usr.bin/gcore/gcore.c

   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  * @(#) Copyright (c) 1992, 1993 The Regents of the University of California.  All rights reserved.
  34  * @(#)gcore.c  8.2 (Berkeley) 9/23/93
  35  * $FreeBSD: src/usr.bin/gcore/gcore.c,v 1.15.2.2 2001/08/17 20:56:22 mikeh Exp $
  36  * $DragonFly: src/usr.bin/gcore/gcore.c,v 1.11 2007/02/25 23:07:08 corecode Exp $
  37  */
  38
  39 /*
  40  * Originally written by Eric Cooper in Fall 1981.
  41  * Inspired by a version 6 program by Len Levin, 1978.
  42  * Several pieces of code lifted from Bill Joy's 4BSD ps.
  43  * Most recently, hacked beyond recognition for 4.4BSD by Steven McCanne,
  44  * Lawrence Berkeley Laboratory.
  45  *
  46  * Portions of this software were developed by the Computer Systems
  47  * Engineering group at Lawrence Berkeley Laboratory under DARPA
  48  * contract BG 91-66 and contributed to Berkeley.
  49  */
  50 #include <sys/param.h>
  51 #include <sys/time.h>
  52 #include <sys/stat.h>
  53 #include <sys/user.h>
  54 #include <sys/sysctl.h>
  55 #include <machine/elf.h>
  56
  57 #include <machine/vmparam.h>
  58
  59 #include <a.out.h>
  60 #include <err.h>
  61 #include <fcntl.h>
  62 #include <kvm.h>
  63 #include <limits.h>
  64 #include <signal.h>
  65 #include <stdio.h>
  66 #include <stdlib.h>
  67 #include <string.h>
  68 #include <unistd.h>
  69
  70 #include "extern.h"
  71
  72 static void     killed(int);
  73 static void     restart_target(void);
  74 static void     usage(void) __dead2;
  75
  76 kvm_t *kd;
  77
  78 static pid_t pid;
  79
  80 int
  81 main(int argc, char **argv)
  82 {
  83         struct exec exec;
  84         int ch, cnt, efd, fd, sflag;
  85         char *binfile, *corefile;
  86         char fname[MAXPATHLEN + 1];
  87
  88         sflag = 0;
  89         corefile = NULL;
  90         while ((ch = getopt(argc, argv, "c:s")) != -1) {
  91                 switch (ch) {
  92                 case 'c':
  93                         corefile = optarg;
  94                         break;
  95                 case 's':
  96                         sflag = 1;
  97                         break;
  98                 default:
  99                         usage();
 100                         break;
 101                 }
 102         }
 103         argv += optind;
 104         argc -= optind;
 105
 106         /* XXX we should check that the pid argument is really a number */
 107         switch (argc) {
 108         case 1:
 109                 pid = atoi(argv[0]);
 110                 asprintf(&binfile, "/proc/%d/file", pid);
 111                 if (binfile == NULL)
 112                         errx(1, "allocation failure");
 113                 break;
 114         case 2:
 115                 pid = atoi(argv[1]);
 116                 binfile = argv[0];
 117                 break;
 118         default:
 119                 usage();
 120         }
 121
 122         efd = open(binfile, O_RDONLY, 0);
 123         if (efd < 0)
 124                 err(1, "%s", binfile);
 125
 126         cnt = read(efd, &exec, sizeof(exec));
 127         if (cnt != sizeof(exec))
 128                 errx(1, "%s exec header: %s",
 129                     binfile, cnt > 0 ? strerror(EIO) : strerror(errno));
 130         if (IS_ELF(*(Elf_Ehdr *)&exec)) {
 131                 close(efd);
 132         } else
 133                 errx(1, "Invalid executable file");
 134
 135         if (corefile == NULL) {
 136                 (void)snprintf(fname, sizeof(fname), "core.%d", pid);
 137                 corefile = fname;
 138         }
 139         fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE);
 140         if (fd < 0)
 141                 err(1, "%s", corefile);
 142
 143         if (sflag) {
 144                 signal(SIGHUP, killed);
 145                 signal(SIGINT, killed);
 146                 signal(SIGTERM, killed);
 147                 if (kill(pid, SIGSTOP) == -1)
 148                         err(1, "%d: stop signal", pid);
 149                 atexit(restart_target);
 150         }
 151
 152         elf_coredump(fd, pid);
 153
 154         (void)close(fd);
 155         exit(0);
 156 }
 157
 158 static void
 159 killed(int sig)
 160 {
 161         restart_target();
 162         signal(sig, SIG_DFL);
 163         kill(getpid(), sig);
 164 }
 165
 166 static void
 167 restart_target(void)
 168 {
 169         kill(pid, SIGCONT);
 170 }
 171
 172 void
 173 usage(void)
 174 {
 175         (void)fprintf(stderr, "usage: gcore [-s] [-c core] [executable] pid\n");
 176         exit(1);
 177 }