From c51c1b3754e8d8c006989e87a6093fd02989294f Mon Sep 17 00:00:00 2001 From: George Rimar Date: Mon, 5 Aug 2019 13:54:35 +0000 Subject: [PATCH] [yaml2obj] - Allow overriding sh_entsize for SHT_GNU_versym sections. This allows to write a test case for one of untested errors in llvm/Object/ELF.h. I did it in this patch to demonstrate. Differential revision: https://reviews.llvm.org/D65394 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@367860 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Object/ELF.h | 5 +++-- test/Object/invalid.test | 25 ++++++++++++++++++++++ test/tools/yaml2obj/versym-section.yaml | 28 ++++++++++++++++++++++--- tools/yaml2obj/yaml2elf.cpp | 2 +- 4 files changed, 54 insertions(+), 6 deletions(-) diff --git a/include/llvm/Object/ELF.h b/include/llvm/Object/ELF.h index aa0864edb78..6febbc7c8de 100644 --- a/include/llvm/Object/ELF.h +++ b/include/llvm/Object/ELF.h @@ -547,8 +547,9 @@ template Expected ELFFile::getEntry(const Elf_Shdr *Section, uint32_t Entry) const { if (sizeof(T) != Section->sh_entsize) - // TODO: this error is untested. - return createError("invalid sh_entsize"); + return createError("section " + getSecIndexForError(this, Section) + + " has invalid sh_entsize: expected " + Twine(sizeof(T)) + + ", but got " + Twine(Section->sh_entsize)); size_t Pos = Section->sh_offset + Entry * sizeof(T); if (Pos + sizeof(T) > Buf.size()) return createError("unable to access section " + diff --git a/test/Object/invalid.test b/test/Object/invalid.test index 7071dee98eb..04a332d5fa4 100644 --- a/test/Object/invalid.test +++ b/test/Object/invalid.test @@ -627,3 +627,28 @@ Sections: Content: "" Symbols: - Name: foo + +## Check that we report an error if SHT_GNU_versym has invalid +## sh_entsize value (3 instead of 2) when trying to access the entries. + +# RUN: yaml2obj %s --docnum=30 -o %t30 +# RUN: not llvm-readobj -V %t30 2>&1 | FileCheck --check-prefix=INVALID-VER-SHENTSIZE %s + +# INVALID-VER-SHENTSIZE: error: section [index 1] has invalid sh_entsize: expected 2, but got 3 + +--- !ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + OSABI: ELFOSABI_FREEBSD + Type: ET_DYN + Machine: EM_X86_64 +Sections: + - Name: .gnu.version + Type: SHT_GNU_versym + EntSize: 0x0000000000000003 + Entries: [ ] +## Needed to trigger creation of .dynsym. +DynamicSymbols: + - Name: foo + Binding: STB_GLOBAL diff --git a/test/tools/yaml2obj/versym-section.yaml b/test/tools/yaml2obj/versym-section.yaml index fa28ae569b6..6e0cecba19e 100644 --- a/test/tools/yaml2obj/versym-section.yaml +++ b/test/tools/yaml2obj/versym-section.yaml @@ -1,9 +1,9 @@ -# RUN: yaml2obj %s -o %t -# RUN: llvm-readobj -V %t | FileCheck %s - ## Check we are able to produce a valid SHT_GNU_versym ## section from its description. +# RUN: yaml2obj --docnum=1 %s -o %t1 +# RUN: llvm-readobj -V %t1 | FileCheck %s + # CHECK: Version symbols { # CHECK-NEXT: Section Name: .gnu.version # CHECK-NEXT: Address: 0x200210 @@ -89,3 +89,25 @@ DynamicSymbols: - Name: f2 Binding: STB_GLOBAL ... + +## Check we are able to set custom sh_entsize field for SHT_GNU_versym section. + +# RUN: yaml2obj --docnum=2 %s -o %t2 +# RUN: llvm-readelf -S %t2 | FileCheck %s --check-prefix=ENTSIZE + +# ENTSIZE: Section Headers: +# ENTSIZE: [Nr] Name Type Address Off Size ES +# ENTSIZE: [ 1] .gnu.version VERSYM 0000000000000000 000180 000000 03 + +--- !ELF +FileHeader: + Class: ELFCLASS64 + Data: ELFDATA2LSB + OSABI: ELFOSABI_FREEBSD + Type: ET_DYN + Machine: EM_X86_64 +Sections: + - Name: .gnu.version + Type: SHT_GNU_versym + EntSize: 0x0000000000000003 + Entries: [ ] diff --git a/tools/yaml2obj/yaml2elf.cpp b/tools/yaml2obj/yaml2elf.cpp index e11d8fe3ff0..bcb390bb5e1 100644 --- a/tools/yaml2obj/yaml2elf.cpp +++ b/tools/yaml2obj/yaml2elf.cpp @@ -796,7 +796,7 @@ bool ELFState::writeSectionContent(Elf_Shdr &SHeader, for (uint16_t Version : Section.Entries) support::endian::write(OS, Version, ELFT::TargetEndianness); - SHeader.sh_entsize = 2; + SHeader.sh_entsize = Section.EntSize ? (uint64_t)*Section.EntSize : 2; SHeader.sh_size = Section.Entries.size() * SHeader.sh_entsize; return true; } -- 2.40.0