platform_bionic/libc/malloc_debug/malloc_debug.h

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Malloc debug rewrite. The major components of the rewrite: - Completely remove the qemu shared library code. Nobody was using it and it appears to have broken at some point. - Adds the ability to enable/disable different options independently. - Adds a new option that can enable the backtrace on alloc/free when a process gets a specific signal. - Adds a new way to enable malloc debug. If a special property is set, and the process has an environment variable set, then debug malloc will be enabled. This allows something that might be a derivative of app_process to be started with an environment variable being enabled. - get_malloc_leak_info() used to return one element for each pointer that had the exact same backtrace. The new version returns information for every one of the pointers with same backtrace. It turns out ddms already automatically coalesces these, so the old method simply hid the fact that there where multiple pointers with the same amount of backtrace. - Moved all of the malloc debug specific code into the library. Nothing related to the malloc debug data structures remains in libc. - Removed the calls to the debug malloc cleanup routine. Instead, I added an atexit call with the debug malloc cleanup routine. This gets around most problems related to the timing of doing the cleanup. The new properties and environment variables: libc.debug.malloc.options Set by option name (such as "backtrace"). Setting this to a bad value will cause a usage statement to be printed to the log. libc.debug.malloc.program Same as before. If this is set, then only the program named will be launched with malloc debug enabled. This is not a complete match, but if any part of the property is in the program name, malloc debug is enabled. libc.debug.malloc.env_enabled If set, then malloc debug is only enabled if the running process has the environment variable LIBC_DEBUG_MALLOC_ENABLE set. Bug: 19145921 Change-Id: I7b0e58cc85cc6d4118173fe1f8627a391b64c0d7
2015-11-17 02:30:32 +01:00
/*
* 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.
*/
#ifndef MALLOC_DEBUG_H
#define MALLOC_DEBUG_H
#include <stdint.h>
#include <private/bionic_malloc_dispatch.h>
// Allocations that require a header include a variable length header.
// This is the order that data structures will be found. If an optional
// part of the header does not exist, the other parts of the header
// will still be in this order.
// Header (Required)
// BacktraceHeader (Optional: For the allocation backtrace)
// BacktraceHeader (Optional: For the free backtrace)
// uint8_t data (Optional: Front guard, will be a multiple of sizeof(uintptr_t))
// allocation data
// uint8_t data (Optional: End guard)
//
// If backtracing is enabled, then both BacktraceHeaders will be present.
//
// In the initialization function, offsets into the header will be set
// for each different header location. The offsets are always from the
// beginning of the Header section.
struct Header {
uint32_t tag;
void* orig_pointer;
size_t size;
size_t usable_size;
size_t real_size() const { return size & ~(1U << 31); }
void set_zygote() { size |= 1U << 31; }
static size_t max_size() { return (1U << 31) - 1; }
} __attribute__((packed));
struct TrackHeader {
Header* prev = nullptr;
Header* next = nullptr;
} __attribute__((packed));
struct BacktraceHeader {
size_t num_frames;
uintptr_t frames[0];
} __attribute__((packed));
constexpr uint32_t DEBUG_TAG = 0x1ee7d00d;
constexpr char LOG_DIVIDER[] = "*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***";
constexpr size_t FREE_TRACK_MEM_BUFFER_SIZE = 4096;
extern const MallocDispatch* g_dispatch;
#endif // MALLOC_DEBUG_H