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 1.7 2005/04/10 20:55:38 drhodus 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/user.h> 54 #include <sys/sysctl.h> 55 #include <machine/elf.h> 56 57 #include <machine/vmparam.h> 58 59 #include <a.out.h> 60 #include <err.h> 61 #include <fcntl.h> 62 #include <kvm.h> 63 #include <limits.h> 64 #include <signal.h> 65 #include <stdio.h> 66 #include <stdlib.h> 67 #include <string.h> 68 #include <unistd.h> 69 70 #include "extern.h" 71 72 static void core(int, int, struct kinfo_proc *); 73 static void datadump(int, int, struct proc *, u_long, int); 74 static void killed(int); 75 static void restart_target(void); 76 static void usage(void) __dead2; 77 static void userdump(int, struct proc *, u_long, int); 78 79 kvm_t *kd; 80 /* XXX undocumented routine, should be in kvm.h? */ 81 ssize_t kvm_uread(kvm_t *, const struct proc *, u_long, char *, size_t); 82 83 static int data_offset; 84 static pid_t pid; 85 86 int 87 main(int argc, char **argv) 88 { 89 struct proc *p; 90 struct kinfo_proc *ki = NULL; 91 struct exec exec; 92 int ch, cnt, efd, fd, sflag, uid; 93 char *binfile, *corefile; 94 char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN + 1]; 95 int is_aout; 96 97 sflag = 0; 98 corefile = NULL; 99 while ((ch = getopt(argc, argv, "c:s")) != -1) { 100 switch (ch) { 101 case 'c': 102 corefile = optarg; 103 break; 104 case 's': 105 sflag = 1; 106 break; 107 default: 108 usage(); 109 break; 110 } 111 } 112 argv += optind; 113 argc -= optind; 114 115 /* XXX we should check that the pid argument is really a number */ 116 switch (argc) { 117 case 1: 118 pid = atoi(argv[0]); 119 asprintf(&binfile, "/proc/%d/file", pid); 120 if (binfile == NULL) 121 errx(1, "allocation failure"); 122 break; 123 case 2: 124 pid = atoi(argv[1]); 125 binfile = argv[0]; 126 break; 127 default: 128 usage(); 129 } 130 131 efd = open(binfile, O_RDONLY, 0); 132 if (efd < 0) 133 err(1, "%s", binfile); 134 135 cnt = read(efd, &exec, sizeof(exec)); 136 if (cnt != sizeof(exec)) 137 errx(1, "%s exec header: %s", 138 binfile, cnt > 0 ? strerror(EIO) : strerror(errno)); 139 if (!N_BADMAG(exec)) { 140 is_aout = 1; 141 /* 142 * This legacy a.out support uses the kvm interface instead 143 * of procfs. 144 */ 145 kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf); 146 if (kd == NULL) 147 errx(1, "%s", errbuf); 148 149 uid = getuid(); 150 151 ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt); 152 if (ki == NULL || cnt != 1) 153 errx(1, "%d: not found", pid); 154 155 p = &ki->kp_proc; 156 if (ki->kp_eproc.e_ucred.cr_ruid != uid && uid != 0) 157 errx(1, "%d: not owner", pid); 158 159 if (p->p_stat == SZOMB) 160 errx(1, "%d: zombie", pid); 161 162 if (p->p_flag & P_WEXIT) 163 errx(1, "%d: process exiting", pid); 164 if (p->p_flag & P_SYSTEM) /* Swapper or pagedaemon. */ 165 errx(1, "%d: system process", pid); 166 if (exec.a_text != ptoa(ki->kp_eproc.e_vm.vm_tsize)) 167 errx(1, "The executable %s does not belong to" 168 " process %d!\n" 169 "Text segment size (in bytes): executable %ld," 170 " process %d", binfile, pid, exec.a_text, 171 ptoa(ki->kp_eproc.e_vm.vm_tsize)); 172 data_offset = N_DATOFF(exec); 173 } else if (IS_ELF(*(Elf_Ehdr *)&exec)) { 174 is_aout = 0; 175 close(efd); 176 } else 177 errx(1, "Invalid executable file"); 178 179 if (corefile == NULL) { 180 (void)snprintf(fname, sizeof(fname), "core.