1 /* 2 * Copryight 1997 Sean Eric Fagan 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. All advertising materials mentioning features or use of this software 13 * must display the following acknowledgement: 14 * This product includes software developed by Sean Eric Fagan 15 * 4. Neither the name of the author may be used to endorse or promote 16 * products derived from this software without specific prior written 17 * permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 /* 36 * The main module for truss. Suprisingly simple, but, then, the other 37 * files handle the bulk of the work. And, of course, the kernel has to 38 * do a lot of the work :). 39 */ 40 41 #include <sys/param.h> 42 #include <sys/ioctl.h> 43 #include <sys/pioctl.h> 44 #include <sys/types.h> 45 #include <sys/time.h> 46 #include <sys/resource.h> 47 48 #include <ctype.h> 49 #include <err.h> 50 #include <errno.h> 51 #include <fcntl.h> 52 #include <signal.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <time.h> 57 #include <unistd.h> 58 59 #include "truss.h" 60 #include "extern.h" 61 62 /* 63 * It's difficult to parameterize this because it must be 64 * accessible in a signal handler. 65 */ 66 67 int Procfd; 68 69 static void 70 usage(void) 71 { 72 fprintf(stderr, "%s\n%s\n", 73 "usage: truss [-faedDS] [-o file] -p pid", 74 " truss [-faedDS] [-o file] command [args]"); 75 exit(1); 76 } 77 78 /* 79 * WARNING! "FreeBSD a.out" must be first, or set_etype will not 80 * work correctly. 81 */ 82 struct ex_types { 83 const char *type; 84 void (*enter_syscall)(struct trussinfo *, int); 85 long (*exit_syscall)(struct trussinfo *, int); 86 } ex_types[] = { 87 #ifdef __alpha__ 88 { "FreeBSD ELF", alpha_syscall_entry, alpha_syscall_exit }, 89 #endif 90 #ifdef __amd64__ 91 { "FreeBSD ELF64", amd64_syscall_entry, amd64_syscall_exit }, 92 #endif 93 #ifdef __i386__ 94 { "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit }, 95 { "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit }, 96 { "FreeBSD ELF32", i386_syscall_entry, i386_syscall_exit }, 97 { "Linux ELF", i386_linux_syscall_entry, i386_linux_syscall_exit }, 98 #endif 99 #ifdef __ia64__ 100 { "FreeBSD ELF64", ia64_syscall_entry, ia64_syscall_exit }, 101 #endif 102 #ifdef __sparc64__ 103 { "FreeBSD ELF64", sparc64_syscall_entry, sparc64_syscall_exit }, 104 #endif 105 { 0, 0, 0 }, 106 }; 107 108 /* 109 * Set the execution type. This is called after every exec, and when 110 * a process is first monitored. The procfs pseudo-file "etype" has 111 * the execution module type -- see /proc/curproc/etype for an example. 112 */ 113 114 static struct ex_types * 115 set_etype(struct trussinfo *trussinfo) 116 { 117 struct ex_types *funcs; 118 char etype[24]; 119 char progt[32]; 120 int fd; 121 122 sprintf(etype, "/proc/%d/etype", trussinfo->pid); 123 if ((fd = open(etype, O_RDONLY)) == -1) { 124 strcpy(progt, "FreeBSD a.out"); 125 } else { 126 int len = read(fd, progt, sizeof(progt)); 127 progt[len-1] = '\0'; 128 close(fd); 129 } 130 131 for (funcs = ex_types; funcs->type; funcs++) 132 if (!strcmp(funcs->type, progt)) 133 break; 134 135 if (funcs->type == NULL) { 136 funcs = &ex_types[0]; 137 warn("execution type %s is not supported -- using %s", 138 progt, funcs->type); 139 } 140 return (funcs); 141 } 142 143 char * 144 strsig(int sig) 145 { 146 char *ret; 147 148 ret = NULL; 149 if (sig > 0 && sig < NSIG) { 150 int i; 151 asprintf(&ret, "sig%s", sys_signame[sig]); 152 if (ret == NULL) 153 return (NULL); 154 for (i = 0; ret[i] != '\0'; ++i) 155 ret[i] = toupper(ret[i]); 156 } 157 return (ret); 158 } 159 160 int 161 main(int ac, char **av) 162 { 163 int c; 164 int i; 165 char **command; 166 struct procfs_status pfs; 167 struct ex_types *funcs; 168 int in_exec, sigexit, initial_open; 169 char *fname; 170 struct trussinfo *trussinfo; 171 char *signame; 172 173 in_exec = 0; 174 sigexit = 0; 175 fname = NULL; 176 initial_open = 1; 177 178 /* Initialize the trussinfo struct */ 179 trussinfo = (struct trussinfo *)malloc(sizeof(struct trussinfo)); 180 if (trussinfo == NULL) 181 errx(1, "malloc() failed"); 182 bzero(trussinfo, sizeof(struct trussinfo)); 183 trussinfo->outfile = stderr; 184 185 while ((c = getopt(ac, av, "p:o:faedDS")) != -1) { 186 switch (c) { 187 case 'p': /* specified pid */ 188 trussinfo->pid = atoi(optarg); 189 break; 190 case 'f': /* Follow fork()'s */ 191 trussinfo->flags |= FOLLOWFORKS; 192 break; 193 case 'a': /* Print execve() argument strings. */ 194 trussinfo->flags |= EXECVEARGS; 195 break; 196 case 'e': /* Print execve() environment strings. */ 197 trussinfo->flags |= EXECVEENVS; 198 break; 199 case 'd': /* Absolute timestamps */ 200 trussinfo->flags |= ABSOLUTETIMESTAMPS; 201 break; 202 case 'D': /* Relative timestamps */ 203 trussinfo->flags |= RELATIVETIMESTAMPS; 204 break; 205 case 'o': /* Specified output file */ 206 fname = optarg; 207 break; 208 case 'S': /* Don't trace signals */ 209 trussinfo->flags |= NOSIGS; 210 break; 211 default: 212 usage(); 213 } 214 } 215 216 ac -= optind; av += optind; 217 if ((trussinfo->pid == 0 && ac == 0) || 218 (trussinfo->pid != 0 && ac != 0)) 219 usage(); 220 221 if (fname != NULL) { /* Use output file */ 222 if ((trussinfo->outfile = fopen(fname, "w")) == NULL) 223 errx(1, "cannot open %s", fname); 224 } 225 226 /* 227 * If truss starts the process itself, it will ignore some signals -- 228 * they should be passed off to the process, which may or may not 229 * exit. If, however, we are examining an already-running process, 230 * then we restore the event mask on these same signals. 231 */ 232 233 if (trussinfo->pid == 0) { /* Start a command ourselves */ 234 command = av; 235 trussinfo->pid = setup_and_wait(command); 236 signal(SIGINT, SIG_IGN); 237 signal(SIGTERM, SIG_IGN); 238 signal(SIGQUIT, SIG_IGN); 239 } else { 240 signal(SIGINT, restore_proc); 241 signal(SIGTERM, restore_proc); 242 signal(SIGQUIT, restore_proc); 243 } 244 245 246 /* 247 * At this point, if we started the process, it is stopped waiting to 248 * be woken up, either in exit() or in execve(). 249 */ 250 251 START_TRACE: 252 Procfd = start_tracing( 253 trussinfo->pid, initial_open, 254 S_EXEC | S_SCE | S_SCX | S_CORE | S_EXIT | 255 ((trussinfo->flags & NOSIGS) ? 0 : S_SIG), 256 ((trussinfo->flags & FOLLOWFORKS) ? PF_FORK : 0)); 257 initial_open = 0; 258 if (Procfd == -1) 259 return (0); 260 261 pfs.why = 0; 262 263 funcs = set_etype(trussinfo); 264 /* 265 * At this point, it's a simple loop, waiting for the process to 266 * stop, finding out why, printing out why, and then continuing it. 267 * All of the grunt work is done in the support routines. 268 */ 269 270 clock_gettime(CLOCK_REALTIME, &trussinfo->start_time); 271 272 do { 273 int val = 0; 274 275 if (ioctl(Procfd, PIOCWAIT, &pfs) == -1) 276 warn("PIOCWAIT top of loop"); 277 else { 278 switch(i = pfs.why) { 279 case S_SCE: 280 funcs->enter_syscall(trussinfo, pfs.val); 281 clock_gettime(CLOCK_REALTIME, 282 &trussinfo->before); 283 break; 284 case S_SCX: 285 clock_gettime(CLOCK_REALTIME, 286 &trussinfo->after); 287 /* 288 * This is so we don't get two messages for 289 * an exec -- one for the S_EXEC, and one for 290 * the syscall exit. It also, conveniently, 291 * ensures that the first message printed out 292 * isn't the return-from-syscall used to 293 * create the process. 294 */ 295 if (in_exec) { 296 in_exec = 0; 297 break; 298 } 299 300 if (trussinfo->in_fork && 301 (trussinfo->flags & FOLLOWFORKS)) { 302 int childpid; 303 304 trussinfo->in_fork = 0; 305 childpid = 306 funcs->exit_syscall(trussinfo, 307 pfs.val); 308 309 /* 310 * Fork a new copy of ourself to trace 311 * the child of the original traced 312 * process. 313 */ 314 if (fork() == 0) { 315 trussinfo->pid = childpid; 316 goto START_TRACE; 317 } 318 break; 319 } 320 funcs->exit_syscall(trussinfo, pfs.val); 321 break; 322 case S_SIG: 323 signame = strsig(pfs.val); 324 fprintf(trussinfo->outfile, 325 "SIGNAL %lu (%s)\n", pfs.val, 326 signame == NULL ? "?" : signame); 327 free(signame); 328 sigexit = pfs.val; 329 break; 330 case S_EXIT: 331 fprintf(trussinfo->outfile, 332 "process exit, rval = %lu\n", pfs.val); 333 break; 334 case S_EXEC: 335 funcs = set_etype(trussinfo); 336 in_exec = 1; 337 break; 338 default: 339 fprintf(trussinfo->outfile, 340 "Process stopped because of: %d\n", i); 341 break; 342 } 343 } 344 if (ioctl(Procfd, PIOCCONT, val) == -1) { 345 if (kill(trussinfo->pid, 0) == -1 && errno == ESRCH) 346 break; 347 else 348 warn("PIOCCONT"); 349 } 350 } while (pfs.why != S_EXIT); 351 fflush(trussinfo->outfile); 352 if (sigexit) { 353 struct rlimit rlp; 354 355 rlp.rlim_cur = 0; 356 rlp.rlim_max = 0; 357 setrlimit(RLIMIT_CORE, &rlp); 358 (void) signal(sigexit, SIG_DFL); 359 (void) kill(getpid(), sigexit); 360 } 361 return (0); 362 } 363