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Differential D13024

[llvm-readobj] Avoid SEGFAULT if a requested symbol section is absent
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Authored by ikudrin on Sep 21 2015, 8:39 AM.

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Summary

Some files can have no dynamic symbols section. Others can even have no regular symbol section. The tool shouldn't crash if it's requested to show such sections.

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ikudrin updated this revision to Diff 35259.Sep 21 2015, 8:39 AM

ikudrin retitled this revision from to [llvm-readobj] Avoid SEGFAULT if a requested symbol section is absent.

ikudrin updated this object.

ikudrin added a reviewer: • rafael.

ikudrin added a subscriber: llvm-commits.

LGTM

This revision is now accepted and ready to land.Sep 21 2015, 8:54 AM

Could you please apply this patch as I don't have write permissions?

r248194

Thank you a lot!

Revision Contents

Path

Size

test/

Object/

readobj-absent.test

2 lines

tools/

llvm-readobj/

2 lines

Diff 35259

test/Object/readobj-absent.test

This file was added.

				// Don't crash if required information is absent
				RUN: llvm-readobj -dyn-symbols %p/Inputs/trivial-object-test.elf-x86-64

tools/llvm-readobj/ELFDumper.cpp

	Show First 20 Lines • Show All 1,146 Lines • ▼ Show 20 Lines		OS << W.hex(Rel.r_offset) << " " << RelocName << " "
	<< (TargetName.size() > 0 ? TargetName : "-") << " "			<< (TargetName.size() > 0 ? TargetName : "-") << " "
	<< W.hex(Rel.r_addend) << "\n";			<< W.hex(Rel.r_addend) << "\n";
	}			}
	}			}

	template<class ELFT>			template<class ELFT>
	void ELFDumper<ELFT>::printSymbolsHelper(bool IsDynamic) {			void ELFDumper<ELFT>::printSymbolsHelper(bool IsDynamic) {
	const Elf_Shdr *Symtab = (IsDynamic) ? DotDynSymSec : DotSymtabSec;			const Elf_Shdr *Symtab = (IsDynamic) ? DotDynSymSec : DotSymtabSec;
				if (!Symtab)
				return;
	ErrorOr<StringRef> StrTableOrErr = Obj->getStringTableForSymtab(*Symtab);			ErrorOr<StringRef> StrTableOrErr = Obj->getStringTableForSymtab(*Symtab);
	error(StrTableOrErr.getError());			error(StrTableOrErr.getError());
	StringRef StrTable = *StrTableOrErr;			StringRef StrTable = *StrTableOrErr;
	for (const Elf_Sym &Sym : Obj->symbols(Symtab))			for (const Elf_Sym &Sym : Obj->symbols(Symtab))
	printSymbol(&Sym, Symtab, StrTable, IsDynamic);			printSymbol(&Sym, Symtab, StrTable, IsDynamic);
	}			}

	template<class ELFT>			template<class ELFT>
	▲ Show 20 Lines • Show All 890 Lines • Show Last 20 Lines