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 * @(#) Copyright (c) 1992, 1993 The Regents of the University of California. All rights reserved. 34 * @(#)gcore.c 8.2 (Berkeley) 9/23/93 35 * $FreeBSD: src/usr.bin/gcore/gcore.c,v 1.15.2.2 2001/08/17 20:56:22 mikeh Exp $ 36 * $DragonFly: src/usr.bin/gcore/gcore.c,v 1.3 2003/07/13 05:45:16 dillon Exp $ 37 */ 38 39 /* 40 * Originally written by Eric Cooper in Fall 1981. 41 * Inspired by a version 6 program by Len Levin, 1978. 42 * Several pieces of code lifted from Bill Joy's 4BSD ps. 43 * Most recently, hacked beyond recognition for 4.4BSD by Steven McCanne, 44 * Lawrence Berkeley Laboratory. 45 * 46 * Portions of this software were developed by the Computer Systems 47 * Engineering group at Lawrence Berkeley Laboratory under DARPA 48 * contract BG 91-66 and contributed to Berkeley. 49 */ 50 #include <sys/param.h> 51 #include <sys/time.h> 52 #include <sys/stat.h> 53 #include <sys/proc.h> 54 #include <sys/user.h> 55 #include <sys/sysctl.h> 56 #include <machine/elf.h> 57 58 #include <machine/vmparam.h> 59 60 #include <a.out.h> 61 #include <err.h> 62 #include <fcntl.h> 63 #include <kvm.h> 64 #include <limits.h> 65 #include <signal.h> 66 #include <stdio.h> 67 #include <stdlib.h> 68 #include <string.h> 69 #include <unistd.h> 70 71 #include "extern.h" 72 73 static void core __P((int, int, struct kinfo_proc *)); 74 static void datadump __P((int, int, struct proc *, u_long, int)); 75 static void killed __P((int)); 76 static void restart_target __P((void)); 77 static void usage __P((void)) __dead2; 78 static void userdump __P((int, struct proc *, u_long, int)); 79 80 kvm_t *kd; 81 /* XXX undocumented routine, should be in kvm.h? */ 82 ssize_t kvm_uread __P((kvm_t *, const struct proc *, u_long, char *, size_t)); 83 84 static int data_offset; 85 static pid_t pid; 86 87 int 88 main(argc, argv) 89 int argc; 90 char *argv[]; 91 { 92 register struct proc *p; 93 struct kinfo_proc *ki = NULL; 94 struct exec exec; 95 int ch, cnt, efd, fd, sflag, uid; 96 char *binfile, *corefile; 97 char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN + 1]; 98 int is_aout; 99 100 sflag = 0; 101 corefile = NULL; 102 while ((ch = getopt(argc, argv, "c:s")) != -1) { 103 switch (ch) { 104 case 'c': 105 corefile = optarg; 106 break; 107 case 's': 108 sflag = 1; 109 break; 110 default: 111 usage(); 112 break; 113 } 114 } 115 argv += optind; 116 argc -= optind; 117 118 /* XXX we should check that the pid argument is really a number */ 119 switch (argc) { 120 case 1: 121 pid = atoi(argv[0]); 122 asprintf(&binfile, "/proc/%d/file", pid); 123 if (binfile == NULL) 124 errx(1, "allocation failure"); 125 break; 126 case 2: 127 pid = atoi(argv[1]); 128 binfile = argv[0]; 129 break; 130 default: 131 usage(); 132 } 133 134 efd = open(binfile, O_RDONLY, 0); 135 if (efd < 0) 136 err(1, "%s", binfile); 137 138 cnt = read(efd, &exec, sizeof(exec)); 139 if (cnt != sizeof(exec)) 140 errx(1, "%s exec header: %s", 141 binfile, cnt > 0 ? strerror(EIO) : strerror(errno)); 142 if (!N_BADMAG(exec)) { 143 is_aout = 1; 144 /* 145 * This legacy a.out support uses the kvm interface instead 146 * of procfs. 147 */ 148 kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf); 149 if (kd == NULL) 150 errx(1, "%s", errbuf); 151 152 uid = getuid(); 153 154 ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt); 155 if (ki == NULL || cnt != 1) 156 errx(1, "%d: not found", pid); 157 158 p = &ki->kp_proc; 159 if (ki->kp_eproc.e_ucred.cr_ruid != uid && uid != 0) 160 errx(1, "%d: not owner", pid); 161 162 if (p->p_stat == SZOMB) 163 errx(1, "%d: zombie", pid); 164 165 if (p->p_flag & P_WEXIT) 166 errx(1, "%d: process exiting", pid); 167 if (p->p_flag & P_SYSTEM) /* Swapper or pagedaemon. */ 168 errx(1, "%d: system process", pid); 169 if (exec.a_text != ptoa(ki->kp_eproc.e_vm.vm_tsize)) 170 errx(1, "The executable %s does not belong to" 171 " process %d!