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/*
*
* Copyright 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 "symbolizer.h"
#include <map>
#include <memory>
#include <unordered_map>
#include <android-base/logging.h>
#include <base/mem_map.h>
#include <build_id.h>
#include <read_dex_file.h>
#include <read_elf.h>
#include <vdex_file.h>
namespace perfprofd {
namespace {
struct SimpleperfSymbolizer : public Symbolizer {
// For simplicity, we assume non-overlapping symbols.
struct Symbol {
Symbol(std::string_view n, uint64_t l) : name(n), length(l) {}
std::string name;
uint64_t length;
};
using SymbolMap = std::map<uint64_t, Symbol>;
std::string Decode(const std::string& dso, uint64_t address) override {
auto it = dsos.find(dso);
if (it == dsos.end()) {
LoadDso(dso);
it = dsos.find(dso);
DCHECK(it != dsos.end());
}
const SymbolMap& map = it->second;
if (map.empty()) {
return "";
}
auto upper_bound = map.upper_bound(address);
if (upper_bound == map.begin()) {
// Nope, not in the map.
return "";
}
upper_bound--;
if (upper_bound->first + upper_bound->second.length > address) {
// This element covers the given address, return its name.
return upper_bound->second.name;
}
return "";
}
void LoadDso(const std::string& dso) {
// See whether it's an ELF file.
{
SymbolMap elf_data;
auto callback = [&elf_data](const ElfFileSymbol& sym) {
if (sym.is_func) {
if (sym.len == 0) {
LOG(ERROR) << "Symbol size is zero for " << sym.name;
}
elf_data.emplace(sym.vaddr, Symbol(sym.name, sym.len));
}
};
ElfStatus status = ParseSymbolsFromElfFile(dso, BuildId(), callback);
if (status == ElfStatus::NO_ERROR) {
dsos.emplace(dso, std::move(elf_data));
return;
}
}
// See whether it's a vdex file.
{
::art::MemMap::Init();
using VdexFile = ::art::VdexFile;
std::string error_msg;
std::unique_ptr<VdexFile> vdex = VdexFile::Open(dso,
/* writable= */ false,
/* low_4gb= */ false,
/* unquicken= */ false,
&error_msg);
if (vdex != nullptr) {
const uint8_t* cur = nullptr;
std::vector<uint64_t> dex_file_offsets;
const uint8_t* base = vdex->Begin();
for (;;) {
cur = vdex->GetNextDexFileData(cur);
if (cur == nullptr) {
break;
}
dex_file_offsets.push_back(cur - base);
}
if (!dex_file_offsets.empty()) {
std::vector<DexFileSymbol> symbols;
if (ReadSymbolsFromDexFile(dso, dex_file_offsets, &symbols)) {
SymbolMap vdex_data;
for (const DexFileSymbol& symbol : symbols) {
vdex_data.emplace(symbol.offset, Symbol(symbol.name, symbol.len));
}
dsos.emplace(dso, std::move(vdex_data));
LOG(INFO) << "Found " << symbols.size() << " dex symbols in " << dso;
return;
} else {
LOG(WARNING) << "Could not read symbols from dex files in " << dso;
}
} else {
LOG(WARNING) << "Could not find dex files for vdex " << dso;
dsos.emplace(dso, SymbolMap());
}
} else {
LOG(WARNING) << dso << " is not a vdex: " << error_msg;
}
}
// TODO: See whether it's a dex file.
// OK, give up.
LOG(WARNING) << "Could not symbolize " << dso;
dsos.emplace(dso, SymbolMap());
}
bool GetMinExecutableVAddr(const std::string& dso, uint64_t* addr) override {
uint64_t file_offset_of_min_vaddr;
ElfStatus status = ReadMinExecutableVirtualAddressFromElfFile(dso, BuildId(), addr,
&file_offset_of_min_vaddr);
if (status != ElfStatus::NO_ERROR) {
return true;
}
{
::art::MemMap::Init();
using VdexFile = ::art::VdexFile;
std::string error_msg;
std::unique_ptr<VdexFile> vdex = VdexFile::Open(dso,
/* writable= */ false,
/* low_4gb= */ false,
/* unquicken= */ false,
&error_msg);
if (vdex != nullptr) {
*addr = 0u;
return true;
}
}
return false;
}
std::unordered_map<std::string, SymbolMap> dsos;
};
} // namespace
std::unique_ptr<Symbolizer> CreateELFSymbolizer() {
return std::unique_ptr<Symbolizer>(new SimpleperfSymbolizer());
}
} // namespace perfprofd
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