455 lines
13 KiB
C
455 lines
13 KiB
C
#ifndef _ASM_UACCES_H_
|
|
#define _ASM_UACCES_H_
|
|
/*
|
|
* User space memory access functions
|
|
*/
|
|
#include <linux/errno.h>
|
|
#include <linux/compiler.h>
|
|
#include <linux/thread_info.h>
|
|
#include <linux/prefetch.h>
|
|
#include <linux/string.h>
|
|
#include <asm/asm.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(-1UL)
|
|
#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 __force)(addr) < \
|
|
(current_thread_info()->addr_limit.seg))
|
|
|
|
/*
|
|
* Test whether a block of memory is a valid user space address.
|
|
* Returns 0 if the range is valid, nonzero otherwise.
|
|
*
|
|
* This is equivalent to the following test:
|
|
* (u33)addr + (u33)size >= (u33)current->addr_limit.seg (u65 for x86_64)
|
|
*
|
|
* This needs 33-bit (65-bit for x86_64) arithmetic. We have a carry...
|
|
*/
|
|
|
|
#define __range_not_ok(addr, size) \
|
|
({ \
|
|
unsigned long flag, roksum; \
|
|
__chk_user_ptr(addr); \
|
|
asm("add %3,%1 ; sbb %0,%0 ; cmp %1,%4 ; sbb $0,%0" \
|
|
: "=&r" (flag), "=r" (roksum) \
|
|
: "1" (addr), "g" ((long)(size)), \
|
|
"rm" (current_thread_info()->addr_limit.seg)); \
|
|
flag; \
|
|
})
|
|
|
|
/**
|
|
* access_ok: - Checks if a user space pointer is valid
|
|
* @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
|
|
* %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
|
|
* to write to a block, it is always safe to read from it.
|
|
* @addr: User space pointer to start of block to check
|
|
* @size: Size of block to check
|
|
*
|
|
* Context: User context only. This function may sleep.
|
|
*
|
|
* Checks if a pointer to a block of memory in user space is valid.
|
|
*
|
|
* Returns true (nonzero) if the memory block may be valid, false (zero)
|
|
* if it is definitely invalid.
|
|
*
|
|
* Note that, depending on architecture, this function probably just
|
|
* checks that the pointer is in the user space range - after calling
|
|
* this function, memory access functions may still return -EFAULT.
|
|
*/
|
|
#define access_ok(type, addr, size) (likely(__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);
|
|
|
|
/*
|
|
* 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).
|
|
*/
|
|
|
|
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_x(size, ret, x, ptr) \
|
|
asm volatile("call __get_user_" #size \
|
|
: "=a" (ret),"=d" (x) \
|
|
: "0" (ptr)) \
|
|
|
|
/* Careful: we have to cast the result to the type of the pointer
|
|
* for sign reasons */
|
|
|
|
/**
|
|
* get_user: - Get a simple variable from user space.
|
|
* @x: Variable to store result.
|
|
* @ptr: Source address, in user space.
|
|
*
|
|
* Context: User context only. This function may sleep.
|
|
*
|
|
* This macro copies a single simple variable from user space to kernel
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and the result of
|
|
* dereferencing @ptr must be assignable to @x without a cast.
|
|
*
|
|
* Returns zero on success, or -EFAULT on error.
|
|
* On error, the variable @x is set to zero.
