[llvm] r208995 - [yaml2obj][ELF] Add an optional `Size` field to the YAML section declaration.
Simon Atanasyan
simon at atanasyan.com
Fri May 16 09:01:00 PDT 2014
Author: atanasyan
Date: Fri May 16 11:01:00 2014
New Revision: 208995
URL: http://llvm.org/viewvc/llvm-project?rev=208995&view=rev
Log:
[yaml2obj][ELF] Add an optional `Size` field to the YAML section declaration.
Now the only method to configure ELF section's content and size is to assign
a hexadecimal string to the `Content` field. Unfortunately this way is
completely useless when you need to declare a really large section.
To solve this problem this patch adds one more optional field `Size`
to the `RawContentSection` structure. When yaml2obj generates an ELF file
it uses the following algorithm:
1. If both `Content` and `Size` fields are missed create an empty section.
2. If only `Content` field is missed take section length from the `Size`
field and fill the section by zero.
3. If only `Size` field is missed create a section using data from
the `Content` field.
4. If both `Content` and `Size` fields are provided validate that the `Size`
value is not less than size of `Content` data. Than take section length
from the `Size`, fill beginning of the section by `Content` and the rest
by zero.
Examples
--------
* Create a section 0x10000 bytes long filled by zero
Name: .data
Type: SHT_PROGBITS
Flags: [ SHF_ALLOC ]
Size: 0x10000
* Create a section 0x10000 bytes long starting from 'CA' 'FE' 'BA' 'BE'
Name: .data
Type: SHT_PROGBITS
Flags: [ SHF_ALLOC ]
Content: CAFEBABE
Size: 0x10000
The patch reviewed by Michael Spencer.
Added:
llvm/trunk/test/Object/yaml2obj-elf-section-invalid-size.yaml
Modified:
llvm/trunk/include/llvm/Object/ELFYAML.h
llvm/trunk/lib/Object/ELFYAML.cpp
llvm/trunk/test/Object/yaml2obj-elf-section-basic.yaml
llvm/trunk/tools/obj2yaml/elf2yaml.cpp
llvm/trunk/tools/yaml2obj/yaml2elf.cpp
Modified: llvm/trunk/include/llvm/Object/ELFYAML.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Object/ELFYAML.h?rev=208995&r1=208994&r2=208995&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Object/ELFYAML.h (original)
+++ llvm/trunk/include/llvm/Object/ELFYAML.h Fri May 16 11:01:00 2014
@@ -83,6 +83,7 @@ struct Section {
};
struct RawContentSection : Section {
object::yaml::BinaryRef Content;
+ llvm::yaml::Hex64 Size;
RawContentSection() : Section(SectionKind::RawContent) {}
static bool classof(const Section *S) {
return S->Kind == SectionKind::RawContent;
@@ -193,6 +194,7 @@ template <> struct MappingTraits<ELFYAML
template <>
struct MappingTraits<std::unique_ptr<ELFYAML::Section>> {
static void mapping(IO &IO, std::unique_ptr<ELFYAML::Section> &Section);
+ static StringRef validate(IO &io, std::unique_ptr<ELFYAML::Section> &Section);
};
template <>
Modified: llvm/trunk/lib/Object/ELFYAML.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Object/ELFYAML.cpp?rev=208995&r1=208994&r2=208995&view=diff
==============================================================================
--- llvm/trunk/lib/Object/ELFYAML.cpp (original)
+++ llvm/trunk/lib/Object/ELFYAML.cpp Fri May 16 11:01:00 2014
@@ -658,6 +658,7 @@ static void commonSectionMapping(IO &IO,
static void sectionMapping(IO &IO, ELFYAML::RawContentSection &Section) {
commonSectionMapping(IO, Section);
IO.mapOptional("Content", Section.Content);
+ IO.mapOptional("Size", Section.Size, Hex64(Section.Content.binary_size()));
}
static void sectionMapping(IO &IO, ELFYAML::RelocationSection &Section) {
@@ -687,6 +688,14 @@ void MappingTraits<std::unique_ptr<ELFYA
}
}
+StringRef MappingTraits<std::unique_ptr<ELFYAML::Section>>::validate(
+ IO &io, std::unique_ptr<ELFYAML::Section> &Section) {
+ const auto *RawSection = dyn_cast<ELFYAML::RawContentSection>(Section.get());
+ if (!RawSection || RawSection->Size >= RawSection->Content.binary_size())
+ return StringRef();
+ return "Section size must be greater or equal to the content size";
+}
+
void MappingTraits<ELFYAML::Relocation>::mapping(IO &IO,
