06e73f071a
Summary: The goal of this patch is two-fold. First, it fixes a use-after-free in the construction of the llvm DWARFContext. This happened because the construction code was throwing away the lldb DataExtractors it got while reading the sections (unlike their llvm counterparts, these are also responsible for memory ownership). In most cases this did not matter, because the sections are just slices of the mmapped file data. But this isn't the case for compressed elf sections, in which case the section is decompressed into a heap buffer. A similar thing also happen with object files which are loaded from process memory. The second goal is to make it explicit which sections go into the llvm DWARFContext -- any access to the sections through both DWARF parsers carries a risk of parsing things twice, so it's better if this is a conscious decision. Also, this avoids loading completely irrelevant sections (e.g. .text). At present, the only section that needs to be present in the llvm DWARFContext is the debug_line_str. Using it through both APIs is not a problem, as there is no parsing involved. The first goal is achieved by loading the sections through the existing lldb DWARFContext APIs, which already do the caching. The second by explicitly enumerating the sections we wish to load. Reviewers: JDevlieghere, aprantl Subscribers: lldb-commits Tags: #lldb Differential Revision: https://reviews.llvm.org/D72917
136 lines
4.8 KiB
C++
136 lines
4.8 KiB
C++
//===-- DWARFContext.cpp ----------------------------------------*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "DWARFContext.h"
|
|
|
|
#include "lldb/Core/Section.h"
|
|
|
|
using namespace lldb;
|
|
using namespace lldb_private;
|
|
|
|
static DWARFDataExtractor LoadSection(SectionList *section_list,
|
|
SectionType section_type) {
|
|
if (!section_list)
|
|
return DWARFDataExtractor();
|
|
|
|
auto section_sp = section_list->FindSectionByType(section_type, true);
|
|
if (!section_sp)
|
|
return DWARFDataExtractor();
|
|
|
|
DWARFDataExtractor data;
|
|
section_sp->GetSectionData(data);
|
|
return data;
|
|
}
|
|
|
|
const DWARFDataExtractor &
|
|
DWARFContext::LoadOrGetSection(SectionType main_section_type,
|
|
llvm::Optional<SectionType> dwo_section_type,
|
|
SectionData &data) {
|
|
llvm::call_once(data.flag, [&] {
|
|
if (dwo_section_type && isDwo())
|
|
data.data = LoadSection(m_dwo_section_list, *dwo_section_type);
|
|
else
|
|
data.data = LoadSection(m_main_section_list, main_section_type);
|
|
});
|
|
return data.data;
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadAbbrevData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugAbbrev,
|
|
eSectionTypeDWARFDebugAbbrevDwo, m_data_debug_abbrev);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadArangesData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugAranges, llvm::None,
|
|
m_data_debug_aranges);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadAddrData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugAddr, llvm::None,
|
|
m_data_debug_addr);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadDebugInfoData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugInfo,
|
|
eSectionTypeDWARFDebugInfoDwo, m_data_debug_info);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadLineData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugLine, llvm::None,
|
|
m_data_debug_line);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadLineStrData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugLineStr, llvm::None,
|
|
m_data_debug_line_str);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadLocData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugLoc,
|
|
eSectionTypeDWARFDebugLocDwo, m_data_debug_loc);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadLocListsData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugLocLists,
|
|
eSectionTypeDWARFDebugLocListsDwo,
|
|
m_data_debug_loclists);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadMacroData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugMacro, llvm::None,
|
|
m_data_debug_macro);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadRangesData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugRanges, llvm::None,
|
|
m_data_debug_ranges);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadRngListsData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugRngLists,
|
|
eSectionTypeDWARFDebugRngListsDwo,
|
|
m_data_debug_rnglists);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadStrData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugStr,
|
|
eSectionTypeDWARFDebugStrDwo, m_data_debug_str);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadStrOffsetsData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugStrOffsets,
|
|
eSectionTypeDWARFDebugStrOffsetsDwo,
|
|
m_data_debug_str_offsets);
|
|
}
|
|
|
|
const DWARFDataExtractor &DWARFContext::getOrLoadDebugTypesData() {
|
|
return LoadOrGetSection(eSectionTypeDWARFDebugTypes,
|
|
eSectionTypeDWARFDebugTypesDwo, m_data_debug_types);
|
|
}
|
|
|
|
llvm::DWARFContext &DWARFContext::GetAsLLVM() {
|
|
if (!m_llvm_context) {
|
|
llvm::StringMap<std::unique_ptr<llvm::MemoryBuffer>> section_map;
|
|
uint8_t addr_size = 0;
|
|
auto AddSection = [&](llvm::StringRef name, DWARFDataExtractor data) {
|
|
// Set the address size the first time we see it.
|
|
if (addr_size == 0)
|
|
addr_size = data.GetAddressByteSize();
|
|
|
|
section_map.try_emplace(
|
|
name, llvm::MemoryBuffer::getMemBuffer(toStringRef(data.GetData()),
|
|
name, false));
|
|
};
|
|
|
|
AddSection("debug_line_str", getOrLoadLineStrData());
|
|
|
|
m_llvm_context = llvm::DWARFContext::create(section_map, addr_size);
|
|
}
|
|
return *m_llvm_context;
|
|
}
|