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