[ELF] Add basic support for PPC LE

This patch adds changes to start supporting the Power 64-Bit ELF V2 ABI.
This includes:
- Changing the ElfSym::GlobalOffsetTable to be named .TOC.
- Creating a GotHeader so the first entry in the .got is .TOC.
- Setting the e_flags to be 1 for ELF V1 and 2 for ELF V2

Differential Revision: https://reviews.llvm.org/D44483

llvm-svn: 327871
This commit is contained in:
Zaara Syeda 2018-03-19 17:40:14 +00:00
parent d791e92b5f
commit 52ed6eb8d9
7 changed files with 395 additions and 6 deletions

View File

@ -14,6 +14,8 @@
#include "llvm/Support/Endian.h"
using namespace llvm;
using namespace llvm::object;
using namespace llvm::support::endian;
using namespace llvm::ELF;
using namespace lld;
using namespace lld::elf;
@ -38,11 +40,13 @@ namespace {
class PPC64 final : public TargetInfo {
public:
PPC64();
uint32_t calcEFlags() const override;
RelExpr getRelExpr(RelType Type, const Symbol &S,
const uint8_t *Loc) const override;
void writePlt(uint8_t *Buf, uint64_t GotPltEntryAddr, uint64_t PltEntryAddr,
int32_t Index, unsigned RelOff) const override;
void relocateOne(uint8_t *Loc, RelType Type, uint64_t Val) const override;
void writeGotHeader(uint8_t *Buf) const override;
};
} // namespace
@ -65,6 +69,10 @@ PPC64::PPC64() {
GotPltEntrySize = 8;
PltEntrySize = 32;
PltHeaderSize = 0;
GotBaseSymInGotPlt = false;
GotBaseSymOff = 0x8000;
if (Config->EKind == ELF64LEKind)
GotHeaderEntriesNum = 1;
// We need 64K pages (at least under glibc/Linux, the loader won't
// set different permissions on a finer granularity than that).
@ -81,6 +89,42 @@ PPC64::PPC64() {
DefaultImageBase = 0x10000000;
}
static uint32_t getEFlags(InputFile *File) {
// Get the e_flag from the input file and if it is unspecified, then set it to
// the e_flag appropriate for the ABI.
// We are currently handling both ELF64LE and ELF64BE but eventually will
// remove BE support once v2 ABI support is complete.
switch (Config->EKind) {
case ELF64BEKind:
if (uint32_t EFlags =
cast<ObjFile<ELF64BE>>(File)->getObj().getHeader()->e_flags)
return EFlags;
return 1;
case ELF64LEKind:
if (uint32_t EFlags =
cast<ObjFile<ELF64LE>>(File)->getObj().getHeader()->e_flags)
return EFlags;
return 2;
default:
llvm_unreachable("unknown Config->EKind");
}
}
uint32_t PPC64::calcEFlags() const {
assert(!ObjectFiles.empty());
uint32_t Ret = getEFlags(ObjectFiles[0]);
// Verify that all input files have the same e_flags.
for (InputFile *F : makeArrayRef(ObjectFiles).slice(1)) {
if (Ret == getEFlags(F))
continue;
error("incompatible e_flags: " + toString(F));
return 0;
}
return Ret;
}
RelExpr PPC64::getRelExpr(RelType Type, const Symbol &S,
const uint8_t *Loc) const {
switch (Type) {
@ -100,6 +144,11 @@ RelExpr PPC64::getRelExpr(RelType Type, const Symbol &S,
}
}
void PPC64::writeGotHeader(uint8_t *Buf) const {
if (Config->EKind == ELF64LEKind)
write64(Buf, getPPC64TocBase());
}
void PPC64::writePlt(uint8_t *Buf, uint64_t GotPltEntryAddr,
uint64_t PltEntryAddr, int32_t Index,
unsigned RelOff) const {

