1 /*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright 1997 Sean Eric Fagan
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by Sean Eric Fagan
17 * 4. Neither the name of the author may be used to endorse or promote
18 * products derived from this software without specific prior written
19 * permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #include <sys/cdefs.h>
35 /*
36 * The main module for truss. Surprisingly 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 :).
39 */
40
41 #include <sys/ptrace.h>
42
43 #include <err.h>
44 #include <signal.h>
45 #include <stdbool.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <sysdecode.h>
49 #include <time.h>
50 #include <unistd.h>
51
52 #include "truss.h"
53 #include "extern.h"
54 #include "syscall.h"
55
56 static __dead2 void
usage(void)57 usage(void)
58 {
59 fprintf(stderr, "%s\n%s\n",
60 "usage: truss [-cfaedDHS] [-o file] [-s strsize] -p pid",
61 " truss [-cfaedDHS] [-o file] [-s strsize] command [args]");
62 exit(1);
63 }
64
65 int
main(int ac,char ** av)66 main(int ac, char **av)
67 {
68 struct sigaction sa;
69 struct trussinfo *trussinfo;
70 char *fname;
71 char **command;
72 const char *errstr;
73 pid_t pid;
74 int c;
75
76 fname = NULL;
77
78 /* Initialize the trussinfo struct */
79 trussinfo = (struct trussinfo *)calloc(1, sizeof(struct trussinfo));
80 if (trussinfo == NULL)
81 errx(1, "calloc() failed");
82
83 pid = 0;
84 trussinfo->outfile = stderr;
85 trussinfo->strsize = 32;
86 trussinfo->curthread = NULL;
87 LIST_INIT(&trussinfo->proclist);
88 while ((c = getopt(ac, av, "p:o:facedDs:SH")) != -1) {
89 switch (c) {
90 case 'p': /* specified pid */
91 pid = atoi(optarg);
92 /* make sure i don't trace me */
93 if (pid == getpid()) {
94 errx(2, "attempt to grab self.");
95 }
96 break;
97 case 'f': /* Follow fork()'s */
98 trussinfo->flags |= FOLLOWFORKS;
99 break;
100 case 'a': /* Print execve() argument strings. */
101 trussinfo->flags |= EXECVEARGS;
102 break;
103 case 'c': /* Count number of system calls and time. */
104 trussinfo->flags |= (COUNTONLY | NOSIGS);
105 break;
106 case 'e': /* Print execve() environment strings. */
107 trussinfo->flags |= EXECVEENVS;
108 break;
109 case 'd': /* Absolute timestamps */
110 trussinfo->flags |= ABSOLUTETIMESTAMPS;
111 break;
112 case 'D': /* Relative timestamps */
113 trussinfo->flags |= RELATIVETIMESTAMPS;
114 break;
115 case 'o': /* Specified output file */
116 fname = optarg;
117 break;
118 case 's': /* Specified string size */
119 trussinfo->strsize = (int)strtonum(optarg, 0, INT_MAX,
120 &errstr);
121 if (errstr)
122 errx(1, "maximum string size is %s: %s", errstr, optarg);
123 break;
124 case 'S': /* Don't trace signals */
125 trussinfo->flags |= NOSIGS;
126 break;
127 case 'H':
128 trussinfo->flags |= DISPLAYTIDS;
129 break;
130 default:
131 usage();
132 }
133 }
134
135 ac -= optind; av += optind;
136 if ((pid == 0 && ac == 0) ||
137 (pid != 0 && ac != 0))
138 usage();
139
140 if (fname != NULL) { /* Use output file */
141 /*
142 * Set close-on-exec ('e'), so that the output file is not
143 * shared with the traced process.
144 */
145 if ((trussinfo->outfile = fopen(fname, "we")) == NULL)
146 err(1, "cannot open %s", fname);
147 }
148
149 /*
150 * If truss starts the process itself, it will ignore some signals --
151 * they should be passed off to the process, which may or may not
152 * exit. If, however, we are examining an already-running process,
153 * then we restore the event mask on these same signals.
154 */
155 if (pid == 0) {
156 /* Start a command ourselves */
157 command = av;
158 setup_and_wait(trussinfo, command);
159 signal(SIGINT, SIG_IGN);
160 signal(SIGTERM, SIG_IGN);
161 signal(SIGQUIT, SIG_IGN);
162 } else {
163 sa.sa_handler = restore_proc;
164 sa.sa_flags = 0;
165 sigemptyset(&sa.sa_mask);
166 sigaction(SIGINT, &sa, NULL);
167 sigaction(SIGQUIT, &sa, NULL);
168 sigaction(SIGTERM, &sa, NULL);
169 start_tracing(trussinfo, pid);
170 }
171
172 /*
173 * At this point, if we started the process, it is stopped waiting to
174 * be woken up, either in exit() or in execve().
175 */
176 if (LIST_FIRST(&trussinfo->proclist)->abi == NULL) {
177 /*
178 * If we are not able to handle this ABI, detach from the
179 * process and exit. If we just created a new process to
180 * run a command, kill the new process rather than letting
181 * it run untraced.
182 */
183 if (pid == 0)
184 kill(LIST_FIRST(&trussinfo->proclist)->pid, SIGKILL);
185 ptrace(PT_DETACH, LIST_FIRST(&trussinfo->proclist)->pid, NULL,
186 0);
187 return (1);
188 }
189 ptrace(PT_SYSCALL, LIST_FIRST(&trussinfo->proclist)->pid, (caddr_t)1,
190 0);
191
192 /*
193 * At this point, it's a simple loop, waiting for the process to
194 * stop, finding out why, printing out why, and then continuing it.
195 * All of the grunt work is done in the support routines.
196 */
197 clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
198
199 eventloop(trussinfo);
200
201 if (trussinfo->flags & COUNTONLY)
202 print_summary(trussinfo);
203
204 fflush(trussinfo->outfile);
205
206 return (0);
207 }
208