Factor out the checking of string tables.

This moves the error checking for string tables to getStringTable which returns
an ErrorOr<StringRef>.

This improves error checking, makes it uniform across all string tables and
makes it possible to check them once instead of once per name.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240950 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Rafael Espindola 2015-06-29 14:39:25 +00:00
parent 528a204ab9
commit 9a6c902332
8 changed files with 67 additions and 38 deletions

View File

@ -172,8 +172,8 @@ private:
const Elf_Ehdr *Header;
const Elf_Shdr *SectionHeaderTable;
const Elf_Shdr *dot_shstrtab_sec; // Section header string table.
const Elf_Shdr *dot_strtab_sec; // Symbol header string table.
StringRef DotShstrtab; // Section header string table.
StringRef DotStrtab; // Symbol header string table.
const Elf_Shdr *dot_symtab_sec; // Symbol table section.
const Elf_Shdr *SymbolTableSectionHeaderIndex;
@ -235,7 +235,7 @@ public:
const T *getEntry(uint32_t Section, uint32_t Entry) const;
template <typename T>
const T *getEntry(const Elf_Shdr *Section, uint32_t Entry) const;
ErrorOr<StringRef> getString(const Elf_Shdr *Section, uint32_t Offset) const;
ErrorOr<StringRef> getStringTable(const Elf_Shdr *Section) const;
const char *getDynamicString(uintX_t Offset) const;
ErrorOr<StringRef> getSymbolVersion(const Elf_Shdr *section,
const Elf_Sym *Symb,
@ -371,8 +371,7 @@ public:
///
/// \p SymTab is used to lookup the string table to use to get the symbol's
/// name.
ErrorOr<StringRef> getSymbolName(const Elf_Shdr *StrTab,
const Elf_Sym *Symb) const;
ErrorOr<StringRef> getSymbolName(StringRef StrTab, const Elf_Sym *Symb) const;
ErrorOr<StringRef> getSectionName(const Elf_Shdr *Section) const;
uint64_t getSymbolIndex(const Elf_Sym *sym) const;
ErrorOr<ArrayRef<uint8_t> > getSectionContents(const Elf_Shdr *Sec) const;
@ -545,15 +544,6 @@ ELFFile<ELFT>::getRelocationSymbol(const Elf_Shdr *Sec, const RelT *Rel) const {
SymTable, getEntry<Elf_Sym>(SymTable, Rel->getSymbol(isMips64EL())));
}
// Verify that the last byte in the string table in a null.
template <class ELFT>
void ELFFile<ELFT>::VerifyStrTab(const Elf_Shdr *sh) const {
const char *strtab = (const char *)base() + sh->sh_offset;
if (strtab[sh->sh_size - 1] != 0)
// FIXME: Proper error handling.
report_fatal_error("String table must end with a null terminator!");
}
template <class ELFT>
uint64_t ELFFile<ELFT>::getNumSections() const {
assert(Header && "Header not initialized!");
@ -577,8 +567,7 @@ typename ELFFile<ELFT>::uintX_t ELFFile<ELFT>::getStringTableIndex() const {
template <class ELFT>
ELFFile<ELFT>::ELFFile(StringRef Object, std::error_code &EC)
: Buf(Object), SectionHeaderTable(nullptr), dot_shstrtab_sec(nullptr),
dot_strtab_sec(nullptr), dot_symtab_sec(nullptr),
: Buf(Object), SectionHeaderTable(nullptr), dot_symtab_sec(nullptr),
SymbolTableSectionHeaderIndex(nullptr), dot_gnu_version_sec(nullptr),
dot_gnu_version_r_sec(nullptr), dot_gnu_version_d_sec(nullptr),
dt_soname(nullptr) {
@ -626,15 +615,18 @@ ELFFile<ELFT>::ELFFile(StringRef Object, std::error_code &EC)
}
SymbolTableSectionHeaderIndex = &Sec;
break;
case ELF::SHT_SYMTAB:
case ELF::SHT_SYMTAB: {
if (dot_symtab_sec) {
// More than one .symtab!
EC = object_error::parse_failed;
return;
}
dot_symtab_sec = &Sec;
dot_strtab_sec = getSection(Sec.sh_link);
break;
ErrorOr<StringRef> SymtabOrErr = getStringTable(getSection(Sec.sh_link));
if ((EC = SymtabOrErr.getError()))
return;
DotStrtab = *SymtabOrErr;
} break;
case ELF::SHT_DYNSYM: {
if (DynSymRegion.Addr) {
// More than one .dynsym!
@ -688,11 +680,11 @@ ELFFile<ELFT>::ELFFile(StringRef Object, std::error_code &EC)
}
// Get string table sections.