\n" 172 "Text segment size (in bytes): executable %ld," 173 " process %d", binfile, pid, exec.a_text, 174 ptoa(ki->kp_eproc.e_vm.vm_tsize)); 175 data_offset = N_DATOFF(exec); 176 } else if (IS_ELF(*(Elf_Ehdr *)&exec)) { 177 is_aout = 0; 178 close(efd); 179 } else 180 errx(1, "Invalid executable file"); 181 182 if (corefile == NULL) { 183 (void)snprintf(fname, sizeof(fname), "core.%d", pid); 184 corefile = fname; 185 } 186 fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE); 187 if (fd < 0) 188 err(1, "%s", corefile); 189 190 if (sflag) { 191 signal(SIGHUP, killed); 192 signal(SIGINT, killed); 193 signal(SIGTERM, killed); 194 if (kill(pid, SIGSTOP) == -1) 195 err(1, "%d: stop signal", pid); 196 atexit(restart_target); 197 } 198 199 if (is_aout) 200 core(efd, fd, ki); 201 else 202 elf_coredump(fd, pid); 203 204 (void)close(fd); 205 exit(0); 206 } 207 208 /* 209 * core -- 210 * Build the core file. 211 */ 212 void 213 core(efd, fd, ki) 214 int efd; 215 int fd; 216 struct kinfo_proc *ki; 217 { 218 union { 219 struct user user; 220 char ubytes[ctob(UPAGES)]; 221 } uarea; 222 struct proc *p = &ki->kp_proc; 223 int tsize = ki->kp_eproc.e_vm.vm_tsize; 224 int dsize = ki->kp_eproc.e_vm.vm_dsize; 225 int ssize = ki->kp_eproc.e_vm.vm_ssize; 226 int cnt; 227 228 /* Read in user struct */ 229 cnt = kvm_read(kd, (u_long)p->p_addr, &uarea, sizeof(uarea)); 230 if (cnt != sizeof(uarea)) 231 errx(1, "read user structure: %s", 232 cnt > 0 ? strerror(EIO) : strerror(errno)); 233 234 /* 235 * Fill in the eproc vm parameters, since these are garbage unless 236 * the kernel is dumping core or something. 237 */ 238 uarea.user.u_kproc = *ki; 239 240 /* Dump user area */ 241 cnt = write(fd, &uarea, sizeof(uarea)); 242 if (cnt != sizeof(uarea)) 243 errx(1, "write user structure: %s", 244 cnt > 0 ? strerror(EIO) : strerror(errno)); 245 246 /* Dump data segment */ 247 datadump(efd, fd, p, USRTEXT + ctob(tsize), dsize); 248 249 /* Dump stack segment */ 250 userdump(fd, p, USRSTACK - ctob(ssize), ssize); 251 252 /* Dump machine dependent portions of the core. */ 253 md_core(kd, fd, ki); 254 } 255 256 void 257 datadump(efd, fd, p, addr, npage) 258 register int efd; 259 register int fd; 260 struct proc *p; 261 register u_long addr; 262 register int npage; 263 { 264 register int cc, delta; 265 char buffer[PAGE_SIZE]; 266 267 delta = data_offset - addr; 268 while (--npage >= 0) { 269 cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE); 270 if (cc != PAGE_SIZE) { 271 /* Try to read the page from the executable. */ 272 if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1) 273 err(1, "seek executable: %s", strerror(errno)); 274 cc = read(efd, buffer, sizeof(buffer)); 275 if (cc != sizeof(buffer)) { 276 if (cc < 0) 277 err(1, "read executable"); 278 else /* Assume untouched bss page. */ 279 bzero(buffer, sizeof(buffer)); 280 } 281 } 282 cc = write(fd, buffer, PAGE_SIZE); 283 if (cc != PAGE_SIZE) 284 errx(1, "write data segment: %s", 285 cc > 0 ? strerror(EIO) : strerror(errno)); 286 addr += PAGE_SIZE; 287 } 288 } 289 290 static void 291 killed(sig) 292 int sig; 293 { 294 restart_target(); 295 signal(sig, SIG_DFL); 296 kill(getpid(), sig); 297 } 298 299 static void 300 restart_target() 301 { 302 kill(pid, SIGCONT); 303 } 304 305 void 306 userdump(fd, p, addr, npage) 307 register int fd; 308 struct proc *p; 309 register u_long addr; 310 register int npage; 311 { 312 register int cc; 313 char buffer[PAGE_SIZE]; 314 315 while (--npage >= 0) { 316 cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE); 317 if (cc != PAGE_SIZE) 318 /* Could be an untouched fill-with-zero page. */ 319 bzero(buffer, PAGE_SIZE); 320 cc = write(fd, buffer, PAGE_SIZE); 321 if (cc != PAGE_SIZE) 322 errx(1, "write stack segment: %s", 323 cc > 0 ? strerror(EIO) : strerror(errno)); 324 addr += PAGE_SIZE; 325 } 326 } 327 328 void 329 usage() 330 { 331 (void)fprintf(stderr, "usage: gcore [-s] [-c core] [executable] pid\n"); 332 exit(1); 333 } 334