ELFYAML::Relocation &Rel) {
IO.mapRequired("Offset", Rel.Offset);
Modified: llvm/trunk/test/Object/yaml2obj-elf-section-basic.yaml
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Object/yaml2obj-elf-section-basic.yaml?rev=208995&r1=208994&r2=208995&view=diff
==============================================================================
--- llvm/trunk/test/Object/yaml2obj-elf-section-basic.yaml (original)
+++ llvm/trunk/test/Object/yaml2obj-elf-section-basic.yaml Fri May 16 11:01:00 2014
@@ -17,6 +17,14 @@ Sections:
Content: EBFE
AddressAlign: 2
+ - Name: .data
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC ]
+ Address: 0xCAFECAFE
+ Content: FEBF
+ Size: 8
+ AddressAlign: 2
+
# CHECK: Section {
# CHECK: Index: 0
# CHECK: Type: SHT_NULL (0x0)
@@ -38,6 +46,23 @@ Sections:
# CHECK-NEXT: )
#
# CHECK: Section {
+# CHECK: Name: .data
+# CHECK-NEXT: Type: SHT_PROGBITS (0x1)
+# CHECK-NEXT: Flags [ (0x2)
+# CHECK-NEXT: SHF_ALLOC (0x2)
+# CHECK-NEXT: ]
+# CHECK-NEXT: Address: 0xCAFECAFE
+# CHECK-NEXT: Offset: 0x1D0
+# CHECK-NEXT: Size: 8
+# CHECK-NEXT: Link: 0
+# CHECK-NEXT: Info: 0
+# CHECK-NEXT: AddressAlignment: 2
+# CHECK-NEXT: EntrySize: 0
+# CHECK-NEXT: SectionData (
+# CHECK-NEXT: 0000: FEBF0000 00000000 |........|
+# CHECK-NEXT: )
+#
+# CHECK: Section {
# CHECK: Name: .symtab (25)
# CHECK: Type: SHT_SYMTAB (0x2)
# CHECK: }
Added: llvm/trunk/test/Object/yaml2obj-elf-section-invalid-size.yaml
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Object/yaml2obj-elf-section-invalid-size.yaml?rev=208995&view=auto
==============================================================================
--- llvm/trunk/test/Object/yaml2obj-elf-section-invalid-size.yaml (added)
+++ llvm/trunk/test/Object/yaml2obj-elf-section-invalid-size.yaml Fri May 16 11:01:00 2014
@@ -0,0 +1,26 @@
+# RUN: not yaml2obj -format=elf -o %t %s 2>&1 | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_X86_64
+
+Sections:
+ - Name: .text
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
+ Content: EBFE
+ AddressAlign: 2
+
+ - Name: .data
+ Type: SHT_PROGBITS
+ Flags: [ SHF_ALLOC ]
+ Content: 0000000000000000
+ Size: 2
+
+# CHECK: YAML:17:5: error: Section size must be greater or equal to the content size
+# CHECK-NEXT: - Name: .data
+# CHECK-NEXT: ^
+# CHECK-NEXT: yaml2obj: Failed to parse YAML file!
Modified: llvm/trunk/tools/obj2yaml/elf2yaml.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/obj2yaml/elf2yaml.cpp?rev=208995&r1=208994&r2=208995&view=diff
==============================================================================
--- llvm/trunk/tools/obj2yaml/elf2yaml.cpp (original)
+++ llvm/trunk/tools/obj2yaml/elf2yaml.cpp Fri May 16 11:01:00 2014
@@ -254,6 +254,7 @@ ELFDumper<ELFT>::dumpContentSection(cons
if (error_code EC = ContentOrErr.getError())
return EC;
S->Content = object::yaml::BinaryRef(ContentOrErr.get());
+ S->Size = S->Content.binary_size();
return S.release();
}
Modified: llvm/trunk/tools/yaml2obj/yaml2elf.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/yaml2obj/yaml2elf.cpp?rev=208995&r1=208994&r2=208995&view=diff
==============================================================================
--- llvm/trunk/tools/yaml2obj/yaml2elf.cpp (original)
+++ llvm/trunk/tools/yaml2obj/yaml2elf.cpp Fri May 16 11:01:00 2014
@@ -314,9 +314,14 @@ void
ELFState<ELFT>::writeSectionContent(Elf_Shdr &SHeader,
const ELFYAML::RawContentSection &Section,
ContiguousBlobAccumulator &CBA) {
- Section.Content.writeAsBinary(CBA.getOSAndAlignedOffset(SHeader.sh_offset));
+ assert(Section.Size >= Section.Content.binary_size() &&
+ "Section size and section content are inconsistent");
+ raw_ostream &OS = CBA.getOSAndAlignedOffset(SHeader.sh_offset);
+ Section.Content.writeAsBinary(OS);
+ for (auto i = Section.Content.binary_size(); i < Section.Size; ++i)
+ OS.write(0);
SHeader.sh_entsize = 0;
- SHeader.sh_size = Section.Content.binary_size();
+ SHeader.sh_size = Section.Size;
}
template <class ELFT>
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