xref: /netbsd-src/external/bsd/tcpdump/dist/machdep.c (revision 3117ece4fc4a4ca4489ba793710b60b0d26bab6c)
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 1.9 2024/09/02 16:15:30 christos Exp $");
25 #endif
26 
27 #include <config.h>
28 
29 #include <stddef.h>
30 
31 #ifdef __osf__
32 #include <stdio.h>
33 #include <sys/sysinfo.h>
34 #include <sys/proc.h>
35 #endif /* __osf__ */
36 
37 #include "varattrs.h"
38 #include "machdep.h"
39 
40 /*
41  * On platforms where the CPU doesn't support unaligned loads, force
42  * unaligned accesses to abort with SIGBUS, rather than being fixed
43  * up (slowly) by the OS kernel; on those platforms, misaligned accesses
44  * are bugs, and we want tcpdump to crash so that the bugs are reported.
45  *
46  * The only OS on which this is necessary is DEC OSF/1^W^WDigital
47  * UNIX^W^WTru64 UNIX.
48  */
49 int
50 abort_on_misalignment(char *ebuf _U_, size_t ebufsiz _U_)
51 {
52 #ifdef __osf__
53 	static int buf[2] = { SSIN_UACPROC, UAC_SIGBUS };
54 
55 	if (setsysinfo(SSI_NVPAIRS, (caddr_t)buf, 1, 0, 0) < 0) {
56 		(void)snprintf(ebuf, ebufsiz, "setsysinfo: errno %d", errno);
57 		return (-1);
58 	}
59 #endif
60 	return (0);
61 }
62