1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright 2019 Alex Richardson <arichardson@FreeBSD.org>
5  *
6  * This software was developed by SRI International and the University of
7  * Cambridge Computer Laboratory (Department of Computer Science and
8  * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
9  * DARPA SSITH research programme.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * $FreeBSD$
33  */
34 #include <sys/cdefs.h>
35 #include <sys/param.h>
36 #include <sys/types.h>
37 #include <sys/sysctl.h>
38 #include <assert.h>
39 #include <signal.h>
40 #include <stdarg.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <stdio.h>
44 
45 #include "rtld.h"
46 #include "rtld_printf.h"
47 #include "rtld_libc.h"
48 
49 /*
50  * Avoid dependencies from various libc calls on abort(). Since this is only
51  * used for assertions in RTLD, we can just raise SIGABRT directly.
52  */
53 void
54 abort(void)
55 {
56 	raise(SIGABRT);
57 	__builtin_trap();
58 }
59 
60 static int rtld_errno;
61 int *__error(void);
62 int *
63 __error(void)
64 {
65 
66 	return (&rtld_errno);
67 }
68 
69 /* Avoid dependency on __libc_interposing, use the system call directly. */
70 #undef sigprocmask
71 int
72 sigprocmask(int how, const sigset_t *set, sigset_t *oset)
73 {
74 
75 	return (__sys_sigprocmask(how, set, oset));
76 }
77 __strong_reference(sigprocmask, __libc_sigprocmask);
78 
79 #if defined DEBUG || !defined(NDEBUG)
80 /* Provide an implementation of __assert that does not pull in fprintf() */
81 void
82 __assert(const char *func, const char *file, int line, const char *failedexpr)
83 {
84 
85 	if (func == NULL)
86 		(void)rtld_fdprintf(STDERR_FILENO,
87 		    "Assertion failed: (%s), file %s, line %d.\n", failedexpr,
88 		    file, line);
89 	else
90 		(void)rtld_fdprintf(STDERR_FILENO,
91 		    "Assertion failed: (%s), function %s, file %s, line %d.\n",
92 		    failedexpr, func, file, line);
93 	abort();
94 	/* NOTREACHED */
95 }
96 #endif
97 
98 /*
99  * Avoid pulling in all of pthreads from getpagesize().
100  * It normally uses libc/gen/auxv.c which pulls in pthread_once().
101  */
102 int
103 getpagesize(void)
104 {
105 	int mib[2], value;
106 	size_t size;
107 	static int pagesize;
108 
109 	if (pagesize != 0)
110 		return (pagesize);
111 
112 	if (npagesizes > 0)
113 		pagesize = pagesizes[0];
114 
115 	if (pagesize == 0) {
116 		mib[0] = CTL_HW;
117 		mib[1] = HW_PAGESIZE;
118 		size = sizeof(value);
119 		if (sysctl(mib, nitems(mib), &value, &size, NULL, 0) == -1)
120 			pagesize = PAGE_SIZE;
121 		else
122 			pagesize = value;
123 	}
124 
125 	return (pagesize);
126 }
127 
128 extern int __sys___sysctl(const int *name, u_int namelen, void *oldp,
129     size_t *oldlenp, const void *newp, size_t newlen);
130 
131 int
132 sysctl(const int *name, u_int namelen, void *oldp, size_t *oldlenp,
133     const void *newp, size_t newlen)
134 {
135 	int retval;
136 
137 	assert(name[0] != CTL_USER && "Not supported inside rtld!");
138 	retval = __sys___sysctl(name, namelen, oldp, oldlenp, newp, newlen);
139 	return (retval);
140 }
141