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/types.h>
42 #include <sys/ptrace.h>
55 #include <machine/reg.h>
63 * setup_and_wait() is called to start a process. All it really does
64 * is fork(), set itself up to stop on exec or exit, and then exec
65 * the given command. At that point, the child process stops, and
66 * the parent can wake up and deal with it.
70 setup_and_wait(char *command[])
77 err(1, "fork failed");
79 if (pid == 0) { /* Child */
80 ptrace(PT_TRACE_ME, 0, 0, 0);
81 execvp(command[0], command);
82 err(1, "execvp %s", command[0]);
85 /* Only in the parent here */
86 if (waitpid(pid, &waitval, 0) < -1) {
87 err(1, "unexpect stop in waitpid");
97 * start_tracing picks up where setup_and_wait() dropped off -- namely,
98 * it sets the event mask for the given process id. Called for both
99 * monitoring an existing process and when we create our own.
103 start_tracing(int pid)
110 ret = ptrace(PT_ATTACH, pid, NULL, 0);
112 } while(ret && retry-- > 0);
114 err(1, "can not attach to target process");
117 if (waitpid(pid, &waitval, 0) < -1)
118 err(1, "Unexpect stop in waitpid");
124 * Restore a process back to it's pre-truss state.
125 * Called for SIGINT, SIGTERM, SIGQUIT. This only
126 * applies if truss was told to monitor an already-existing
130 restore_proc(int signo __unused)
134 /* stop the child so that we can detach */
135 kill(child_pid, SIGSTOP);
136 if (waitpid(child_pid, &waitval, 0) < -1)
137 err(1, "Unexpected stop in waitpid");
139 if (ptrace(PT_DETACH, child_pid, (caddr_t)1, 0) < 0)
140 err(1, "Can not detach the process");
142 kill(child_pid, SIGCONT);
147 * Change curthread member based on lwpid.
148 * If it is a new thread, create a threadinfo structure
151 find_thread(struct trussinfo *info, lwpid_t lwpid)
153 info->curthread = NULL;
154 struct threadinfo *np;
155 SLIST_FOREACH(np, &info->threadlist, entries) {
156 if (np->tid == lwpid) {
157 info->curthread = np;
162 np = (struct threadinfo *)malloc(sizeof(struct threadinfo));
164 errx(1, "malloc() failed");
168 SLIST_INSERT_HEAD(&info->threadlist, np, entries);
169 info->curthread = np;
173 * Start the traced process and wait until it stoped.
174 * Fill trussinfo structure.
175 * When this even returns, the traced process is in stop state.
178 waitevent(struct trussinfo *info)
181 static int pending_signal = 0;
183 ptrace(PT_SYSCALL, info->pid, (caddr_t)1, pending_signal);
186 if (waitpid(info->pid, &waitval, 0) < -1) {
187 err(1, "Unexpected stop in waitpid");
190 if (WIFCONTINUED(waitval)) {
191 info->pr_why = S_NONE;
194 if (WIFEXITED(waitval)) {
195 info->pr_why = S_EXIT;
196 info->pr_data = WEXITSTATUS(waitval);
199 if (WIFSTOPPED(waitval)) {
200 struct ptrace_lwpinfo lwpinfo;
201 ptrace(PT_LWPINFO, info->pid, (caddr_t)&lwpinfo, sizeof(lwpinfo));
202 find_thread(info, lwpinfo.pl_lwpid);
203 switch(WSTOPSIG(waitval)) {
205 info->pr_why = info->curthread->in_syscall?S_SCX:S_SCE;
206 info->curthread->in_syscall = 1 - info->curthread->in_syscall;
209 info->pr_why = S_SIG;
210 info->pr_data = WSTOPSIG(waitval);
211 pending_signal = info->pr_data;
215 if (WIFSIGNALED(waitval)) {
216 info->pr_why = S_EXIT;