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 #endif /* not lint */ 45 46 #include <sys/cdefs.h> 47 __FBSDID("$FreeBSD$"); 48 49 /* 50 * Originally written by Eric Cooper in Fall 1981. 51 * Inspired by a version 6 program by Len Levin, 1978. 52 * Several pieces of code lifted from Bill Joy's 4BSD ps. 53 * Most recently, hacked beyond recognition for 4.4BSD by Steven McCanne, 54 * Lawrence Berkeley Laboratory. 55 * 56 * Portions of this software were developed by the Computer Systems 57 * Engineering group at Lawrence Berkeley Laboratory under DARPA 58 * contract BG 91-66 and contributed to Berkeley. 59 */ 60 61 #include <sys/param.h> 62 #include <sys/time.h> 63 #include <sys/stat.h> 64 #include <sys/proc.h> 65 #include <sys/user.h> 66 #include <sys/sysctl.h> 67 68 #include <machine/elf.h> 69 #include <machine/vmparam.h> 70 71 #include <a.out.h> 72 #include <err.h> 73 #include <fcntl.h> 74 #include <kvm.h> 75 #include <limits.h> 76 #include <signal.h> 77 #include <stdio.h> 78 #include <stdlib.h> 79 #include <string.h> 80 #include <unistd.h> 81 82 #include "extern.h" 83 84 static void core(int, int, struct kinfo_proc *); 85 static void datadump(int, int, struct kinfo_proc *, u_long, int); 86 static void killed(int); 87 static void restart_target(void); 88 static void usage(void) __dead2; 89 static void userdump(int, struct kinfo_proc *, u_long, int); 90 91 kvm_t *kd; 92 93 static int data_offset; 94 static pid_t pid; 95 96 int 97 main(argc, argv) 98 int argc; 99 char *argv[]; 100 { 101 struct kinfo_proc *ki = NULL; 102 struct exec exec; 103 int ch, cnt, efd, fd, sflag, uid; 104 char *binfile, *corefile; 105 char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN]; 106 int is_aout; 107 108 sflag = 0; 109 corefile = NULL; 110 while ((ch = getopt(argc, argv, "c:s")) != -1) { 111 switch (ch) { 112 case 'c': 113 corefile = optarg; 114 break; 115 case 's': 116 sflag = 1; 117 break; 118 default: 119 usage(); 120 break; 121 } 122 } 123 argv += optind; 124 argc -= optind; 125 126 /* XXX we should check that the pid argument is really a number */ 127 switch (argc) { 128 case 1: 129 pid = atoi(argv[0]); 130 asprintf(&binfile, "/proc/%d/file", pid); 131 if (binfile == NULL) 132 errx(1, "allocation failure"); 133 break; 134 case 2: 135 pid = atoi(argv[1]); 136 binfile = argv[0]; 137 break; 138 default: 139 usage(); 140 } 141 142 efd = open(binfile, O_RDONLY, 0); 143 if (efd < 0) 144 err(1, "%s", binfile); 145 146 cnt = read(efd, &exec, sizeof(exec)); 147 if (cnt != sizeof(exec)) 148 errx(1, "%s exec header: %s", 149 binfile, cnt > 0 ? strerror(EIO) : strerror(errno)); 150 if (!N_BADMAG(exec)) { 151 is_aout = 1; 152 /* 153 * This legacy a.out support uses the kvm interface instead 154 * of procfs. 155 */ 156 kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf); 157 if (kd == NULL) 158 errx(1, "%s", errbuf); 159 160 uid = getuid(); 161 162 ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt); 163 if (ki == NULL || cnt != 1) 164 errx(1, "%d: not found", pid); 165 166 if (ki->ki_ruid != uid && uid != 0) 167 errx(1, "%d: not owner", pid); 168 169 if (ki->ki_stat == SZOMB) 170 errx(1, "%d: zombie", pid); 171 172 if (ki->ki_flag & P_WEXIT) 173 errx(1, "%d: process exiting", pid); 174 if (ki->ki_flag & P_SYSTEM) /* Swapper or pagedaemon. */ 175 errx(1, "%d: system process", pid); 176 if (exec.a_text != ptoa(ki->ki_tsize)) 177 errx(1, "The executable %s does not belong to" 178 " process %d!\n" 179 "Text segment size (in bytes): executable %ld," 180 " process %d", binfile, pid, exec.a_text, 181 ptoa(ki->ki_tsize)); 182 data_offset = N_DATOFF(exec); 183 } else if (IS_ELF(*(Elf_Ehdr *)&exec)) { 184 is_aout = 0; 185 close(efd); 186 } else 187 errx(1, "Invalid executable file"); 188 189 if (corefile == NULL) { 190 (void)snprintf(fname, sizeof(fname), "core.