From: George Rimar Date: Tue, 16 Jul 2019 11:07:30 +0000 (+0000) Subject: [Object/llvm-readelf/llvm-readobj] - Improve error reporting when e_shstrndx is broken. X-Git-Tag: android-x86-9.0-r1~246 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=14563227452c3f20c5c4ac073e2c17020e826126;p=android-x86%2Fexternal-llvm.git [Object/llvm-readelf/llvm-readobj] - Improve error reporting when e_shstrndx is broken. When e_shstrndx is broken, it is impossible to get a section name. In this patch I improved the error message we show and added tests for Object and for llvm-readelf/llvm-readobj Message was changed in two places: 1) llvm-readelf/llvm-readobj previously used a code from Object/ELF.h, now they have a modified version of it (it has less checks and allows dumping broken things). 2) Code in Object/ELF.h is still used for generic cases. Differential revision: https://reviews.llvm.org/D64714 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@366203 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/include/llvm/Object/ELF.h b/include/llvm/Object/ELF.h index 7bc6dc4620c..cf8e4529bad 100644 --- a/include/llvm/Object/ELF.h +++ b/include/llvm/Object/ELF.h @@ -466,9 +466,10 @@ ELFFile::getSectionStringTable(Elf_Shdr_Range Sections) const { if (!Index) // no section string table. return ""; + // TODO: Test a case when the sh_link of the section with index 0 is broken. if (Index >= Sections.size()) - // TODO: this error is untested. - return createError("invalid section index"); + return createError("section header string table index " + Twine(Index) + + " does not exist"); return getStringTable(&Sections[Index]); } diff --git a/test/Object/invalid.test b/test/Object/invalid.test index 97ebb9f8573..5723c4aef33 100644 --- a/test/Object/invalid.test +++ b/test/Object/invalid.test @@ -536,3 +536,19 @@ ProgramHeaders: FileSize: 0xffff0000 Sections: - Section: .dynamic + +# RUN: yaml2obj --docnum=25 %s -o %t25 +# RUN: not obj2yaml 2>&1 %t25 | FileCheck %s -DFILE=%t25 --check-prefix=INVALID-SHSTRNDX + +# INVALID-SHSTRNDX: Error reading file: [[FILE]]: section header string table index 255 does not exist + +--- !ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_REL + Machine: EM_X86_64 + SHStrNdx: 0xFF +Sections: + - Name: .foo + Type: SHT_PROGBITS diff --git a/test/tools/llvm-readobj/elf-invalid-shstrndx.test b/test/tools/llvm-readobj/elf-invalid-shstrndx.test new file mode 100644 index 00000000000..6dc3b11dfd2 --- /dev/null +++ b/test/tools/llvm-readobj/elf-invalid-shstrndx.test @@ -0,0 +1,26 @@ +# RUN: yaml2obj %s -o %t +# RUN: not llvm-readelf --headers -S 2>&1 %t | FileCheck %s -DFILE=%t --check-prefix=GNU +# RUN: not llvm-readobj --headers -S 2>&1 %t | FileCheck %s -DFILE=%t --check-prefix=LLVM + +# GNU: ELF Header: +# GNU: Section header string table index: 255 +# GNU-NEXT: There are 4 section headers, starting at offset 0x40: +# GNU: Section Headers: +# GNU-NEXT: [Nr] Name +# GNU-EMPTY: +# GNU-NEXT: error: '[[FILE]]': section header string table index 255 does not exist + +# LLVM: ElfHeader { +# LLVM: StringTableSectionIndex: 255 +# LLVM-NEXT: } +# LLVM-NEXT: Sections [ +# LLVM-EMPTY: +# LLVM-NEXT: error: '[[FILE]]': section header string table index 255 does not exist + +--- !ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + Type: ET_REL + Machine: EM_X86_64 + SHStrNdx: 0xFF diff --git a/tools/llvm-readobj/ELFDumper.cpp b/tools/llvm-readobj/ELFDumper.cpp index 589199c009f..4e1cb7d544e 100644 --- a/tools/llvm-readobj/ELFDumper.cpp +++ b/tools/llvm-readobj/ELFDumper.cpp @@ -183,6 +183,8 @@ public: void printELFLinkerOptions() override; + const object::ELFObjectFile *getElfObject() const { return ObjF; }; + private: std::unique_ptr> ELFDumperStyle; @@ -3009,15 +3011,19 @@ static std::string getSectionTypeString(unsigned Arch, unsigned Type) { template static StringRef getSectionName(const typename ELFT::Shdr &Sec, - const ELFFile &Obj, + const ELFObjectFile &ElfObj, ArrayRef Sections) { + const ELFFile &Obj = *ElfObj.getELFFile(); uint32_t Index = Obj.getHeader()->e_shstrndx; if (Index == ELF::SHN_XINDEX) Index = Sections[0].sh_link; if (!Index) // no section string table. return ""; + // TODO: Test a case when the sh_link of the section with index 0 is broken. if (Index >= Sections.size()) - reportError("invalid section index"); + reportError(ElfObj.getFileName(), + createError("section header string table index " + + Twine(Index) + " does not exist")); StringRef Data = toStringRef(unwrapOrError( Obj.template getSectionContentsAsArray(&Sections[Index]))); return unwrapOrError(Obj.getSectionName(&Sec, Data)); @@ -3040,10 +3046,11 @@ void GNUStyle::printSectionHeaders(const ELFO *Obj) { printField(F); OS << "\n"; + const ELFObjectFile *ElfObj = this->dumper()->getElfObject(); size_t SectionIndex = 0; for (const Elf_Shdr &Sec : Sections) { Fields[0].Str = to_string(SectionIndex); - Fields[1].Str = getSectionName(Sec, *Obj, Sections); + Fields[1].Str = getSectionName(Sec, *ElfObj, Sections); Fields[2].Str = getSectionTypeString(Obj->getHeader()->e_machine, Sec.sh_type); Fields[3].Str = @@ -4590,8 +4597,9 @@ void LLVMStyle::printSectionHeaders(const ELFO *Obj) { int SectionIndex = -1; ArrayRef Sections = unwrapOrError(Obj->sections()); + const ELFObjectFile *ElfObj = this->dumper()->getElfObject(); for (const Elf_Shdr &Sec : Sections) { - StringRef Name = getSectionName(Sec, *Obj, Sections); + StringRef Name = getSectionName(Sec, *ElfObj, Sections); DictScope SectionD(W, "Section"); W.printNumber("Index", ++SectionIndex); W.printNumber("Name", Name, Sec.sh_name); diff --git a/tools/llvm-readobj/llvm-readobj.cpp b/tools/llvm-readobj/llvm-readobj.cpp index b6d0493af70..1bd5bb74bf2 100644 --- a/tools/llvm-readobj/llvm-readobj.cpp +++ b/tools/llvm-readobj/llvm-readobj.cpp @@ -371,11 +371,18 @@ namespace opts { namespace llvm { LLVM_ATTRIBUTE_NORETURN void reportError(Twine Msg) { + fouts().flush(); errs() << "\n"; WithColor::error(errs()) << Msg << "\n"; exit(1); } +void reportError(StringRef Input, Error Err) { + if (Input == "-") + Input = ""; + error(createFileError(Input, std::move(Err))); +} + void reportWarning(Twine Msg) { fouts().flush(); errs() << "\n"; @@ -403,12 +410,6 @@ void error(std::error_code EC) { } // namespace llvm -static void reportError(StringRef Input, Error Err) { - if (Input == "-") - Input = ""; - error(createFileError(Input, std::move(Err))); -} - static void reportError(StringRef Input, std::error_code EC) { reportError(Input, errorCodeToError(EC)); } diff --git a/tools/llvm-readobj/llvm-readobj.h b/tools/llvm-readobj/llvm-readobj.h index ac8ced6121f..0e02da4cb84 100644 --- a/tools/llvm-readobj/llvm-readobj.h +++ b/tools/llvm-readobj/llvm-readobj.h @@ -22,6 +22,7 @@ namespace llvm { // Various helper functions. LLVM_ATTRIBUTE_NORETURN void reportError(Twine Msg); + void reportError(StringRef Input, Error Err); void reportWarning(Twine Msg); void warn(llvm::Error Err); void error(std::error_code EC);