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 1.10 2007/02/18 16:15:24 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 core(int, int, struct kinfo_proc *); 73 static void datadump(int, int, pid_t, u_long, int); 74 static void killed(int); 75 static void restart_target(void); 76 static void usage(void) __dead2; 77 static void userdump(int, pid_t, u_long, int); 78 79 kvm_t *kd; 80 81 static int data_offset; 82 static pid_t pid; 83 84 int 85 main(int argc, char **argv) 86 { 87 struct kinfo_proc *ki = NULL; 88 struct exec exec; 89 int ch, cnt, efd, fd, sflag, uid; 90 char *binfile, *corefile; 91 char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN + 1]; 92 int is_aout; 93 94 sflag = 0; 95 corefile = NULL; 96 while ((ch = getopt(argc, argv, "c:s")) != -1) { 97 switch (ch) { 98 case 'c': 99 corefile = optarg; 100 break; 101 case 's': 102 sflag = 1; 103 break; 104 default: 105 usage(); 106 break; 107 } 108 } 109 argv += optind; 110 argc -= optind; 111 112 /* XXX we should check that the pid argument is really a number */ 113 switch (argc) { 114 case 1: 115 pid = atoi(argv[0]); 116 asprintf(&binfile, "/proc/%d/file", pid); 117 if (binfile == NULL) 118 errx(1, "allocation failure"); 119 break; 120 case 2: 121 pid = atoi(argv[1]); 122 binfile = argv[0]; 123 break; 124 default: 125 usage(); 126 } 127 128 efd = open(binfile, O_RDONLY, 0); 129 if (efd < 0) 130 err(1, "%s", binfile); 131 132 cnt = read(efd, &exec, sizeof(exec)); 133 if (cnt != sizeof(exec)) 134 errx(1, "%s exec header: %s", 135 binfile, cnt > 0 ? strerror(EIO) : strerror(errno)); 136 if (!N_BADMAG(exec)) { 137 is_aout = 1; 138 /* 139 * This legacy a.out support uses the kvm interface instead 140 * of procfs. 141 */ 142 kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf); 143 if (kd == NULL) 144 errx(1, "%s", errbuf); 145 146 uid = getuid(); 147 148 ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt); 149 if (ki == NULL || cnt != 1) 150 errx(1, "%d: not found", pid); 151 152 if (ki->kp_ruid != uid && uid != 0) 153 errx(1, "%d: not owner", pid); 154 155 if (ki->kp_stat == SZOMB) 156 errx(1, "%d: zombie", pid); 157 158 if (ki->kp_flags & P_WEXIT) 159 errx(1, "%d: process exiting", pid); 160 if (ki->kp_flags & P_SYSTEM) /* Swapper or pagedaemon. */ 161 errx(1, "%d: system process", pid); 162 if (exec.a_text != ptoa(ki->kp_vm_tsize)) 163 errx(1, "The executable %s does not belong to" 164 " process %d!\n" 165 "Text segment size (in bytes): executable %ld," 166 " process %d", binfile, pid, exec.a_text, 167 ptoa(ki->kp_vm_tsize)); 168 data_offset = N_DATOFF(exec); 169 } else if (IS_ELF(*(Elf_Ehdr *)&exec)) { 170 is_aout = 0; 171 close(efd); 172 } else 173 errx(1, "Invalid executable file"); 174 175 if (corefile == NULL) { 176 (void)snprintf(fname, sizeof(fname), "core.