xref: /dragonfly/usr.bin/gcore/gcore.c (revision 0db87cb7)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#) Copyright (c) 1992, 1993 The Regents of the University of California.  All rights reserved.
30  * @(#)gcore.c	8.2 (Berkeley) 9/23/93
31  * $FreeBSD: src/usr.bin/gcore/gcore.c,v 1.15.2.2 2001/08/17 20:56:22 mikeh Exp $
32  * $DragonFly: src/usr.bin/gcore/gcore.c,v 1.11 2007/02/25 23:07:08 corecode Exp $
33  */
34 
35 /*
36  * Originally written by Eric Cooper in Fall 1981.
37  * Inspired by a version 6 program by Len Levin, 1978.
38  * Several pieces of code lifted from Bill Joy's 4BSD ps.
39  * Most recently, hacked beyond recognition for 4.4BSD by Steven McCanne,
40  * Lawrence Berkeley Laboratory.
41  *
42  * Portions of this software were developed by the Computer Systems
43  * Engineering group at Lawrence Berkeley Laboratory under DARPA
44  * contract BG 91-66 and contributed to Berkeley.
45  */
46 #include <sys/user.h>
47 #include <sys/param.h>
48 #include <sys/time.h>
49 #include <sys/stat.h>
50 #include <sys/sysctl.h>
51 #include <machine/elf.h>
52 
53 #include <machine/vmparam.h>
54 
55 #include <a.out.h>
56 #include <err.h>
57 #include <fcntl.h>
58 #include <kvm.h>
59 #include <limits.h>
60 #include <signal.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #include <unistd.h>
65 
66 #include "extern.h"
67 
68 static void	killed(int);
69 static void	restart_target(void);
70 static void	usage(void) __dead2;
71 
72 kvm_t *kd;
73 
74 static pid_t pid;
75 
76 int
77 main(int argc, char **argv)
78 {
79 	struct exec exec;
80 	int ch, cnt, efd, fd, sflag;
81 	char *binfile, *corefile;
82 	char fname[MAXPATHLEN + 1];
83 
84 	sflag = 0;
85 	corefile = NULL;
86         while ((ch = getopt(argc, argv, "c:s")) != -1) {
87                 switch (ch) {
88                 case 'c':
89 			corefile = optarg;
90                         break;
91 		case 's':
92 			sflag = 1;
93 			break;
94 		default:
95 			usage();
96 			break;
97 		}
98 	}
99 	argv += optind;
100 	argc -= optind;
101 
102 	/* XXX we should check that the pid argument is really a number */
103 	switch (argc) {
104 	case 1:
105 		pid = atoi(argv[0]);
106 		asprintf(&binfile, "/proc/%d/file", pid);
107 		if (binfile == NULL)
108 			errx(1, "allocation failure");
109 		break;
110 	case 2:
111 		pid = atoi(argv[1]);
112 		binfile = argv[0];
113 		break;
114 	default:
115 		usage();
116 	}
117 
118 	efd = open(binfile, O_RDONLY, 0);
119 	if (efd < 0)
120 		err(1, "%s", binfile);
121 
122 	cnt = read(efd, &exec, sizeof(exec));
123 	if (cnt != sizeof(exec))
124 		errx(1, "%s exec header: %s",
125 		    binfile, cnt > 0 ? strerror(EIO) : strerror(errno));
126 	if (IS_ELF(*(Elf_Ehdr *)&exec)) {
127 		close(efd);
128 	} else
129 		errx(1, "Invalid executable file");
130 
131 	if (corefile == NULL) {
132 		(void)snprintf(fname, sizeof(fname), "core.%d", pid);
133 		corefile = fname;
134 	}
135 	fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE);
136 	if (fd < 0)
137 		err(1, "%s", corefile);
138 
139 	if (sflag) {
140 		signal(SIGHUP, killed);
141 		signal(SIGINT, killed);
142 		signal(SIGTERM, killed);
143 		if (kill(pid, SIGSTOP) == -1)
144 			err(1, "%d: stop signal", pid);
145 		atexit(restart_target);
146 	}
147 
148 	elf_coredump(fd, pid);
149 
150 	(void)close(fd);
151 	exit(0);
152 }
153 
154 static void
155 killed(int sig)
156 {
157 	restart_target();
158 	signal(sig, SIG_DFL);
159 	kill(getpid(), sig);
160 }
161 
162 static void
163 restart_target(void)
164 {
165 	kill(pid, SIGCONT);
166 }
167 
168 void
169 usage(void)
170 {
171 	(void)fprintf(stderr, "usage: gcore [-s] [-c core] [executable] pid\n");
172 	exit(1);
173 }
174