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 #ifndef lint 33 static const char rcsid[] = 34 "$FreeBSD$"; 35 #endif /* not lint */ 36 37 /* 38 * The main module for truss. Suprisingly simple, but, then, the other 39 * files handle the bulk of the work. And, of course, the kernel has to 40 * do a lot of the work :). 41 */ 42 43 #include <sys/param.h> 44 #include <sys/ioctl.h> 45 #include <sys/pioctl.h> 46 #include <sys/time.h> 47 48 #include <err.h> 49 #include <errno.h> 50 #include <fcntl.h> 51 #include <signal.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <time.h> 56 #include <unistd.h> 57 58 #include "truss.h" 59 #include "extern.h" 60 61 /* 62 * It's difficult to parameterize this because it must be 63 * accessible in a signal handler. 64 */ 65 66 int Procfd; 67 68 static __inline void 69 usage(void) 70 { 71 fprintf(stderr, "%s\n%s\n", 72 "usage: truss [-faedDS] [-o file] -p pid", 73 " truss [-faedDS] [-o file] command [args]"); 74 exit(1); 75 } 76 77 /* 78 * WARNING! "FreeBSD a.out" must be first, or set_etype will not 79 * work correctly. 80 */ 81 struct ex_types { 82 const char *type; 83 void (*enter_syscall)(struct trussinfo *, int); 84 int (*exit_syscall)(struct trussinfo *, int); 85 } ex_types[] = { 86 #ifdef __alpha__ 87 { "FreeBSD ELF", alpha_syscall_entry, alpha_syscall_exit }, 88 #endif 89 #ifdef __i386__ 90 { "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit }, 91 { "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit }, 92 { "FreeBSD ELF32", i386_syscall_entry, i386_syscall_exit }, 93 { "Linux ELF", i386_linux_syscall_entry, i386_linux_syscall_exit }, 94 #endif 95 #ifdef __sparc64__ 96 { "FreeBSD ELF64", sparc64_syscall_entry, sparc64_syscall_exit }, 97 #endif 98 { 0, 0, 0 }, 99 }; 100 101 /* 102 * Set the execution type. This is called after every exec, and when 103 * a process is first monitored. The procfs pseudo-file "etype" has 104 * the execution module type -- see /proc/curproc/etype for an example. 105 */ 106 107 static struct ex_types * 108 set_etype(struct trussinfo *trussinfo) { 109 struct ex_types *funcs; 110 char etype[24]; 111 char progt[32]; 112 int fd; 113 114 sprintf(etype, "/proc/%d/etype", trussinfo->pid); 115 if ((fd = open(etype, O_RDONLY)) == -1) { 116 strcpy(progt, "FreeBSD a.out"); 117 } else { 118 int len = read(fd, progt, sizeof(progt)); 119 progt[len-1] = '\0'; 120 close(fd); 121 } 122 123 for (funcs = ex_types; funcs->type; funcs++) 124 if (!strcmp(funcs->type, progt)) 125 break; 126 127 if (funcs->type == NULL) { 128 funcs = &ex_types[0]; 129 warn("Execution type %s is not supported -- using %s\n", 130 progt, funcs->type); 131 } 132 return funcs; 133 } 134 135 int 136 main(int ac, char **av) { 137 int c; 138 int i; 139 char **command; 140 struct procfs_status pfs; 141 struct ex_types *funcs; 142 int in_exec = 0; 143 char *fname = NULL; 144 int sigexit = 0; 145 struct trussinfo *trussinfo; 146 147 /* Initialize the trussinfo struct */ 148 trussinfo = (struct trussinfo *)malloc(sizeof(struct trussinfo)); 149 if (trussinfo == NULL) 150 errx(1, "malloc() failed"); 151 bzero(trussinfo, sizeof(struct trussinfo)); 152 trussinfo->outfile = stderr; 153 154 while ((c = getopt(ac, av, "p:o:faedDS")) != -1) { 155 switch (c) { 156 case 'p': /* specified pid */ 157 trussinfo->pid = atoi(optarg); 158 break; 159 case 'f': /* Follow fork()'s */ 160 trussinfo->flags |= FOLLOWFORKS; 161 break; 162 case 'a': /* Print execve() argument strings. */ 163 trussinfo->flags |= EXECVEARGS; 164 break; 165 case 'e': /* Print execve() environment strings. */ 166 trussinfo->flags |= EXECVEENVS; 167 break; 168 case 'd': /* Absolute timestamps */ 169 trussinfo->flags |= ABSOLUTETIMESTAMPS; 170 break; 171 case 'D': /* Relative timestamps */ 172 trussinfo->flags |= RELATIVETIMESTAMPS; 173 break; 174 case 'o': /* Specified output file */ 175 fname = optarg; 176 break; 177 case 'S': /* Don't trace signals */ 178 trussinfo->flags |= NOSIGS; 179 break; 180 default: 181 usage(); 182 } 183 } 184 185 ac -= optind; av += optind; 186 if ((trussinfo->pid == 0 && ac == 0) || (trussinfo->pid != 0 && ac != 0)) 187 usage(); 188 189 if (fname != NULL) { /* Use output file */ 190 if ((trussinfo->outfile = fopen(fname, "w")) == NULL) 191 errx(1, "cannot open %s", fname); 192 } 193 194 /* 195 * If truss starts the process itself, it will ignore some signals -- 196 * they should be passed off to the process, which may or may not 197 * exit. If, however, we are examining an already-running process, 198 * then we restore the event mask on these same signals. 199 */ 200 201 if (trussinfo->pid == 0) { /* Start a command ourselves */ 202 command = av; 203 trussinfo->pid = setup_and_wait(command); 204 signal(SIGINT, SIG_IGN); 205 signal(SIGTERM, SIG_IGN); 206 signal(SIGQUIT, SIG_IGN); 207 } else { 208 signal(SIGINT, restore_proc); 209 signal(SIGTERM, restore_proc); 210 signal(SIGQUIT, restore_proc); 211 } 212 213 214 /* 215 * At this point, if we started the process, it is stopped waiting to 216 * be woken up, either in exit() or in execve(). 217 */ 218 219 START_TRACE: 220 Procfd = start_tracing( 221 trussinfo->pid, S_EXEC | S_SCE | S_SCX | S_CORE | S_EXIT | 222 ((trussinfo->flags & NOSIGS) ? 0 : S_SIG), 223 ((trussinfo->flags & FOLLOWFORKS) ? PF_FORK : 0)); 224 if (Procfd == -1) 225 return 0; 226 227 pfs.why = 0; 228 229 funcs = set_etype(trussinfo); 230 /* 231 * At this point, it's a simple loop, waiting for the process to 232 * stop, finding out why, printing out why, and then continuing it. 233 * All of the grunt work is done in the support routines. 234 */ 235 236 clock_gettime(CLOCK_REALTIME, &trussinfo->start_time); 237 238 do { 239 int val = 0; 240 241 if (ioctl(Procfd, PIOCWAIT, &pfs) == -1) 242 warn("PIOCWAIT top of loop"); 243 else { 244 switch(i = pfs.why) { 245 case S_SCE: 246 funcs->enter_syscall(trussinfo, pfs.val); 247 clock_gettime(CLOCK_REALTIME, &trussinfo->before); 248 break; 249 case S_SCX: 250 clock_gettime(CLOCK_REALTIME, &trussinfo->after); 251 /* 252 * This is so we don't get two messages for an exec -- one 253 * for the S_EXEC, and one for the syscall exit. It also, 254 * conveniently, ensures that the first message printed out 255 * isn't the return-from-syscall used to create the process. 256 */ 257 258 if (in_exec) { 259 in_exec = 0; 260 break; 261 } 262 263 if (trussinfo->in_fork && (trussinfo->flags & FOLLOWFORKS)) { 264 int childpid; 265 266 trussinfo->in_fork = 0; 267 childpid = funcs->exit_syscall(trussinfo, pfs.val); 268 269 /* 270 * Fork a new copy of ourself to trace the child of the 271 * original traced process. 272 */ 273 if (fork() == 0) { 274 trussinfo->pid = childpid; 275 goto START_TRACE; 276 } 277 break; 278 } 279 funcs->exit_syscall(trussinfo, pfs.val); 280 break; 281 case S_SIG: 282 fprintf(trussinfo->outfile, "SIGNAL %lu\n", pfs.val); 283 sigexit = pfs.val; 284 break; 285 case S_EXIT: 286 fprintf (trussinfo->outfile, "process exit, rval = %lu\n", pfs.val); 287 break; 288 case S_EXEC: 289 funcs = set_etype(trussinfo); 290 in_exec = 1; 291 break; 292 default: 293 fprintf (trussinfo->outfile, "Process stopped because of: %d\n", i); 294 break; 295 } 296 } 297 if (ioctl(Procfd, PIOCCONT, val) == -1) { 298 if (kill(trussinfo->pid, 0) == -1 && errno == ESRCH) 299 break; 300 else 301 warn("PIOCCONT"); 302 } 303 } while (pfs.why != S_EXIT); 304 fflush(trussinfo->outfile); 305 if (sigexit) { 306 if (sigexit == SIGQUIT) 307 exit(sigexit); 308 (void) signal(sigexit, SIG_DFL); 309 (void) kill(getpid(), sigexit); 310 } 311 return 0; 312 } 313