gcore.c revision 1591 
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 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#ifndef lint
41static char sccsid[] = "@(#)gcore.c	8.2 (Berkeley) 9/23/93";
42#endif /* not lint */
43
44/*
45 * Originally written by Eric Cooper in Fall 1981.
46 * Inspired by a version 6 program by Len Levin, 1978.
47 * Several pieces of code lifted from Bill Joy's 4BSD ps.
48 * Most recently, hacked beyond recognition for 4.4BSD by Steven McCanne,
49 * Lawrence Berkeley Laboratory.
50 *
51 * Portions of this software were developed by the Computer Systems
52 * Engineering group at Lawrence Berkeley Laboratory under DARPA
53 * contract BG 91-66 and contributed to Berkeley.
54 */
55#include <sys/param.h>
56#include <sys/time.h>
57#include <sys/stat.h>
58#include <sys/proc.h>
59#include <sys/user.h>
60#include <sys/sysctl.h>
61
62#include <machine/vmparam.h>
63
64#include <a.out.h>
65#include <fcntl.h>
66#include <kvm.h>
67#include <limits.h>
68#include <signal.h>
69#include <stdio.h>
70#include <stdlib.h>
71#include <string.h>
72#include <unistd.h>
73
74#include "extern.h"
75
76void	core __P((int, int, struct kinfo_proc *));
77void	datadump __P((int, int, struct proc *, u_long, int));
78void	usage __P((void));
79void	userdump __P((int, struct proc *, u_long, int));
80
81kvm_t *kd;
82/* XXX undocumented routine, should be in kvm.h? */
83ssize_t kvm_uread __P((kvm_t *, struct proc *, u_long, char *, size_t));
84
85static int data_offset;
86
87int
88main(argc, argv)
89	int argc;
90	char *argv[];
91{
92	register struct proc *p;
93	struct kinfo_proc *ki;
94	struct exec exec;
95	int ch, cnt, efd, fd, pid, sflag, uid;
96	char *corefile, errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN + 1];
97
98	sflag = 0;
99	corefile = NULL;
100        while ((ch = getopt(argc, argv, "c:s")) != EOF) {
101                switch (ch) {
102                case 'c':
103			corefile = optarg;
104                        break;
105		case 's':
106			sflag = 1;
107			break;
108		default:
109			usage();
110			break;
111		}
112	}
113	argv += optind;
114	argc -= optind;
115
116	if (argc != 2)
117		usage();
118
119	kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf);
120	if (kd == NULL)
121		err(1, "%s", errbuf);
122
123	uid = getuid();
124	pid = atoi(argv[1]);
125
126	ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt);
127	if (ki == NULL || cnt != 1)
128		err(1, "%d: not found", pid);
129
130	p = &ki->kp_proc;
131	if (ki->kp_eproc.e_pcred.p_ruid != uid && uid != 0)
132		err(1, "%d: not owner", pid);
133
134	if (p->p_stat == SZOMB)
135		err(1, "%d: zombie", pid);
136
137	if (p->p_flag & P_WEXIT)
138		err(0, "process exiting");
139	if (p->p_flag & P_SYSTEM)	/* Swapper or pagedaemon. */
140		err(1, "%d: system process");
141
142	if (corefile == NULL) {
143		(void)snprintf(fname, sizeof(fname), "core.%d", pid);
144		corefile = fname;
145	}
146	fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE);
147	if (fd < 0)
148		err(1, "%s: %s\n", corefile, strerror(errno));
149
150	efd = open(argv[0], O_RDONLY, 0);
151	if (efd < 0)
152		err(1, "%s: %s\n", argv[0], strerror(errno));
153
154	cnt = read(efd, &exec, sizeof(exec));
155	if (cnt != sizeof(exec))
156		err(1, "%s exec header: %s",
157		    argv[0], cnt > 0 ? strerror(EIO) : strerror(errno));
158
159	data_offset = N_DATOFF(exec);
160
161	if (sflag && kill(pid, SIGSTOP) < 0)
162		err(0, "%d: stop signal: %s", pid, strerror(errno));
163
164	core(efd, fd, ki);
165
166	if (sflag && kill(pid, SIGCONT) < 0)
167		err(0, "%d: continue signal: %s", pid, strerror(errno));
168	(void)close(fd);
169
170	exit(0);
171}
172
173/*
174 * core --
175 *	Build the core file.