View File

@ -590,7 +590,7 @@ GotSection::GotSection()
Target->GotEntrySize, ".got") {}
void GotSection::addEntry(Symbol &Sym) {
Sym.GotIndex = NumEntries;
Sym.GotIndex = Target->GotHeaderEntriesNum + NumEntries;
++NumEntries;
}
@ -621,7 +621,9 @@ uint64_t GotSection::getGlobalDynOffset(const Symbol &B) const {
return B.GlobalDynIndex * Config->Wordsize;
}
void GotSection::finalizeContents() { Size = NumEntries * Config->Wordsize; }
void GotSection::finalizeContents() {
Size = (NumEntries + Target->GotHeaderEntriesNum) * Config->Wordsize;
}
bool GotSection::empty() const {
// We need to emit a GOT even if it's empty if there's a relocation that is
@ -635,6 +637,8 @@ void GotSection::writeTo(uint8_t *Buf) {
// Buf points to the start of this section's buffer,
// whereas InputSectionBase::relocateAlloc() expects its argument
// to point to the start of the output section.
Target->writeGotHeader(Buf);
Buf += Target->GotHeaderEntriesNum * Target->GotEntrySize;
relocateAlloc(Buf - OutSecOff, Buf - OutSecOff + Size);
}

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@ -28,6 +28,7 @@ public:
virtual bool isPicRel(RelType Type) const { return true; }
virtual RelType getDynRel(RelType Type) const { return Type; }
virtual void writeGotPltHeader(uint8_t *Buf) const {}
virtual void writeGotHeader(uint8_t *Buf) const {}
virtual void writeGotPlt(uint8_t *Buf, const Symbol &S) const {};
virtual void writeIgotPlt(uint8_t *Buf, const Symbol &S) const;
virtual int64_t getImplicitAddend(const uint8_t *Buf, RelType Type) const;
@ -102,6 +103,9 @@ public:
// to support lazy loading.
unsigned GotPltHeaderEntriesNum = 3;
// On PPC ELF V2 abi, the first entry in the .got is the .TOC.
unsigned GotHeaderEntriesNum = 0;
// Set to 0 for variant 2
unsigned TcbSize = 0;

View File

@ -190,8 +190,14 @@ void elf::addReservedSymbols() {
Symtab->addAbsolute("__gnu_local_gp", STV_HIDDEN, STB_GLOBAL);
}
// The 64-bit PowerOpen ABI defines a TableOfContents (TOC) which combines the
// typical ELF GOT with the small data sections. It commonly includes .got
// .toc .sdata .sbss. The .TOC. symbol replaces both _GLOBAL_OFFSET_TABLE_ and
// _SDA_BASE_ from the 32-bit ABI. It is used to represent the TOC base which
// is offset by 0x8000 bytes from the start of the .got section.
ElfSym::GlobalOffsetTable = addOptionalRegular(
"_GLOBAL_OFFSET_TABLE_", Out::ElfHeader, Target->GotBaseSymOff);
(Config->EMachine == EM_PPC64) ? ".TOC." : "_GLOBAL_OFFSET_TABLE_",
Out::ElfHeader, Target->GotBaseSymOff);
// __ehdr_start is the location of ELF file headers. Note that we define
// this symbol unconditionally even when using a linker script, which

