usr.bin/gcore/gcore.c

   1 /*-
   2  * Copyright (c) 1992, 1993, 2019
   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  */
  33
  34 /*
  35  * Originally written by Eric Cooper in Fall 1981.
  36  * Inspired by a version 6 program by Len Levin, 1978.
  37  * Several pieces of code lifted from Bill Joy's 4BSD ps.
  38  * Most recently, hacked beyond recognition for 4.4BSD by Steven McCanne,
  39  * Lawrence Berkeley Laboratory.
  40  *
  41  * Portions of this software were developed by the Computer Systems
  42  * Engineering group at Lawrence Berkeley Laboratory under DARPA
  43  * contract BG 91-66 and contributed to Berkeley.
  44  */
  45 #include <sys/param.h>
  46 #include <sys/time.h>
  47 #include <sys/stat.h>
  48 #include <sys/sysctl.h>
  49 #include <machine/elf.h>
  50
  51 #include <machine/vmparam.h>
  52
  53 #include <err.h>
  54 #include <errno.h>
  55 #include <fcntl.h>
  56 #include <kvm.h>
  57 #include <limits.h>
  58 #include <signal.h>
  59 #include <stdio.h>
  60 #include <stdlib.h>
  61 #include <string.h>
  62 #include <unistd.h>
  63
  64 #include "extern.h"
  65
  66 static void     killed(int);
  67 static void     restart_target(void);
  68 static void     usage(void) __dead2;
  69
  70 kvm_t *kd;
  71
  72 static pid_t pid;
  73 ssize_t gcore_seg_limit = -1;
  74 int gcore_verbose;
  75
  76 int
  77 main(int argc, char **argv)
  78 {
  79         void *exec;
  80         int ch, cnt, efd, fd, sflag;
  81         char *binfile, *corefile;
  82         char *eptr;
  83         char fname[MAXPATHLEN + 1];
  84
  85         sflag = 0;
  86         corefile = NULL;
  87         while ((ch = getopt(argc, argv, "c:l:sv")) != -1) {
  88                 switch (ch) {
  89                 case 'c':
  90                         corefile = optarg;
  91                         break;
  92                 case 'l':
  93                         gcore_seg_limit = strtol(optarg, &eptr, 0);
  94                         switch(*eptr) {
  95                         case 0:
  96                                 break;
  97                         case 't':
  98                         case 'T':
  99                                 gcore_seg_limit *= 1024;
 100                                 /* fall through */
 101                         case 'g':
 102                         case 'G':
 103                                 gcore_seg_limit *= 1024;
 104                                 /* fall through */
 105                         case 'm':
 106                         case 'M':
 107                                 gcore_seg_limit *= 1024;
 108                                 /* fall through */
 109                         case 'k':
 110                         case 'K':
 111                                 gcore_seg_limit *= 1024;
 112                                 break;
 113                         default:
 114                                 usage();
 115                                 break;
 116                         }
 117                         break;
 118                 case 's':
 119                         sflag = 1;
 120                         break;
 121                 case 'v':
 122                         gcore_verbose = 1;
 123                         break;
 124                 default:
 125                         usage();
 126                         break;
 127                 }
 128         }
 129         argv += optind;
 130         argc -= optind;
 131
 132         /* XXX we should check that the pid argument is really a number */
 133         switch (argc) {
 134         case 1:
 135                 pid = atoi(argv[0]);
 136                 asprintf(&binfile, "/proc/%d/file", pid);
 137                 if (binfile == NULL)
 138                         errx(1, "allocation failure");
 139                 break;
 140         case 2:
 141                 pid = atoi(argv[1]);
 142                 binfile = argv[0];
 143                 break;
 144         default:
 145                 usage();
 146         }
 147
 148         efd = open(binfile, O_RDONLY, 0);
 149         if (efd < 0)
 150                 err(1, "%s", binfile);
 151
 152         cnt = read(efd, &exec, sizeof(Elf_Ehdr));
 153         if (cnt != sizeof(Elf_Ehdr))
 154                 errx(1, "%s exec header: %s",
 155                     binfile, cnt > 0 ? strerror(EIO) : strerror(errno));
 156         if (IS_ELF(*(Elf_Ehdr *)&exec)) {
 157                 close(efd);
 158         } else
 159                 errx(1, "Invalid executable file");
 160
 161         if (corefile == NULL) {
 162                 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         if (sflag) {
 170                 signal(SIGHUP, killed);
 171                 signal(SIGINT, killed);
 172                 signal(SIGTERM, killed);
 173                 if (kill(pid, SIGSTOP) == -1)
 174                         err(1, "%d: stop signal", pid);
 175                 atexit(restart_target);
 176         }
 177
 178         elf_coredump(fd, pid);
 179
 180         close(fd);
 181         exit(0);
 182 }
 183
 184 static void
 185 killed(int sig)
 186 {
 187         restart_target();
 188         signal(sig, SIG_DFL);
 189         kill(getpid(), sig);
 190 }
 191
 192 static void
 193 restart_target(void)
 194 {
 195         kill(pid, SIGCONT);
 196 }
 197
 198 void
 199 usage(void)
 200 {
 201         fprintf(stderr,
 202             "usage: gcore [-sv] [-c core] [-l seglimit] [executable] pid\n");
 203         exit(1);
 204 }