1 /* $NetBSD: uaccess.h,v 1.10 2021/12/19 11:33:30 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 44 static inline bool 45 access_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 53 static inline int 54 copy_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 60 static inline int 61 copy_to_user(void *user_addr, const void *kernel_addr, size_t len) 62 { 63 /* XXX errno NetBSD->Linux */ 64 return -copyout(kernel_addr, user_addr, len); 65 } 66 67 #define get_user(KERNEL_LVAL, USER_PTR) \ 68 copy_from_user(&(KERNEL_LVAL), (USER_PTR), sizeof(*(USER_PTR)) + \ 69 0*sizeof(&(KERNEL_LVAL) - (USER_PTR))) 70 71 #define put_user(KERNEL_RVAL, USER_PTR) ({ \ 72 const typeof(*(USER_PTR)) __put_user_tmp = (KERNEL_RVAL); \ 73 copy_to_user((USER_PTR), &__put_user_tmp, sizeof(__put_user_tmp)); \ 74 }) 75 76 #define __get_user get_user 77 #define __put_user put_user 78 79 #define user_access_begin(P,N) access_ok(P,N) 80 #define user_access_end() __nothing 81 82 #define unsafe_put_user(KERNEL_RVAL, USER_PTR, LABEL) do { \ 83 if (__put_user(KERNEL_RVAL, USER_PTR)) \ 84 goto LABEL; \ 85 } while (0) 86 87 static inline size_t 88 clear_user(void __user *user_ptr, size_t size) 89 { 90 char __user *p = user_ptr; 91 size_t n = size; 92 93 /* 94 * This loop which sets up a fault handler on every iteration 95 * is not going to win any speed records, but it'll do to copy 96 * out an int. 97 */ 98 while (n --> 0) { 99 if (ustore_char(p, 0) != 0) 100 return ++n; 101 } 102 103 return 0; 104 } 105 106 #if 0 107 /* 108 * XXX These `inatomic' versions are a cop out, but they should do for 109 * now -- they are used only in fast paths which can't fault but which 110 * can fall back to slower paths that arrange things so faulting is OK. 111 */ 112 113 static inline int 114 __copy_from_user_inatomic(void *kernel_addr __unused, 115 const void *user_addr __unused, size_t len __unused) 116 { 117 return -EFAULT; 118 } 119 120 static inline int 121 __copy_to_user_inatomic(void *user_addr __unused, 122 const void *kernel_addr __unused, size_t len __unused) 123 { 124 return -EFAULT; 125 } 126 #endif /* 0 */ 127 128 static inline int 129 __copy_from_user_inatomic_nocache(void *kernel_addr __unused, 130 const void *user_addr __unused, size_t len __unused) 131 { 132 return -EFAULT; 133 } 134 135 #endif /* _ASM_UACCESS_H_ */ 136