libltrace.c revision 62a0d390cdcfa42397fa892c8400b59e34e41434
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 if (options.summary) { 92 show_summary(); 93 } 94 if (options.output) { 95 fclose(options.output); 96 options.output = NULL; 97 } 98} 99 100void 101ltrace_init(int argc, char **argv) { 102 struct opt_p_t *opt_p_tmp; 103 104 atexit(normal_exit); 105 signal(SIGINT, signal_exit); /* Detach processes when interrupted */ 106 signal(SIGTERM, signal_exit); /* ... or killed */ 107 108 argv = process_options(argc, argv); 109 init_global_config(); 110 while (opt_F) { 111 /* If filename begins with ~, expand it to the user's home */ 112 /* directory. This does not correctly handle ~yoda, but that */ 113 /* isn't as bad as it seems because the shell will normally */ 114 /* be doing the expansion for us; only the hardcoded */ 115 /* ~/.ltrace.conf should ever use this code. */ 116 if (opt_F->filename[0] == '~') { 117 char path[PATH_MAX]; 118 char *home_dir = getenv("HOME"); 119 if (home_dir) { 120 strncpy(path, home_dir, PATH_MAX - 1); 121 path[PATH_MAX - 1] = '\0'; 122 strncat(path, opt_F->filename + 1, 123 PATH_MAX - strlen(path) - 1); 124 read_config_file(path); 125 } 126 } else { 127 read_config_file(opt_F->filename); 128 } 129 130 struct opt_F_t *next = opt_F->next; 131 if (opt_F->own_filename) 132 free(opt_F->filename); 133 free(opt_F); 134 opt_F = next; 135 } 136 if (command) { 137 /* Check that the binary ABI is supported before 138 * calling execute_program. */ 139 struct ltelf lte = {}; 140 open_elf(<e, command); 141 do_close_elf(<e); 142 143 pid_t pid = execute_program(command, argv); 144 struct Process *proc = open_program(command, pid); 145 if (proc == NULL) { 146 fprintf(stderr, "couldn't open program '%s': %s\n", 147 command, strerror(errno)); 148 exit(EXIT_FAILURE); 149 } 150 151 trace_set_options(proc); 152 continue_process(pid); 153 } 154 opt_p_tmp = opt_p; 155 while (opt_p_tmp) { 156 open_pid(opt_p_tmp->pid); 157 opt_p_tmp = opt_p_tmp->next; 158 } 159} 160 161static int num_ltrace_callbacks[EVENT_MAX]; 162static callback_func * ltrace_callbacks[EVENT_MAX]; 163 164void 165ltrace_add_callback(callback_func func, Event_type type) { 166 ltrace_callbacks[type] = realloc(ltrace_callbacks[type], (num_ltrace_callbacks[type]+1)*sizeof(callback_func)); 167 ltrace_callbacks[type][num_ltrace_callbacks[type]++] = func; 168} 169 170static void 171dispatch_callbacks(Event * ev) { 172 int i; 173 /* Ignoring case 1: signal into a dying tracer */ 174 if (ev->type==EVENT_SIGNAL && 175 exiting && ev->e_un.signum == SIGSTOP) { 176 return; 177 } 178 /* Ignoring case 2: process being born before a clone event */ 179 if (ev->proc && ev->proc->state == STATE_IGNORED) { 180 return; 181 } 182 for (i=0; i<num_ltrace_callbacks[ev->type]; i++) { 183 ltrace_callbacks[ev->type][i](ev); 184 } 185} 186 187void 188ltrace_main(void) { 189 Event * ev; 190 while (1) { 191 ev = next_event(); 192 dispatch_callbacks(ev); 193 handle_event(ev); 194 } 195} 196