1/* $NetBSD: uaccess.h,v 1.11 2022/10/25 23:38:33 riastradh Exp $ */ 2 3/*- 4 * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#ifndef _ASM_UACCESS_H_ 33#define _ASM_UACCESS_H_ 34 35#include <sys/types.h> 36#include <sys/errno.h> 37#include <sys/systm.h> 38 39#include <linux/compiler.h> 40 41/* XXX This is a cop-out. */ 42#define VERIFY_READ 0 43#define VERIFY_WRITE 1 44static inline bool 45access_ok(const void *uaddr __unused, size_t nbytes __unused) 46{ 47 return true; 48} 49 50#define __copy_from_user copy_from_user 51#define __copy_to_user copy_to_user 52 53static inline int 54copy_from_user(void *kernel_addr, const void *user_addr, size_t len) 55{ 56 /* XXX errno NetBSD->Linux */ 57 return -copyin(user_addr, kernel_addr, len); 58} 59 60static inline long 61strncpy_from_user(char *kernel_addr, const void *user_addr, long len) 62{ 63 size_t done; 64 int error; 65 66 if (len <= 0) 67 return 0; 68 error = copyinstr(user_addr, kernel_addr, len, &done); 69 if (error) 70 return error; 71 KASSERT(done <= (size_t)len); 72 KASSERT(done >= 1); 73 return done - 1; 74} 75 76static inline int 77copy_to_user(void *user_addr, const void *kernel_addr, size_t len) 78{ 79 /* XXX errno NetBSD->Linux */ 80 return -copyout(kernel_addr, user_addr, len); 81} 82 83#define get_user(KERNEL_LVAL, USER_PTR) \ 84 copy_from_user(&(KERNEL_LVAL), (USER_PTR), sizeof(*(USER_PTR)) + \ 85 0*sizeof(&(KERNEL_LVAL) - (USER_PTR))) 86 87#define put_user(KERNEL_RVAL, USER_PTR) ({ \ 88 const typeof(*(USER_PTR)) __put_user_tmp = (KERNEL_RVAL); \ 89 copy_to_user((USER_PTR), &__put_user_tmp, sizeof(__put_user_tmp)); \ 90}) 91 92#define __get_user get_user 93#define __put_user put_user 94 95#define user_access_begin(P,N) access_ok(P,N) 96#define user_access_end() __nothing 97 98#define unsafe_put_user(KERNEL_RVAL, USER_PTR, LABEL) do { \ 99 if (__put_user(KERNEL_RVAL, USER_PTR)) \ 100 goto LABEL; \ 101} while (0) 102 103static inline size_t 104clear_user(void __user *user_ptr, size_t size) 105{ 106 char __user *p = user_ptr; 107 size_t n = size; 108 109 /* 110 * This loop which sets up a fault handler on every iteration 111 * is not going to win any speed records, but it'll do to copy 112 * out an int. 113 */ 114 while (n --> 0) { 115 if (ustore_char(p, 0) != 0) 116 return ++n; 117 } 118 119 return 0; 120} 121 122#if 0 123/* 124 * XXX These `inatomic' versions are a cop out, but they should do for 125 * now -- they are used only in fast paths which can't fault but which 126 * can fall back to slower paths that arrange things so faulting is OK. 127 */ 128 129static inline int 130__copy_from_user_inatomic(void *kernel_addr __unused, 131 const void *user_addr __unused, size_t len __unused) 132{ 133 return -EFAULT; 134} 135 136static inline int 137__copy_to_user_inatomic(void *user_addr __unused, 138 const void *kernel_addr __unused, size_t len __unused) 139{ 140 return -EFAULT; 141} 142#endif /* 0 */ 143 144static inline int 145__copy_from_user_inatomic_nocache(void *kernel_addr __unused, 146 const void *user_addr __unused, size_t len __unused) 147{ 148 return -EFAULT; 149} 150 151#endif /* _ASM_UACCESS_H_ */ 152