%d", pid); 177 corefile = fname; 178 } 179 fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE); 180 if (fd < 0) 181 err(1, "%s", corefile); 182 183 if (sflag) { 184 signal(SIGHUP, killed); 185 signal(SIGINT, killed); 186 signal(SIGTERM, killed); 187 if (kill(pid, SIGSTOP) == -1) 188 err(1, "%d: stop signal", pid); 189 atexit(restart_target); 190 } 191 192 if (is_aout) 193 core(efd, fd, ki); 194 else 195 elf_coredump(fd, pid); 196 197 (void)close(fd); 198 exit(0); 199 } 200 201 /* 202 * core -- 203 * Build the core file. 204 */ 205 void 206 core(int efd, int fd, struct kinfo_proc *ki) 207 { 208 union { 209 struct user user; 210 char ubytes[ctob(UPAGES)]; 211 } uarea; 212 int tsize = ki->kp_vm_tsize; 213 int dsize = ki->kp_vm_dsize; 214 int ssize = ki->kp_vm_ssize; 215 int cnt; 216 217 /* Read in user struct */ 218 cnt = kvm_read(kd, ki->kp_pid, &uarea, sizeof(uarea)); 219 if (cnt != sizeof(uarea)) 220 errx(1, "read user structure: %s", 221 cnt > 0 ? strerror(EIO) : strerror(errno)); 222 223 /* 224 * Fill in the eproc vm parameters, since these are garbage unless 225 * the kernel is dumping core or something. 226 */ 227 uarea.user.u_kproc = *ki; 228 229 /* Dump user area */ 230 cnt = write(fd, &uarea, sizeof(uarea)); 231 if (cnt != sizeof(uarea)) 232 errx(1, "write user structure: %s", 233 cnt > 0 ? strerror(EIO) : strerror(errno)); 234 235 /* Dump data segment */ 236 datadump(efd, fd, ki->kp_pid, USRTEXT + ctob(tsize), dsize); 237 238 /* Dump stack segment */ 239 userdump(fd, ki->kp_pid, USRSTACK - ctob(ssize), ssize); 240 241 /* Dump machine dependent portions of the core. */ 242 md_core(kd, fd, ki); 243 } 244 245 void 246 datadump(int efd, int fd, pid_t pid, 247 u_long addr, int npage) 248 { 249 int cc, delta; 250 char buffer[PAGE_SIZE]; 251 252 delta = data_offset - addr; 253 while (--npage >= 0) { 254 cc = kvm_uread(kd, pid, addr, buffer, PAGE_SIZE); 255 if (cc != PAGE_SIZE) { 256 /* Try to read the page from the executable. */ 257 if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1) 258 err(1, "seek executable: %s", strerror(errno)); 259 cc = read(efd, buffer, sizeof(buffer)); 260 if (cc != sizeof(buffer)) { 261 if (cc < 0) 262 err(1, "read executable"); 263 else /* Assume untouched bss page. */ 264 bzero(buffer, sizeof(buffer)); 265 } 266 } 267 cc = write(fd, buffer, PAGE_SIZE); 268 if (cc != PAGE_SIZE) 269 errx(1, "write data segment: %s", 270 cc > 0 ? strerror(EIO) : strerror(errno)); 271 addr += PAGE_SIZE; 272 } 273 } 274 275 static void 276 killed(int sig) 277 { 278 restart_target(); 279 signal(sig, SIG_DFL); 280 kill(getpid(), sig); 281 } 282 283 static void 284 restart_target(void) 285 { 286 kill(pid, SIGCONT); 287 } 288 289 void 290 userdump(int fd, pid_t pid, u_long addr, 291 int npage) 292 { 293 int cc; 294 char buffer[PAGE_SIZE]; 295 296 while (--npage >= 0) { 297 cc = kvm_uread(kd, pid, addr, buffer, PAGE_SIZE); 298 if (cc != PAGE_SIZE) 299 /* Could be an untouched fill-with-zero page. */ 300 bzero(buffer, PAGE_SIZE); 301 cc = write(fd, buffer, PAGE_SIZE); 302 if (cc != PAGE_SIZE) 303 errx(1, "write stack segment: %s", 304 cc > 0 ? strerror(EIO) : strerror(errno)); 305 addr += PAGE_SIZE; 306 } 307 } 308 309 void 310 usage(void) 311 { 312 (void)fprintf(stderr, "usage: gcore [-s] [-c core] [executable] pid\n"); 313 exit(1); 314 } 315