2 * Copryight 1997 Sean Eric Fagan
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
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
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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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
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31 * $FreeBSD: src/usr.bin/truss/main.c,v 1.15.2.3 2002/05/16 23:41:23 peter Exp $
32 * $DragonFly: src/usr.bin/truss/main.c,v 1.5 2005/05/28 00:22:04 swildner Exp $
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 :).
41 #include <sys/param.h>
42 #include <sys/ioctl.h>
43 #include <sys/pioctl.h>
44 #include <sys/ucred.h>
45 #include <sys/mount.h>
59 * These should really be parameterized -- I don't like having globals,
60 * but this is the easiest way, right now, to deal with them.
71 fprintf(stderr, "%s\n%s\n",
72 "usage: truss [-S] [-o file] -p pid",
73 " truss [-S] [-o file] command [args]");
78 * WARNING! "FreeBSD a.out" must be first, or set_etype will not
83 void (*enter_syscall)(int, int);
84 void (*exit_syscall)(int, int);
87 { "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit },
88 { "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit },
89 { "Linux ELF", i386_linux_syscall_entry, i386_linux_syscall_exit },
95 * Set the execution type. This is called after every exec, and when
96 * a process is first monitored. The procfs pseudo-file "etype" has
97 * the execution module type -- see /proc/curproc/etype for an example.
100 static struct ex_types *
102 struct ex_types *funcs;
107 asprintf(&etype, "%s/%d/etype", procfs_path, pid);
109 err(1, "Out of memory");
110 if ((fd = open(etype, O_RDONLY)) == -1) {
111 strcpy(progt, "FreeBSD a.out");
113 int len = read(fd, progt, sizeof(progt));
119 for (funcs = ex_types; funcs->type; funcs++)
120 if (!strcmp(funcs->type, progt))
123 if (funcs->type == NULL) {
124 funcs = &ex_types[0];
125 warn("Execution type %s is not supported -- using %s\n",
132 main(int ac, char **av) {
135 struct procfs_status pfs;
136 struct ex_types *funcs;
137 struct statfs *mntbuf;
142 /* Check where procfs is mounted if it is mounted */
143 if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
144 err(1, "getmntinfo");
145 for (i = 0; i < mntsize; i++) {
146 if (strcasecmp(mntbuf[i].f_mntfromname, "procfs") == 0) {
147 strlcpy(procfs_path, mntbuf[i].f_mntonname, sizeof(procfs_path));
154 err(1, "You must have a mounted procfs to use truss");
158 while ((c = getopt(ac, av, "p:o:S")) != -1) {
160 case 'p': /* specified pid */
162 if (pid == getpid()) {
163 /* make sure truss doesn't trace itself */
164 fprintf(stderr, "truss: attempt to self trace: %d\n", pid);
168 case 'o': /* Specified output file */
171 case 'S': /* Don't trace signals */
179 ac -= optind; av += optind;
180 if ((pid == 0 && ac == 0) || (pid != 0 && ac != 0))
183 if (fname != NULL) { /* Use output file */
184 if ((outfile = fopen(fname, "w")) == NULL)
185 errx(1, "cannot open %s", fname);
189 * If truss starts the process itself, it will ignore some signals --
190 * they should be passed off to the process, which may or may not
191 * exit. If, however, we are examining an already-running process,
192 * then we restore the event mask on these same signals.
195 if (pid == 0) { /* Start a command ourselves */
197 pid = setup_and_wait(command);
198 signal(SIGINT, SIG_IGN);
199 signal(SIGTERM, SIG_IGN);
200 signal(SIGQUIT, SIG_IGN);
202 signal(SIGINT, restore_proc);
203 signal(SIGTERM, restore_proc);
204 signal(SIGQUIT, restore_proc);
209 * At this point, if we started the process, it is stopped waiting to
210 * be woken up, either in exit() or in execve().
213 Procfd = start_tracing(pid, S_EXEC | S_SCE | S_SCX | S_CORE | S_EXIT |
214 (nosigs ? 0 : S_SIG));
222 * At this point, it's a simple loop, waiting for the process to
223 * stop, finding out why, printing out why, and then continuing it.
224 * All of the grunt work is done in the support routines.
230 if (ioctl(Procfd, PIOCWAIT, &pfs) == -1)
231 warn("PIOCWAIT top of loop");
233 switch(i = pfs.why) {
235 funcs->enter_syscall(pid, pfs.val);
239 * This is so we don't get two messages for an exec -- one
240 * for the S_EXEC, and one for the syscall exit. It also,
241 * conveniently, ensures that the first message printed out
242 * isn't the return-from-syscall used to create the process.
249 funcs->exit_syscall(pid, pfs.val);
252 fprintf(outfile, "SIGNAL %lu\n", pfs.val);
256 fprintf (outfile, "process exit, rval = %lu\n", pfs.val);
263 fprintf (outfile, "Process stopped because of: %d\n", i);
267 if (ioctl(Procfd, PIOCCONT, val) == -1) {
268 if (kill(pid, 0) == -1 && errno == ESRCH)
273 } while (pfs.why != S_EXIT);
276 if (sigexit == SIGQUIT)
278 (void) signal(sigexit, SIG_DFL);
279 (void) kill(getpid(), sigexit);