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