323
lld/test/ELF/basic-ppc64.s Normal file
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@ -0,0 +1,323 @@
# # RUN: llvm-mc -filetype=obj -triple=powerpc64le-unknown-linux %s -o %t
# RUN: ld.lld --hash-style=sysv -discard-all -shared %t -o %t2
# RUN: llvm-readobj -file-headers -sections -section-data -program-headers %t2 | FileCheck %s
# REQUIRES: ppc
.abiversion 2
# Exits with return code 55 on linux.
.text
li 0,1
li 3,55
sc
// CHECK:Format: ELF64-ppc64
// CHECK-NEXT:Arch: powerpc64le
// CHECK-NEXT:AddressSize: 64bit
// CHECK-NEXT:LoadName:
// CHECK-NEXT:ElfHeader {
// CHECK-NEXT: Ident {
// CHECK-NEXT: Magic: (7F 45 4C 46)
// CHECK-NEXT: Class: 64-bit (0x2)
// CHECK-NEXT: DataEncoding: LittleEndian (0x1)
// CHECK-NEXT: FileVersion: 1
// CHECK-NEXT: OS/ABI: SystemV (0x0)
// CHECK-NEXT: ABIVersion: 0
// CHECK-NEXT: Unused: (00 00 00 00 00 00 00)
// CHECK-NEXT: }
// CHECK-NEXT: Type: SharedObject (0x3)
// CHECK-NEXT: Machine: EM_PPC64 (0x15)
// CHECK-NEXT: Version: 1
// CHECK-NEXT: Entry: 0x10000
// CHECK-NEXT: ProgramHeaderOffset: 0x40
// CHECK-NEXT: SectionHeaderOffset: 0x200F0
// CHECK-NEXT: Flags [ (0x2)
// CHECK-NEXT: 0x2
// CHECK-NEXT: ]
// CHECK-NEXT: HeaderSize: 64
// CHECK-NEXT: ProgramHeaderEntrySize: 56
// CHECK-NEXT: ProgramHeaderCount: 7
// CHECK-NEXT: SectionHeaderEntrySize: 64
// CHECK-NEXT: SectionHeaderCount: 10
// CHECK-NEXT: StringTableSectionIndex: 8
// CHECK-NEXT:}
// CHECK-NEXT:Sections [
// CHECK-NEXT: Section {
// CHECK-NEXT: Index: 0
// CHECK-NEXT: Name: (0)
// CHECK-NEXT: Type: SHT_NULL (0x0)
// CHECK-NEXT: Flags [ (0x0)
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x0
// CHECK-NEXT: Offset: 0x0
// CHECK-NEXT: Size: 0
// CHECK-NEXT: Link: 0
// CHECK-NEXT: Info: 0
// CHECK-NEXT: AddressAlignment: 0
// CHECK-NEXT: EntrySize: 0
// CHECK-NEXT: SectionData (
// CHECK-NEXT: )
// CHECK-NEXT: }
// CHECK-NEXT: Section {
// CHECK-NEXT: Index: 1
// CHECK-NEXT: Name: .dynsym (1)
// CHECK-NEXT: Type: SHT_DYNSYM (0xB)
// CHECK-NEXT: Flags [ (0x2)
// CHECK-NEXT: SHF_ALLOC (0x2)
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x1C8
// CHECK-NEXT: Offset: 0x1C8
// CHECK-NEXT: Size: 24
// CHECK-NEXT: Link: 3
// CHECK-NEXT: Info: 1
// CHECK-NEXT: AddressAlignment: 8
// CHECK-NEXT: EntrySize: 24
// CHECK-NEXT: SectionData (
// CHECK-NEXT: 0000: 00000000 00000000 00000000 00000000 |................|
// CHECK-NEXT: 0010: 00000000 00000000 |........|
// CHECK-NEXT: )
// CHECK-NEXT: }
// CHECK-NEXT: Section {
// CHECK-NEXT: Index: 2
// CHECK-NEXT: Name: .hash (9)
// CHECK-NEXT: Type: SHT_HASH (0x5)
// CHECK-NEXT: Flags [ (0x2)
// CHECK-NEXT: SHF_ALLOC (0x2)
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x1E0
// CHECK-NEXT: Offset: 0x1E0
// CHECK-NEXT: Size: 16
// CHECK-NEXT: Link: 1
// CHECK-NEXT: Info: 0
// CHECK-NEXT: AddressAlignment: 4
// CHECK-NEXT: EntrySize: 4
// CHECK-NEXT: SectionData (
// CHECK-NEXT: 0000: 01000000 01000000 00000000 00000000 |................|
// CHECK-NEXT: )
// CHECK-NEXT: }
// CHECK-NEXT: Section {
// CHECK-NEXT: Index: 3
// CHECK-NEXT: Name: .dynstr (15)
// CHECK-NEXT: Type: SHT_STRTAB (0x3)
// CHECK-NEXT: Flags [ (0x2)
// CHECK-NEXT: SHF_ALLOC (0x2)
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x1F0
// CHECK-NEXT: Offset: 0x1F0
// CHECK-NEXT: Size: 1
// CHECK-NEXT: Link: 0
// CHECK-NEXT: Info: 0
// CHECK-NEXT: AddressAlignment: 1
