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 35 static 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 42 static char sccsid[] = "@(#)gcore.c 8.2 (Berkeley) 9/23/93"; 43 #endif 44 static const char rcsid[] = 45 "$FreeBSD$"; 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 <elf.h> 70 #include <err.h> 71 #include <fcntl.h> 72 #include <kvm.h> 73 #include <limits.h> 74 #include <signal.h> 75 #include <stdio.h> 76 #include <stdlib.h> 77 #include <string.h> 78 #include <unistd.h> 79 80 #include "extern.h" 81 82 static void core __P((int, int, struct kinfo_proc *)); 83 static void datadump __P((int, int, struct kinfo_proc *, u_long, int)); 84 static void killed __P((int)); 85 static void restart_target __P((void)); 86 static void usage __P((void)) __dead2; 87 static void userdump __P((int, struct kinfo_proc *, u_long, int)); 88 89 kvm_t *kd; 90 91 static int data_offset; 92 static pid_t pid; 93 94 int 95 main(argc, argv) 96 int argc; 97 char *argv[]; 98 { 99 struct kinfo_proc *ki = NULL; 100 struct exec exec; 101 int ch, cnt, efd, fd, sflag, uid; 102 char *binfile, *corefile; 103 char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN + 1]; 104 int is_aout; 105 106 sflag = 0; 107 corefile = NULL; 108 while ((ch = getopt(argc, argv, "c:s")) != -1) { 109 switch (ch) { 110 case 'c': 111 corefile = optarg; 112 break; 113 case 's': 114 sflag = 1; 115 break; 116 default: 117 usage(); 118 break; 119 } 120 } 121 argv += optind; 122 argc -= optind; 123 124 /* XXX we should check that the pid argument is really a number */ 125 switch (argc) { 126 case 1: 127 pid = atoi(argv[0]); 128 asprintf(&binfile, "/proc/%d/file", pid); 129 if (binfile == NULL) 130 errx(1, "allocation failure"); 131 break; 132 case 2: 133 pid = atoi(argv[1]); 134 binfile = argv[0]; 135 break; 136 default: 137 usage(); 138 } 139 140 efd = open(binfile, O_RDONLY, 0); 141 if (efd < 0) 142 err(1, "%s", binfile); 143 144 cnt = read(efd, &exec, sizeof(exec)); 145 if (cnt != sizeof(exec)) 146 errx(1, "%s exec header: %s", 147 binfile, cnt > 0 ? strerror(EIO) : strerror(errno)); 148 if (!N_BADMAG(exec)) { 149 is_aout = 1; 150 /* 151 * This legacy a.out support uses the kvm interface instead 152 * of procfs. 153 */ 154 kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf); 155 if (kd == NULL) 156 errx(1, "%s", errbuf); 157 158 uid = getuid(); 159 160 ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt); 161 if (ki == NULL || cnt != 1) 162 errx(1, "%d: not found", pid); 163 164 if (ki->ki_ruid != uid && uid != 0) 165 errx(1, "%d: not owner", pid); 166 167 if (ki->ki_stat == SZOMB) 168 errx(1, "%d: zombie", pid); 169 170 if (ki->ki_flag & P_WEXIT) 171 errx(1, "%d: process exiting", pid); 172 if (ki->ki_flag & P_SYSTEM) /* Swapper or pagedaemon. */ 173 errx(1, "%d: system process", pid); 174 if (exec.a_text != ptoa(ki->ki_tsize)) 175 errx(1, "The executable %s does not belong to" 176 " process %d!\n" 177 "Text segment size (in bytes): executable %ld," 178 " process %d", binfile, pid, exec.a_text, 179 ptoa(ki->ki_tsize)); 180 data_offset = N_DATOFF(exec); 181 } else if (IS_ELF(*(Elf_Ehdr *)&exec)) { 182 is_aout = 0; 183 close(efd); 184 } else 185 errx(1, "Invalid executable file"); 186 187 if (corefile == NULL) { 188 (void)snprintf(fname, sizeof(fname), "core.