xref: /freebsd/contrib/tcpdump/machdep.c (revision 7937bfbc0ca53fe7cdd0d54414f9296e273a518e)
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 <config.h>
23 
24 #include <stddef.h>
25 
26 #ifdef __osf__
27 #include <stdio.h>
28 #include <sys/sysinfo.h>
29 #include <sys/proc.h>
30 #endif /* __osf__ */
31 
32 #include "varattrs.h"
33 #include "machdep.h"
34 
35 /*
36  * On platforms where the CPU doesn't support unaligned loads, force
37  * unaligned accesses to abort with SIGBUS, rather than being fixed
38  * up (slowly) by the OS kernel; on those platforms, misaligned accesses
39  * are bugs, and we want tcpdump to crash so that the bugs are reported.
40  *
41  * The only OS on which this is necessary is DEC OSF/1^W^WDigital
42  * UNIX^W^WTru64 UNIX.
43  */
44 int
45 abort_on_misalignment(char *ebuf _U_, size_t ebufsiz _U_)
46 {
47 #ifdef __osf__
48 	static int buf[2] = { SSIN_UACPROC, UAC_SIGBUS };
49 
50 	if (setsysinfo(SSI_NVPAIRS, (caddr_t)buf, 1, 0, 0) < 0) {
51 		(void)snprintf(ebuf, ebufsiz, "setsysinfo: errno %d", errno);
52 		return (-1);
53 	}
54 #endif
55 	return (0);
56 }
57