[llvm-objcopy] Fill .symtab_shndx section correctly
Differential revision: https://reviews.llvm.org/D60555
llvm-svn: 358278
diff --git a/llvm/tools/llvm-objcopy/ELF/Object.cpp b/llvm/tools/llvm-objcopy/ELF/Object.cpp
index de51851..979ab0a 100644
--- a/llvm/tools/llvm-objcopy/ELF/Object.cpp
+++ b/llvm/tools/llvm-objcopy/ELF/Object.cpp
@@ -486,22 +486,30 @@
}
void SymbolTableSection::prepareForLayout() {
- // Add all potential section indexes before file layout so that the section
- // index section has the approprite size.
- if (SectionIndexTable != nullptr) {
- for (const auto &Sym : Symbols) {
- if (Sym->DefinedIn != nullptr && Sym->DefinedIn->Index >= SHN_LORESERVE)
- SectionIndexTable->addIndex(Sym->DefinedIn->Index);
- else
- SectionIndexTable->addIndex(SHN_UNDEF);
- }
- }
+ // Reserve proper amount of space in section index table, so we can
+ // layout sections correctly. We will fill the table with correct
+ // indexes later in fillShdnxTable.
+ if (SectionIndexTable)
+ SectionIndexTable->reserve(Symbols.size());
// Add all of our strings to SymbolNames so that SymbolNames has the right
// size before layout is decided.
for (auto &Sym : Symbols)
SymbolNames->addString(Sym->Name);
}
+void SymbolTableSection::fillShndxTable() {
+ if (SectionIndexTable == nullptr)
+ return;
+ // Fill section index table with real section indexes. This function must
+ // be called after assignOffsets.
+ for (const auto &Sym : Symbols) {
+ if (Sym->DefinedIn != nullptr && Sym->DefinedIn->Index >= SHN_LORESERVE)
+ SectionIndexTable->addIndex(Sym->DefinedIn->Index);
+ else
+ SectionIndexTable->addIndex(SHN_UNDEF);
+ }
+}
+
const Symbol *SymbolTableSection::getSymbolByIndex(uint32_t Index) const {
if (Symbols.size() <= Index)
error("Invalid symbol index: " + Twine(Index));
@@ -1661,6 +1669,11 @@
assignOffsets();
+ // layoutSections could have modified section indexes, so we need
+ // to fill the index table after assignOffsets.
+ if (Obj.SymbolTable != nullptr)
+ Obj.SymbolTable->fillShndxTable();
+
// Finally now that all offsets and indexes have been set we can finalize any
// remaining issues.
uint64_t Offset = Obj.SHOffset + sizeof(Elf_Shdr);
diff --git a/llvm/tools/llvm-objcopy/ELF/Object.h b/llvm/tools/llvm-objcopy/ELF/Object.h
index 4e0e23e..31e2c65 100644
--- a/llvm/tools/llvm-objcopy/ELF/Object.h
+++ b/llvm/tools/llvm-objcopy/ELF/Object.h
@@ -481,9 +481,14 @@
public:
virtual ~SectionIndexSection() {}
void addIndex(uint32_t Index) {
- Indexes.push_back(Index);
- Size += 4;
+ assert(Size > 0);
+ Indexes.push_back(Index);
}
+
+ void reserve(size_t NumSymbols) {
+ Indexes.reserve(NumSymbols);
+ Size = NumSymbols * 4;
+ }
void setSymTab(SymbolTableSection *SymTab) { Symbols = SymTab; }
void initialize(SectionTableRef SecTable) override;
void finalize() override;
@@ -524,6 +529,7 @@
SectionIndexTable = ShndxTable;
}
const SectionIndexSection *getShndxTable() const { return SectionIndexTable; }
+ void fillShndxTable();
const SectionBase *getStrTab() const { return SymbolNames; }
const Symbol *getSymbolByIndex(uint32_t Index) const;
Symbol *getSymbolByIndex(uint32_t Index);