// CHECK-NEXT: EntrySize: 0
// CHECK-NEXT: SectionData (
// CHECK-NEXT: 0000: 00 |.|
// CHECK-NEXT: )
// CHECK-NEXT: }
// CHECK-NEXT: Section {
// CHECK-NEXT: Index: 4
// CHECK-NEXT: Name: .text (23)
// CHECK-NEXT: Type: SHT_PROGBITS (0x1)
// CHECK-NEXT: Flags [ (0x6)
// CHECK-NEXT: SHF_ALLOC (0x2)
// CHECK-NEXT: SHF_EXECINSTR (0x4)
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x10000
// CHECK-NEXT: Offset: 0x10000
// CHECK-NEXT: Size: 12
// CHECK-NEXT: Link: 0
// CHECK-NEXT: Info: 0
// CHECK-NEXT: AddressAlignment: 4
// CHECK-NEXT: EntrySize: 0
// CHECK-NEXT: SectionData (
// CHECK-NEXT: 0000: 01000038 37006038 02000044 |...87.`8...D|
// CHECK-NEXT: )
// CHECK-NEXT: }
// CHECK-NEXT: Section {
// CHECK-NEXT: Index: 5
// CHECK-NEXT: Name: .dynamic (29)
// CHECK-NEXT: Type: SHT_DYNAMIC (0x6)
// CHECK-NEXT: Flags [ (0x3)
// CHECK-NEXT: SHF_ALLOC (0x2)
// CHECK-NEXT: SHF_WRITE (0x1)
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x20000
// CHECK-NEXT: Offset: 0x20000
// CHECK-NEXT: Size: 96
// CHECK-NEXT: Link: 3
// CHECK-NEXT: Info: 0
// CHECK-NEXT: AddressAlignment: 8
// CHECK-NEXT: EntrySize: 16
// CHECK-NEXT: SectionData (
// CHECK-NEXT: 0000: 06000000 00000000 C8010000 00000000 |................|
// CHECK-NEXT: 0010: 0B000000 00000000 18000000 00000000 |................|
// CHECK-NEXT: 0020: 05000000 00000000 F0010000 00000000 |................|
// CHECK-NEXT: 0030: 0A000000 00000000 01000000 00000000 |................|
// CHECK-NEXT: 0040: 04000000 00000000 E0010000 00000000 |................|
// CHECK-NEXT: 0050: 00000000 00000000 00000000 00000000 |................|
// CHECK-NEXT: )
// CHECK-NEXT: }
// CHECK-NEXT: Section {
// CHECK-NEXT: Index: 6
// CHECK-NEXT: Name: .comment (38)
// CHECK-NEXT: Type: SHT_PROGBITS (0x1)
// CHECK-NEXT: Flags [ (0x30)
// CHECK-NEXT: SHF_MERGE (0x10)
// CHECK-NEXT: SHF_STRINGS (0x20)
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x0
// CHECK-NEXT: Offset: 0x20060
// CHECK-NEXT: Size: 8
// CHECK-NEXT: Link: 0
// CHECK-NEXT: Info: 0
// CHECK-NEXT: AddressAlignment: 1
// CHECK-NEXT: EntrySize: 1
// CHECK-NEXT: SectionData (
// CHECK-NEXT: 0000: 4C4C4420 312E3000 |LLD 1.0.|
// CHECK-NEXT: )
// CHECK-NEXT: }
// CHECK-NEXT: Section {
// CHECK-NEXT: Index: 7
// CHECK-NEXT: Name: .symtab (47)
// CHECK-NEXT: Type: SHT_SYMTAB (0x2)
// CHECK-NEXT: Flags [ (0x0)
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x0
// CHECK-NEXT: Offset: 0x20068
// CHECK-NEXT: Size: 48
// CHECK-NEXT: Link: 9
// CHECK-NEXT: Info: 2
// CHECK-NEXT: AddressAlignment: 8
// CHECK-NEXT: EntrySize: 24
// CHECK-NEXT: SectionData (
// CHECK-NEXT: 0000: 00000000 00000000 00000000 00000000 |................|
// CHECK-NEXT: 0010: 00000000 00000000 01000000 00020500 |................|
// CHECK-NEXT: 0020: 00000200 00000000 00000000 00000000 |................|
// CHECK-NEXT: )
// CHECK-NEXT: }
// CHECK-NEXT: Section {
// CHECK-NEXT: Index: 8
// CHECK-NEXT: Name: .shstrtab (55)
// CHECK-NEXT: Type: SHT_STRTAB (0x3)
// CHECK-NEXT: Flags [ (0x0)
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x0
// CHECK-NEXT: Offset: 0x20098
// CHECK-NEXT: Size: 73
// CHECK-NEXT: Link: 0
// CHECK-NEXT: Info: 0
// CHECK-NEXT: AddressAlignment: 1
// CHECK-NEXT: EntrySize: 0
// CHECK-NEXT: SectionData (
// CHECK-NEXT: 0000: 002E6479 6E73796D 002E6861 7368002E |..dynsym..hash..|
// CHECK-NEXT: 0010: 64796E73 7472002E 74657874 002E6479 |dynstr..text..dy|
