1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS 22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <errno.h> 30 #include <signal.h> 31 #include <stdint.h> 32 #include <stdlib.h> 33 #include <sys/types.h> 34 #include <unistd.h> 35 36 #include <private/bionic_macros.h> 37 38 #include "BacktraceData.h" 39 #include "Config.h" 40 #include "DebugData.h" 41 #include "debug_log.h" 42 #include "malloc_debug.h" 43 BacktraceData(const Config & config,size_t * offset)44 BacktraceData::BacktraceData(const Config& config, size_t* offset) { 45 size_t hdr_len = sizeof(BacktraceHeader) + sizeof(uintptr_t) * config.backtrace_frames; 46 alloc_offset_ = *offset; 47 *offset += BIONIC_ALIGN(hdr_len, MINIMUM_ALIGNMENT_BYTES); 48 } 49 50 static BacktraceData* g_backtrace_data = nullptr; 51 EnableToggle(int,siginfo_t *,void *)52 static void EnableToggle(int, siginfo_t*, void*) { 53 if (g_backtrace_data->enabled()) { 54 g_backtrace_data->set_enabled(false); 55 } else { 56 g_backtrace_data->set_enabled(true); 57 } 58 } 59 Initialize(const Config & config)60 bool BacktraceData::Initialize(const Config& config) { 61 enabled_ = config.backtrace_enabled; 62 if (config.backtrace_enable_on_signal) { 63 g_backtrace_data = this; 64 65 struct sigaction enable_act; 66 memset(&enable_act, 0, sizeof(enable_act)); 67 68 enable_act.sa_sigaction = EnableToggle; 69 enable_act.sa_flags = SA_RESTART | SA_SIGINFO | SA_ONSTACK; 70 sigemptyset(&enable_act.sa_mask); 71 if (sigaction(config.backtrace_signal, &enable_act, nullptr) != 0) { 72 error_log("Unable to set up backtrace signal enable function: %s", strerror(errno)); 73 return false; 74 } 75 info_log("%s: Run: 'kill -%d %d' to enable backtracing.", getprogname(), 76 config.backtrace_signal, getpid()); 77 } 78 return true; 79 } 80