dot_shstrtab_sec = getSection(getStringTableIndex());
if (dot_shstrtab_sec) {
// Verify that the last byte in the string table in a null.
VerifyStrTab(dot_shstrtab_sec);
}
ErrorOr<StringRef> SymtabOrErr =
getStringTable(getSection(getStringTableIndex()));
if ((EC = SymtabOrErr.getError()))
return;
DotShstrtab = *SymtabOrErr;
// Build symbol name side-mapping if there is one.
if (SymbolTableSectionHeaderIndex) {
@ -865,13 +857,18 @@ ELFFile<ELFT>::getSection(uint32_t index) const {
}
template <class ELFT>
ErrorOr<StringRef> ELFFile<ELFT>::getString(const Elf_Shdr *Section,
ELF::Elf32_Word Offset) const {
ErrorOr<StringRef>
ELFFile<ELFT>::getStringTable(const Elf_Shdr *Section) const {
if (Section->sh_type != ELF::SHT_STRTAB)
return object_error::parse_failed;
if (Offset >= Section->sh_size)
uint64_t Offset = Section->sh_offset;
uint64_t Size = Section->sh_size;
if (Offset + Size > Buf.size())
return object_error::parse_failed;
return StringRef((const char *)base() + Section->sh_offset + Offset);
StringRef Data((const char *)base() + Section->sh_offset, Size);
if (Data[Size - 1] != '\0')
return object_error::string_table_non_null_end;
return Data;
}
template <class ELFT>
@ -884,7 +881,7 @@ const char *ELFFile<ELFT>::getDynamicString(uintX_t Offset) const {
template <class ELFT>
ErrorOr<StringRef>
ELFFile<ELFT>::getStaticSymbolName(const Elf_Sym *Symb) const {
return getSymbolName(dot_strtab_sec, Symb);
return getSymbolName(DotStrtab, Symb);
}
template <class ELFT>
@ -902,27 +899,40 @@ ErrorOr<StringRef> ELFFile<ELFT>::getSymbolName(const Elf_Sym *Symb,
}
template <class ELFT>
ErrorOr<StringRef> ELFFile<ELFT>::getSymbolName(const Elf_Shdr *StrTab,
ErrorOr<StringRef> ELFFile<ELFT>::getSymbolName(StringRef StrTab,
const Elf_Sym *Sym) const {
return getString(StrTab, Sym->st_name);
uint32_t Offset = Sym->st_name;
if (Offset >= StrTab.size())
return object_error::parse_failed;
return StringRef(StrTab.data() + Offset);
}
template <class ELFT>
ErrorOr<StringRef>
ELFFile<ELFT>::getSectionName(const Elf_Shdr *Section) const {
return getString(dot_shstrtab_sec, Section->sh_name);
uint32_t Offset = Section->sh_name;
if (Offset >= DotShstrtab.size())
return object_error::parse_failed;
return StringRef(DotShstrtab.data() + Offset);
}
template <class ELFT>
ErrorOr<StringRef> ELFFile<ELFT>::getSymbolVersion(const Elf_Shdr *section,
const Elf_Sym *symb,
bool &IsDefault) const {
StringRef StrTab;
if (section) {
ErrorOr<StringRef> StrTabOrErr = getStringTable(section);
if (std::error_code EC = StrTabOrErr.getError())
return EC;
StrTab = *StrTabOrErr;
}
// Handle non-dynamic symbols.
if (section != DynSymRegion.Addr && section != nullptr) {
// Non-dynamic symbols can have versions in their names
// A name of the form 'foo@V1' indicates version 'V1', non-default.
// A name of the form 'foo@@V2' indicates version 'V2', default version.
ErrorOr<StringRef> SymName = getSymbolName(section, symb);
ErrorOr<StringRef> SymName = getSymbolName(StrTab, symb);
if (!SymName)
return SymName;
StringRef Name = *SymName;

View File

@ -27,6 +27,7 @@ enum class object_error {
invalid_file_type,
parse_failed,
unexpected_eof,
string_table_non_null_end,
bitcode_section_not_found,
macho_small_load_command,
macho_load_segment_too_many_sections,

View File

@ -41,6 +41,8 @@ std::string _object_error_category::message(int EV) const {
return "Invalid data was encountered while parsing the file";
case object_error::unexpected_eof:
return "The end of the file was unexpectedly encountered";
case object_error::string_table_non_null_end:
return "String table must end with a null terminator";
case object_error::bitcode_section_not_found:
return "Bitcode section not found in object file";
case object_error::macho_small_load_command:

Binary file not shown.