|
|
*/
|
|
#ifdef CONFIG_X86_32
|
|
#define __get_user_8(__ret_gu, __val_gu, ptr) \
|
|
__get_user_x(X, __ret_gu, __val_gu, ptr)
|
|
#else
|
|
#define __get_user_8(__ret_gu, __val_gu, ptr) \
|
|
__get_user_x(8, __ret_gu, __val_gu, ptr)
|
|
#endif
|
|
|
|
#define get_user(x, ptr) \
|
|
({ \
|
|
int __ret_gu; \
|
|
unsigned long __val_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_8(__ret_gu, __val_gu, ptr); \
|
|
break; \
|
|
default: \
|
|
__get_user_x(X, __ret_gu, __val_gu, ptr); \
|
|
break; \
|
|
} \
|
|
(x) = (__typeof__(*(ptr)))__val_gu; \
|
|
__ret_gu; \
|
|
})
|
|
|
|
#define __put_user_x(size, x, ptr, __ret_pu) \
|
|
asm volatile("call __put_user_" #size : "=a" (__ret_pu) \
|
|
:"0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
|
|
|
|
|
|
|
|
#ifdef CONFIG_X86_32
|
|
#define __put_user_u64(x, addr, err) \
|
|
asm volatile("1: movl %%eax,0(%2)\n" \
|
|
"2: movl %%edx,4(%2)\n" \
|
|
"3:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"4: movl %3,%0\n" \
|
|
" jmp 3b\n" \
|
|
".previous\n" \
|
|
_ASM_EXTABLE(1b, 4b) \
|
|
_ASM_EXTABLE(2b, 4b) \
|
|
: "=r" (err) \
|
|
: "A" (x), "r" (addr), "i" (-EFAULT), "0" (err))
|
|
|
|
#define __put_user_x8(x, ptr, __ret_pu) \
|
|
asm volatile("call __put_user_8" : "=a" (__ret_pu) \
|
|
: "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
|
|
#else
|
|
#define __put_user_u64(x, ptr, retval) \
|
|
__put_user_asm(x, ptr, retval, "q", "", "Zr", -EFAULT)
|
|
#define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu)
|
|
#endif
|
|
|
|
extern void __put_user_bad(void);
|
|
|
|
/*
|
|
* Strange magic calling convention: pointer in %ecx,
|
|
* value in %eax(:%edx), return value in %eax. clobbers %rbx
|
|
*/
|
|
extern void __put_user_1(void);
|
|
extern void __put_user_2(void);
|
|
extern void __put_user_4(void);
|
|
extern void __put_user_8(void);
|
|
|
|
#ifdef CONFIG_X86_WP_WORKS_OK
|
|
|
|
/**
|
|
* put_user: - Write a simple value into user space.
|
|
* @x: Value to copy to user space.
|
|
* @ptr: Destination address, in user space.
|
|
*
|
|
* Context: User context only. This function may sleep.
|
|
*
|
|
* This macro copies a single simple value from kernel space to user
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
|
|
* to the result of dereferencing @ptr.
|
|
*
|
|
* Returns zero on success, or -EFAULT on error.
|
|
*/
|
|
#define put_user(x, ptr) \
|
|
({ \
|
|
int __ret_pu; \
|
|
__typeof__(*(ptr)) __pu_val; \
|
|
__chk_user_ptr(ptr); \
|
|
__pu_val = x; \
|
|
switch (sizeof(*(ptr))) { \
|
|
case 1: \
|
|
__put_user_x(1, __pu_val, ptr, __ret_pu); \
|
|
break; \
|
|
case 2: \
|
|
__put_user_x(2, __pu_val, ptr, __ret_pu); \
|
|
break; \
|
|
case 4: \
|
|
__put_user_x(4, __pu_val, ptr, __ret_pu); \
|
|
break; \
|
|
case 8: \
|
|
__put_user_x8(__pu_val, ptr, __ret_pu); \
|
|
break; \
|
|
default: \
|
|
__put_user_x(X, __pu_val, ptr, __ret_pu); \
|
|
break; \
|
|
} \
|
|
__ret_pu; \
|
|
})
|
|
|
|
#define __put_user_size(x, ptr, size, retval, errret) \
|
|
do { \
|
|
retval = 0; \
|
|
__chk_user_ptr(ptr); \
|
|
switch (size) { \
|
|
case 1: \
|
|
__put_user_asm(x, ptr, retval, "b", "b", "iq", errret); \
|
|
break; \
|
|
case 2: \
|
|
__put_user_asm(x, ptr, retval, "w", "w", "ir", errret); \
|
|
break; \
|
|
case 4: \
|
|
__put_user_asm(x, ptr, retval, "l", "k", "ir", errret);\
|
|
break; \
|
|
case 8: \
|
|
__put_user_u64((__typeof__(*ptr))(x), ptr, retval); \
|
|
break; \
|
|
default: \
|
|
__put_user_bad(); \
|
|
} \
|
|
} while (0)
|
|
|
|
#else
|
|
|
|
#define __put_user_size(x, ptr, size, retval, errret) \
|
|
do { \
|
|
__typeof__(*(ptr))__pus_tmp = x; \
|
|
