libltrace.c revision 50a42857c740a3bc344aa73569513d14d7c775a2
1/* 2 * This file is part of ltrace. 3 * Copyright (C) 2011,2012 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 <signal.h> 28#include <stdio.h> 29#include <stdlib.h> 30#include <string.h> 31#include <unistd.h> 32 33#include "common.h" 34#include "proc.h" 35#include "read_config_file.h" 36#include "backend.h" 37 38char *command = NULL; 39 40int exiting = 0; /* =1 if a SIGINT or SIGTERM has been received */ 41 42static enum callback_status 43stop_non_p_processes(Process *proc, void *data) 44{ 45 int stop = 1; 46 47 struct opt_p_t *it; 48 for (it = opt_p; it != NULL; it = it->next) { 49 Process * p_proc = pid2proc(it->pid); 50 if (p_proc == NULL) { 51 printf("stop_non_p_processes: %d terminated?\n", it->pid); 52 continue; 53 } 54 if (p_proc == proc || p_proc->leader == proc->leader) { 55 stop = 0; 56 break; 57 } 58 } 59 60 if (stop) { 61 debug(2, "Sending SIGSTOP to process %u", proc->pid); 62 kill(proc->pid, SIGSTOP); 63 } 64 65 return CBS_CONT; 66} 67 68static void 69signal_alarm(int sig) { 70 signal(SIGALRM, SIG_DFL); 71 each_process(NULL, &stop_non_p_processes, NULL); 72} 73 74static void 75signal_exit(int sig) 76{ 77 if (exiting != 0) 78 return; 79 80 exiting = 1 + !!os_ltrace_exiting_sighandler(); 81 82 signal(SIGINT, SIG_IGN); 83 signal(SIGTERM, SIG_IGN); 84 signal(SIGALRM, signal_alarm); 85 //alarm(1); 86} 87 88static void 89normal_exit(void) 90{ 91 output_line(NULL, NULL); 92 if (options.summary) { 93 show_summary(); 94 } 95 if (options.output) { 96 fclose(options.output); 97 options.output = NULL; 98 } 99} 100 101void 102ltrace_init(int argc, char **argv) { 103 struct opt_p_t *opt_p_tmp; 104 105 atexit(normal_exit); 106 signal(SIGINT, signal_exit); /* Detach processes when interrupted */ 107 signal(SIGTERM, signal_exit); /* ... or killed */ 108 109 argv = process_options(argc, argv); 110 init_global_config(); 111 while (opt_F) { 112 /* If filename begins with ~, expand it to the user's home */ 113 /* directory. This does not correctly handle ~yoda, but that */ 114 /* isn't as bad as it seems because the shell will normally */ 115 /* be doing the expansion for us; only the hardcoded */ 116 /* ~/.ltrace.conf should ever use this code. */ 117 if (opt_F->filename[0] == '~') { 118 char path[PATH_MAX]; 119 char *home_dir = getenv("HOME"); 120 if (home_dir) { 121 strncpy(path, home_dir, PATH_MAX - 1); 122 path[PATH_MAX - 1] = '\0'; 123 strncat(path, opt_F->filename + 1, 124 PATH_MAX - strlen(path) - 1); 125 read_config_file(path); 126 } 127 } else { 128 read_config_file(opt_F->filename); 129 } 130 131 struct opt_F_t *next = opt_F->next; 132 if (opt_F->own_filename) 133 free(opt_F->filename); 134 free(opt_F); 135 opt_F = next; 136 } 137 if (command) { 138 /* Check that the binary ABI is supported before 139 * calling execute_program. */ 140 struct ltelf lte = {}; 141 open_elf(<e, command); 142 do_close_elf(<e); 143 144 pid_t pid = execute_program(command, argv); 145 struct Process *proc = open_program(command, pid); 146 if (proc == NULL) { 147 fprintf(stderr, "couldn't open program '%s': %s\n", 148 command, strerror(errno)); 149 exit(EXIT_FAILURE); 150 } 151 152 trace_set_options(proc); 153 continue_process(pid); 154 } 155 opt_p_tmp = opt_p; 156 while (opt_p_tmp) { 157 open_pid(opt_p_tmp->pid); 158 opt_p_tmp = opt_p_tmp->next; 159 } 160} 161 162static int num_ltrace_callbacks[EVENT_MAX]; 163static callback_func * ltrace_callbacks[EVENT_MAX]; 164 165void 166ltrace_add_callback(callback_func func, Event_type type) { 167 ltrace_callbacks[type] = realloc(ltrace_callbacks[type], (num_ltrace_callbacks[type]+1)*sizeof(callback_func)); 168 ltrace_callbacks[type][num_ltrace_callbacks[type]++] = func; 169} 170 171static void 172dispatch_callbacks(Event * ev) { 173 int i; 174 /* Ignoring case 1: signal into a dying tracer */ 175 if (ev->type==EVENT_SIGNAL && 176 exiting && ev->e_un.signum == SIGSTOP) { 177 return; 178 } 179 /* Ignoring case 2: process being born before a clone event */ 180 if (ev->proc && ev->proc->state == STATE_IGNORED) { 181 return; 182 } 183 for (i=0; i<num_ltrace_callbacks[ev->type]; i++) { 184 ltrace_callbacks[ev->type][i](ev); 185 } 186} 187 188void 189ltrace_main(void) { 190 Event * ev; 191 while (1) { 192 ev = next_event(); 193 dispatch_callbacks(ev); 194 handle_event(ev); 195 } 196} 197