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/lock.h> 61 #include <sys/time.h> 62 #include <sys/stat.h> 63 #include <sys/proc.h> 64 #include <sys/user.h> 65 #include <sys/sysctl.h> 66 67 #include <machine/elf.h> 68 #include <machine/vmparam.h> 69 70 #include <a.out.h> 71 #include <err.h> 72 #include <fcntl.h> 73 #include <kvm.h> 74 #include <limits.h> 75 #include <signal.h> 76 #include <stdio.h> 77 #include <stdlib.h> 78 #include <string.h> 79 #include <unistd.h> 80 81 #include "extern.h" 82 83 static void core __P((int, int, struct kinfo_proc *)); 84 static void datadump __P((int, int, struct kinfo_proc *, u_long, int)); 85 static void killed __P((int)); 86 static void restart_target __P((void)); 87 static void usage __P((void)) __dead2; 88 static void userdump __P((int, struct kinfo_proc *, u_long, int)); 89 90 kvm_t *kd; 91 92 static int data_offset; 93 static pid_t pid; 94 95 int 96 main(argc, argv) 97 int argc; 98 char *argv[]; 99 { 100 struct kinfo_proc *ki = NULL; 101 struct exec exec; 102 int ch, cnt, efd, fd, sflag, uid; 103 char *binfile, *corefile; 104 char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN]; 105 int is_aout; 106 107 sflag = 0; 108 corefile = NULL; 109 while ((ch = getopt(argc, argv, "c:s")) != -1) { 110 switch (ch) { 111 case 'c': 112 corefile = optarg; 113 break; 114 case 's': 115 sflag = 1; 116 break; 117 default: 118 usage(); 119 break; 120 } 121 } 122 argv += optind; 123 argc -= optind; 124 125 /* XXX we should check that the pid argument is really a number */ 126 switch (argc) { 127 case 1: 128 pid = atoi(argv[0]); 129 asprintf(&binfile, "/proc/%d/file", pid); 130 if (binfile == NULL) 131 errx(1, "allocation failure"); 132 break; 133 case 2: 134 pid = atoi(argv[1]); 135 binfile = argv[0]; 136 break; 137 default: 138 usage(); 139 } 140 141 efd = open(binfile, O_RDONLY, 0); 142 if (efd < 0) 143 err(1, "%s", binfile); 144 145 cnt = read(efd, &exec, sizeof(exec)); 146 if (cnt != sizeof(exec)) 147 errx(1, "%s exec header: %s", 148 binfile, cnt > 0 ? strerror(EIO) : strerror(errno)); 149 if (!N_BADMAG(exec)) { 150 is_aout = 1; 151 /* 152 * This legacy a.out support uses the kvm interface instead 153 * of procfs. 154 */ 155 kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf); 156 if (kd == NULL) 157 errx(1, "%s", errbuf); 158 159 uid = getuid(); 160 161 ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt); 162 if (ki == NULL || cnt != 1) 163 errx(1, "%d: not found", pid); 164 165 if (ki->ki_ruid != uid && uid != 0) 166 errx(1, "%d: not owner", pid); 167 168 if (ki->ki_stat == SZOMB) 169 errx(1, "%d: zombie", pid); 170 171 if (ki->ki_flag & P_WEXIT) 172 errx(1, "%d: process exiting", pid); 173 if (ki->ki_flag & P_SYSTEM) /* Swapper or pagedaemon. */ 174 errx(1, "%d: system process", pid); 175 if (exec.a_text != ptoa(ki->ki_tsize)) 176 errx(1, "The executable %s does not belong to" 177 " process %d!\n" 178 "Text segment size (in bytes): executable %ld," 179 " process %d", binfile, pid, exec.a_text, 180 ptoa(ki->ki_tsize)); 181 data_offset = N_DATOFF(exec); 182 } else if (IS_ELF(*(Elf_Ehdr *)&exec)) { 183 is_aout = 0; 184 close(efd); 185 } else 186 errx(1, "Invalid executable file"); 187 188 if (corefile == NULL) { 189 (void)snprintf(fname, sizeof(fname), "core.