Merge "Fix which maps to search for globals." (7cffd151) · Commits · e / os / android_system_core

libunwindstack/Android.bp

+1 −0

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

libunwindstack/DexFiles.cpp

+8 −32

Original line number	Diff line number	Diff line
		@@ -43,10 +43,10 @@ struct DEXFileEntry64 {
		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)
		: memory_(memory), search_libs_(search_libs) {}
		: Global(memory, search_libs) {}

		DexFiles::~DexFiles() {
		for (auto& entry : files_) {
		@@ -117,6 +117,11 @@ bool DexFiles::ReadEntry64() {
		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) {
		if (initialized_) {
		return;
		@@ -124,36 +129,7 @@ void DexFiles::Init(Maps* maps) {
		initialized_ = true;
		entry_addr_ = 0;

		const std::string dex_debug_name("__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;
		}
		}
		}
		FindAndReadVariable(maps, "__dex_debug_descriptor");
		}

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

libunwindstack/Global.cpp

0 → 100644

+96 −0

Original line number	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	Diff line number	Diff line
		@@ -69,10 +69,10 @@ struct JITDescriptor64 {
		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)
		: memory_(memory), search_libs_(search_libs) {}
		: Global(memory, search_libs) {}

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

		const std::string descriptor_name("__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;
		}
		}
		}
		FindAndReadVariable(maps, "__jit_debug_descriptor");
		}

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

libunwindstack/include/unwindstack/DexFiles.h

+5 −4

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

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

		namespace unwindstack {

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

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

		bool ReadEntry64();

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

		std::mutex lock_;
		bool initialized_ = false;