x86: merge common parts of uaccess.

Common parts of uaccess_32.h and uaccess_64.h
are put in uaccess.h. Bits in uaccess_32.h and
uaccess_64.h that come to this file are equal
except for comments and whitespaces differences.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Glauber Costa 2008-06-13 14:39:25 -03:00 committed by Ingo Molnar
parent be9d06bfd4
commit ca23386216
3 changed files with 124 additions and 193 deletions

View file

@ -1,5 +1,129 @@
#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)
/*
* 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)) \
#ifdef CONFIG_X86_32
# include "uaccess_32.h"
#else
# include "uaccess_64.h"
#endif
#endif

View file

@ -11,29 +11,6 @@
#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)
/*
* movsl can be slow when source and dest are not both 8-byte aligned
*/
@ -47,91 +24,6 @@ extern struct movsl_mask {
((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
*
* This needs 33-bit 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 void __get_user_1(void);
extern void __get_user_2(void);
extern void __get_user_4(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 */
@ -386,8 +278,6 @@ struct __large_struct { unsigned long buf[100]; };
__gu_err; \
})
extern long __get_user_bad(void);
#define __get_user_size(x, ptr, size, retval, errret) \
do { \
retval = 0; \

View file

@ -9,88 +9,11 @@
#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(-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)(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("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; \
})
#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);
#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) \
: "0" (ptr)) \
/* Careful: we have to cast the result to the type of the pointer
* for sign reasons */
@ -226,12 +149,6 @@ struct __large_struct { unsigned long buf[100]; };
__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; \