#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;
};
extern int fixup_exception(struct pt_regs *regs);
#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" \
_ASM_EXTABLE(1b, 3b) \
: "=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" \
_ASM_EXTABLE(1b, 3b) \
: "=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 */