// CHECK-NEXT: 0020: 6E616D69 63002E63 6F6D6D65 6E74002E |namic..comment..|
// CHECK-NEXT: 0030: 73796D74 6162002E 73687374 72746162 |symtab..shstrtab|
// CHECK-NEXT: 0040: 002E7374 72746162 00 |..strtab.|
// CHECK-NEXT: )
// CHECK-NEXT: }
// CHECK-NEXT: Section {
// CHECK-NEXT: Index: 9
// CHECK-NEXT: Name: .strtab (65)
// CHECK-NEXT: Type: SHT_STRTAB (0x3)
// CHECK-NEXT: Flags [ (0x0)
// CHECK-NEXT: ]
// CHECK-NEXT: Address: 0x0
// CHECK-NEXT: Offset: 0x200E1
// CHECK-NEXT: Size: 10
// CHECK-NEXT: Link: 0
// CHECK-NEXT: Info: 0
// CHECK-NEXT: AddressAlignment: 1
// CHECK-NEXT: EntrySize: 0
// CHECK-NEXT: SectionData (
// CHECK-NEXT: 0000: 005F4459 4E414D49 4300 |._DYNAMIC.|
// CHECK-NEXT: )
// CHECK-NEXT: }
// CHECK-NEXT:]
// CHECK-NEXT:ProgramHeaders [
// CHECK-NEXT: ProgramHeader {
// CHECK-NEXT: Type: PT_PHDR (0x6)
// CHECK-NEXT: Offset: 0x40
// CHECK-NEXT: VirtualAddress: 0x40
// CHECK-NEXT: PhysicalAddress: 0x40
// CHECK-NEXT: FileSize: 392
// CHECK-NEXT: MemSize: 392
// CHECK-NEXT: Flags [ (0x4)
// CHECK-NEXT: PF_R (0x4)
// CHECK-NEXT: ]
// CHECK-NEXT: Alignment: 8
// CHECK-NEXT: }
// CHECK-NEXT: ProgramHeader {
// CHECK-NEXT: Type: PT_LOAD (0x1)
// CHECK-NEXT: Offset: 0x0
// CHECK-NEXT: VirtualAddress: 0x0
// CHECK-NEXT: PhysicalAddress: 0x0
// CHECK-NEXT: FileSize: 497
// CHECK-NEXT: MemSize: 497
// CHECK-NEXT: Flags [ (0x4)
// CHECK-NEXT: PF_R (0x4)
// CHECK-NEXT: ]
// CHECK-NEXT: Alignment: 65536
// CHECK-NEXT: }
// CHECK-NEXT: ProgramHeader {
// CHECK-NEXT: Type: PT_LOAD (0x1)
// CHECK-NEXT: Offset: 0x10000
// CHECK-NEXT: VirtualAddress: 0x10000
// CHECK-NEXT: PhysicalAddress: 0x10000
// CHECK-NEXT: FileSize: 12
// CHECK-NEXT: MemSize: 12
// CHECK-NEXT: Flags [ (0x5)
// CHECK-NEXT: PF_R (0x4)
// CHECK-NEXT: PF_X (0x1)
// CHECK-NEXT: ]
// CHECK-NEXT: Alignment: 65536
// CHECK-NEXT: }
// CHECK-NEXT: ProgramHeader {
// CHECK-NEXT: Type: PT_LOAD (0x1)
// CHECK-NEXT: Offset: 0x20000
// CHECK-NEXT: VirtualAddress: 0x20000
// CHECK-NEXT: PhysicalAddress: 0x20000
// CHECK-NEXT: FileSize: 96
// CHECK-NEXT: MemSize: 96
// CHECK-NEXT: Flags [ (0x6)
// CHECK-NEXT: PF_R (0x4)
// CHECK-NEXT: PF_W (0x2)
// CHECK-NEXT: ]
// CHECK-NEXT: Alignment: 65536
// CHECK-NEXT: }
// CHECK-NEXT: ProgramHeader {
// CHECK-NEXT: Type: PT_DYNAMIC (0x2)
// CHECK-NEXT: Offset: 0x20000
// CHECK-NEXT: VirtualAddress: 0x20000
// CHECK-NEXT: PhysicalAddress: 0x20000
// CHECK-NEXT: FileSize: 96
// CHECK-NEXT: MemSize: 96
// CHECK-NEXT: Flags [ (0x6)
// CHECK-NEXT: PF_R (0x4)
// CHECK-NEXT: PF_W (0x2)
// CHECK-NEXT: ]
// CHECK-NEXT: Alignment: 8
// CHECK-NEXT: }
// CHECK-NEXT: ProgramHeader {
// CHECK-NEXT: Type: PT_GNU_RELRO (0x6474E552)
// CHECK-NEXT: Offset: 0x20000
// CHECK-NEXT: VirtualAddress: 0x20000
// CHECK-NEXT: PhysicalAddress: 0x20000
// CHECK-NEXT: FileSize: 96
// CHECK-NEXT: MemSize: 4096
// CHECK-NEXT: Flags [ (0x4)
// CHECK-NEXT: PF_R (0x4)
// CHECK-NEXT: ]
// CHECK-NEXT: Alignment: 1
// CHECK-NEXT: }
// CHECK-NEXT: ProgramHeader {
// CHECK-NEXT: Type: PT_GNU_STACK (0x6474E551)
// CHECK-NEXT: Offset: 0x0
// CHECK-NEXT: VirtualAddress: 0x0
// CHECK-NEXT: PhysicalAddress: 0x0
// CHECK-NEXT: FileSize: 0
// CHECK-NEXT: MemSize: 0
// CHECK-NEXT: Flags [ (0x6)
// CHECK-NEXT: PF_R (0x4)
// CHECK-NEXT: PF_W (0x2)
// CHECK-NEXT: ]
// CHECK-NEXT: Alignment: 0
// CHECK-NEXT: }
// CHECK-NEXT:]

