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      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 #ifndef MALLOC_DEBUG_H
     30 #define MALLOC_DEBUG_H
     31 
     32 #include <stdint.h>
     33 
     34 #include <private/bionic_malloc_dispatch.h>
     35 
     36 // Allocations that require a header include a variable length header.
     37 // This is the order that data structures will be found. If an optional
     38 // part of the header does not exist, the other parts of the header
     39 // will still be in this order.
     40 //   Header          (Required)
     41 //   BacktraceHeader (Optional: For the allocation backtrace)
     42 //   uint8_t data    (Optional: Front guard, will be a multiple of MINIMUM_ALIGNMENT_BYTES)
     43 //   allocation data
     44 //   uint8_t data    (Optional: End guard)
     45 //
     46 // If backtracing is enabled, then both BacktraceHeaders will be present.
     47 //
     48 // In the initialization function, offsets into the header will be set
     49 // for each different header location. The offsets are always from the
     50 // beginning of the Header section.
     51 struct Header {
     52   uint32_t tag;
     53   void* orig_pointer;
     54   size_t size;
     55   size_t usable_size;
     56   size_t real_size() const { return size & ~(1U << 31); }
     57   void set_zygote() { size |= 1U << 31; }
     58   static size_t max_size() { return (1U << 31) - 1; }
     59 } __attribute__((packed));
     60 
     61 struct BacktraceHeader {
     62   size_t num_frames;
     63   uintptr_t frames[0];
     64 } __attribute__((packed));
     65 
     66 constexpr uint32_t DEBUG_TAG = 0x1ee7d00d;
     67 constexpr uint32_t DEBUG_FREE_TAG = 0x1cc7dccd;
     68 constexpr char LOG_DIVIDER[] = "*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***";
     69 constexpr size_t FREE_TRACK_MEM_BUFFER_SIZE = 4096;
     70 
     71 extern const MallocDispatch* g_dispatch;
     72 
     73 #endif // MALLOC_DEBUG_H
     74