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 1.5 2003/11/03 19:31:29 eirikn 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(int, int, struct kinfo_proc *); 74 static void datadump(int, int, struct proc *, u_long, int); 75 static void killed(int); 76 static void restart_target(void); 77 static void usage(void) __dead2; 78 static void userdump(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(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(int argc, char **argv) 89 { 90 register struct proc *p; 91 struct kinfo_proc *ki = NULL; 92 struct exec exec; 93 int ch, cnt, efd, fd, sflag, uid; 94 char *binfile, *corefile; 95 char errbuf[_POSIX2_LINE_MAX], fname[MAXPATHLEN + 1]; 96 int is_aout; 97 98 sflag = 0; 99 corefile = NULL; 100 while ((ch = getopt(argc, argv, "c:s")) != -1) { 101 switch (ch) { 102 case 'c': 103 corefile = optarg; 104 break; 105 case 's': 106 sflag = 1; 107 break; 108 default: 109 usage(); 110 break; 111 } 112 } 113 argv += optind; 114 argc -= optind; 115 116 /* XXX we should check that the pid argument is really a number */ 117 switch (argc) { 118 case 1: 119 pid = atoi(argv[0]); 120 asprintf(&binfile, "/proc/%d/file", pid); 121 if (binfile == NULL) 122 errx(1, "allocation failure"); 123 break; 124 case 2: 125 pid = atoi(argv[1]); 126 binfile = argv[0]; 127 break; 128 default: 129 usage(); 130 } 131 132 efd = open(binfile, O_RDONLY, 0); 133 if (efd < 0) 134 err(1, "%s", binfile); 135 136 cnt = read(efd, &exec, sizeof(exec)); 137 if (cnt != sizeof(exec)) 138 errx(1, "%s exec header: %s", 139 binfile, cnt > 0 ? strerror(EIO) : strerror(errno)); 140 if (!N_BADMAG(exec)) { 141 is_aout = 1; 142 /* 143 * This legacy a.out support uses the kvm interface instead 144 * of procfs. 145 */ 146 kd = kvm_openfiles(0, 0, 0, O_RDONLY, errbuf); 147 if (kd == NULL) 148 errx(1, "%s", errbuf); 149 150 uid = getuid(); 151 152 ki = kvm_getprocs(kd, KERN_PROC_PID, pid, &cnt); 153 if (ki == NULL || cnt != 1) 154 errx(1, "%d: not found", pid); 155 156 p = &ki->kp_proc; 157 if (ki->kp_eproc.e_ucred.cr_ruid != uid && uid != 0) 158 errx(1, "%d: not owner", pid); 159 160 if (p->p_stat == SZOMB) 161 errx(1, "%d: zombie", pid); 162 163 if (p->p_flag & P_WEXIT) 164 errx(1, "%d: process exiting", pid); 165 if (p->p_flag & P_SYSTEM) /* Swapper or pagedaemon. */ 166 errx(1, "%d: system process", pid); 167 if (exec.a_text != ptoa(ki->kp_eproc.e_vm.vm_tsize)) 168 errx(1, "The executable %s does not belong to" 169 " process %d!\n" 170 "Text segment size (in bytes): executable %ld," 171 " process %d", binfile, pid, exec.a_text, 172 ptoa(ki->kp_eproc.e_vm.vm_tsize)); 173 data_offset = N_DATOFF(exec); 174 } else if (IS_ELF(*(Elf_Ehdr *)&exec)) { 175 is_aout = 0; 176 close(efd); 177 } else 178 errx(1, "Invalid executable file"); 179 180 if (corefile == NULL) { 181 (void)snprintf(fname, sizeof(fname), "core.