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@ -1,5 +1,6 @@
RUN: not llvm-dwarfdump %p/Inputs/invalid-bad-rel-type.elf 2>&1 | FileCheck %s
RUN: not llvm-objdump -s %p/Inputs/invalid-strtab-type.elf 2>&1 | FileCheck %s
RUN: not llvm-objdump -s %p/Inputs/invalid-strtab-size.elf 2>&1 | FileCheck %s
CHECK: Invalid data was encountered while parsing the file
RUN: not llvm-objdump -s %p/Inputs/invalid-strtab-non-null.elf 2>&1 | FileCheck --check-prefix=NON-NULL %s

View File

@ -324,7 +324,11 @@ static std::error_code getRelocationValueString(const ELFObjectFile<ELFT> *Obj,
const Elf_Shdr *SymTab = EF.getSection(sec->sh_link);
assert(SymTab->sh_type == ELF::SHT_SYMTAB ||
SymTab->sh_type == ELF::SHT_DYNSYM);
const Elf_Shdr *StrTab = EF.getSection(SymTab->sh_link);
const Elf_Shdr *StrTabSec = EF.getSection(SymTab->sh_link);
ErrorOr<StringRef> StrTabOrErr = EF.getStringTable(StrTabSec);
if (std::error_code EC = StrTabOrErr.getError())
return EC;
StringRef StrTab = *StrTabOrErr;
uint8_t type;
StringRef res;
int64_t addend = 0;

View File

@ -757,8 +757,11 @@ void ELFDumper<ELFT>::printRelocation(const Elf_Shdr *Sec,
TargetName = SecName.get();
} else if (Sym.first) {
const Elf_Shdr *SymTable = Sym.first;
const Elf_Shdr *StrTable = Obj->getSection(SymTable->sh_link);
TargetName = errorOrDefault(Obj->getSymbolName(StrTable, Sym.second));
const Elf_Shdr *StrTableSec = Obj->getSection(SymTable->sh_link);
ErrorOr<StringRef> StrTableOrErr = Obj->getStringTable(StrTableSec);
if (!error(StrTableOrErr.getError()))
TargetName =
errorOrDefault(Obj->getSymbolName(*StrTableOrErr, Sym.second));
}
if (opts::ExpandRelocs) {

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@ -183,7 +183,11 @@ std::error_code ELFDumper<ELFT>::dumpRelocation(const Elf_Shdr *Shdr,
return obj2yaml_error::success;
const Elf_Shdr *SymTab = NamePair.first;
const Elf_Shdr *StrTab = Obj.getSection(SymTab->sh_link);
const Elf_Shdr *StrTabSec = Obj.getSection(SymTab->sh_link);
ErrorOr<StringRef> StrTabOrErr = Obj.getStringTable(StrTabSec);
if (std::error_code EC = StrTabOrErr.getError())
return EC;
StringRef StrTab = *StrTabOrErr;
ErrorOr<StringRef> NameOrErr = Obj.getSymbolName(StrTab, NamePair.second);
if (std::error_code EC = NameOrErr.getError())
@ -302,7 +306,11 @@ ErrorOr<ELFYAML::Group *> ELFDumper<ELFT>::dumpGroup(const Elf_Shdr *Shdr) {
// Get sh_info which is the signature.
const Elf_Sym *symbol = Obj.getSymbol(Shdr->sh_info);
const Elf_Shdr *symtab = Obj.getSection(Shdr->sh_link);
const Elf_Shdr *StrTab = Obj.getSection(symtab->sh_link);
const Elf_Shdr *StrTabSec = Obj.getSection(symtab->sh_link);
ErrorOr<StringRef> StrTabOrErr = Obj.getStringTable(StrTabSec);
if (std::error_code EC = StrTabOrErr.getError())
return EC;
StringRef StrTab = *StrTabOrErr;
auto sectionContents = Obj.getSectionContents(Shdr);
if (std::error_code ec = sectionContents.getError())
return ec;