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
33 static const char rcsid[] =
34 "$FreeBSD: src/usr.bin/truss/setup.c,v 1.10.2.2 2002/02/15 11:43:51 des Exp $";
38 * Various setup functions for truss. Not the cleanest-written code,
42 #include <sys/param.h>
43 #include <sys/ioctl.h>
44 #include <sys/pioctl.h>
58 static int evflags = 0;
61 * setup_and_wait() is called to start a process. All it really does
62 * is fork(), set itself up to stop on exec or exit, and then exec
63 * the given command. At that point, the child process stops, and
64 * the parent can wake up and deal with it.
68 setup_and_wait(char *command[]) {
69 struct procfs_status pfs;
77 err(1, "fork failed");
79 if (pid == 0) { /* Child */
80 int mask = S_EXEC | S_EXIT;
81 fd = open("/proc/curproc/mem", O_WRONLY);
83 err(2, "cannot open /proc/curproc/mem");
84 fcntl(fd, F_SETFD, 1);
85 if (ioctl(fd, PIOCBIS, mask) == -1)
89 * The PF_LINGER flag tells procfs not to wake up the
90 * process on last close; normally, this is the behaviour
93 if (ioctl(fd, PIOCSFL, flags) == -1)
94 warn("cannot set PF_LINGER");
95 execvp(command[0], command);
97 ioctl(fd, PIOCBIC, ~0);
98 err(4, "execvp %s", command[0]);
100 /* Only in the parent here */
102 if (waitpid(pid, NULL, WNOHANG) != 0) {
104 * Process exited before it got to us -- meaning the exec failed
105 * miserably -- so we just quietly exit.
110 sprintf(buf, "/proc/%d/mem", pid);
111 if ((fd = open(buf, O_RDWR)) == -1)
112 err(5, "cannot open %s", buf);
113 if (ioctl(fd, PIOCWAIT, &pfs) == -1)
115 if (pfs.why == S_EXIT) {
116 fprintf(stderr, "process exited before exec'ing\n");
117 ioctl(fd, PIOCCONT, 0);
126 * start_tracing picks up where setup_and_wait() dropped off -- namely,
127 * it sets the event mask for the given process id. Called for both
128 * monitoring an existing process and when we create our own.
132 start_tracing(int pid, int flags) {
135 struct procfs_status tmp;
136 sprintf(buf, "/proc/%d/mem", pid);
138 fd = open(buf, O_RDWR);
141 * The process may have run away before we could start -- this
142 * happens with SUGID programs. So we need to see if it still
143 * exists before we complain bitterly.
145 if (kill(pid, 0) == -1)
147 err(8, "cannot open %s", buf);
150 if (ioctl(fd, PIOCSTATUS, &tmp) == -1) {
151 err(10, "cannot get procfs status struct");
153 evflags = tmp.events;
155 if (ioctl(fd, PIOCBIS, flags) == -1)
156 err(9, "cannot set procfs event bit mask");
159 * This clears the PF_LINGER set above in setup_and_wait();
160 * if truss happens to die before this, then the process
161 * needs to be woken up via procctl.
164 if (ioctl(fd, PIOCSFL, 0) == -1)
165 warn("cannot clear PF_LINGER");
171 * Restore a process back to it's pre-truss state.
172 * Called for SIGINT, SIGTERM, SIGQUIT. This only
173 * applies if truss was told to monitor an already-existing
177 restore_proc(int signo __unused) {
180 ioctl(Procfd, PIOCBIC, ~0);
182 ioctl(Procfd, PIOCBIS, evflags);