1 /*
2 * This file is part of ltrace.
3 * Copyright (C) 2011,2012,2013 Petr Machata, Red Hat Inc.
4 * Copyright (C) 2009 Juan Cespedes
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation; either version 2 of the
9 * License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19 * 02110-1301 USA
20 */
21
22 #include "config.h"
23
24 #include <sys/param.h>
25 #include <sys/wait.h>
26 #include <errno.h>
27 #include <limits.h>
28 #include <locale.h>
29 #include <signal.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <unistd.h>
34
35 #include "backend.h"
36 #include "common.h"
37 #include "proc.h"
38 #include "prototype.h"
39 #include "read_config_file.h"
40 #include "summary.h"
41
42 char *command = NULL;
43
44 int exiting = 0; /* =1 if a SIGINT or SIGTERM has been received */
45
46 static enum callback_status
stop_non_p_processes(struct process * proc,void * data)47 stop_non_p_processes(struct process *proc, void *data)
48 {
49 int stop = 1;
50
51 struct opt_p_t *it;
52 for (it = opt_p; it != NULL; it = it->next) {
53 struct process *p_proc = pid2proc(it->pid);
54 if (p_proc == NULL) {
55 printf("stop_non_p_processes: %d terminated?\n", it->pid);
56 continue;
57 }
58 if (p_proc == proc || p_proc->leader == proc->leader) {
59 stop = 0;
60 break;
61 }
62 }
63
64 if (stop) {
65 debug(2, "Sending SIGSTOP to process %u", proc->pid);
66 kill(proc->pid, SIGSTOP);
67 }
68
69 return CBS_CONT;
70 }
71
72 static void
signal_alarm(int sig)73 signal_alarm(int sig) {
74 signal(SIGALRM, SIG_DFL);
75 each_process(NULL, &stop_non_p_processes, NULL);
76 }
77
78 static void
signal_exit(int sig)79 signal_exit(int sig)
80 {
81 if (exiting != 0)
82 return;
83
84 exiting = 1 + !!os_ltrace_exiting_sighandler();
85
86 signal(SIGINT, SIG_IGN);
87 signal(SIGTERM, SIG_IGN);
88 signal(SIGALRM, signal_alarm);
89 //alarm(1);
90 }
91
92 static void
normal_exit(void)93 normal_exit(void)
94 {
95 if (options.summary)
96 show_summary();
97 if (options.output) {
98 fclose(options.output);
99 options.output = NULL;
100 }
101 }
102
103 void
ltrace_init(int argc,char ** argv)104 ltrace_init(int argc, char **argv)
105 {
106 setlocale(LC_ALL, "");
107
108 struct opt_p_t *opt_p_tmp;
109
110 atexit(normal_exit);
111 signal(SIGINT, signal_exit); /* Detach processes when interrupted */
112 signal(SIGTERM, signal_exit); /* ... or killed */
113
114 argv = process_options(argc, argv);
115 init_global_config();
116
117 if (command) {
118 /* Check that the binary ABI is supported before
119 * calling execute_program. */
120 {
121 struct ltelf lte;
122 if (ltelf_init(<e, command) == 0)
123 ltelf_destroy(<e);
124 else
125 exit(EXIT_FAILURE);
126 }
127
128 pid_t pid = execute_program(command, argv);
129 struct process *proc = open_program(command, pid);
130 if (proc == NULL) {
131 fprintf(stderr, "couldn't open program '%s': %s\n",
132 command, strerror(errno));
133 exit(EXIT_FAILURE);
134 }
135
136 trace_set_options(proc);
137 continue_process(pid);
138 }
139 opt_p_tmp = opt_p;
140 while (opt_p_tmp) {
141 open_pid(opt_p_tmp->pid);
142 opt_p_tmp = opt_p_tmp->next;
143 }
144 }
145
146 static int num_ltrace_callbacks[EVENT_MAX];
147 static callback_func * ltrace_callbacks[EVENT_MAX];
148
149 void
ltrace_add_callback(callback_func func,Event_type type)150 ltrace_add_callback(callback_func func, Event_type type) {
151 ltrace_callbacks[type] = realloc(ltrace_callbacks[type], (num_ltrace_callbacks[type]+1)*sizeof(callback_func));
152 ltrace_callbacks[type][num_ltrace_callbacks[type]++] = func;
153 }
154
155 static void
dispatch_callbacks(Event * ev)156 dispatch_callbacks(Event * ev) {
157 int i;
158 /* Ignoring case 1: signal into a dying tracer */
159 if (ev->type==EVENT_SIGNAL &&
160 exiting && ev->e_un.signum == SIGSTOP) {
161 return;
162 }
163 /* Ignoring case 2: process being born before a clone event */
164 if (ev->proc && ev->proc->state == STATE_IGNORED) {
165 return;
166 }
167 for (i=0; i<num_ltrace_callbacks[ev->type]; i++) {
168 ltrace_callbacks[ev->type][i](ev);
169 }
170 }
171
172 void
ltrace_main(void)173 ltrace_main(void) {
174 Event * ev;
175 while (1) {
176 ev = next_event();
177 dispatch_callbacks(ev);
178 handle_event(ev);
179 }
180 }
181