%d", pid); 191 corefile = fname; 192 } 193 fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE); 194 if (fd < 0) 195 err(1, "%s", corefile); 196 197 if (sflag) { 198 signal(SIGHUP, killed); 199 signal(SIGINT, killed); 200 signal(SIGTERM, killed); 201 if (kill(pid, SIGSTOP) == -1) 202 err(1, "%d: stop signal", pid); 203 atexit(restart_target); 204 } 205 206 if (is_aout) 207 core(efd, fd, ki); 208 else 209 elf_coredump(fd, pid); 210 211 (void)close(fd); 212 exit(0); 213 } 214 215 /* 216 * core -- 217 * Build the core file. 218 */ 219 void 220 core(efd, fd, ki) 221 int efd; 222 int fd; 223 struct kinfo_proc *ki; 224 { 225 union { 226 struct user user; 227 struct { 228 char uabytes[ctob(UAREA_PAGES)]; 229 char ksbytes[ctob(KSTACK_PAGES)]; 230 } bytes; 231 } uarea; 232 int tsize = ki->ki_tsize; 233 int dsize = ki->ki_dsize; 234 int ssize = ki->ki_ssize; 235 int cnt; 236 237 /* Read in user struct */ 238 cnt = kvm_read(kd, (u_long)ki->ki_addr, uarea.bytes.uabytes, 239 ctob(UAREA_PAGES)); 240 if (cnt != ctob(UAREA_PAGES)) 241 errx(1, "read upages structure: %s", 242 cnt > 0 ? strerror(EIO) : strerror(errno)); 243 244 cnt = kvm_read(kd, (u_long)ki->ki_kstack, uarea.bytes.ksbytes, 245 ctob(KSTACK_PAGES)); 246 if (cnt != ctob(KSTACK_PAGES)) 247 errx(1, "read kstack structure: %s", 248 cnt > 0 ? strerror(EIO) : strerror(errno)); 249 250 /* 251 * Fill in the eproc vm parameters, since these are garbage unless 252 * the kernel is dumping core or something. 253 */ 254 uarea.user.u_kproc = *ki; 255 256 /* Dump user area */ 257 cnt = write(fd, &uarea, sizeof(uarea)); 258 if (cnt != sizeof(uarea)) 259 errx(1, "write user structure: %s", 260 cnt > 0 ? strerror(EIO) : strerror(errno)); 261 262 /* Dump data segment */ 263 datadump(efd, fd, ki, USRTEXT + ctob(tsize), dsize); 264 265 /* Dump stack segment */ 266 userdump(fd, ki, USRSTACK - ctob(ssize), ssize); 267 268 /* Dump machine dependent portions of the core. */ 269 md_core(kd, fd, ki); 270 } 271 272 void 273 datadump(efd, fd, kp, addr, npage) 274 register int efd; 275 register int fd; 276 struct kinfo_proc *kp; 277 register u_long addr; 278 register int npage; 279 { 280 register int cc, delta; 281 char buffer[PAGE_SIZE]; 282 283 delta = data_offset - addr; 284 while (--npage >= 0) { 285 cc = kvm_uread(kd, kp, addr, buffer, PAGE_SIZE); 286 if (cc != PAGE_SIZE) { 287 /* Try to read the page from the executable. */ 288 if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1) 289 err(1, "seek executable"); 290 cc = read(efd, buffer, sizeof(buffer)); 291 if (cc != sizeof(buffer)) { 292 if (cc < 0) 293 err(1, "read executable"); 294 else /* Assume untouched bss page. */ 295 bzero(buffer, sizeof(buffer)); 296 } 297 } 298 cc = write(fd, buffer, PAGE_SIZE); 299 if (cc != PAGE_SIZE) 300 errx(1, "write data segment: %s", 301 cc > 0 ? strerror(EIO) : strerror(errno)); 302 addr += PAGE_SIZE; 303 } 304 } 305 306 static void 307 killed(sig) 308 int sig; 309 { 310 restart_target(); 311 signal(sig, SIG_DFL); 312 kill(getpid(), sig); 313 } 314 315 static void 316 restart_target() 317 { 318 kill(pid, SIGCONT); 319 } 320 321 void 322 userdump(fd, kp, addr, npage) 323 register int fd; 324 struct kinfo_proc *kp; 325 register u_long addr; 326 register int npage; 327 { 328 register int cc; 329 char buffer[PAGE_SIZE]; 330 331 while (--npage >= 0) { 332 cc = kvm_uread(kd, kp, addr, buffer, PAGE_SIZE); 333 if (cc != PAGE_SIZE) 334 /* Could be an untouched fill-with-zero page. */ 335 bzero(buffer, PAGE_SIZE); 336 cc = write(fd, buffer, PAGE_SIZE); 337 if (cc != PAGE_SIZE) 338 errx(1, "write stack segment: %s", 339 cc > 0 ? strerror(EIO) : strerror(errno)); 340 addr += PAGE_SIZE; 341 } 342 } 343 344 void 345 usage() 346 { 347 (void)fprintf(stderr, "usage: gcore [-s] [-c core] [executable] pid\n"); 348 exit(1); 349 } 350