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/*
* Copyright (C) 2016 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.
*/
#ifndef _LIBUNWINDSTACK_MAP_INFO_H
#define _LIBUNWINDSTACK_MAP_INFO_H
#include <stdint.h>
#include <atomic>
#include <memory>
#include <mutex>
#include <string>
#include <unwindstack/Elf.h>
namespace unwindstack {
class MemoryFileAtOffset;
struct MapInfo {
MapInfo(MapInfo* prev_map, MapInfo* prev_real_map, uint64_t start, uint64_t end, uint64_t offset,
uint64_t flags, const char* name)
: start(start),
end(end),
offset(offset),
flags(flags),
name(name),
prev_map(prev_map),
prev_real_map(prev_real_map),
load_bias(INT64_MAX),
build_id(0) {
if (prev_real_map != nullptr) prev_real_map->next_real_map = this;
}
MapInfo(MapInfo* prev_map, MapInfo* prev_real_map, uint64_t start, uint64_t end, uint64_t offset,
uint64_t flags, const std::string& name)
: start(start),
end(end),
offset(offset),
flags(flags),
name(name),
prev_map(prev_map),
prev_real_map(prev_real_map),
load_bias(INT64_MAX),
build_id(0) {
if (prev_real_map != nullptr) prev_real_map->next_real_map = this;
}
~MapInfo();
uint64_t start = 0;
uint64_t end = 0;
uint64_t offset = 0;
uint16_t flags = 0;
std::string name;
std::shared_ptr<Elf> elf;
// The offset of the beginning of this mapping to the beginning of the
// ELF file.
// elf_offset == offset - elf_start_offset.
// This value is only non-zero if the offset is non-zero but there is
// no elf signature found at that offset.
uint64_t elf_offset = 0;
// This value is the offset into the file of the map in memory that is the
// start of the elf. This is not equal to offset when the linker splits
// shared libraries into a read-only and read-execute map.
uint64_t elf_start_offset = 0;
MapInfo* prev_map = nullptr;
// This is the previous map that is not empty with a 0 offset. For
// example, this set of maps:
// 1000-2000 r--p 000000 00:00 0 libc.so
// 2000-3000 ---p 000000 00:00 0 libc.so
// 3000-4000 r-xp 003000 00:00 0 libc.so
// The last map's prev_map would point to the 2000-3000 map, while the
// prev_real_map would point to the 1000-2000 map.
MapInfo* prev_real_map = nullptr;
// Same as above but set to point to the next map.
MapInfo* next_real_map = nullptr;
std::atomic_int64_t load_bias;
// This is a pointer to a new'd std::string.
// Using an atomic value means that we don't need to lock and will
// make it easier to move to a fine grained lock in the future.
std::atomic<std::string*> build_id;
// Set to true if the elf file data is coming from memory.
bool memory_backed_elf = false;
// This function guarantees it will never return nullptr.
Elf* GetElf(const std::shared_ptr<Memory>& process_memory, ArchEnum expected_arch);
uint64_t GetLoadBias(const std::shared_ptr<Memory>& process_memory);
Memory* CreateMemory(const std::shared_ptr<Memory>& process_memory);
bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset);
// Returns the raw build id read from the elf data.
const std::string& GetBuildID();
// Returns the printable version of the build id (hex dump of raw data).
std::string GetPrintableBuildID();
inline bool IsBlank() { return offset == 0 && flags == 0 && name.empty(); }
private:
MapInfo(const MapInfo&) = delete;
void operator=(const MapInfo&) = delete;
Memory* GetFileMemory();
bool InitFileMemoryFromPreviousReadOnlyMap(MemoryFileAtOffset* memory);
// Protect the creation of the elf object.
std::mutex mutex_;
};
} // namespace unwindstack
#endif // _LIBUNWINDSTACK_MAP_INFO_H