case 2: __put_user_x(2,__pu_err,x,__pu_addr); break; \
case 4: __put_user_x(4,__pu_err,x,__pu_addr); break; \
case 8: __put_user_x(8,__pu_err,x,__pu_addr); break; \
default: __put_user_bad(); \
} \
__pu_err; \
})
#define __put_user_size(x,ptr,size,retval) \
do { \
retval = 0; \
__chk_user_ptr(ptr); \
switch (size) { \
case 1: __put_user_asm(x,ptr,retval,"b","b","iq",-EFAULT); break;\
case 2: __put_user_asm(x,ptr,retval,"w","w","ir",-EFAULT); break;\
case 4: __put_user_asm(x,ptr,retval,"l","k","ir",-EFAULT); break;\
case 8: __put_user_asm(x,ptr,retval,"q","","Zr",-EFAULT); break;\
default: __put_user_bad(); \
} \
} while (0)
/* FIXME: this hack is definitely wrong -AK */
struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct __user *)(x))
/*
* Tell gcc we read from memory instead of writing: this is because
* we do not write to any memory gcc knows about, so there are no
* aliasing issues.
*/
#define __put_user_asm(x, addr, err, itype, rtype, ltype, errno) \
asm volatile( \
"1: mov"itype" %"rtype"1,%2\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: mov %3,%0\n" \
" jmp 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 8\n" \
" .quad 1b,3b\n" \
".previous" \
: "=r"(err) \
: ltype (x), "m"(__m(addr)), "i"(errno), "0"(err))
#define __get_user_nocheck(x,ptr,size) \
({ \
int __gu_err; \
unsigned long __gu_val; \
__get_user_size(__gu_val,(ptr),(size),__gu_err); \
(x) = (__force typeof(*(ptr)))__gu_val; \
__gu_err; \
})
extern int __get_user_1(void);
extern int __get_user_2(void);
extern int __get_user_4(void);
extern int __get_user_8(void);
extern int __get_user_bad(void);
#define __get_user_size(x,ptr,size,retval) \
do { \
retval = 0; \
__chk_user_ptr(ptr); \
switch (size) { \
case 1: __get_user_asm(x,ptr,retval,"b","b","=q",-EFAULT); break;\
case 2: __get_user_asm(x,ptr,retval,"w","w","=r",-EFAULT); break;\
case 4: __get_user_asm(x,ptr,retval,"l","k","=r",-EFAULT); break;\
case 8: __get_user_asm(x,ptr,retval,"q","","=r",-EFAULT); break;\
default: (x) = __get_user_bad(); \
} \
} while (0)
#define __get_user_asm(x, addr, err, itype, rtype, ltype, errno) \
asm volatile( \
"1: mov"itype" %2,%"rtype"1\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: mov %3,%0\n" \
" xor"itype" %"rtype"1,%"rtype"1\n" \
" jmp 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 8\n" \
" .quad 1b,3b\n" \
".previous" \
: "=r"(err), ltype (x) \
: "m"(__m(addr)), "i"(errno), "0"(err))
/*
* Copy To/From Userspace
*/
/* Handles exceptions in both to and from, but doesn't do access_ok */
__must_check unsigned long
copy_user_generic(void *to, const void *from, unsigned len);
__must_check unsigned long
copy_to_user(void __user *to, const void *from, unsigned len);
__must_check unsigned long
copy_from_user(void *to, const void __user *from, unsigned len);
__must_check unsigned long
copy_in_user(void __user *to, const void __user *from, unsigned len);
static __always_inline __must_check
int __copy_from_user(void *dst, const void __user *src, unsigned size)
{
int ret = 0;
if (!__builtin_constant_p(size))
return copy_user_generic(dst,(__force void *)src,size);
switch (size) {
case 1:__get_user_asm(*(u8*)dst,(u8 __user *)src,ret,"b","b","=q",1);
return ret;
case 2:__get_user_asm(*(u16*)dst,(u16 __user *)src,ret,"w","w","=r",2);
return ret;
case 4:__get_user_asm(*(u32*)dst,(u32 __user *)src,ret,"l","k","=r",4);
return ret;
case 8:__get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",8);
return ret;
case 10:
__get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",16);
if (unlikely(ret)) return ret;