%d", pid); 181 corefile = fname; 182 } 183 fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE); 184 if (fd < 0) 185 err(1, "%s", corefile); 186 187 if (sflag) { 188 signal(SIGHUP, killed); 189 signal(SIGINT, killed); 190 signal(SIGTERM, killed); 191 if (kill(pid, SIGSTOP) == -1) 192 err(1, "%d: stop signal", pid); 193 atexit(restart_target); 194 } 195 196 if (is_aout) 197 core(efd, fd, ki); 198 else 199 elf_coredump(fd, pid); 200 201 (void)close(fd); 202 exit(0); 203 } 204 205 /* 206 * core -- 207 * Build the core file. 208 */ 209 void 210 core(int efd, int fd, struct kinfo_proc *ki) 211 { 212 union { 213 struct user user; 214 char ubytes[ctob(UPAGES)]; 215 } uarea; 216 struct proc *p = &ki->kp_proc; 217 int tsize = ki->kp_eproc.e_vm.vm_tsize; 218 int dsize = ki->kp_eproc.e_vm.vm_dsize; 219 int ssize = ki->kp_eproc.e_vm.vm_ssize; 220 int cnt; 221 222 /* Read in user struct */ 223 cnt = kvm_read(kd, (u_long)p->p_addr, &uarea, sizeof(uarea)); 224 if (cnt != sizeof(uarea)) 225 errx(1, "read user structure: %s", 226 cnt > 0 ? strerror(EIO) : strerror(errno)); 227 228 /* 229 * Fill in the eproc vm parameters, since these are garbage unless 230 * the kernel is dumping core or something. 231 */ 232 uarea.user.u_kproc = *ki; 233 234 /* Dump user area */ 235 cnt = write(fd, &uarea, sizeof(uarea)); 236 if (cnt != sizeof(uarea)) 237 errx(1, "write user structure: %s", 238 cnt > 0 ? strerror(EIO) : strerror(errno)); 239 240 /* Dump data segment */ 241 datadump(efd, fd, p, USRTEXT + ctob(tsize), dsize); 242 243 /* Dump stack segment */ 244 userdump(fd, p, USRSTACK - ctob(ssize), ssize); 245 246 /* Dump machine dependent portions of the core. */ 247 md_core(kd, fd, ki); 248 } 249 250 void 251 datadump(int efd, int fd, struct proc *p, 252 u_long addr, int npage) 253 { 254 int cc, delta; 255 char buffer[PAGE_SIZE]; 256 257 delta = data_offset - addr; 258 while (--npage >= 0) { 259 cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE); 260 if (cc != PAGE_SIZE) { 261 /* Try to read the page from the executable. */ 262 if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1) 263 err(1, "seek executable: %s", strerror(errno)); 264 cc = read(efd, buffer, sizeof(buffer)); 265 if (cc != sizeof(buffer)) { 266 if (cc < 0) 267 err(1, "read executable"); 268 else /* Assume untouched bss page. */ 269 bzero(buffer, sizeof(buffer)); 270 } 271 } 272 cc = write(fd, buffer, PAGE_SIZE); 273 if (cc != PAGE_SIZE) 274 errx(1, "write data segment: %s", 275 cc > 0 ? strerror(EIO) : strerror(errno)); 276 addr += PAGE_SIZE; 277 } 278 } 279 280 static void 281 killed(int sig) 282 { 283 restart_target(); 284 signal(sig, SIG_DFL); 285 kill(getpid(), sig); 286 } 287 288 static void 289 restart_target(void) 290 { 291 kill(pid, SIGCONT); 292 } 293 294 void 295 userdump(int fd, struct proc *p, u_long addr, 296 int npage) 297 { 298 int cc; 299 char buffer[PAGE_SIZE]; 300 301 while (--npage >= 0) { 302 cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE); 303 if (cc != PAGE_SIZE) 304 /* Could be an untouched fill-with-zero page. */ 305 bzero(buffer, PAGE_SIZE); 306 cc = write(fd, buffer, PAGE_SIZE); 307 if (cc != PAGE_SIZE) 308 errx(1, "write stack segment: %s", 309 cc > 0 ? strerror(EIO) : strerror(errno)); 310 addr += PAGE_SIZE; 311 } 312 } 313 314 void 315 usage(void) 316 { 317 (void)fprintf(stderr, "usage: gcore [-s] [-c core] [executable] pid\n"); 318 exit(1); 319 } 320