uaccess.h
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上传日期：2013-04-10
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- /*
- * include/asm-s390/uaccess.h
- *
- * S390 version
- * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
- * Author(s): Hartmut Penner (hpenner@de.ibm.com),
- * Martin Schwidefsky (schwidefsky@de.ibm.com)
- *
- * Derived from "include/asm-i386/uaccess.h"
- */
- #ifndef __S390_UACCESS_H
- #define __S390_UACCESS_H
- /*
- * User space memory access functions
- */
- #include <linux/sched.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(0)
- #define USER_DS MAKE_MM_SEG(1)
- #define get_ds() (KERNEL_DS)
- #define get_fs() (current->addr_limit)
- #define set_fs(x) ({asm volatile("sar 4,%0"::"a" ((x).ar4));
- current->addr_limit = (x);})
- #define segment_eq(a,b) ((a).ar4 == (b).ar4)
- #define __access_ok(addr,size) (1)
- #define access_ok(type,addr,size) __access_ok(addr,size)
- extern inline int verify_area(int type, const void * addr, unsigned long size)
- {
- return access_ok(type,addr,size)?0:-EFAULT;
- }
- /*
- * 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.
- */
- extern inline int __put_user_asm_8(__u64 x, void *ptr)
- {
- int err;
- __asm__ __volatile__ ( " sr %1,%1n"
- " la 4,%0n"
- " sacf 512n"
- "0: stg %2,0(4)n"
- "1: sacf 0n"
- ".section .fixup,"ax"n"
- "2: lhi %1,%h3n"
- " jg 1bn"
- ".previousn"
- ".section __ex_table,"a"n"
- " .align 8n"
- " .quad 0b,2bn"
- ".previous"
- : "=m" (*((__u64*) ptr)) , "=&d" (err)
- : "d" (x), "K" (-EFAULT)
- : "cc", "4" );
- return err;
- }
- extern inline int __put_user_asm_4(__u32 x, void *ptr)
- {
- int err;
- __asm__ __volatile__ ( " sr %1,%1n"
- " la 4,%0n"
- " sacf 512n"
- "0: st %2,0(4)n"
- "1: sacf 0n"
- ".section .fixup,"ax"n"
- "2: lhi %1,%h3n"
- " jg 1bn"
- ".previousn"
- ".section __ex_table,"a"n"
- " .align 8n"
- " .quad 0b,2bn"
- ".previous"
- : "=m" (*((__u32*) ptr)) , "=&d" (err)
- : "d" (x), "K" (-EFAULT)
- : "cc", "4" );
- return err;
- }
- extern inline int __put_user_asm_2(__u16 x, void *ptr)
- {
- int err;
- __asm__ __volatile__ ( " sr %1,%1n"
- " la 4,%0n"
- " sacf 512n"
- "0: sth %2,0(4)n"
- "1: sacf 0n"
- ".section .fixup,"ax"n"
- "2: lhi %1,%h3n"
- " jg 1bn"
- ".previousn"
- ".section __ex_table,"a"n"
- " .align 8n"
- " .quad 0b,2bn"
- ".previous"
- : "=m" (*((__u16*) ptr)) , "=&d" (err)
- : "d" (x), "K" (-EFAULT)
- : "cc", "4" );
- return err;
- }
- extern inline int __put_user_asm_1(__u8 x, void *ptr)
- {
- int err;
- __asm__ __volatile__ ( " sr %1,%1n"
- " la 4,%0n"
- " sacf 512n"
- "0: stc %2,0(4)n"
- "1: sacf 0n"
- ".section .fixup,"ax"n"
- "2: lhi %1,%h3n"
- " jg 1bn"
- ".previousn"
- ".section __ex_table,"a"n"
- " .align 8n"
- " .quad 0b,2bn"
- ".previous"
- : "=m" (*((__u8*) ptr)) , "=&d" (err)
- : "d" (x), "K" (-EFAULT)
- : "cc", "1", "4" );
- return err;
- }
- /*
- * (u?)(u64) ... autsch, but that the only way we can suppress the
- * warnings when compiling binfmt_elf.c
- */
- #define __put_user(x, ptr)
- ({
- __typeof__(*(ptr)) *__pu_addr = (ptr);
- __typeof__(*(ptr)) __x = (x);
- int __pu_err;
- switch (sizeof (*(__pu_addr))) {
- case 1:
- __pu_err = __put_user_asm_1((__u8)(__u64)(__x),
- __pu_addr);
- break;
- case 2:
- __pu_err = __put_user_asm_2((__u16)(__u64)(__x),
- __pu_addr);
- break;
- case 4:
- __pu_err = __put_user_asm_4((__u32)(__u64)(__x),
- __pu_addr);
- break;
- case 8:
- __pu_err = __put_user_asm_8((__u64)(__x),
- __pu_addr);
- break;
- default:
- __pu_err = __put_user_bad();
- break;
- }
- __pu_err;
- })
- #define put_user(x, ptr) __put_user(x, ptr)
- extern int __put_user_bad(void);
- #define __get_user_asm_8(x, ptr, err)
- ({
- __asm__ __volatile__ ( " sr %1,%1n"
- " la 4,%2n"
- " sacf 512n"
- "0: lg %0,0(4)n"
- "1: sacf 0n"
- ".section .fixup,"ax"n"
- "2: lhi %1,%h3n"
- " jg 1bn"
- ".previousn"
- ".section __ex_table,"a"n"
- " .align 8n"
- " .quad 0b,2bn"
- ".previous"
- : "=d" (x) , "=&d" (err)
- : "m" (*(const __u64*)(ptr)),"K" (-EFAULT)
- : "cc", "4" );
- })
- #define __get_user_asm_4(x, ptr, err)
- ({
- __asm__ __volatile__ ( " sr %1,%1n"
- " la 4,%2n"
- " sacf 512n"
- "0: l %0,0(4)n"
- "1: sacf 0n"
- ".section .fixup,"ax"n"
- "2: lhi %1,%h3n"
- " jg 1bn"
- ".previousn"
- ".section __ex_table,"a"n"
- " .align 8n"
- " .quad 0b,2bn"
- ".previous"
- : "=d" (x) , "=&d" (err)
- : "m" (*(const __u32*)(ptr)),"K" (-EFAULT)
- : "cc", "4" );
- })
- #define __get_user_asm_2(x, ptr, err)
- ({
- __asm__ __volatile__ ( " sr %1,%1n"
- " la 4,%2n"
- " sacf 512n"
- "0: lh %0,0(4)n"
- "1: sacf 0n"
- ".section .fixup,"ax"n"
- "2: lhi %1,%h3n"
- " jg 1bn"
- ".previousn"
- ".section __ex_table,"a"n"
- " .align 8n"
- " .quad 0b,2bn"
- ".previous"
- : "=d" (x) , "=&d" (err)
- : "m" (*(const __u16*)(ptr)),"K" (-EFAULT)
- : "cc", "4" );
- })
- #define __get_user_asm_1(x, ptr, err)
- ({
- __asm__ __volatile__ ( " sr %1,%1n"
- " la 4,%2n"
- " sr %0,%0n"
- " sacf 512n"
- "0: ic %0,0(4)n"
- "1: sacf 0n"
- ".section .fixup,"ax"n"
- "2: lhi %1,%h3n"
- " jg 1bn"
- ".previousn"
- ".section __ex_table,"a"n"
- " .align 8n"
- " .quad 0b,2bn"
- ".previous"
- : "=d" (x) , "=&d" (err)
- : "m" (*(const __u8*)(ptr)),"K" (-EFAULT)
- : "cc", "4" );
- })
- #define __get_user(x, ptr)
- ({
- __typeof__(ptr) __gu_addr = (ptr);
- __typeof__(*(ptr)) __x;
- int __gu_err;
- switch (sizeof(*(ptr))) {
- case 1:
- __get_user_asm_1(__x,__gu_addr,__gu_err);
- break;
- case 2:
- __get_user_asm_2(__x,__gu_addr,__gu_err);
- break;
- case 4:
- __get_user_asm_4(__x,__gu_addr,__gu_err);
- break;
- case 8:
- __get_user_asm_8(__x,__gu_addr,__gu_err);
- break;
- default:
- __x = 0;
- __gu_err = __get_user_bad();
- break;
- }
- (x) = __x;
- __gu_err;
- })
- #define get_user(x, ptr) __get_user(x, ptr)
- extern int __get_user_bad(void);
- /*
- * access register are set up, that 4 points to secondary (user) , 2 to primary (kernel)
- */
- extern long __copy_to_user_asm(const void *from, long n, void *to);
- #define __copy_to_user(to, from, n)
- ({
- __copy_to_user_asm(from, n, to);
- })
- #define copy_to_user(to, from, n)
- ({
- long err = 0;
- __typeof__(n) __n = (n);
- if (__access_ok(to,__n)) {
- err = __copy_to_user_asm(from, __n, to);
- }
- else
- err = __n;
- err;
- })
- extern long __copy_from_user_asm(void *to, long n, const void *from);
- #define __copy_from_user(to, from, n)
- ({
- __copy_from_user_asm(to, n, from);
- })
- #define copy_from_user(to, from, n)
- ({
- long err = 0;
- __typeof__(n) __n = (n);
- if (__access_ok(from,__n)) {
- err = __copy_from_user_asm(to, __n, from);
- }
- else
- err = __n;
- err;
- })
- /*
- * Copy a null terminated string from userspace.