__get_user_asm(*(u16*)(8+(char*)dst),(u16 __user *)(8+(char __user *)src),ret,"w","w","=r",2);
return ret;
case 16:
__get_user_asm(*(u64*)dst,(u64 __user *)src,ret,"q","","=r",16);
if (unlikely(ret)) return ret;
__get_user_asm(*(u64*)(8+(char*)dst),(u64 __user *)(8+(char __user *)src),ret,"q","","=r",8);
return ret;
default:
return copy_user_generic(dst,(__force void *)src,size);
}
}
static __always_inline __must_check
int __copy_to_user(void __user *dst, const void *src, unsigned size)
{
int ret = 0;
if (!__builtin_constant_p(size))
return copy_user_generic((__force void *)dst,src,size);
switch (size) {
case 1:__put_user_asm(*(u8*)src,(u8 __user *)dst,ret,"b","b","iq",1);
return ret;
case 2:__put_user_asm(*(u16*)src,(u16 __user *)dst,ret,"w","w","ir",2);
return ret;
case 4:__put_user_asm(*(u32*)src,(u32 __user *)dst,ret,"l","k","ir",4);
return ret;
case 8:__put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",8);
return ret;
case 10:
__put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",10);
if (unlikely(ret)) return ret;
asm("":::"memory");
__put_user_asm(4[(u16*)src],4+(u16 __user *)dst,ret,"w","w","ir",2);
return ret;
case 16:
__put_user_asm(*(u64*)src,(u64 __user *)dst,ret,"q","","ir",16);
if (unlikely(ret)) return ret;
asm("":::"memory");
__put_user_asm(1[(u64*)src],1+(u64 __user *)dst,ret,"q","","ir",8);
return ret;
default:
return copy_user_generic((__force void *)dst,src,size);
}
}
static __always_inline __must_check
int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
{
int ret = 0;
if (!__builtin_constant_p(size))
return copy_user_generic((__force void *)dst,(__force void *)src,size);
switch (size) {
case 1: {
u8 tmp;
__get_user_asm(tmp,(u8 __user *)src,ret,"b","b","=q",1);
if (likely(!ret))
__put_user_asm(tmp,(u8 __user *)dst,ret,"b","b","iq",1);
return ret;
}
case 2: {
u16 tmp;
__get_user_asm(tmp,(u16 __user *)src,ret,"w","w","=r",2);
if (likely(!ret))
__put_user_asm(tmp,(u16 __user *)dst,ret,"w","w","ir",2);
return ret;
}
case 4: {
u32 tmp;
__get_user_asm(tmp,(u32 __user *)src,ret,"l","k","=r",4);
if (likely(!ret))
__put_user_asm(tmp,(u32 __user *)dst,ret,"l","k","ir",4);
return ret;
}
case 8: {
u64 tmp;
__get_user_asm(tmp,(u64 __user *)src,ret,"q","","=r",8);
if (likely(!ret))
__put_user_asm(tmp,(u64 __user *)dst,ret,"q","","ir",8);
return ret;
}
default:
return copy_user_generic((__force void *)dst,(__force void *)src,size);
}
}
__must_check long
strncpy_from_user(char *dst, const char __user *src, long count);
__must_check long
__strncpy_from_user(char *dst, const char __user *src, long count);
__must_check long strnlen_user(const char __user *str, long n);
__must_check long __strnlen_user(const char __user *str, long n);
__must_check long strlen_user(const char __user *str);
__must_check unsigned long clear_user(void __user *mem, unsigned long len);
__must_check unsigned long __clear_user(void __user *mem, unsigned long len);
__must_check long __copy_from_user_inatomic(void *dst, const void __user *src, unsigned size);
static __must_check __always_inline int
__copy_to_user_inatomic(void __user *dst, const void *src, unsigned size)
{
return copy_user_generic((__force void *)dst, src, size);
}
#define ARCH_HAS_NOCACHE_UACCESS 1
extern long __copy_user_nocache(void *dst, const void __user *src, unsigned size, int zerorest);
static inline int __copy_from_user_nocache(void *dst, const void __user *src, unsigned size)
{
might_sleep();
return __copy_user_nocache(dst, src, size, 1);
}
static inline int __copy_from_user_inatomic_nocache(void *dst, const void __user *src, unsigned size)
{
return __copy_user_nocache(dst, src, size, 0);
}
#endif /* __X86_64_UACCESS_H */
