LXR linux/arch/um/include/shared/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/elf.h>
  10#include <asm/fixmap.h>
  11#include "sysdep/archsetjmp.h"
  12
  13#define __under_task_size(addr, size) \
  14        (((unsigned long) (addr) < TASK_SIZE) && \
  15         (((unsigned long) (addr) + (size)) < TASK_SIZE))
  16
  17#define __access_ok_vsyscall(type, addr, size) \
  18         ((type == VERIFY_READ) && \
  19          ((unsigned long) (addr) >= FIXADDR_USER_START) && \
  20          ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
  21          ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
  22
  23#define __addr_range_nowrap(addr, size) \
  24        ((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
  25
  26#define access_ok(type, addr, size) \
  27        (__addr_range_nowrap(addr, size) && \
  28         (__under_task_size(addr, size) || \
  29          __access_ok_vsyscall(type, addr, size) || \
  30          segment_eq(get_fs(), KERNEL_DS)))
  31
  32extern int copy_from_user(void *to, const void __user *from, int n);
  33extern int copy_to_user(void __user *to, const void *from, int n);
  34
  35extern int __do_copy_to_user(void *to, const void *from, int n,
  36                             void **fault_addr, jmp_buf **fault_catcher);
  37
  38/*
  39 * strncpy_from_user: - Copy a NUL terminated string from userspace.
  40 * @dst:   Destination address, in kernel space.  This buffer must be at
  41 *         least @count bytes long.
  42 * @src:   Source address, in user space.
  43 * @count: Maximum number of bytes to copy, including the trailing NUL.
  44 *
  45 * Copies a NUL-terminated string from userspace to kernel space.
  46 *
  47 * On success, returns the length of the string (not including the trailing
  48 * NUL).
  49 *
  50 * If access to userspace fails, returns -EFAULT (some data may have been
  51 * copied).
  52 *
  53 * If @count is smaller than the length of the string, copies @count bytes
  54 * and returns @count.
  55 */
  56
  57extern int strncpy_from_user(char *dst, const char __user *src, int count);
  58
  59/*
  60 * __clear_user: - Zero a block of memory in user space, with less checking.
  61 * @to:   Destination address, in user space.
  62 * @n:    Number of bytes to zero.
  63 *
  64 * Zero a block of memory in user space.  Caller must check
  65 * the specified block with access_ok() before calling this function.
  66 *
  67 * Returns number of bytes that could not be cleared.
  68 * On success, this will be zero.
  69 */
  70extern int __clear_user(void __user *mem, int len);
  71
  72/*
  73 * clear_user: - Zero a block of memory in user space.
  74 * @to:   Destination address, in user space.
  75 * @n:    Number of bytes to zero.
  76 *
  77 * Zero a block of memory in user space.
  78 *
  79 * Returns number of bytes that could not be cleared.
  80 * On success, this will be zero.
  81 */
  82extern int clear_user(void __user *mem, int len);
  83
  84/*
  85 * strlen_user: - Get the size of a string in user space.
  86 * @str: The string to measure.
  87 * @n:   The maximum valid length
  88 *
  89 * Get the size of a NUL-terminated string in user space.
  90 *
  91 * Returns the size of the string INCLUDING the terminating NUL.
  92 * On exception, returns 0.
  93 * If the string is too long, returns a value greater than @n.
  94 */
  95extern int strnlen_user(const void __user *str, int len);
  96
  97#endif
  98