LXR linux/arch/um/include/um

   1/* 
   2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3 * Licensed under the GPL
   4 */
   5
   6#ifndef __ARCH_UM_UACCESS_H
   7#define __ARCH_UM_UACCESS_H
   8
   9#include "asm/fixmap.h"
  10
  11#define __under_task_size(addr, size) \
  12        (((unsigned long) (addr) < TASK_SIZE) && \
  13         (((unsigned long) (addr) + (size)) < TASK_SIZE))
  14
  15#define __access_ok_vsyscall(type, addr, size) \
  16         ((type == VERIFY_READ) && \
  17          ((unsigned long) (addr) >= FIXADDR_USER_START) && \
  18          ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
  19          ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
  20
  21#define __addr_range_nowrap(addr, size) \
  22        ((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
  23
  24#define access_ok(type, addr, size) \
  25        (__addr_range_nowrap(addr, size) && \
  26         (__under_task_size(addr, size) || \
  27          __access_ok_vsyscall(type, addr, size) || \
  28          segment_eq(get_fs(), KERNEL_DS)))
  29
  30extern int copy_from_user(void *to, const void __user *from, int n);
  31extern int copy_to_user(void __user *to, const void *from, int n);
  32
  33extern int __do_copy_to_user(void *to, const void *from, int n,
  34                             void **fault_addr, jmp_buf **fault_catcher);
  35extern void __do_copy(void *to, const void *from, int n);
  36
  37/*
  38 * strncpy_from_user: - Copy a NUL terminated string from userspace.
  39 * @dst:   Destination address, in kernel space.  This buffer must be at
  40 *         least @count bytes long.
  41 * @src:   Source address, in user space.
  42 * @count: Maximum number of bytes to copy, including the trailing NUL.
  43 *
  44 * Copies a NUL-terminated string from userspace to kernel space.
  45 *
  46 * On success, returns the length of the string (not including the trailing
  47 * NUL).
  48 *
  49 * If access to userspace fails, returns -EFAULT (some data may have been
  50 * copied).
  51 *
  52 * If @count is smaller than the length of the string, copies @count bytes
  53 * and returns @count.
  54 */
  55
  56extern int strncpy_from_user(char *dst, const char __user *src, int count);
  57
  58/*
  59 * __clear_user: - Zero a block of memory in user space, with less checking.
  60 * @to:   Destination address, in user space.
  61 * @n:    Number of bytes to zero.
  62 *
  63 * Zero a block of memory in user space.  Caller must check
  64 * the specified block with access_ok() before calling this function.
  65 *
  66 * Returns number of bytes that could not be cleared.
  67 * On success, this will be zero.
  68 */
  69extern int __clear_user(void __user *mem, int len);
  70
  71/*
  72 * clear_user: - Zero a block of memory in user space.
  73 * @to:   Destination address, in user space.
  74 * @n:    Number of bytes to zero.
  75 *
  76 * Zero a block of memory in user space.
  77 *
  78 * Returns number of bytes that could not be cleared.
  79 * On success, this will be zero.
  80 */
  81extern int clear_user(void __user *mem, int len);
  82
  83/*
  84 * strlen_user: - Get the size of a string in user space.
  85 * @str: The string to measure.
  86 * @n:   The maximum valid length
  87 *
  88 * Get the size of a NUL-terminated string in user space.
  89 *
  90 * Returns the size of the string INCLUDING the terminating NUL.
  91 * On exception, returns 0.
  92 * If the string is too long, returns a value greater than @n.
  93 */
  94extern int strnlen_user(const void __user *str, int len);
  95
  96#endif
  97