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@ -39,7 +39,8 @@ _start:
# CHECK-NEXT: Entry: 0x10020040
# CHECK-NEXT: ProgramHeaderOffset: 0x40
# CHECK-NEXT: SectionHeaderOffset: 0x30080
# CHECK-NEXT: Flags [ (0x0)
# CHECK-NEXT: Flags [ (0x1)
# CHECK-NEXT: 0x1
# CHECK-NEXT: ]
# CHECK-NEXT: HeaderSize: 64
# CHECK-NEXT: ProgramHeaderEntrySize: 56

View File

@ -208,7 +208,8 @@
# PPC64-NEXT: Entry:
# PPC64-NEXT: ProgramHeaderOffset: 0x40
# PPC64-NEXT: SectionHeaderOffset:
# PPC64-NEXT: Flags [ (0x0)
# PPC64-NEXT: Flags [ (0x1)
# PPC64-NEXT: 0x1
# PPC64-NEXT: ]
# PPC64-NEXT: HeaderSize: 64
# PPC64-NEXT: ProgramHeaderEntrySize: 56
@ -239,7 +240,8 @@
# PPC64LE-NEXT: Entry:
# PPC64LE-NEXT: ProgramHeaderOffset: 0x40
# PPC64LE-NEXT: SectionHeaderOffset:
# PPC64LE-NEXT: Flags [ (0x0)
# PPC64LE-NEXT: Flags [ (0x2)
# PPC64LE-NEXT: 0x2
# PPC64LE-NEXT: ]
# PPC64LE-NEXT: HeaderSize: 64
# PPC64LE-NEXT: ProgramHeaderEntrySize: 56