kicad/thirdparty/sentry-native/external/libunwindstack-ndk/include/unwindstack/MapInfo.h

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8.9 KiB
C++

/*
* 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.
*/
#pragma once
#include <stdint.h>
#include <atomic>
#include <memory>
#include <mutex>
#include <string>
#include <unwindstack/Elf.h>
#include <unwindstack/SharedString.h>
namespace unwindstack {
class MemoryFileAtOffset;
// Represents virtual memory map (as obtained from /proc/*/maps).
//
// Note that we have to be surprisingly careful with memory usage here,
// since in system-wide profiling this data can take considerable space.
// (for example, 400 process * 400 maps * 128 bytes = 20 MB + string data).
class MapInfo {
public:
MapInfo(std::shared_ptr<MapInfo>& prev_map, uint64_t start, uint64_t end, uint64_t offset,
uint64_t flags, SharedString name)
: start_(start),
end_(end),
offset_(offset),
flags_(flags),
name_(name),
elf_fields_(nullptr),
prev_map_(prev_map) {}
MapInfo(uint64_t start, uint64_t end, uint64_t offset, uint64_t flags, SharedString name)
: start_(start),
end_(end),
offset_(offset),
flags_(flags),
name_(name),
elf_fields_(nullptr) {}
static inline std::shared_ptr<MapInfo> Create(std::shared_ptr<MapInfo>& prev_map,
uint64_t start, uint64_t end, uint64_t offset,
uint64_t flags, SharedString name) {
auto map_info = std::make_shared<MapInfo>(prev_map, start, end, offset, flags, name);
if (prev_map) {
prev_map->next_map_ = map_info;
}
return map_info;
}
static inline std::shared_ptr<MapInfo> Create(uint64_t start, uint64_t end, uint64_t offset,
uint64_t flags, SharedString name) {
return std::make_shared<MapInfo>(start, end, offset, flags, name);
}
~MapInfo();
// Cached data for mapped ELF files.
// We allocate this structure lazily since there are much fewer ELFs than maps.
struct ElfFields {
ElfFields() : load_bias_(UINT64_MAX), build_id_(0) {}
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;
std::atomic_uint64_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<SharedString*> build_id_;
// Set to true if the elf file data is coming from memory.
bool memory_backed_elf_ = false;
// Protect the creation of the elf object.
std::mutex elf_mutex_;
};
// True if the file named by this map is not actually readable and the
// elf is using the data in memory.
bool ElfFileNotReadable();
// This is the previous map with the same name that is not empty and 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
// 3000-4000 r-xp 003000 00:00 0 libc.so
// The last map's prev_map would point to the 2000-3000 map, while
// GetPrevRealMap() would point to the 1000-2000 map.
// NOTE: If a map is encountered that has a non-zero offset, or has a
// a name different from the current map, then GetPrevRealMap()
// returns nullptr.
std::shared_ptr<MapInfo> GetPrevRealMap();
// This is the next map with the same name that is not empty and with
// a 0 offset. For the example above, the first map's GetNextRealMap()
// would be the 3000-4000 map.
// NOTE: If a map is encountered that has a non-zero offset, or has a
// a name different from the current map, then GetNextRealMap()
// returns nullptr.
std::shared_ptr<MapInfo> GetNextRealMap();
// This is guaranteed to give out the Elf object associated with the
// object. The invariant is that once the Elf object is set under the
// lock in a MapInfo object it never changes and is not freed until
// the MapInfo object is destructed.
inline Elf* GetElfObj() {
std::lock_guard<std::mutex> guard(elf_mutex());
return elf().get();
}
inline uint64_t start() const { return start_; }
inline void set_start(uint64_t value) { start_ = value; }
inline uint64_t end() const { return end_; }
inline void set_end(uint64_t value) { end_ = value; }
inline uint64_t offset() const { return offset_; }
inline void set_offset(uint64_t value) { offset_ = value; }
inline uint16_t flags() const { return flags_; }
inline void set_flags(uint16_t value) { flags_ = value; }
inline SharedString& name() { return name_; }
inline void set_name(SharedString& value) { name_ = value; }
inline void set_name(const char* value) { name_ = value; }
inline std::shared_ptr<Elf>& elf() { return GetElfFields().elf_; }
inline void set_elf(std::shared_ptr<Elf>& value) { GetElfFields().elf_ = value; }
inline void set_elf(Elf* value) { GetElfFields().elf_.reset(value); }
inline uint64_t elf_offset() { return GetElfFields().elf_offset_; }
inline void set_elf_offset(uint64_t value) { GetElfFields().elf_offset_ = value; }
inline uint64_t elf_start_offset() { return GetElfFields().elf_start_offset_; }
inline void set_elf_start_offset(uint64_t value) { GetElfFields().elf_start_offset_ = value; }
inline std::atomic_uint64_t& load_bias() { return GetElfFields().load_bias_; }
inline void set_load_bias(uint64_t value) { GetElfFields().load_bias_ = value; }
inline std::atomic<SharedString*>& build_id() { return GetElfFields().build_id_; }
inline void set_build_id(SharedString* value) { GetElfFields().build_id_ = value; }
inline bool memory_backed_elf() { return GetElfFields().memory_backed_elf_; }
inline void set_memory_backed_elf(bool value) { GetElfFields().memory_backed_elf_ = value; }
inline std::shared_ptr<MapInfo> prev_map() const { return prev_map_.lock(); }
inline void set_prev_map(std::shared_ptr<MapInfo>& value) { prev_map_ = value; }
inline std::shared_ptr<MapInfo> next_map() const { return next_map_.lock(); }
inline void set_next_map(std::shared_ptr<MapInfo>& value) { next_map_ = value; }
// This function guarantees it will never return nullptr.
Elf* GetElf(const std::shared_ptr<Memory>& process_memory, ArchEnum expected_arch);
// Guaranteed to return the proper value if GetElf() has been called.
uint64_t GetLoadBias();
// Will get the proper value even if GetElf() hasn't been called.
uint64_t GetLoadBias(const std::shared_ptr<Memory>& process_memory);
// This returns the name of the map plus the soname if this particular
// map represents an elf file that is contained inside of another file.
// The format of this soname embedded name is:
// file.apk!libutils.so
// Otherwise, this function only returns the name of the map.
std::string GetFullName();
Memory* CreateMemory(const std::shared_ptr<Memory>& process_memory);
bool GetFunctionName(uint64_t addr, SharedString* name, uint64_t* func_offset);
// Returns the raw build id read from the elf data.
SharedString GetBuildID();
// Used internally, and by tests. It sets the value only if it was not already set.
SharedString SetBuildID(std::string&& new_build_id);
// 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(); }
// Returns elf_fields_. It will create the object if it is null.
ElfFields& GetElfFields();
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& elf_mutex() { return GetElfFields().elf_mutex_; }
uint64_t start_ = 0;
uint64_t end_ = 0;
uint64_t offset_ = 0;
uint16_t flags_ = 0;
SharedString name_;
std::atomic<ElfFields*> elf_fields_;
std::weak_ptr<MapInfo> prev_map_;
std::weak_ptr<MapInfo> next_map_;
};
} // namespace unwindstack