1 /* 2 * Copyright (C) 2017 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 <android/set_abort_message.h> 30 31 #include <pthread.h> 32 #include <sys/mman.h> 33 34 #include "private/ScopedPthreadMutexLocker.h" 35 36 static pthread_mutex_t g_abort_msg_lock = PTHREAD_MUTEX_INITIALIZER; 37 38 struct abort_msg_t { 39 size_t size; 40 char msg[0]; 41 }; 42 43 abort_msg_t** __abort_message_ptr; // Accessible to __libc_init_common. 44 45 void android_set_abort_message(const char* msg) { 46 ScopedPthreadMutexLocker locker(&g_abort_msg_lock); 47 48 if (__abort_message_ptr == nullptr) { 49 // We must have crashed _very_ early. 50 return; 51 } 52 53 if (*__abort_message_ptr != nullptr) { 54 // We already have an abort message. 55 // Assume that the first crash is the one most worth reporting. 56 return; 57 } 58 59 size_t size = sizeof(abort_msg_t) + strlen(msg) + 1; 60 void* map = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0); 61 if (map == MAP_FAILED) { 62 return; 63 } 64 65 abort_msg_t* new_abort_message = reinterpret_cast<abort_msg_t*>(map); 66 new_abort_message->size = size; 67 strcpy(new_abort_message->msg, msg); 68 *__abort_message_ptr = new_abort_message; 69 } 70