Merge "Fix which maps to search for globals." am: 7cffd15110 am: 00a95a939e (b570a9ba) · Commits · e / os / android_system_core

libunwindstack/Android.bp

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -58,6 +58,7 @@ cc_library {
	"Elf.cpp",		"Elf.cpp",
	"ElfInterface.cpp",		"ElfInterface.cpp",
	"ElfInterfaceArm.cpp",		"ElfInterfaceArm.cpp",
			"Global.cpp",
	"JitDebug.cpp",		"JitDebug.cpp",
	"Log.cpp",		"Log.cpp",
	"MapInfo.cpp",		"MapInfo.cpp",

libunwindstack/DexFiles.cpp

+8 −32

Original line number	Original line	Diff line number	Diff line
	@@ -43,10 +43,10 @@ struct DEXFileEntry64 {
	uint64_t dex_file;		uint64_t dex_file;
	};		};

	DexFiles::DexFiles(std::shared_ptr<Memory>& memory) : memory_(memory) {}		DexFiles::DexFiles(std::shared_ptr<Memory>& memory) : Global(memory) {}

	DexFiles::DexFiles(std::shared_ptr<Memory>& memory, std::vector<std::string>& search_libs)		DexFiles::DexFiles(std::shared_ptr<Memory>& memory, std::vector<std::string>& search_libs)
	: memory_(memory), search_libs_(search_libs) {}		: Global(memory, search_libs) {}

	DexFiles::~DexFiles() {		DexFiles::~DexFiles() {
	for (auto& entry : files_) {		for (auto& entry : files_) {
	@@ -117,6 +117,11 @@ bool DexFiles::ReadEntry64() {
	return true;		return true;
	}		}

			bool DexFiles::ReadVariableData(uint64_t ptr_offset) {
			entry_addr_ = (this->*read_entry_ptr_func_)(ptr_offset);
			return entry_addr_ != 0;
			}

	void DexFiles::Init(Maps* maps) {		void DexFiles::Init(Maps* maps) {
	if (initialized_) {		if (initialized_) {
	return;		return;
	@@ -124,36 +129,7 @@ void DexFiles::Init(Maps* maps) {
	initialized_ = true;		initialized_ = true;
	entry_addr_ = 0;		entry_addr_ = 0;

	const std::string dex_debug_name("__dex_debug_descriptor");		FindAndReadVariable(maps, "__dex_debug_descriptor");
	for (MapInfo* info : *maps) {
	if (!(info->flags & PROT_READ) \|\| info->offset != 0) {
	continue;
	}

	if (!search_libs_.empty()) {
	bool found = false;
	const char* lib = basename(info->name.c_str());
	for (const std::string& name : search_libs_) {
	if (name == lib) {
	found = true;
	break;
	}
	}
	if (!found) {
	continue;
	}
	}

	Elf* elf = info->GetElf(memory_, true);
	uint64_t ptr;
	// Find first non-empty list (libart might be loaded multiple times).
	if (elf->GetGlobalVariable(dex_debug_name, &ptr) && ptr != 0) {
	entry_addr_ = (this->*read_entry_ptr_func_)(ptr + info->start);
	if (entry_addr_ != 0) {
	break;
	}
	}
	}
	}		}

	DexFile* DexFiles::GetDexFile(uint64_t dex_file_offset, MapInfo* info) {		DexFile* DexFiles::GetDexFile(uint64_t dex_file_offset, MapInfo* info) {

libunwindstack/Global.cpp

0 → 100644

+96 −0

Original line number	Original line	Diff line number	Diff line
			/*
			* Copyright (C) 2018 The Android Open Source Project
			*
			* Licensed under the Apache License, Version 2.0 (the "License");
			* you may not use this file except in compliance with the License.
			* You may obtain a copy of the License at
			*
			* http://www.apache.org/licenses/LICENSE-2.0
			*
			* Unless required by applicable law or agreed to in writing, software
			* distributed under the License is distributed on an "AS IS" BASIS,
			* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
			* See the License for the specific language governing permissions and
			* limitations under the License.
			*/

			#include <stdint.h>
			#include <sys/mman.h>

			#include <string>
			#include <vector>

			#include <unwindstack/Global.h>
			#include <unwindstack/MapInfo.h>
			#include <unwindstack/Maps.h>
			#include <unwindstack/Memory.h>

			namespace unwindstack {

			Global::Global(std::shared_ptr<Memory>& memory) : memory_(memory) {}
			Global::Global(std::shared_ptr<Memory>& memory, std::vector<std::string>& search_libs)
			: memory_(memory), search_libs_(search_libs) {}

			uint64_t Global::GetVariableOffset(MapInfo* info, const std::string& variable) {
			if (!search_libs_.empty()) {
			bool found = false;
			const char* lib = basename(info->name.c_str());
			for (const std::string& name : search_libs_) {
			if (name == lib) {
			found = true;
			break;
			}
			}
			if (!found) {
			return 0;
			}
			}