%d", pid); 190 corefile = fname; 191 } 192 fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE); 193 if (fd < 0) 194 err(1, "%s", corefile); 195 196 if (sflag) { 197 signal(SIGHUP, killed); 198 signal(SIGINT, killed); 199 signal(SIGTERM, killed); 200 if (kill(pid, SIGSTOP) == -1) 201 err(1, "%d: stop signal", pid); 202 atexit(restart_target); 203 } 204 205 if (is_aout) 206 core(efd, fd, ki); 207 else 208 elf_coredump(fd, pid); 209 210 (void)close(fd); 211 exit(0); 212 } 213 214 /* 215 * core -- 216 * Build the core file. 217 */ 218 void 219 core(efd, fd, ki) 220 int efd; 221 int fd; 222 struct kinfo_proc *ki; 223 { 224 union { 225 struct user user; 226 char ubytes[ctob(UPAGES)]; 227 } uarea; 228 int tsize = ki->ki_tsize; 229 int dsize = ki->ki_dsize; 230 int ssize = ki->ki_ssize; 231 int cnt; 232 233 /* Read in user struct */ 234 cnt = kvm_read(kd, (u_long)ki->ki_addr, &uarea, sizeof(uarea)); 235 if (cnt != sizeof(uarea)) 236 errx(1, "read user structure: %s", 237 cnt > 0 ? strerror(EIO) : strerror(errno)); 238 239 /* 240 * Fill in the eproc vm parameters, since these are garbage unless 241 * the kernel is dumping core or something. 242 */ 243 uarea.user.u_kproc = *ki; 244 245 /* Dump user area */ 246 cnt = write(fd, &uarea, sizeof(uarea)); 247 if (cnt != sizeof(uarea)) 248 errx(1, "write user structure: %s", 249 cnt > 0 ? strerror(EIO) : strerror(errno)); 250 251 /* Dump data segment */ 252 datadump(efd, fd, ki, USRTEXT + ctob(tsize), dsize); 253 254 /* Dump stack segment */ 255 userdump(fd, ki, USRSTACK - ctob(ssize), ssize); 256 257 /* Dump machine dependent portions of the core. */ 258 md_core(kd, fd, ki); 259 } 260 261 void 262 datadump(efd, fd, kp, addr, npage) 263 register int efd; 264 register int fd; 265 struct kinfo_proc *kp; 266 register u_long addr; 267 register int npage; 268 { 269 register int cc, delta; 270 char buffer[PAGE_SIZE]; 271 272 delta = data_offset - addr; 273 while (--npage >= 0) { 274 cc = kvm_uread(kd, kp, addr, buffer, PAGE_SIZE); 275 if (cc != PAGE_SIZE) { 276 /* Try to read the page from the executable. */ 277 if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1) 278 err(1, "seek executable: %s", strerror(errno)); 279 cc = read(efd, buffer, sizeof(buffer)); 280 if (cc != sizeof(buffer)) { 281 if (cc < 0) 282 err(1, "read executable"); 283 else /* Assume untouched bss page. */ 284 bzero(buffer, sizeof(buffer)); 285 } 286 } 287 cc = write(fd, buffer, PAGE_SIZE); 288 if (cc != PAGE_SIZE) 289 errx(1, "write data segment: %s", 290 cc > 0 ? strerror(EIO) : strerror(errno)); 291 addr += PAGE_SIZE; 292 } 293 } 294 295 static void 296 killed(sig) 297 int sig; 298 { 299 restart_target(); 300 signal(sig, SIG_DFL); 301 kill(getpid(), sig); 302 } 303 304 static void 305 restart_target() 306 { 307 kill(pid, SIGCONT); 308 } 309 310 void 311 userdump(fd, kp, addr, npage) 312 register int fd; 313 struct kinfo_proc *kp; 314 register u_long addr; 315 register int npage; 316 { 317 register int cc; 318 char buffer[PAGE_SIZE]; 319 320 while (--npage >= 0) { 321 cc = kvm_uread(kd, kp, addr, buffer, PAGE_SIZE); 322 if (cc != PAGE_SIZE) 323 /* Could be an untouched fill-with-zero page. */ 324 bzero(buffer, PAGE_SIZE); 325 cc = write(fd, buffer, PAGE_SIZE); 326 if (cc != PAGE_SIZE) 327 errx(1, "write stack segment: %s", 328 cc > 0 ? strerror(EIO) : strerror(errno)); 329 addr += PAGE_SIZE; 330 } 331 } 332 333 void 334 usage() 335 { 336 (void)fprintf(stderr, "usage: gcore [-s] [-c core] executable pid\n"); 337 exit(1); 338 } 339