65e349d6c8
Rather than only updating the maps when a pc can't be found, always update the maps before using them. This avoids issues where the maps change and it could cause a crash reading from a map that has been modified. This assumes that executed code never gets unloaded, or that the code is unloaded so infrequently that it doesn't matter. This happens because the pcs for the backtraces are gathered as the program runs and those pcs are symbolized and made into relative pcs at a later time. Also, add safe reading of the elf data when necessary to avoid any crashes if maps are changing while this is running. Since the MapEntry objects can be deleted, copy the values for the current map in the backtrace code to detect when in our own code instead of keeping a pointer. Bug: 340988785 Test: malloc_debug unit/system tests pass. Test: libmemunreachable tests pass. Change-Id: Ica2ba50a5bcf9e19c7e4033e29a5a67a1847d1a6
103 lines
3.1 KiB
C++
103 lines
3.1 KiB
C++
/*
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* Copyright (C) 2012 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#pragma once
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#include <sys/cdefs.h>
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#include <mutex>
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#include <set>
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#include <string>
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#include <platform/bionic/macros.h>
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class MapEntry {
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public:
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MapEntry() = default;
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MapEntry(uintptr_t start, uintptr_t end, uintptr_t offset, const char* name, size_t name_len,
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int flags)
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: start_(start), end_(end), offset_(offset), name_(name, name_len), flags_(flags) {}
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explicit MapEntry(uintptr_t pc) : start_(pc), end_(pc) {}
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void Init();
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uintptr_t GetLoadBias();
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void SetInvalid() {
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valid_ = false;
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init_ = true;
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load_bias_read_ = true;
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}
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bool valid() { return valid_; }
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uintptr_t start() const { return start_; }
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uintptr_t end() const { return end_; }
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uintptr_t offset() const { return offset_; }
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uintptr_t elf_start_offset() const { return elf_start_offset_; }
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void set_elf_start_offset(uintptr_t elf_start_offset) { elf_start_offset_ = elf_start_offset; }
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const std::string& name() const { return name_; }
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int flags() const { return flags_; }
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private:
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uintptr_t start_;
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uintptr_t end_;
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uintptr_t offset_;
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uintptr_t load_bias_ = 0;
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uintptr_t elf_start_offset_ = 0;
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std::string name_;
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int flags_;
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bool init_ = false;
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bool valid_ = false;
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bool load_bias_read_ = false;
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};
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// Ordering comparator that returns equivalence for overlapping entries
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struct compare_entries {
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bool operator()(const MapEntry* a, const MapEntry* b) const { return a->end() <= b->start(); }
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};
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class MapData {
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public:
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MapData() = default;
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~MapData();
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const MapEntry* find(uintptr_t pc, uintptr_t* rel_pc = nullptr);
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size_t NumMaps() { return entries_.size(); }
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void ReadMaps();
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private:
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std::mutex m_;
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std::set<MapEntry*, compare_entries> entries_;
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void ClearEntries();
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BIONIC_DISALLOW_COPY_AND_ASSIGN(MapData);
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};
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