			Elf* elf = info->GetElf(memory_, true);
			uint64_t ptr;
			// Find first non-empty list (libraries might be loaded multiple times).
			if (elf->GetGlobalVariable(variable, &ptr) && ptr != 0) {
			return ptr + info->start;
			}
			return 0;
			}

			void Global::FindAndReadVariable(Maps* maps, const char* var_str) {
			std::string variable(var_str);
			// When looking for global variables, do not arbitrarily search every
			// readable map. Instead look for a specific pattern that must exist.
			// The pattern should be a readable map, followed by a read-write
			// map with a non-zero offset.
			// For example:
			// f0000-f1000 0 r-- /system/lib/libc.so
			// f1000-f2000 1000 r-x /system/lib/libc.so
			// f2000-f3000 2000 rw- /system/lib/libc.so
			// This also works:
			// f0000-f2000 0 r-- /system/lib/libc.so
			// f2000-f3000 2000 rw- /system/lib/libc.so
			MapInfo* map_start = nullptr;
			for (MapInfo* info : *maps) {
			if (map_start != nullptr) {
			if (map_start->name == info->name) {
			if (info->offset != 0 &&
			(info->flags & (PROT_READ \| PROT_WRITE)) == (PROT_READ \| PROT_WRITE)) {
			uint64_t ptr = GetVariableOffset(map_start, variable);
			if (ptr != 0 && ReadVariableData(ptr)) {
			break;
			} else {
			// Failed to find the global variable, do not bother trying again.
			map_start = nullptr;
			}
			}
			} else {
			map_start = nullptr;
			}
			}
			if (map_start == nullptr && (info->flags & PROT_READ) && info->offset == 0 &&
			!info->name.empty()) {
			map_start = info;
			}
			}
			}

			} // namespace unwindstack

libunwindstack/JitDebug.cpp

+8 −32

Original line number	Original line	Diff line number	Diff line
	@@ -69,10 +69,10 @@ struct JITDescriptor64 {
	uint64_t first_entry;		uint64_t first_entry;
	};		};

	JitDebug::JitDebug(std::shared_ptr<Memory>& memory) : memory_(memory) {}		JitDebug::JitDebug(std::shared_ptr<Memory>& memory) : Global(memory) {}

	JitDebug::JitDebug(std::shared_ptr<Memory>& memory, std::vector<std::string>& search_libs)		JitDebug::JitDebug(std::shared_ptr<Memory>& memory, std::vector<std::string>& search_libs)
	: memory_(memory), search_libs_(search_libs) {}		: Global(memory, search_libs) {}

	JitDebug::~JitDebug() {		JitDebug::~JitDebug() {
	for (auto* elf : elf_list_) {		for (auto* elf : elf_list_) {
	@@ -165,6 +165,11 @@ void JitDebug::SetArch(ArchEnum arch) {
	}		}
	}		}

			bool JitDebug::ReadVariableData(uint64_t ptr) {
			entry_addr_ = (this->*read_descriptor_func_)(ptr);
			return entry_addr_ != 0;
			}

	void JitDebug::Init(Maps* maps) {		void JitDebug::Init(Maps* maps) {
	if (initialized_) {		if (initialized_) {
	return;		return;
	@@ -172,36 +177,7 @@ void JitDebug::Init(Maps* maps) {
	// Regardless of what happens below, consider the init finished.		// Regardless of what happens below, consider the init finished.
	initialized_ = true;		initialized_ = true;

	const std::string descriptor_name("__jit_debug_descriptor");		FindAndReadVariable(maps, "__jit_debug_descriptor");
	for (MapInfo* info : *maps) {
	if (!(info->flags & PROT_READ) \|\| info->offset != 0) {
	continue;
	}

	if (!search_libs_.empty()) {
	bool found = false;
	const char* lib = basename(info->name.c_str());
	for (std::string& name : search_libs_) {
	if (strcmp(name.c_str(), lib) == 0) {
	found = true;
	break;
	}
	}
	if (!found) {
	continue;
	}
	}

	Elf* elf = info->GetElf(memory_, true);
	uint64_t descriptor_addr;
	// Find first non-empty entry (libart might be loaded multiple times).
	if (elf->GetGlobalVariable(descriptor_name, &descriptor_addr) && descriptor_addr != 0) {
	entry_addr_ = (this->*read_descriptor_func_)(descriptor_addr + info->start);
	if (entry_addr_ != 0) {
	break;
	}
	}
	}
	}		}

	Elf* JitDebug::GetElf(Maps* maps, uint64_t pc) {		Elf* JitDebug::GetElf(Maps* maps, uint64_t pc) {

libunwindstack/include/unwindstack/DexFiles.h

+5 −4

Original line number	Original line	Diff line number	Diff line
	@@ -25,16 +25,18 @@
	#include <unordered_map>		#include <unordered_map>
	#include <vector>		#include <vector>

			#include <unwindstack/Global.h>
			#include <unwindstack/Memory.h>

	namespace unwindstack {		namespace unwindstack {

	// Forward declarations.		// Forward declarations.
	class DexFile;		class DexFile;
	class Maps;		class Maps;
	struct MapInfo;		struct MapInfo;
	class Memory;
	enum ArchEnum : uint8_t;		enum ArchEnum : uint8_t;

	class DexFiles {		class DexFiles : public Global {
	public:		public:
	explicit DexFiles(std::shared_ptr<Memory>& memory);		explicit DexFiles(std::shared_ptr<Memory>& memory);
	DexFiles(std::shared_ptr<Memory>& memory, std::vector<std::string>& search_libs);		DexFiles(std::shared_ptr<Memory>& memory, std::vector<std::string>& search_libs);
	@@ -60,8 +62,7 @@ class DexFiles {

	bool ReadEntry64();		bool ReadEntry64();

	std::shared_ptr<Memory> memory_;		bool ReadVariableData(uint64_t ptr_offset) override;
	std::vector<std::string> search_libs_;

	std::mutex lock_;		std::mutex lock_;
	bool initialized_ = false;		bool initialized_ = false;