gcore.c revision 17142 
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 *, const struct proc *, u_long, char *, size_t));
84
85
86static int data_offset;
87
88int
89main(argc, argv)
90	int argc;
91	char *argv[];
92{
93	register struct proc *p;
94	struct kinfo_proc *ki;
95	struct exec exec;
96	int ch, cnt, efd, fd, pid, sflag, uid;
97	char *corefile, errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN + 1];
98
99	sflag = 0;
100	corefile = NULL;
101        while ((ch = getopt(argc, argv, "c:s")) != EOF) {
102                switch (ch) {
103                case 'c':
104			corefile = optarg;
105                        break;
106		case 's':
107			sflag = 1;
108			break;
109		default:
110			usage();
111			break;
112		}
113	}
114	argv += optind;
115	argc -= optind;
116
117	if (argc != 2)
118		usage();
119
120	kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf);
121	if (kd == NULL)
122		err(1, "%s", errbuf);
123
124	uid = getuid();
125	pid = atoi(argv[1]);
126
127	ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt);
128	if (ki == NULL || cnt != 1)
129		err(1, "%d: not found", pid);
130
131	p = &ki->kp_proc;
132	if (ki->kp_eproc.e_pcred.p_ruid != uid && uid != 0)
133		err(1, "%d: not owner", pid);
134
135	if (p->p_stat == SZOMB)
136		err(1, "%d: zombie", pid);
137
138	if (p->p_flag & P_WEXIT)
139		err(0, "process exiting");
140	if (p->p_flag & P_SYSTEM)	/* Swapper or pagedaemon. */
141		err(1, "%d: system process");
142
143	if (corefile == NULL) {
144		(void)snprintf(fname, sizeof(fname), "core.%d", pid);
145		corefile = fname;
146	}
147	fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE);
148	if (fd < 0)
149		err(1, "%s: %s\n", corefile, strerror(errno));
150
151	efd = open(argv[0], O_RDONLY, 0);
152	if (efd < 0)
153		err(1, "%s: %s\n", argv[0], strerror(errno));
154
155	cnt = read(efd, &exec, sizeof(exec));
156	if (cnt != sizeof(exec))
157		err(1, "%s exec header: %s",
158		    argv[0], cnt > 0 ? strerror(EIO) : strerror(errno));
159
160	data_offset = N_DATOFF(exec);
161
162	if (sflag && kill(pid, SIGSTOP) < 0)
163		err(0, "%d: stop signal: %s", pid, strerror(errno));
164
165	core(efd, fd, ki);
166
167	if (sflag && kill(pid, SIGCONT) < 0)
168		err(0, "%d: continue signal: %s", pid, strerror(errno));
169	(void)close(fd);
170
171	exit(0);
172}
173
174/*
175 * core --
176 *	Build the core file.
177 */
178void
179core(efd, fd, ki)
180	int efd;
181	int fd;
182	struct kinfo_proc *ki;
183{
184	union {
185		struct user user;
186		char ubytes[ctob(UPAGES)];
187	} uarea;
188	struct proc *p = &ki->kp_proc;
189	int tsize = ki->kp_eproc.e_vm.vm_tsize;
190	int dsize = ki->kp_eproc.e_vm.vm_dsize;
191	int ssize = ki->kp_eproc.e_vm.vm_ssize;
192	int cnt;
193
194	/* Read in user struct */
195	cnt = kvm_read(kd, (u_long)p->p_addr, &uarea, sizeof(uarea));
196	if (cnt != sizeof(uarea))
197		err(1, "read user structure: %s",
198		    cnt > 0 ? strerror(EIO) : strerror(errno));
199
200	/*
201	 * Fill in the eproc vm parameters, since these are garbage unless
202	 * the kernel is dumping core or something.
203	 */
204	uarea.user.u_kproc = *ki;
205
206	/* Dump user area */
207	cnt = write(fd, &uarea, sizeof(uarea));
208	if (cnt != sizeof(uarea))
209		err(1, "write user structure: %s",
210		    cnt > 0 ? strerror(EIO) : strerror(errno));
211
212	/* Dump data segment */
213	datadump(efd, fd, p, USRTEXT + ctob(tsize), dsize);
214
215	/* Dump stack segment */
216	userdump(fd, p, USRSTACK - ctob(ssize), ssize);
217
218	/* Dump machine dependent portions of the core. */
219	md_core(kd, fd, ki);
220}
221
222void
223datadump(efd, fd, p, addr, npage)
224	register int efd;
225	register int fd;
226	struct proc *p;
227	register u_long addr;
228	register int npage;
229{
230	register int cc, delta;
231	char buffer[PAGE_SIZE];
232
233	delta = data_offset - addr;
234	while (--npage >= 0) {
235		cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE);
236		if (cc != PAGE_SIZE) {
237			/* Try to read the page from the executable. */
238			if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1)
239				err(1, "seek executable: %s", strerror(errno));
240			cc = read(efd, buffer, sizeof(buffer));
241			if (cc != sizeof(buffer))
242				if (cc < 0)
243					err(1, "read executable: %s",
244					    strerror(errno));
245				else	/* Assume untouched bss page. */
246					bzero(buffer, sizeof(buffer));
247		}
248		cc = write(fd, buffer, PAGE_SIZE);
249		if (cc != PAGE_SIZE)
250			err(1, "write data segment: %s",
251			    cc > 0 ? strerror(EIO) : strerror(errno));
252		addr += PAGE_SIZE;
253	}
254}
255
256void
257userdump(fd, p, addr, npage)
258	register int fd;
259	struct proc *p;
260	register u_long addr;
261	register int npage;
262{
263	register int cc;
264	char buffer[PAGE_SIZE];
265
266	while (--npage >= 0) {
267		cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE);
268		if (cc != PAGE_SIZE)
269			/* Could be an untouched fill-with-zero page. */
270			bzero(buffer, PAGE_SIZE);
271		cc = write(fd, buffer, PAGE_SIZE);
272		if (cc != PAGE_SIZE)
273			err(1, "write stack segment: %s",
274			    cc > 0 ? strerror(EIO) : strerror(errno));
275		addr += PAGE_SIZE;
276	}
277}
278
279void
280usage()
281{
282	(void)fprintf(stderr, "usage: gcore [-s] [-c core] executable pid\n");
283	exit(1);
284}
285
286#if __STDC__
287#include <stdarg.h>
288#else
289#include <varargs.h>
290#endif
291
292void
293#if __STDC__
294err(int fatal, const char *fmt, ...)
295#else
296err(fatal, fmt, va_alist)
297	int fatal;
298	char *fmt;
299        va_dcl
300#endif
301{
302	va_list ap;
303#if __STDC__
304	va_start(ap, fmt);
305#else
306	va_start(ap);
307#endif
308	(void)fprintf(stderr, "gcore: ");
309	(void)vfprintf(stderr, fmt, ap);
310	va_end(ap);
311	(void)fprintf(stderr, "\n");
312	exit(1);
313	/* NOTREACHED */
314}
315