Commit 2120612e authored by Peter Smith's avatar Peter Smith
Browse files

[ELF] Support for PT_GNU_PROPERTY in header and tools 

The PT_GNU_PROPERTY is generated by a linker to describe the
.note.gnu.property section. The Linux kernel uses this program header to
locate the .note.gnu.property section.

It is described in "The Linux gABI extension"

Include support for llvm-readelf, llvm-readobj and the yaml reader and
writers.

Differential Revision: https://reviews.llvm.org/D70959
parent 678f1284

llvm/include/llvm/BinaryFormat/ELF.h

+3 −2
Original line number Diff line number Diff line
@@ -1201,6 +1201,7 @@ enum { 


  PT_GNU_STACK = 0x6474e551,    // Indicates stack executability.

  PT_GNU_RELRO = 0x6474e552,    // Read-only after relocation.

  PT_GNU_PROPERTY = 0x6474e553, // .note.gnu.property notes sections.



  PT_OPENBSD_RANDOMIZE = 0x65a3dbe6, // Fill with random data.

  PT_OPENBSD_WXNEEDED = 0x65a3dbe7,  // Program does W^X violations.

llvm/lib/ObjectYAML/ELFYAML.cpp

+1 −0
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ void ScalarEnumerationTraits<ELFYAML::ELF_PT>::enumeration( 
  ECase(PT_GNU_EH_FRAME);

  ECase(PT_GNU_STACK);

  ECase(PT_GNU_RELRO);

  ECase(PT_GNU_PROPERTY);

#undef ECase

  IO.enumFallback<Hex32>(Value);

}

llvm/test/tools/llvm-objdump/elf-pt-gnu-property.test

0 → 100644
+14 −0
Original line number Diff line number Diff line 
# RUN: yaml2obj %s -o %t

# RUN: llvm-objdump -p %t | FileCheck %s



# CHECK: Program Header:

# CHECK-NEXT: {{ }}PROPERTY{{ }}



--- !ELF

FileHeader:

  Class:   ELFCLASS64

  Data:    ELFDATA2LSB

  Type:    ET_EXEC

  Machine: EM_AARCH64

ProgramHeaders:

  - Type: PT_GNU_PROPERTY

llvm/test/tools/llvm-readobj/elf-pt-gnu-property.test

0 → 100644
+17 −0
Original line number Diff line number Diff line 
# RUN: yaml2obj %s -o %t

# RUN: llvm-readelf --program-headers %t | FileCheck %s --check-prefix=GNU

# RUN: llvm-readobj --program-headers %t | FileCheck %s --check-prefix=LLVM



# GNU: {{ }}GNU_PROPERTY{{ }}



# LLVM:        ProgramHeader {

# LLVM-NEXT:     Type: PT_GNU_PROPERTY (0x6474E553)



--- !ELF

FileHeader:

  Class:   ELFCLASS64

  Data:    ELFDATA2LSB

  Type:    ET_EXEC

  Machine: EM_AARCH64

ProgramHeaders:

  - Type: PT_GNU_PROPERTY

llvm/test/tools/yaml2obj/ELF/program-header.yaml

+4 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ ProgramHeaders: 
  - Type: PT_GNU_EH_FRAME

  - Type: PT_GNU_STACK

  - Type: PT_GNU_RELRO

  - Type: PT_GNU_PROPERTY



#CHECK:     ProgramHeaders [

#CHECK-NEXT:   ProgramHeader {
@@ -76,6 +77,9 @@ ProgramHeaders: 
#CHECK-NEXT:  ProgramHeader {

#CHECK-NEXT:    Type: PT_GNU_RELRO (0x6474E552)

#CHECK:       }

#CHECK-NEXT:  ProgramHeader {

#CHECK-NEXT:    Type: PT_GNU_PROPERTY (0x6474E553)

#CHECK:       }

#CHECK-NEXT:]



## Check we do not allow referencing sections that do not exist.