libltrace.c revision efc9436b1ac30e73347696cf3fcfc9ad3f60772f
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 debug(1, "Received interrupt signal; exiting..."); 78 if (exiting != 0) 79 return; 80 81 exiting = 1 + !!os_ltrace_exiting_sighandler(); 82 83 signal(SIGINT, SIG_IGN); 84 signal(SIGTERM, SIG_IGN); 85 signal(SIGALRM, signal_alarm); 86 //alarm(1); 87} 88 89static void 90normal_exit(void) 91{ 92 output_line(NULL, NULL); 93 if (options.summary) { 94 show_summary(); 95 } 96 if (options.output) { 97 fclose(options.output); 98 options.output = NULL; 99 } 100} 101 102void 103ltrace_init(int argc, char **argv) { 104 struct opt_p_t *opt_p_tmp; 105 106 atexit(normal_exit); 107 signal(SIGINT, signal_exit); /* Detach processes when interrupted */ 108 signal(SIGTERM, signal_exit); /* ... or killed */ 109 110 argv = process_options(argc, argv); 111 init_global_config(); 112 while (opt_F) { 113 /* If filename begins with ~, expand it to the user's home */ 114 /* directory. This does not correctly handle ~yoda, but that */ 115 /* isn't as bad as it seems because the shell will normally */ 116 /* be doing the expansion for us; only the hardcoded */ 117 /* ~/.ltrace.conf should ever use this code. */ 118 if (opt_F->filename[0] == '~') { 119 char path[PATH_MAX]; 120 char *home_dir = getenv("HOME"); 121 if (home_dir) { 122 strncpy(path, home_dir, PATH_MAX - 1); 123 path[PATH_MAX - 1] = '\0'; 124 strncat(path, opt_F->filename + 1, 125 PATH_MAX - strlen(path) - 1); 126 read_config_file(path); 127 } 128 } else { 129 read_config_file(opt_F->filename); 130 } 131 132 struct opt_F_t *next = opt_F->next; 133 if (opt_F->own_filename) 134 free(opt_F->filename); 135 free(opt_F); 136 opt_F = next; 137 } 138 if (command) { 139 /* Check that the binary ABI is supported before 140 * calling execute_program. */ 141 struct ltelf lte = {}; 142 open_elf(<e, command); 143 do_close_elf(<e); 144 145 pid_t pid = execute_program(command, argv); 146 struct Process *proc = open_program(command, pid); 147 if (proc == NULL) { 148 fprintf(stderr, "couldn't open program '%s': %s\n", 149 command, strerror(errno)); 150 exit(EXIT_FAILURE); 151 } 152 153 trace_set_options(proc); 154 continue_process(pid); 155 } 156 opt_p_tmp = opt_p; 157 while (opt_p_tmp) { 158 open_pid(opt_p_tmp->pid); 159 opt_p_tmp = opt_p_tmp->next; 160 } 161} 162 163static int num_ltrace_callbacks[EVENT_MAX]; 164static callback_func * ltrace_callbacks[EVENT_MAX]; 165 166void 167ltrace_add_callback(callback_func func, Event_type type) { 168 ltrace_callbacks[type] = realloc(ltrace_callbacks[type], (num_ltrace_callbacks[type]+1)*sizeof(callback_func)); 169 ltrace_callbacks[type][num_ltrace_callbacks[type]++] = func; 170} 171 172static void 173dispatch_callbacks(Event * ev) { 174 int i; 175 /* Ignoring case 1: signal into a dying tracer */ 176 if (ev->type==EVENT_SIGNAL && 177 exiting && ev->e_un.signum == SIGSTOP) { 178 return; 179 } 180 /* Ignoring case 2: process being born before a clone event */ 181 if (ev->proc && ev->proc->state == STATE_IGNORED) { 182 return; 183 } 184 for (i=0; i<num_ltrace_callbacks[ev->type]; i++) { 185 ltrace_callbacks[ev->type][i](ev); 186 } 187} 188 189void 190ltrace_main(void) { 191 Event * ev; 192 while (1) { 193 ev = next_event(); 194 dispatch_callbacks(ev); 195 handle_event(ev); 196 } 197} 198