%d", pid); 189 corefile = fname; 190 } 191 fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE); 192 if (fd < 0) 193 err(1, "%s", corefile); 194 195 if (sflag) { 196 signal(SIGHUP, killed); 197 signal(SIGINT, killed); 198 signal(SIGTERM, killed); 199 if (kill(pid, SIGSTOP) == -1) 200 err(1, "%d: stop signal", pid); 201 atexit(restart_target); 202 } 203 204 if (is_aout) 205 core(efd, fd, ki); 206 else 207 elf_coredump(fd, pid); 208 209 (void)close(fd); 210 exit(0); 211 } 212 213 /* 214 * core -- 215 * Build the core file. 216 */ 217 void 218 core(efd, fd, ki) 219 int efd; 220 int fd; 221 struct kinfo_proc *ki; 222 { 223 union { 224 struct user user; 225 char ubytes[ctob(UPAGES)]; 226 } uarea; 227 int tsize = ki->ki_tsize; 228 int dsize = ki->ki_dsize; 229 int ssize = ki->ki_ssize; 230 int cnt; 231 232 /* Read in user struct */ 233 cnt = kvm_read(kd, (u_long)ki->ki_addr, &uarea, sizeof(uarea)); 234 if (cnt != sizeof(uarea)) 235 errx(1, "read user structure: %s", 236 cnt > 0 ? strerror(EIO) : strerror(errno)); 237 238 /* 239 * Fill in the eproc vm parameters, since these are garbage unless 240 * the kernel is dumping core or something. 241 */ 242 uarea.user.u_kproc = *ki; 243 244 /* Dump user area */ 245 cnt = write(fd, &uarea, sizeof(uarea)); 246 if (cnt != sizeof(uarea)) 247 errx(1, "write user structure: %s", 248 cnt > 0 ? strerror(EIO) : strerror(errno)); 249 250 /* Dump data segment */ 251 datadump(efd, fd, ki, USRTEXT + ctob(tsize), dsize); 252 253 /* Dump stack segment */ 254 userdump(fd, ki, USRSTACK - ctob(ssize), ssize); 255 256 /* Dump machine dependent portions of the core. */ 257 md_core(kd, fd, ki); 258 } 259 260 void 261 datadump(efd, fd, kp, addr, npage) 262 register int efd; 263 register int fd; 264 struct kinfo_proc *kp; 265 register u_long addr; 266 register int npage; 267 { 268 register int cc, delta; 269 char buffer[PAGE_SIZE]; 270 271 delta = data_offset - addr; 272 while (--npage >= 0) { 273 cc = kvm_uread(kd, kp, addr, buffer, PAGE_SIZE); 274 if (cc != PAGE_SIZE) { 275 /* Try to read the page from the executable. */ 276 if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1) 277 err(1, "seek executable: %s", strerror(errno)); 278 cc = read(efd, buffer, sizeof(buffer)); 279 if (cc != sizeof(buffer)) { 280 if (cc < 0) 281 err(1, "read executable"); 282 else /* Assume untouched bss page. */ 283 bzero(buffer, sizeof(buffer)); 284 } 285 } 286 cc = write(fd, buffer, PAGE_SIZE); 287 if (cc != PAGE_SIZE) 288 errx(1, "write data segment: %s", 289 cc > 0 ? strerror(EIO) : strerror(errno)); 290 addr += PAGE_SIZE; 291 } 292 } 293 294 static void 295 killed(sig) 296 int sig; 297 { 298 restart_target(); 299 signal(sig, SIG_DFL); 300 kill(getpid(), sig); 301 } 302 303 static void 304 restart_target() 305 { 306 kill(pid, SIGCONT); 307 } 308 309 void 310 userdump(fd, kp, addr, npage) 311 register int fd; 312 struct kinfo_proc *kp; 313 register u_long addr; 314 register int npage; 315 { 316 register int cc; 317 char buffer[PAGE_SIZE]; 318 319 while (--npage >= 0) { 320 cc = kvm_uread(kd, kp, addr, buffer, PAGE_SIZE); 321 if (cc != PAGE_SIZE) 322 /* Could be an untouched fill-with-zero page. */ 323 bzero(buffer, PAGE_SIZE); 324 cc = write(fd, buffer, PAGE_SIZE); 325 if (cc != PAGE_SIZE) 326 errx(1, "write stack segment: %s", 327 cc > 0 ? strerror(EIO) : strerror(errno)); 328 addr += PAGE_SIZE; 329 } 330 } 331 332 void 333 usage() 334 { 335 (void)fprintf(stderr, "usage: gcore [-s] [-c core] executable pid\n"); 336 exit(1); 337 } 338