gcore.c revision 210063 
1/*-
2 * Copyright (c) 1992, 1993
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 the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static const char copyright[] =
36"@(#) Copyright (c) 1992, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#if 0
41#ifndef lint
42static char sccsid[] = "@(#)gcore.c	8.2 (Berkeley) 9/23/93";
43#endif /* not lint */
44#endif
45#include <sys/cdefs.h>
46__FBSDID("$FreeBSD: head/usr.bin/gcore/gcore.c 210063 2010-07-14 17:16:25Z attilio $");
47
48/*
49 * Originally written by Eric Cooper in Fall 1981.
50 * Inspired by a version 6 program by Len Levin, 1978.
51 * Several pieces of code lifted from Bill Joy's 4BSD ps.
52 * Most recently, hacked beyond recognition for 4.4BSD by Steven McCanne,
53 * Lawrence Berkeley Laboratory.
54 *
55 * Portions of this software were developed by the Computer Systems
56 * Engineering group at Lawrence Berkeley Laboratory under DARPA
57 * contract BG 91-66 and contributed to Berkeley.
58 */
59
60#include <sys/param.h>
61#include <sys/time.h>
62#include <sys/stat.h>
63#include <sys/linker_set.h>
64#include <sys/sysctl.h>
65
66#include <err.h>
67#include <fcntl.h>
68#include <stdio.h>
69#include <stdlib.h>
70#include <string.h>
71#include <unistd.h>
72
73#include "extern.h"
74int pflags;
75
76static void	killed(int);
77static void	usage(void) __dead2;
78
79static pid_t pid;
80
81SET_DECLARE(dumpset, struct dumpers);
82
83int
84main(int argc, char *argv[])
85{
86	int ch, efd, fd, name[4];
87	char *binfile, *corefile;
88	char passpath[MAXPATHLEN], fname[MAXPATHLEN];
89	struct dumpers **d, *dumper;
90	size_t len;
91
92	pflags = 0;
93	corefile = NULL;
94        while ((ch = getopt(argc, argv, "c:fs")) != -1) {
95                switch (ch) {
96                case 'c':
97			corefile = optarg;
98                        break;
99		case 'f':
100			pflags |= PFLAGS_FULL;
101			break;
102		case 's':
103			pflags |= PFLAGS_RESUME;
104			break;
105		default:
106			usage();
107			break;
108		}
109	}
110	argv += optind;
111	argc -= optind;
112	/* XXX we should check that the pid argument is really a number */
113	switch (argc) {
114	case 1:
115		pid = atoi(argv[0]);
116		name[0] = CTL_KERN;
117		name[1] = KERN_PROC;
118		name[2] = KERN_PROC_PATHNAME;
119		name[3] = pid;
120		len = sizeof(passpath);
121		if (sysctl(name, 4, passpath, &len, NULL, 0) == -1)
122			errx(1, "kern.proc.pathname failure");
123		binfile = passpath;
124		break;
125	case 2:
126		pid = atoi(argv[1]);
127		binfile = argv[0];
128		break;
129	default:
130		usage();
131	}
132	efd = open(binfile, O_RDONLY, 0);
133	if (efd < 0)
134		err(1, "%s", binfile);
135	dumper = NULL;
136	SET_FOREACH(d, dumpset) {
137		lseek(efd, 0, SEEK_SET);
138		if (((*d)->ident)(efd, pid, binfile)) {
139			dumper = (*d);
140			lseek(efd, 0, SEEK_SET);
141			break;
142		}
143	}
144	if (dumper == NULL)
145		errx(1, "Invalid executable file");
146	if (corefile == NULL) {
147		(void)snprintf(fname, sizeof(fname), "core.%d", pid);
148		corefile = fname;
149	}
150	fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE);
151	if (fd < 0)
152		err(1, "%s", corefile);
153	/*
154	 * The semantics of the 's' flag is to stop the target process.
155	 * Previous versions of gcore would manage this by trapping SIGHUP,
156	 * SIGINT and SIGTERM (to be passed to the target pid), and then
157	 * signal the child to stop.
158	 *
159	 * However, this messes up if the selected dumper uses ptrace calls
160	 * that leave the child already stopped. The waitpid call in elfcore
161	 * never returns.
162	 *
163	 * The best thing to do here is to externalize the 's' flag and let
164	 * each dumper dispose of what that means, if anything. For the elfcore
165	 * dumper, the 's' flag is a no-op since the ptrace attach stops the
166	 * process in question already.
167	 */
168
169	dumper->dump(efd, fd, pid);
170	(void)close(fd);
171	(void)close(efd);
172	exit(0);
173}
174
175void
176usage(void)
177{
178
179	(void)fprintf(stderr, "usage: gcore [-s] [-c core] [executable] pid\n");
180	exit(1);
181}
182