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
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
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
36 * Various setup functions for truss. Not the cleanest-written code,
40 #include <sys/param.h>
41 #include <sys/ioctl.h>
42 #include <sys/pioctl.h>
57 static int evflags = 0;
60 * setup_and_wait() is called to start a process. All it really does
61 * is fork(), set itself up to stop on exec or exit, and then exec
62 * the given command. At that point, the child process stops, and
63 * the parent can wake up and deal with it.
67 setup_and_wait(char *command[])
69 struct procfs_status pfs;
78 err(1, "fork failed");
80 if (pid == 0) { /* Child */
81 int mask = S_EXEC | S_EXIT;
82 fd = open("/proc/curproc/mem", O_WRONLY);
84 err(2, "cannot open /proc/curproc/mem");
85 fcntl(fd, F_SETFD, 1);
86 if (ioctl(fd, PIOCBIS, mask) == -1)
90 * The PF_LINGER flag tells procfs not to wake up the
91 * process on last close; normally, this is the behaviour
94 if (ioctl(fd, PIOCSFL, flags) == -1)
95 warn("cannot set PF_LINGER");
96 execvp(command[0], command);
98 ioctl(fd, PIOCBIC, ~0);
99 err(4, "execvp %s", command[0]);
101 /* Only in the parent here */
103 if (waitpid(pid, NULL, WNOHANG) != 0) {
105 * Process exited before it got to us -- meaning the exec failed
106 * miserably -- so we just quietly exit.
111 sprintf(buf, "/proc/%d/mem", pid);
113 /* Try 6 times to trace our child, waiting 1/2 second each time */
114 for (loop=6 ;; loop--) {
117 if ((fd = open(buf, O_RDWR)) == -1) {
121 err(5, "cannot open1 %s", buf);
123 if (ioctl(fd, PIOCWAIT, &pfs) == -1) {
129 if (pfs.why == S_EXIT) {
130 warnx("process exited before exec'ing");
131 ioctl(fd, PIOCCONT, 0);
142 * start_tracing picks up where setup_and_wait() dropped off -- namely,
143 * it sets the event mask for the given process id. Called for both
144 * monitoring an existing process and when we create our own.
148 start_tracing(int pid, int failisfatal, int eventflags, int flags)
152 struct procfs_status tmp;
154 sprintf(buf, "/proc/%d/mem", pid);
155 /* usleep(500000); */
157 fd = open(buf, O_RDWR);
160 * The process may have run away before we could start -- this
161 * happens with SUGID programs. So we need to see if it still
162 * exists before we complain bitterly.
164 if (!failisfatal && kill(pid, 0) == -1)
166 err(8, "cannot open2 %s", buf);
169 if (ioctl(fd, PIOCSTATUS, &tmp) == -1) {
170 err(10, "cannot get procfs status struct");
172 evflags = tmp.events;
174 if (ioctl(fd, PIOCBIS, eventflags) == -1)
175 err(9, "cannot set procfs event bit mask");
178 * This clears the PF_LINGER set above in setup_and_wait();
179 * if truss happens to die before this, then the process
180 * needs to be woken up via procctl.
183 if (ioctl(fd, PIOCSFL, flags) == -1)
184 warn("cannot clear PF_LINGER");
190 * Restore a process back to it's pre-truss state.
191 * Called for SIGINT, SIGTERM, SIGQUIT. This only
192 * applies if truss was told to monitor an already-existing
196 restore_proc(int signo __unused) {
198 ioctl(Procfd, PIOCBIC, ~0);
200 ioctl(Procfd, PIOCBIS, evflags);