fb141292f4
-gdwarf-5 -fdebug-types-section may produce multiple .debug_info sections. All except one are type units (.debug_types before DWARF v5). When constructing .gdb_index, we should ignore these type units. We use a simple heuristic: the compile unit does not have the SHF_GROUP flag. (This needs to be revisited if people place compile unit .debug_info in COMDAT groups.) This issue manifests as a data race: because an object file may have multiple .debug_info sections, we may concurrently construct `LLDDwarfObj` for the same file in multiple threads. The threads may access `InputSectionBase::data()` concurrently on the same input section. `InputSectionBase::data()` does a lazy uncompress() and rewrites the member variable `rawData`. A thread running zlib `inflate()` (transitively called by uncompress()) on a buffer with `rawData` tampered by another thread may fail with `uncompress failed: zlib error: Z_DATA_ERROR`. Even if no data race occurred in an optimistic run, if there are N .debug_info, one CU entry and its address ranges will be replicated N times. The result .gdb_index can be much larger than a correct one. The new test gdb-index-dwarf5-type-unit.s actually has two compile units. This cannot be produced with regular approaches (it can be produced with -r --unique). This is used to demonstrate that the .gdb_index construction code only considers the last non-SHF_GROUP .debug_info Reviewed By: grimar Differential Revision: https://reviews.llvm.org/D85579
107 lines
3 KiB
C++
107 lines
3 KiB
C++
//===- DWARF.h -----------------------------------------------*- 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
|
|
//
|
|
//===-------------------------------------------------------------------===//
|
|
|
|
#ifndef LLD_ELF_DWARF_H
|
|
#define LLD_ELF_DWARF_H
|
|
|
|
#include "InputFiles.h"
|
|
#include "llvm/ADT/STLExtras.h"
|
|
#include "llvm/DebugInfo/DWARF/DWARFContext.h"
|
|
#include "llvm/Object/ELF.h"
|
|
|
|
namespace lld {
|
|
namespace elf {
|
|
|
|
class InputSection;
|
|
|
|
struct LLDDWARFSection final : public llvm::DWARFSection {
|
|
InputSectionBase *sec = nullptr;
|
|
};
|
|
|
|
template <class ELFT> class LLDDwarfObj final : public llvm::DWARFObject {
|
|
public:
|
|
explicit LLDDwarfObj(ObjFile<ELFT> *obj);
|
|
|
|
void forEachInfoSections(
|
|
llvm::function_ref<void(const llvm::DWARFSection &)> f) const override {
|
|
f(infoSection);
|
|
}
|
|
|
|
InputSection *getInfoSection() const {
|
|
return cast<InputSection>(infoSection.sec);
|
|
}
|
|
|
|
const llvm::DWARFSection &getLoclistsSection() const override {
|
|
return loclistsSection;
|
|
}
|
|
|
|
const llvm::DWARFSection &getRangesSection() const override {
|
|
return rangesSection;
|
|
}
|
|
|
|
const llvm::DWARFSection &getRnglistsSection() const override {
|
|
return rnglistsSection;
|
|
}
|
|
|
|
const llvm::DWARFSection &getStrOffsetsSection() const override {
|
|
return strOffsetsSection;
|
|
}
|
|
|
|
const llvm::DWARFSection &getLineSection() const override {
|
|
return lineSection;
|
|
}
|
|
|
|
const llvm::DWARFSection &getAddrSection() const override {
|
|
return addrSection;
|
|
}
|
|
|
|
const LLDDWARFSection &getGnuPubnamesSection() const override {
|
|
return gnuPubnamesSection;
|
|
}
|
|
|
|
const LLDDWARFSection &getGnuPubtypesSection() const override {
|
|
return gnuPubtypesSection;
|
|
}
|
|
|
|
StringRef getFileName() const override { return ""; }
|
|
StringRef getAbbrevSection() const override { return abbrevSection; }
|
|
StringRef getStrSection() const override { return strSection; }
|
|
StringRef getLineStrSection() const override { return lineStrSection; }
|
|
|
|
bool isLittleEndian() const override {
|
|
return ELFT::TargetEndianness == llvm::support::little;
|
|
}
|
|
|
|
llvm::Optional<llvm::RelocAddrEntry> find(const llvm::DWARFSection &sec,
|
|
uint64_t pos) const override;
|
|
|
|
private:
|
|
template <class RelTy>
|
|
llvm::Optional<llvm::RelocAddrEntry> findAux(const InputSectionBase &sec,
|
|
uint64_t pos,
|
|
ArrayRef<RelTy> rels) const;
|
|
|
|
LLDDWARFSection gnuPubnamesSection;
|
|
LLDDWARFSection gnuPubtypesSection;
|
|
LLDDWARFSection infoSection;
|
|
LLDDWARFSection loclistsSection;
|
|
LLDDWARFSection rangesSection;
|
|
LLDDWARFSection rnglistsSection;
|
|
LLDDWARFSection strOffsetsSection;
|
|
LLDDWARFSection lineSection;
|
|
LLDDWARFSection addrSection;
|
|
StringRef abbrevSection;
|
|
StringRef strSection;
|
|
StringRef lineStrSection;
|
|
};
|
|
|
|
} // namespace elf
|
|
} // namespace lld
|
|
|
|
#endif
|