176 */
177void
178core(efd, fd, ki)
179	int efd;
180	int fd;
181	struct kinfo_proc *ki;
182{
183	union {
184		struct user user;
185		char ubytes[ctob(UPAGES)];
186	} uarea;
187	struct proc *p = &ki->kp_proc;
188	int tsize = ki->kp_eproc.e_vm.vm_tsize;
189	int dsize = ki->kp_eproc.e_vm.vm_dsize;
190	int ssize = ki->kp_eproc.e_vm.vm_ssize;
191	int cnt;
192
193	/* Read in user struct */
194	cnt = kvm_read(kd, (u_long)p->p_addr, &uarea, sizeof(uarea));
195	if (cnt != sizeof(uarea))
196		err(1, "read user structure: %s",
197		    cnt > 0 ? strerror(EIO) : strerror(errno));
198
199	/*
200	 * Fill in the eproc vm parameters, since these are garbage unless
201	 * the kernel is dumping core or something.
202	 */
203	uarea.user.u_kproc = *ki;
204
205	/* Dump user area */
206	cnt = write(fd, &uarea, sizeof(uarea));
207	if (cnt != sizeof(uarea))
208		err(1, "write user structure: %s",
209		    cnt > 0 ? strerror(EIO) : strerror(errno));
210
211	/* Dump data segment */
212	datadump(efd, fd, p, USRTEXT + ctob(tsize), dsize);
213
214	/* Dump stack segment */
215	userdump(fd, p, USRSTACK - ctob(ssize), ssize);
216
217	/* Dump machine dependent portions of the core. */
218	md_core(kd, fd, ki);
219}
220
221void
222datadump(efd, fd, p, addr, npage)
223	register int efd;
224	register int fd;
225	struct proc *p;
226	register u_long addr;
227	register int npage;
228{
229	register int cc, delta;
230	char buffer[NBPG];
231
232	delta = data_offset - addr;
233	while (--npage >= 0) {
234		cc = kvm_uread(kd, p, addr, buffer, NBPG);
235		if (cc != NBPG) {
236			/* Try to read the page from the executable. */
237			if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1)
238				err(1, "seek executable: %s", strerror(errno));
239			cc = read(efd, buffer, sizeof(buffer));
240			if (cc != sizeof(buffer))
241				if (cc < 0)
242					err(1, "read executable: %s",
243					    strerror(errno));
244				else	/* Assume untouched bss page. */
245					bzero(buffer, sizeof(buffer));
246		}
247		cc = write(fd, buffer, NBPG);
248		if (cc != NBPG)
249			err(1, "write data segment: %s",
250			    cc > 0 ? strerror(EIO) : strerror(errno));
251		addr += NBPG;
252	}
253}
254
255void
256userdump(fd, p, addr, npage)
257	register int fd;
258	struct proc *p;
259	register u_long addr;
260	register int npage;
261{
262	register int cc;
263	char buffer[NBPG];
264
265	while (--npage >= 0) {
266		cc = kvm_uread(kd, p, addr, buffer, NBPG);
267		if (cc != NBPG)
268			/* Could be an untouched fill-with-zero page. */
269			bzero(buffer, NBPG);
270		cc = write(fd, buffer, NBPG);
271		if (cc != NBPG)
272			err(1, "write stack segment: %s",
273			    cc > 0 ? strerror(EIO) : strerror(errno));
274		addr += NBPG;
275	}
276}
277
278void
279usage()
280{
281	(void)fprintf(stderr, "usage: gcore [-s] [-c core] executable pid\n");
282	exit(1);
283}
284
285#if __STDC__
286#include <stdarg.h>
287#else
288#include <varargs.h>
289#endif
290
291void
292#if __STDC__
293err(int fatal, const char *fmt, ...)
294#else
295err(fatal, fmt, va_alist)
296	int fatal;
297	char *fmt;
298        va_dcl
299#endif
300{
301	va_list ap;
302#if __STDC__
303	va_start(ap, fmt);
304#else
305	va_start(ap);
306#endif
307	(void)fprintf(stderr, "gcore: ");
308	(void)vfprintf(stderr, fmt, ap);
309	va_end(ap);
310	(void)fprintf(stderr, "\n");
311	exit(1);
312	/* NOTREACHED */
313}
314