gcore.c revision 69896
155682Smarkm/*- 278527Sassar * Copyright (c) 1992, 1993 355682Smarkm * The Regents of the University of California. All rights reserved. 455682Smarkm * 555682Smarkm * Redistribution and use in source and binary forms, with or without 655682Smarkm * modification, are permitted provided that the following conditions 755682Smarkm * are met: 855682Smarkm * 1. Redistributions of source code must retain the above copyright 955682Smarkm * notice, this list of conditions and the following disclaimer. 1055682Smarkm * 2. Redistributions in binary form must reproduce the above copyright 1155682Smarkm * notice, this list of conditions and the following disclaimer in the 1255682Smarkm * documentation and/or other materials provided with the distribution. 1355682Smarkm * 3. All advertising materials mentioning features or use of this software 1455682Smarkm * must display the following acknowledgement: 1555682Smarkm * This product includes software developed by the University of 1655682Smarkm * California, Berkeley and its contributors. 1755682Smarkm * 4. Neither the name of the University nor the names of its contributors 1855682Smarkm * may be used to endorse or promote products derived from this software 1955682Smarkm * without specific prior written permission. 2055682Smarkm * 2155682Smarkm * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2255682Smarkm * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2355682Smarkm * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2455682Smarkm * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2555682Smarkm * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2655682Smarkm * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2755682Smarkm * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2855682Smarkm * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2955682Smarkm * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3055682Smarkm * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3155682Smarkm * SUCH DAMAGE. 3255682Smarkm */ 3355682Smarkm 3455682Smarkm#ifndef lint 3555682Smarkmstatic const char copyright[] = 36178825Sdfr"@(#) Copyright (c) 1992, 1993\n\ 3755682Smarkm The Regents of the University of California. All rights reserved.\n"; 3855682Smarkm#endif /* not lint */ 3955682Smarkm 4055682Smarkm#ifndef lint 4155682Smarkm#if 0 4278527Sassarstatic char sccsid[] = "@(#)gcore.c 8.2 (Berkeley) 9/23/93"; 4378527Sassar#endif 4478527Sassarstatic const char rcsid[] = 4578527Sassar "$FreeBSD: head/usr.bin/gcore/gcore.c 69896 2000-12-12 07:25:57Z mckusick $"; 4678527Sassar#endif /* not lint */ 4778527Sassar 4878527Sassar/* 4978527Sassar * Originally written by Eric Cooper in Fall 1981. 5078527Sassar * Inspired by a version 6 program by Len Levin, 1978. 5178527Sassar * Several pieces of code lifted from Bill Joy's 4BSD ps. 5278527Sassar * Most recently, hacked beyond recognition for 4.4BSD by Steven McCanne, 53178825Sdfr * Lawrence Berkeley Laboratory. 54178825Sdfr * 55178825Sdfr * Portions of this software were developed by the Computer Systems 56178825Sdfr * Engineering group at Lawrence Berkeley Laboratory under DARPA 57178825Sdfr * contract BG 91-66 and contributed to Berkeley. 58178825Sdfr */ 5955682Smarkm#include <sys/param.h> 60178825Sdfr#include <sys/time.h> 61178825Sdfr#include <sys/stat.h> 6255682Smarkm#include <sys/proc.h> 6355682Smarkm#include <sys/user.h> 6455682Smarkm#include <sys/sysctl.h> 6578527Sassar 6655682Smarkm#include <machine/vmparam.h> 67178825Sdfr 6855682Smarkm#include <a.out.h> 6978527Sassar#include <elf.h> 7078527Sassar#include <err.h> 7178527Sassar#include <fcntl.h> 7278527Sassar#include <kvm.h> 7378527Sassar#include <limits.h> 7478527Sassar#include <signal.h> 7578527Sassar#include <stdio.h> 7678527Sassar#include <stdlib.h> 7778527Sassar#include <string.h> 7855682Smarkm#include <unistd.h> 7978527Sassar 8078527Sassar#include "extern.h" 8178527Sassar 8278527Sassarstatic void core __P((int, int, struct kinfo_proc *)); 8378527Sassarstatic void datadump __P((int, int, struct kinfo_proc *, u_long, int)); 8478527Sassarstatic void killed __P((int)); 8578527Sassarstatic void restart_target __P((void)); 8678527Sassarstatic void usage __P((void)) __dead2; 8778527Sassarstatic void userdump __P((int, struct kinfo_proc *, u_long, int)); 8878527Sassar 8978527Sassarkvm_t *kd; 9078527Sassar 9178527Sassarstatic int data_offset; 9255682Smarkmstatic pid_t pid; 9355682Smarkm 9455682Smarkmint 9555682Smarkmmain(argc, argv) 96178825Sdfr int argc; 97178825Sdfr char *argv[]; 98178825Sdfr{ 99178825Sdfr struct kinfo_proc *ki = NULL; 100178825Sdfr struct exec exec; 101178825Sdfr int ch, cnt, efd, fd, sflag, uid; 102178825Sdfr char *binfile, *corefile; 103178825Sdfr char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN + 1]; 104178825Sdfr int is_aout; 105178825Sdfr 106178825Sdfr sflag = 0; 107178825Sdfr corefile = NULL; 108178825Sdfr while ((ch = getopt(argc, argv, "c:s")) != -1) { 109178825Sdfr switch (ch) { 110178825Sdfr case 'c': 111178825Sdfr corefile = optarg; 112178825Sdfr break; 113178825Sdfr case 's': 114178825Sdfr sflag = 1; 115178825Sdfr 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 */ 217void 218core(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 260void 261datadump(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 294static void 295killed(sig) 296 int sig; 297{ 298 restart_target(); 299 signal(sig, SIG_DFL); 300 kill(getpid(), sig); 301} 302 303static void 304restart_target() 305{ 306 kill(pid, SIGCONT); 307} 308 309void 310userdump(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 332void 333usage() 334{ 335 (void)fprintf(stderr, "usage: gcore [-s] [-c core] executable pid\n"); 336 exit(1); 337} 338