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: src/usr.bin/gcore/gcore.c,v 1.15.2.2 2001/08/17 20:56:22 mikeh Exp $"; 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 #include <machine/elf.h> 66 67 #include <machine/vmparam.h> 68 69 #include <a.out.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 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 proc *, u_long, int)); 88 89 kvm_t *kd; 90 /* XXX undocumented routine, should be in kvm.h? */ 91 ssize_t kvm_uread __P((kvm_t *, const struct proc *, u_long, char *, size_t)); 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 register struct proc *p; 102 struct kinfo_proc *ki = NULL; 103 struct exec exec; 104 int ch, cnt, efd, fd, sflag, uid; 105 char *binfile, *corefile; 106 char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN + 1]; 107 int is_aout; 108 109 sflag = 0; 110 corefile = NULL; 111 while ((ch = getopt(argc, argv, "c:s")) != -1) { 112 switch (ch) { 113 case 'c': 114 corefile = optarg; 115 break; 116 case 's': 117 sflag = 1; 118 break; 119 default: 120 usage(); 121 break; 122 } 123 } 124 argv += optind; 125 argc -= optind; 126 127 /* XXX we should check that the pid argument is really a number */ 128 switch (argc) { 129 case 1: 130 pid = atoi(argv[0]); 131 asprintf(&binfile, "/proc/%d/file", pid); 132 if (binfile == NULL) 133 errx(1, "allocation failure"); 134 break; 135 case 2: 136 pid = atoi(argv[1]); 137 binfile = argv[0]; 138 break; 139 default: 140 usage(); 141 } 142 143 efd = open(binfile, O_RDONLY, 0); 144 if (efd < 0) 145 err(1, "%s", binfile); 146 147 cnt = read(efd, &exec, sizeof(exec)); 148 if (cnt != sizeof(exec)) 149 errx(1, "%s exec header: %s", 150 binfile, cnt > 0 ? strerror(EIO) : strerror(errno)); 151 if (!N_BADMAG(exec)) { 152 is_aout = 1; 153 /* 154 * This legacy a.out support uses the kvm interface instead 155 * of procfs. 156 */ 157 kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf); 158 if (kd == NULL) 159 errx(1, "%s", errbuf); 160 161 uid = getuid(); 162 163 ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt); 164 if (ki == NULL || cnt != 1) 165 errx(1, "%d: not found", pid); 166 167 p = &ki->kp_proc; 168 if (ki->kp_eproc.e_pcred.p_ruid != uid && uid != 0) 169 errx(1, "%d: not owner", pid); 170 171 if (p->p_stat == SZOMB) 172 errx(1, "%d: zombie", pid); 173 174 if (p->p_flag & P_WEXIT) 175 errx(1, "%d: process exiting", pid); 176 if (p->p_flag & P_SYSTEM) /* Swapper or pagedaemon. */ 177 errx(1, "%d: system process", pid); 178 if (exec.a_text != ptoa(ki->kp_eproc.e_vm.vm_tsize)) 179 errx(1, "The executable %s does not belong to" 180 " process %d!\n" 181 "Text segment size (in bytes): executable %ld," 182 " process %d", binfile, pid, exec.a_text, 183 ptoa(ki->kp_eproc.e_vm.vm_tsize)); 184 data_offset = N_DATOFF(exec); 185 } else if (IS_ELF(*(Elf_Ehdr *)&exec)) { 186 is_aout = 0; 187 close(efd); 188 } else 189 errx(1, "Invalid executable file"); 190 191 if (corefile == NULL) { 192 (void)snprintf(fname, sizeof(fname), "core.