xref: /freebsd/contrib/tcpdump/machdep.c (revision a0409676120c1e558d0ade943019934e0f15118d)
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 #ifdef HAVE_CONFIG_H
23 #include "config.h"
24 #endif
25 
26 /*
27  * XXX - all we need, on platforms other than DEC OSF/1 (a/k/a Digital UNIX,
28  * a/k/a Tru64 UNIX), is "size_t", which is a standard C type; what do we
29  * need to do to get it defined?  This is clearly wrong, as we shouldn't
30  * have to include UNIX or Windows system header files to get it.
31  */
32 #include <netdissect-stdinc.h>
33 
34 #ifndef HAVE___ATTRIBUTE__
35 #define __attribute__(x)
36 #endif /* HAVE___ATTRIBUTE__ */
37 
38 #ifdef __osf__
39 #include <sys/sysinfo.h>
40 #include <sys/proc.h>
41 
42 #if !defined(HAVE_SNPRINTF)
43 int snprintf(char *, size_t, const char *, ...)
44 #ifdef __ATTRIBUTE___FORMAT_OK
45      __attribute__((format(printf, 3, 4)))
46 #endif /* __ATTRIBUTE___FORMAT_OK */
47      ;
48 #endif /* !defined(HAVE_SNPRINTF) */
49 #endif /* __osf__ */
50 
51 #include "machdep.h"
52 
53 /*
54  * On platforms where the CPU doesn't support unaligned loads, force
55  * unaligned accesses to abort with SIGBUS, rather than being fixed
56  * up (slowly) by the OS kernel; on those platforms, misaligned accesses
57  * are bugs, and we want tcpdump to crash so that the bugs are reported.
58  *
59  * The only OS on which this is necessary is DEC OSF/1^W^WDigital
60  * UNIX^W^WTru64 UNIX.
61  */
62 int
63 abort_on_misalignment(char *ebuf _U_, size_t ebufsiz _U_)
64 {
65 #ifdef __osf__
66 	static int buf[2] = { SSIN_UACPROC, UAC_SIGBUS };
67 
68 	if (setsysinfo(SSI_NVPAIRS, (caddr_t)buf, 1, 0, 0) < 0) {
69 		(void)snprintf(ebuf, ebufsiz, "setsysinfo: errno %d", errno);
70 		return (-1);
71 	}
72 #endif
73 	return (0);
74 }
75