gcore.c revision 39164 
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#ifndef lint
41#if 0
42static char sccsid[] = "@(#)gcore.c	8.2 (Berkeley) 9/23/93";
43#endif
44static const char rcsid[] =
45	"$Id: gcore.c,v 1.8 1998/08/24 16:25:30 wosch Exp $";
46#endif /* not lint */
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#include <sys/param.h>
60#include <sys/time.h>
61#include <sys/stat.h>
62#include <sys/proc.h>
63#include <sys/user.h>
64#include <sys/sysctl.h>
65
66#include <machine/vmparam.h>
67
68#include <a.out.h>
69#include <err.h>
70#include <fcntl.h>
71#include <kvm.h>
72#include <limits.h>
73#include <signal.h>
74#include <stdio.h>
75#include <stdlib.h>
76#include <string.h>
77#include <unistd.h>
78
79#include "extern.h"
80
81void	core __P((int, int, struct kinfo_proc *));
82void	datadump __P((int, int, struct proc *, u_long, int));
83void	usage __P((void));
84void	userdump __P((int, struct proc *, u_long, int));
85
86kvm_t *kd;
87/* XXX undocumented routine, should be in kvm.h? */
88ssize_t kvm_uread __P((kvm_t *, const struct proc *, u_long, char *, size_t));
89
90
91static int data_offset;
92
93int
94main(argc, argv)
95	int argc;
96	char *argv[];
97{
98	register struct proc *p;
99	struct kinfo_proc *ki;
100	struct exec exec;
101	int ch, cnt, efd, fd, pid, sflag, uid;
102	char *binfile, *corefile;
103	char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN + 1];
104
105	sflag = 0;
106	corefile = NULL;
107        while ((ch = getopt(argc, argv, "c:s")) != -1) {
108                switch (ch) {
109                case 'c':
110			corefile = optarg;
111                        break;
112		case 's':
113			sflag = 1;
114			break;
115		default:
116			usage();
117			break;
118		}
119	}
120	argv += optind;
121	argc -= optind;
122
123	/* XXX we should check that the pid argument is really a number */
124	switch (argc) {
125	case 1:
126		pid = atoi(argv[0]);
127		asprintf(&binfile, "/proc/%d/file", pid);
128		if (binfile == NULL)
129			errx(1, "allocation failure");
130		break;
131	case 2:
132		pid = atoi(argv[1]);
133		binfile = argv[0];
134		break;
135	default:
136		usage();
137	}
138
139	kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf);
140	if (kd == NULL)
141		errx(1, "%s", errbuf);
142
143	uid = getuid();
144
145	ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt);
146	if (ki == NULL || cnt != 1)
147		errx(1, "%d: not found", pid);
148
149	p = &ki->kp_proc;
150	if (ki->kp_eproc.e_pcred.p_ruid != uid && uid != 0)
151		errx(1, "%d: not owner", pid);
152
153	if (p->p_stat == SZOMB)
154		errx(1, "%d: zombie", pid);
155
156	if (p->p_flag & P_WEXIT)
157		errx(1, "%d: process exiting", pid);
158	if (p->p_flag & P_SYSTEM)	/* Swapper or pagedaemon. */
159		errx(1, "%d: system process", pid);
160
161	if (corefile == NULL) {
162		(void)snprintf(fname, sizeof(fname), "core.%d", pid);
163		corefile = fname;
164	}
165	fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE);
166	if (fd < 0)
167		err(1, "%s", corefile);
168
169	efd = open(binfile, O_RDONLY, 0);
170	if (efd < 0)
171		err(1, "%s", binfile);
172
173	cnt = read(efd, &exec, sizeof(exec));
174	if (cnt != sizeof(exec))
175		errx(1, "%s exec header: %s",
176		    binfile, cnt > 0 ? strerror(EIO) : strerror(errno));
177
178	/* check the text segment size of the executable and the process */
179	if (exec.a_text != ptoa(ki->kp_eproc.e_vm.vm_tsize))
180		errx(1,
181		     "The executable %s does not belong to process %d!\n"
182		     "Text segment size (in bytes): executable %d, process %d",
183		     binfile, pid, exec.a_text,
184		     ptoa(ki->kp_eproc.e_vm.vm_tsize));
185
186	data_offset = N_DATOFF(exec);
187
188	if (sflag && kill(pid, SIGSTOP) < 0)
189		err(1, "%d: stop signal", pid);
190
191	core(efd, fd, ki);
192
193	if (sflag && kill(pid, SIGCONT) < 0)
194		err(1, "%d: continue signal", pid);
195	(void)close(fd);
196
197	exit(0);
198}
199
200/*
201 * core --
202 *	Build the core file.