%d", pid); 193 corefile = fname; 194 } 195 fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE); 196 if (fd < 0) 197 err(1, "%s", corefile); 198 199 if (sflag) { 200 signal(SIGHUP, killed); 201 signal(SIGINT, killed); 202 signal(SIGTERM, killed); 203 if (kill(pid, SIGSTOP) == -1) 204 err(1, "%d: stop signal", pid); 205 atexit(restart_target); 206 } 207 208 if (is_aout) 209 core(efd, fd, ki); 210 else 211 elf_coredump(fd, pid); 212 213 (void)close(fd); 214 exit(0); 215 } 216 217 /* 218 * core -- 219 * Build the core file. 220 */ 221 void 222 core(efd, fd, ki) 223 int efd; 224 int fd; 225 struct kinfo_proc *ki; 226 { 227 union { 228 struct user user; 229 char ubytes[ctob(UPAGES)]; 230 } uarea; 231 struct proc *p = &ki->kp_proc; 232 int tsize = ki->kp_eproc.e_vm.vm_tsize; 233 int dsize = ki->kp_eproc.e_vm.vm_dsize; 234 int ssize = ki->kp_eproc.e_vm.vm_ssize; 235 int cnt; 236 237 /* Read in user struct */ 238 cnt = kvm_read(kd, (u_long)p->p_addr, &uarea, sizeof(uarea)); 239 if (cnt != sizeof(uarea)) 240 errx(1, "read user structure: %s", 241 cnt > 0 ? strerror(EIO) : strerror(errno)); 242 243 /* 244 * Fill in the eproc vm parameters, since these are garbage unless 245 * the kernel is dumping core or something. 246 */ 247 uarea.user.u_kproc = *ki; 248 249 /* Dump user area */ 250 cnt = write(fd, &uarea, sizeof(uarea)); 251 if (cnt != sizeof(uarea)) 252 errx(1, "write user structure: %s", 253 cnt > 0 ? strerror(EIO) : strerror(errno)); 254 255 /* Dump data segment */ 256 datadump(efd, fd, p, USRTEXT + ctob(tsize), dsize); 257 258 /* Dump stack segment */ 259 userdump(fd, p, USRSTACK - ctob(ssize), ssize); 260 261 /* Dump machine dependent portions of the core. */ 262 md_core(kd, fd, ki); 263 } 264 265 void 266 datadump(efd, fd, p, addr, npage) 267 register int efd; 268 register int fd; 269 struct proc *p; 270 register u_long addr; 271 register int npage; 272 { 273 register int cc, delta; 274 char buffer[PAGE_SIZE]; 275 276 delta = data_offset - addr; 277 while (--npage >= 0) { 278 cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE); 279 if (cc != PAGE_SIZE) { 280 /* Try to read the page from the executable. */ 281 if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1) 282 err(1, "seek executable: %s", strerror(errno)); 283 cc = read(efd, buffer, sizeof(buffer)); 284 if (cc != sizeof(buffer)) { 285 if (cc < 0) 286 err(1, "read executable"); 287 else /* Assume untouched bss page. */ 288 bzero(buffer, sizeof(buffer)); 289 } 290 } 291 cc = write(fd, buffer, PAGE_SIZE); 292 if (cc != PAGE_SIZE) 293 errx(1, "write data segment: %s", 294 cc > 0 ? strerror(EIO) : strerror(errno)); 295 addr += PAGE_SIZE; 296 } 297 } 298 299 static void 300 killed(sig) 301 int sig; 302 { 303 restart_target(); 304 signal(sig, SIG_DFL); 305 kill(getpid(), sig); 306 } 307 308 static void 309 restart_target() 310 { 311 kill(pid, SIGCONT); 312 } 313 314 void 315 userdump(fd, p, addr, npage) 316 register int fd; 317 struct proc *p; 318 register u_long addr; 319 register int npage; 320 { 321 register int cc; 322 char buffer[PAGE_SIZE]; 323 324 while (--npage >= 0) { 325 cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE); 326 if (cc != PAGE_SIZE) 327 /* Could be an untouched fill-with-zero page. */ 328 bzero(buffer, PAGE_SIZE); 329 cc = write(fd, buffer, PAGE_SIZE); 330 if (cc != PAGE_SIZE) 331 errx(1, "write stack segment: %s", 332 cc > 0 ? strerror(EIO) : strerror(errno)); 333 addr += PAGE_SIZE; 334 } 335 } 336 337 void 338 usage() 339 { 340 (void)fprintf(stderr, "usage: gcore [-s] [-c core] [executable] pid\n"); 341 exit(1); 342 } 343