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 "choose-mode.h"
  10
  11 #ifdef CONFIG_MODE_TT
  12 #include "uaccess-tt.h"
  13 #endif
  14
  15 #ifdef CONFIG_MODE_SKAS
  16 #include "uaccess-skas.h"
  17 #endif
  18
  19 #include "asm/fixmap.h"
  20
  21 #define __under_task_size(addr, size) \
  22         (((unsigned long) (addr) < TASK_SIZE) && \
  23          (((unsigned long) (addr) + (size)) < TASK_SIZE))
  24
  25 #define __access_ok_vsyscall(type, addr, size) \
  26          ((type == VERIFY_READ) && \
  27           ((unsigned long) (addr) >= FIXADDR_USER_START) && \
  28           ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
  29           ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
  30
  31 #define __addr_range_nowrap(addr, size) \
  32         ((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
  33
  34 #define access_ok(type, addr, size) \
  35         (__addr_range_nowrap(addr, size) && \
  36          (__under_task_size(addr, size) || \
  37           __access_ok_vsyscall(type, addr, size) || \
  38           segment_eq(get_fs(), KERNEL_DS) || \
  39           CHOOSE_MODE_PROC(access_ok_tt, access_ok_skas, type, addr, size)))
  40
  41 static inline int copy_from_user(void *to, const void __user *from, int n)
  42 {
  43         return(CHOOSE_MODE_PROC(copy_from_user_tt, copy_from_user_skas, to,
  44                                 from, n));
  45 }
  46
  47 static inline int copy_to_user(void __user *to, const void *from, int n)
  48 {
  49         return(CHOOSE_MODE_PROC(copy_to_user_tt, copy_to_user_skas, to,
  50                                 from, n));
  51 }
  52
  53 /*
  54  * strncpy_from_user: - Copy a NUL terminated string from userspace.
  55  * @dst:   Destination address, in kernel space.  This buffer must be at
  56  *         least @count bytes long.
  57  * @src:   Source address, in user space.
  58  * @count: Maximum number of bytes to copy, including the trailing NUL.
  59  *
  60  * Copies a NUL-terminated string from userspace to kernel space.
  61  *
  62  * On success, returns the length of the string (not including the trailing
  63  * NUL).
  64  *
  65  * If access to userspace fails, returns -EFAULT (some data may have been
  66  * copied).
  67  *
  68  * If @count is smaller than the length of the string, copies @count bytes
  69  * and returns @count.
  70  */
  71
  72 static inline int strncpy_from_user(char *dst, const char __user *src, int count)
  73 {
  74         return(CHOOSE_MODE_PROC(strncpy_from_user_tt, strncpy_from_user_skas,
  75                                 dst, src, count));
  76 }
  77
  78 /*
  79  * __clear_user: - Zero a block of memory in user space, with less checking.
  80  * @to:   Destination address, in user space.
  81  * @n:    Number of bytes to zero.
  82  *
  83  * Zero a block of memory in user space.  Caller must check
  84  * the specified block with access_ok() before calling this function.
  85  *
  86  * Returns number of bytes that could not be cleared.
  87  * On success, this will be zero.
  88  */
  89 static inline int __clear_user(void *mem, int len)
  90 {
  91         return(CHOOSE_MODE_PROC(__clear_user_tt, __clear_user_skas, mem, len));
  92 }
  93
  94 /*
  95  * clear_user: - Zero a block of memory in user space.
  96  * @to:   Destination address, in user space.
  97  * @n:    Number of bytes to zero.
  98  *
  99  * Zero a block of memory in user space.
 100  *
 101  * Returns number of bytes that could not be cleared.
 102  * On success, this will be zero.
 103  */
 104 static inline int clear_user(void __user *mem, int len)
 105 {
 106         return(CHOOSE_MODE_PROC(clear_user_tt, clear_user_skas, mem, len));
 107 }
 108
 109 /*
 110  * strlen_user: - Get the size of a string in user space.
 111  * @str: The string to measure.
 112  * @n:   The maximum valid length
 113  *
 114  * Get the size of a NUL-terminated string in user space.
 115  *
 116  * Returns the size of the string INCLUDING the terminating NUL.
 117  * On exception, returns 0.
 118  * If the string is too long, returns a value greater than @n.
 119  */
 120 static inline int strnlen_user(const void __user *str, long len)
 121 {
 122         return(CHOOSE_MODE_PROC(strnlen_user_tt, strnlen_user_skas, str, len));
 123 }
 124
 125 #endif
 126
 127 /*
 128  * Overrides for Emacs so that we follow Linus's tabbing style.
 129  * Emacs will notice this stuff at the end of the file and automatically
 130  * adjust the settings for this buffer only.  This must remain at the end
 131  * of the file.
 132  * ---------------------------------------------------------------------------
 133  * Local variables:
 134  * c-file-style: "linux"
 135  * End:
 136  */