xref: /netbsd-src/external/bsd/tcpdump/dist/machdep.c (revision ccd9df534e375a4366c5b55f23782053c7a98d82)
1 /*
2  * Copyright (c) 1996, 1997
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that: (1) source code distributions
7  * retain the above copyright notice and this paragraph in its entirety, (2)
8  * distributions including binary code include the above copyright notice and
9  * this paragraph in its entirety in the documentation or other materials
10  * provided with the distribution, and (3) all advertising materials mentioning
11  * features or use of this software display the following acknowledgement:
12  * ``This product includes software developed by the University of California,
13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14  * the University nor the names of its contributors may be used to endorse
15  * or promote products derived from this software without specific prior
16  * written permission.
17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20  */
21 
22 #include <sys/cdefs.h>
23 #ifndef lint
24 __RCSID("$NetBSD: machdep.c,v 1.8 2023/08/17 20:19:40 christos Exp $");
25 #endif
26 
27 #ifdef HAVE_CONFIG_H
28 #include <config.h>
29 #endif
30 
31 #include <stddef.h>
32 
33 #ifdef __osf__
34 #include <stdio.h>
35 #include <sys/sysinfo.h>
36 #include <sys/proc.h>
37 #endif /* __osf__ */
38 
39 #include "varattrs.h"
40 #include "machdep.h"
41 
42 /*
43  * On platforms where the CPU doesn't support unaligned loads, force
44  * unaligned accesses to abort with SIGBUS, rather than being fixed
45  * up (slowly) by the OS kernel; on those platforms, misaligned accesses
46  * are bugs, and we want tcpdump to crash so that the bugs are reported.
47  *
48  * The only OS on which this is necessary is DEC OSF/1^W^WDigital
49  * UNIX^W^WTru64 UNIX.
50  */
51 int
52 abort_on_misalignment(char *ebuf _U_, size_t ebufsiz _U_)
53 {
54 #ifdef __osf__
55 	static int buf[2] = { SSIN_UACPROC, UAC_SIGBUS };
56 
57 	if (setsysinfo(SSI_NVPAIRS, (caddr_t)buf, 1, 0, 0) < 0) {
58 		(void)snprintf(ebuf, ebufsiz, "setsysinfo: errno %d", errno);
59 		return (-1);
60 	}
61 #endif
62 	return (0);
63 }
64