%d", pid); 182 corefile = fname; 183 } 184 fd = open(corefile, O_RDWR|O_CREAT|O_TRUNC, DEFFILEMODE); 185 if (fd < 0) 186 err(1, "%s", corefile); 187 188 if (sflag) { 189 signal(SIGHUP, killed); 190 signal(SIGINT, killed); 191 signal(SIGTERM, killed); 192 if (kill(pid, SIGSTOP) == -1) 193 err(1, "%d: stop signal", pid); 194 atexit(restart_target); 195 } 196 197 if (is_aout) 198 core(efd, fd, ki); 199 else 200 elf_coredump(fd, pid); 201 202 (void)close(fd); 203 exit(0); 204 } 205 206 /* 207 * core -- 208 * Build the core file. 209 */ 210 void 211 core(int efd, int fd, struct kinfo_proc *ki) 212 { 213 union { 214 struct user user; 215 char ubytes[ctob(UPAGES)]; 216 } uarea; 217 struct proc *p = &ki->kp_proc; 218 int tsize = ki->kp_eproc.e_vm.vm_tsize; 219 int dsize = ki->kp_eproc.e_vm.vm_dsize; 220 int ssize = ki->kp_eproc.e_vm.vm_ssize; 221 int cnt; 222 223 /* Read in user struct */ 224 cnt = kvm_read(kd, (u_long)p->p_addr, &uarea, sizeof(uarea)); 225 if (cnt != sizeof(uarea)) 226 errx(1, "read user structure: %s", 227 cnt > 0 ? strerror(EIO) : strerror(errno)); 228 229 /* 230 * Fill in the eproc vm parameters, since these are garbage unless 231 * the kernel is dumping core or something. 232 */ 233 uarea.user.u_kproc = *ki; 234 235 /* Dump user area */ 236 cnt = write(fd, &uarea, sizeof(uarea)); 237 if (cnt != sizeof(uarea)) 238 errx(1, "write user structure: %s", 239 cnt > 0 ? strerror(EIO) : strerror(errno)); 240 241 /* Dump data segment */ 242 datadump(efd, fd, p, USRTEXT + ctob(tsize), dsize); 243 244 /* Dump stack segment */ 245 userdump(fd, p, USRSTACK - ctob(ssize), ssize); 246 247 /* Dump machine dependent portions of the core. */ 248 md_core(kd, fd, ki); 249 } 250 251 void 252 datadump(register int efd, register int fd, struct proc *p, 253 register u_long addr, register int npage) 254 { 255 register int cc, delta; 256 char buffer[PAGE_SIZE]; 257 258 delta = data_offset - addr; 259 while (--npage >= 0) { 260 cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE); 261 if (cc != PAGE_SIZE) { 262 /* Try to read the page from the executable. */ 263 if (lseek(efd, (off_t)addr + delta, SEEK_SET) == -1) 264 err(1, "seek executable: %s", strerror(errno)); 265 cc = read(efd, buffer, sizeof(buffer)); 266 if (cc != sizeof(buffer)) { 267 if (cc < 0) 268 err(1, "read executable"); 269 else /* Assume untouched bss page. */ 270 bzero(buffer, sizeof(buffer)); 271 } 272 } 273 cc = write(fd, buffer, PAGE_SIZE); 274 if (cc != PAGE_SIZE) 275 errx(1, "write data segment: %s", 276 cc > 0 ? strerror(EIO) : strerror(errno)); 277 addr += PAGE_SIZE; 278 } 279 } 280 281 static void 282 killed(int sig) 283 { 284 restart_target(); 285 signal(sig, SIG_DFL); 286 kill(getpid(), sig); 287 } 288 289 static void 290 restart_target(void) 291 { 292 kill(pid, SIGCONT); 293 } 294 295 void 296 userdump(register int fd, struct proc *p, register u_long addr, 297 register int npage) 298 { 299 register int cc; 300 char buffer[PAGE_SIZE]; 301 302 while (--npage >= 0) { 303 cc = kvm_uread(kd, p, addr, buffer, PAGE_SIZE); 304 if (cc != PAGE_SIZE) 305 /* Could be an untouched fill-with-zero page. */ 306 bzero(buffer, PAGE_SIZE); 307 cc = write(fd, buffer, PAGE_SIZE); 308 if (cc != PAGE_SIZE) 309 errx(1, "write stack segment: %s", 310 cc > 0 ? strerror(EIO) : strerror(errno)); 311 addr += PAGE_SIZE; 312 } 313 } 314 315 void 316 usage(void) 317 { 318 (void)fprintf(stderr, "usage: gcore [-s] [-c core] [executable] pid\n"); 319 exit(1); 320 } 321