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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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
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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 1.4 2003/11/04 15:34:41 eirikn 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 ELF", alpha_syscall_entry, alpha_syscall_exit },
90 { "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit },
91 { "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit },
92 { "Linux ELF", i386_linux_syscall_entry, i386_linux_syscall_exit },
98 * Set the execution type. This is called after every exec, and when
99 * a process is first monitored. The procfs pseudo-file "etype" has
100 * the execution module type -- see /proc/curproc/etype for an example.
103 static struct ex_types *
105 struct ex_types *funcs;
110 asprintf(&etype, "%s/%d/etype", procfs_path, pid);
112 err(1, "Out of memory");
113 if ((fd = open(etype, O_RDONLY)) == -1) {
114 strcpy(progt, "FreeBSD a.out");
116 int len = read(fd, progt, sizeof(progt));
122 for (funcs = ex_types; funcs->type; funcs++)
123 if (!strcmp(funcs->type, progt))
126 if (funcs->type == NULL) {
127 funcs = &ex_types[0];
128 warn("Execution type %s is not supported -- using %s\n",
135 main(int ac, char **av) {
138 struct procfs_status pfs;
139 struct ex_types *funcs;
140 struct statfs *mntbuf;
145 /* Check where procfs is mounted if it is mounted */
146 if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
147 err(1, "getmntinfo");
148 for (i = 0; i < mntsize; i++) {
149 if (strcasecmp(mntbuf[i].f_mntfromname, "procfs") == 0) {
150 strlcpy(procfs_path, mntbuf[i].f_mntonname, sizeof(procfs_path));
157 err(1, "You must have a mounted procfs to use truss");
161 while ((c = getopt(ac, av, "p:o:S")) != -1) {
163 case 'p': /* specified pid */
165 if (pid == getpid()) {
166 /* make sure truss doesn't trace itself */
167 fprintf(stderr, "truss: attempt to self trace: %d\n", pid);
171 case 'o': /* Specified output file */
174 case 'S': /* Don't trace signals */
182 ac -= optind; av += optind;
183 if ((pid == 0 && ac == 0) || (pid != 0 && ac != 0))
186 if (fname != NULL) { /* Use output file */
187 if ((outfile = fopen(fname, "w")) == NULL)
188 errx(1, "cannot open %s", fname);
192 * If truss starts the process itself, it will ignore some signals --
193 * they should be passed off to the process, which may or may not
194 * exit. If, however, we are examining an already-running process,
195 * then we restore the event mask on these same signals.
198 if (pid == 0) { /* Start a command ourselves */
200 pid = setup_and_wait(command);
201 signal(SIGINT, SIG_IGN);
202 signal(SIGTERM, SIG_IGN);
203 signal(SIGQUIT, SIG_IGN);
205 signal(SIGINT, restore_proc);
206 signal(SIGTERM, restore_proc);
207 signal(SIGQUIT, restore_proc);
212 * At this point, if we started the process, it is stopped waiting to
213 * be woken up, either in exit() or in execve().
216 Procfd = start_tracing(pid, S_EXEC | S_SCE | S_SCX | S_CORE | S_EXIT |
217 (nosigs ? 0 : S_SIG));
225 * At this point, it's a simple loop, waiting for the process to
226 * stop, finding out why, printing out why, and then continuing it.
227 * All of the grunt work is done in the support routines.
233 if (ioctl(Procfd, PIOCWAIT, &pfs) == -1)
234 warn("PIOCWAIT top of loop");
236 switch(i = pfs.why) {
238 funcs->enter_syscall(pid, pfs.val);
242 * This is so we don't get two messages for an exec -- one
243 * for the S_EXEC, and one for the syscall exit. It also,
244 * conveniently, ensures that the first message printed out
245 * isn't the return-from-syscall used to create the process.
252 funcs->exit_syscall(pid, pfs.val);
255 fprintf(outfile, "SIGNAL %lu\n", pfs.val);
259 fprintf (outfile, "process exit, rval = %lu\n", pfs.val);
266 fprintf (outfile, "Process stopped because of: %d\n", i);
270 if (ioctl(Procfd, PIOCCONT, val) == -1) {
271 if (kill(pid, 0) == -1 && errno == ESRCH)
276 } while (pfs.why != S_EXIT);
279 if (sigexit == SIGQUIT)
281 (void) signal(sigexit, SIG_DFL);
282 (void) kill(getpid(), sigexit);