- */
- static inline long
- __strncpy_from_user(char *dst, const char *src, long count)
- {
- long len;
- __asm__ __volatile__ ( " slgr %0,%0n"
- " lgr 2,%1n"
- " lgr 4,%2n"
- " slr 3,3n"
- " sacf 512n"
- "0: ic 3,0(%0,4)n"
- "1: stc 3,0(%0,2)n"
- " ltr 3,3n"
- " jz 2fn"
- " aghi %0,1n"
- " cgr %0,%3n"
- " jl 0bn"
- "2: sacf 0n"
- ".section .fixup,"ax"n"
- "3: lghi %0,%h4n"
- " jg 2bn"
- ".previousn"
- ".section __ex_table,"a"n"
- " .align 8n"
- " .quad 0b,3bn"
- " .quad 1b,3bn"
- ".previous"
- : "=&a" (len)
- : "a" (dst), "d" (src), "d" (count),
- "K" (-EFAULT)
- : "cc", "2" ,"3", "4" );
- return len;
- }
- static inline long
- strncpy_from_user(char *dst, const char *src, long count)
- {
- long res = -EFAULT;
- if (access_ok(VERIFY_READ, src, 1))
- res = __strncpy_from_user(dst, src, count);
- return res;
- }
- /*
- * Return the size of a string (including the ending 0)
- *
- * Return 0 for error
- */
- static inline unsigned long
- strnlen_user(const char * src, unsigned long n)
- {
- #if 0
- __asm__ __volatile__ (" algr %0,%1n"
- " slgr 0,0n"
- " lgr 4,%1n"
- " sacf 512n"
- "0: srst %0,4n"
- " jo 0bn"
- " slgr %0,%1n"
- " aghi %0,1n"
- "1: sacf 0n"
- ".section .fixup,"ax"n"
- "2: slgr %0,%0n"
- " jg 1bn"
- ".previousn"
- ".section __ex_table,"a"n"
- " .align 8n"
- " .quad 0b,2bn"
- ".previous"
- : "+&a" (n) : "d" (src)
- : "cc", "0", "4" );
- #else
- __asm__ __volatile__ (" lgr 4,%1n"
- " sacf 512n"
- "0: cli 0(4),0x00n"
- " la 4,1(4)n"
- " je 1fn"
- " brctg %0,0bn"
- "1: lgr %0,4n"
- " slgr %0,%1n"
- "2: sacf 0n"
- ".section .fixup,"ax"n"
- "3: slgr %0,%0n"
- " jg 2bn"
- ".previousn"
- ".section __ex_table,"a"n"
- " .align 8n"
- " .quad 0b,3bn"
- ".previous"
- : "+&a" (n) : "d" (src)
- : "cc", "4" );
- #endif
- return n;
- }
- #define strlen_user(str) strnlen_user(str, ~0UL)
- /*
- * Zero Userspace
- */
- extern long __clear_user_asm(void *to, long n);
- #define __clear_user(to, n)
- ({
- __clear_user_asm(to, n);
- })
- static inline unsigned long
- clear_user(void *to, unsigned long n)
- {
- if (access_ok(VERIFY_WRITE, to, n))
- n = __clear_user(to, n);
- return n;
- }
- #endif /* _S390_UACCESS_H */
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