203 */
204void
205core(efd, fd, ki)
206	int efd;
207	int fd;
208	struct kinfo_proc *ki;
209{
210	union {
211		struct user user;
212		char ubytes[ctob(UPAGES)];
213	} uarea;
214	struct proc *p = &ki->kp_proc;
215	int tsize = ki->kp_eproc.e_vm.vm_tsize;
216	int dsize = ki->kp_eproc.e_vm.vm_dsize;
217	int ssize = ki->kp_eproc.e_vm.vm_ssize;
218	int cnt;
219
220	/* Read in user struct */
221	cnt = kvm_read(kd, (u_long)p->p_addr, &uarea, sizeof(uarea));
222	if (cnt != sizeof(uarea))
223		errx(1, "read user structure: %s",
224		    cnt > 0 ? strerror(EIO) : strerror(errno));
225
226	/*
227	 * Fill in the eproc vm parameters, since these are garbage unless
228	 * the kernel is dumping core or something.
229	 */
230	uarea.user.u_kproc = *ki;
231
232	/* Dump user area */
233	cnt = write(fd, &uarea, sizeof(uarea));
234	if (cnt != sizeof(uarea))
235		errx(1, "write user structure: %s",
236		    cnt > 0 ? strerror(EIO) : strerror(errno));
237
238	/* Dump data segment */
239	datadump(efd, fd, p, USRTEXT + ctob(tsize), dsize);
240
241	/* Dump stack segment */
242	userdump(fd, p, USRSTACK - ctob(ssize), ssize);
243
244	/* Dump machine dependent portions of the core. */
245	md_core(kd, fd, ki);
246}
247
248void
249datadump(efd, fd, p, addr, npage)
250	register int efd;
251	register int fd;
252	struct proc *p;
253	register u_long addr;
254	register int npage;
255{
256	register int cc, delta;
257	char buffer[PAGE_SIZE];
258
259	delta = data_offset - addr;
260	while (--npage >= 0) {
261		cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE);
262		if (cc != PAGE_SIZE) {
263			/* Try to read the page from the executable. */
264			if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1)
265				err(1, "seek executable: %s", strerror(errno));
266			cc = read(efd, buffer, sizeof(buffer));
267			if (cc != sizeof(buffer))
268				if (cc < 0)
269					err(1, "read executable");
270				else	/* Assume untouched bss page. */
271					bzero(buffer, sizeof(buffer));
272		}
273		cc = write(fd, buffer, PAGE_SIZE);
274		if (cc != PAGE_SIZE)
275			errx(1, "write data segment: %s",
276			    cc > 0 ? strerror(EIO) : strerror(errno));
277		addr += PAGE_SIZE;
278	}
279}
280
281void
282userdump(fd, p, addr, npage)
283	register int fd;
284	struct proc *p;
285	register u_long addr;
286	register int npage;
287{
288	register int cc;
289	char buffer[PAGE_SIZE];
290
291	while (--npage >= 0) {
292		cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE);
293		if (cc != PAGE_SIZE)
294			/* Could be an untouched fill-with-zero page. */
295			bzero(buffer, PAGE_SIZE);
296		cc = write(fd, buffer, PAGE_SIZE);
297		if (cc != PAGE_SIZE)
298			errx(1, "write stack segment: %s",
299			    cc > 0 ? strerror(EIO) : strerror(errno));
300		addr += PAGE_SIZE;
301	}
302}
303
304void
305usage()
306{
307	(void)fprintf(stderr, "usage: gcore [-s] [-c core] executable pid\n");
308	exit(1);
309}
310