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 "linker_allocator.h" 30 31 #include <stdlib.h> 32 #include <sys/cdefs.h> 33 #include <unistd.h> 34 35 #include "private/libc_logging.h" 36 37 static LinkerMemoryAllocator g_linker_allocator; 38 static pid_t fallback_tid = 0; 39 40 // Used by libdebuggerd_handler to switch allocators during a crash dump, in 41 // case the linker heap is corrupted. Do not use this function. 42 extern "C" void __linker_enable_fallback_allocator() { 43 if (fallback_tid != 0) { 44 __libc_fatal("attempted to use currently-in-use fallback allocator"); 45 } 46 47 fallback_tid = gettid(); 48 } 49 50 extern "C" void __linker_disable_fallback_allocator() { 51 if (fallback_tid == 0) { 52 __libc_fatal("attempted to disable unused fallback allocator"); 53 } 54 55 fallback_tid = 0; 56 } 57 58 static LinkerMemoryAllocator& get_fallback_allocator() { 59 static LinkerMemoryAllocator fallback_allocator; 60 return fallback_allocator; 61 } 62 63 static LinkerMemoryAllocator& get_allocator() { 64 if (__predict_false(fallback_tid) && __predict_false(gettid() == fallback_tid)) { 65 return get_fallback_allocator(); 66 } 67 return g_linker_allocator; 68 } 69 70 void* malloc(size_t byte_count) { 71 return get_allocator().alloc(byte_count); 72 } 73 74 void* calloc(size_t item_count, size_t item_size) { 75 return get_allocator().alloc(item_count*item_size); 76 } 77 78 void* realloc(void* p, size_t byte_count) { 79 return get_allocator().realloc(p, byte_count); 80 } 81 82 void free(void* ptr) { 83 get_allocator().free(ptr); 84 } 85 86