retval = 0; \
|
|
\
|
|
if (unlikely(__copy_to_user_ll(ptr, &__pus_tmp, size) != 0)) \
|
|
retval = errret; \
|
|
} while (0)
|
|
|
|
#define put_user(x, ptr) \
|
|
({ \
|
|
int __ret_pu; \
|
|
__typeof__(*(ptr))__pus_tmp = x; \
|
|
__ret_pu = 0; \
|
|
if (unlikely(__copy_to_user_ll(ptr, &__pus_tmp, \
|
|
sizeof(*(ptr))) != 0)) \
|
|
__ret_pu = -EFAULT; \
|
|
__ret_pu; \
|
|
})
|
|
#endif
|
|
|
|
#ifdef CONFIG_X86_32
|
|
#define __get_user_asm_u64(x, ptr, retval, errret) (x) = __get_user_bad()
|
|
#else
|
|
#define __get_user_asm_u64(x, ptr, retval, errret) \
|
|
__get_user_asm(x, ptr, retval, "q", "", "=r", errret)
|
|
#endif
|
|
|
|
#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, "b", "b", "=q", errret); \
|
|
break; \
|
|
case 2: \
|
|
__get_user_asm(x, ptr, retval, "w", "w", "=r", errret); \
|
|
break; \
|
|
case 4: \
|
|
__get_user_asm(x, ptr, retval, "l", "k", "=r", errret); \
|
|
break; \
|
|
case 8: \
|
|
__get_user_asm_u64(x, ptr, retval, errret); \
|
|
break; \
|
|
default: \
|
|
(x) = __get_user_bad(); \
|
|
} \
|
|
} while (0)
|
|
|
|
#define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \
|
|
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" (errret), "0" (err))
|
|
|
|
#define __put_user_nocheck(x, ptr, size) \
|
|
({ \
|
|
long __pu_err; \
|
|
__put_user_size((x), (ptr), (size), __pu_err, -EFAULT); \
|
|
__pu_err; \
|
|
})
|
|
|
|
#define __get_user_nocheck(x, ptr, size) \
|
|
({ \
|
|
long __gu_err; \
|
|
unsigned long __gu_val; \
|
|
__get_user_size(__gu_val, (ptr), (size), __gu_err, -EFAULT); \
|
|
(x) = (__force __typeof__(*(ptr)))__gu_val; \
|
|
__gu_err; \
|
|
})
|
|
|
|
/* 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, errret) \
|
|
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" (errret), "0" (err))
|
|
/**
|
|
* __get_user: - Get a simple variable from user space, with less checking.
|
|
* @x: Variable to store result.
|
|
* @ptr: Source address, in user space.
|
|
*
|
|
* Context: User context only. This function may sleep.
|
|
*
|
|
* This macro copies a single simple variable from user space to kernel
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and the result of
|
|
* dereferencing @ptr must be assignable to @x without a cast.
|
|
*
|
|
* Caller must check the pointer with access_ok() before calling this
|
|
* function.
|
|
*
|
|
* Returns zero on success, or -EFAULT on error.
|
|
* On error, the variable @x is set to zero.
|
|
*/
|
|
|
|
#define __get_user(x, ptr) \
|
|
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
|
|
/**
|
|
* __put_user: - Write a simple value into user space, with less checking.
|
|
* @x: Value to copy to user space.
|
|
* @ptr: Destination address, in user space.
|
|
*
|
|
* Context: User context only. This function may sleep.
|
|
*
|
|
* This macro copies a single simple value from kernel space to user
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
|
|
* to the result of dereferencing @ptr.
|
|
*
|
|
* Caller must check the pointer with access_ok() before calling this
|
|
* function.
|
|
*
|
|
* Returns zero on success, or -EFAULT on error.
|
|
*/
|
|
|
|
#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
|
|
|
|
/*
|
|
* movsl can be slow when source and dest are not both 8-byte aligned
|
|
*/
|
|
#ifdef CONFIG_X86_INTEL_USERCOPY
|
|
extern struct movsl_mask {
|
|
int mask;
|
|
} ____cacheline_aligned_in_smp movsl_mask;
|
|
#endif
|
|
|
|
#define ARCH_HAS_NOCACHE_UACCESS 1
|
|
|
|
#ifdef CONFIG_X86_32
|
|
# include "uaccess_32.h"
|
|
#else
|
|
# define ARCH_HAS_SEARCH_EXTABLE
|
|
# include "uaccess_64.h"
|
|
#endif
|
|
|
|
#endif
|
|
|