arch/um/include/um_uaccess.h

   1 /*
   2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #ifndef __ARCH_UM_UACCESS_H
   7 #define __ARCH_UM_UACCESS_H
   8
   9 #include "linux/config.h"
  10 #include "choose-mode.h"
  11
  12 #ifdef CONFIG_MODE_TT
  13 #include "uaccess-tt.h"
  14 #endif
  15
  16 #ifdef CONFIG_MODE_SKAS
  17 #include "uaccess-skas.h"
  18 #endif
  19
  20 #define __under_task_size(addr, size) \
  21         (((unsigned long) (addr) < TASK_SIZE) && \
  22          (((unsigned long) (addr) + (size)) < TASK_SIZE))
  23
  24 #define __access_ok_vsyscall(type, addr, size) \
  25          ((type == VERIFY_READ) && \
  26           ((unsigned long) (addr) >= FIXADDR_USER_START) && \
  27           ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
  28           ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
  29
  30 #define __addr_range_nowrap(addr, size) \
  31         ((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
  32
  33 #define access_ok(type, addr, size) \
  34         (__addr_range_nowrap(addr, size) && \
  35          (__under_task_size(addr, size) || \
  36           __access_ok_vsyscall(type, addr, size) || \
  37           segment_eq(get_fs(), KERNEL_DS) || \
  38           CHOOSE_MODE_PROC(access_ok_tt, access_ok_skas, type, addr, size)))
  39
  40 static inline int copy_from_user(void *to, const void __user *from, int n)
  41 {
  42         return(CHOOSE_MODE_PROC(copy_from_user_tt, copy_from_user_skas, to,
  43                                 from, n));
  44 }
  45
  46 static inline int copy_to_user(void __user *to, const void *from, int n)
  47 {
  48         return(CHOOSE_MODE_PROC(copy_to_user_tt, copy_to_user_skas, to,
  49                                 from, n));
  50 }
  51
  52 /*
  53  * strncpy_from_user: - Copy a NUL terminated string from userspace.
  54  * @dst:   Destination address, in kernel space.  This buffer must be at
  55  *         least @count bytes long.
  56  * @src:   Source address, in user space.
  57  * @count: Maximum number of bytes to copy, including the trailing NUL.
  58  *
  59  * Copies a NUL-terminated string from userspace to kernel space.
  60  *
  61  * On success, returns the length of the string (not including the trailing
  62  * NUL).
  63  *
  64  * If access to userspace fails, returns -EFAULT (some data may have been
  65  * copied).
  66  *
  67  * If @count is smaller than the length of the string, copies @count bytes
  68  * and returns @count.
  69  */
  70
  71 static inline int strncpy_from_user(char *dst, const char __user *src, int count)
  72 {
  73         return(CHOOSE_MODE_PROC(strncpy_from_user_tt, strncpy_from_user_skas,
  74                                 dst, src, count));
  75 }
  76
  77 /*
  78  * __clear_user: - Zero a block of memory in user space, with less checking.
  79  * @to:   Destination address, in user space.
  80  * @n:    Number of bytes to zero.
  81  *
  82  * Zero a block of memory in user space.  Caller must check
  83  * the specified block with access_ok() before calling this function.
  84  *
  85  * Returns number of bytes that could not be cleared.
  86  * On success, this will be zero.
  87  */
  88 static inline int __clear_user(void *mem, int len)
  89 {
  90         return(CHOOSE_MODE_PROC(__clear_user_tt, __clear_user_skas, mem, len));
  91 }
  92
  93 /*
  94  * clear_user: - Zero a block of memory in user space.
  95  * @to:   Destination address, in user space.
  96  * @n:    Number of bytes to zero.
  97  *
  98  * Zero a block of memory in user space.
  99  *
 100  * Returns number of bytes that could not be cleared.
 101  * On success, this will be zero.
 102  */
 103 static inline int clear_user(void __user *mem, int len)
 104 {
 105         return(CHOOSE_MODE_PROC(clear_user_tt, clear_user_skas, mem, len));
 106 }
 107
 108 /*
 109  * strlen_user: - Get the size of a string in user space.
 110  * @str: The string to measure.
 111  * @n:   The maximum valid length
 112  *
 113  * Get the size of a NUL-terminated string in user space.
 114  *
 115  * Returns the size of the string INCLUDING the terminating NUL.
 116  * On exception, returns 0.
 117  * If the string is too long, returns a value greater than @n.
 118  */
 119 static inline int strnlen_user(const void __user *str, long len)
 120 {
 121         return(CHOOSE_MODE_PROC(strnlen_user_tt, strnlen_user_skas, str, len));
 122 }
 123
 124 #endif
 125
 126 /*
 127  * Overrides for Emacs so that we follow Linus's tabbing style.
 128  * Emacs will notice this stuff at the end of the file and automatically
 129  * adjust the settings for this buffer only.  This must remain at the end
 130  * of the file.
 131  * ---------------------------------------------------------------------------
 132  * Local variables:
 133  * c-file-style: "linux"
 134  * End:
 135  */