platform_bionic/linker/linker_memory.cpp
Ryan Prichard 083d850b30 Move the linker allocator into libc
Rename LinkerMemoryAllocator -> BionicAllocator
Rename LinkerSmallObjectAllocator -> BionicSmallObjectAllocator

libc and the linker need to share an instance of the allocator for
allocating and freeing dynamic ELF TLS memory (DTVs and segments). The
linker also continues to use this allocator.

Bug: http://b/78026329
Test: /data/nativetest/bionic-unit-tests-static
Test: /data/nativetest64/bionic-unit-tests-static
Test: /data/nativetest/linker-unit-tests/linker-unit-tests32
Test: /data/nativetest64/linker-unit-tests/linker-unit-tests64
Change-Id: I2da037006ddf8041a75f3eba2071a8fcdcc223ce
2019-01-25 15:31:35 -08:00

94 lines
3.1 KiB
C++

/*
* Copyright (C) 2015 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "private/bionic_allocator.h"
#include <stdlib.h>
#include <sys/cdefs.h>
#include <unistd.h>
#include <atomic>
#include <async_safe/log.h>
static BionicAllocator g_bionic_allocator;
static std::atomic<pid_t> fallback_tid(0);
// Used by libdebuggerd_handler to switch allocators during a crash dump, in
// case the linker heap is corrupted. Do not use this function.
extern "C" bool __linker_enable_fallback_allocator() {
pid_t expected = 0;
return fallback_tid.compare_exchange_strong(expected, gettid());
}
extern "C" void __linker_disable_fallback_allocator() {
pid_t previous = fallback_tid.exchange(0);
if (previous == 0) {
async_safe_fatal("attempted to disable unused fallback allocator");
} else if (previous != gettid()) {
async_safe_fatal("attempted to disable fallback allocator in use by another thread (%d)",
previous);
}
}
static BionicAllocator& get_fallback_allocator() {
static BionicAllocator fallback_allocator;
return fallback_allocator;
}
static BionicAllocator& get_allocator() {
if (__predict_false(fallback_tid) && __predict_false(gettid() == fallback_tid)) {
return get_fallback_allocator();
}
return g_bionic_allocator;
}
void* malloc(size_t byte_count) {
return get_allocator().alloc(byte_count);
}
void* calloc(size_t item_count, size_t item_size) {
return get_allocator().alloc(item_count*item_size);
}
void* realloc(void* p, size_t byte_count) {
return get_allocator().realloc(p, byte_count);
}
void* reallocarray(void* p, size_t item_count, size_t item_size) {
size_t byte_count;
if (__builtin_mul_overflow(item_count, item_size, &byte_count)) {
errno = ENOMEM;
return nullptr;
}
return get_allocator().realloc(p, byte_count);
}
void free(void* ptr) {
get_allocator().free(ptr);
}