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-rw-r--r--include/llvm/MC/MCELFObjectWriter.h3
-rw-r--r--include/llvm/MC/MCSection.h7
-rw-r--r--lib/MC/ELFObjectWriter.cpp3
-rw-r--r--lib/MC/MCELFObjectTargetWriter.cpp3
-rw-r--r--lib/MC/MCObjectStreamer.cpp6
-rw-r--r--lib/MC/MCSection.cpp3
-rw-r--r--lib/Target/ARM/ARMTargetObjectFile.cpp14
-rw-r--r--lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp18
-rw-r--r--test/CodeGen/ARM/execute-only.ll3
-rw-r--r--test/MC/ARM/elf-execute-only-section.ll13
-rw-r--r--test/MC/ELF/ARM/execute-only-populated-text-section.s27
-rw-r--r--test/MC/ELF/ARM/execute-only-section.s3
-rw-r--r--test/MC/ELF/ARM/execute-only-text-section-data.s27
13 files changed, 127 insertions, 3 deletions
diff --git a/include/llvm/MC/MCELFObjectWriter.h b/include/llvm/MC/MCELFObjectWriter.h
index bff58fef6af..389a4d71b6a 100644
--- a/include/llvm/MC/MCELFObjectWriter.h
+++ b/include/llvm/MC/MCELFObjectWriter.h
@@ -13,6 +13,7 @@
#include "llvm/ADT/Triple.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/MCObjectWriter.h"
+#include "llvm/MC/MCSectionELF.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdint>
@@ -90,6 +91,8 @@ public:
virtual void sortRelocs(const MCAssembler &Asm,
std::vector<ELFRelocationEntry> &Relocs);
+ virtual void addTargetSectionFlags(MCContext &Ctx, MCSectionELF &Sec);
+
/// \name Accessors
/// @{
uint8_t getOSABI() const { return OSABI; }
diff --git a/include/llvm/MC/MCSection.h b/include/llvm/MC/MCSection.h
index ba5c60d3ba5..eb210b4e9df 100644
--- a/include/llvm/MC/MCSection.h
+++ b/include/llvm/MC/MCSection.h
@@ -78,6 +78,10 @@ private:
/// Whether this section has had instructions emitted into it.
bool HasInstructions : 1;
+ /// Whether this section has had data emitted into it.
+ /// Right now this is only used by the ARM backend.
+ bool HasData : 1;
+
bool IsRegistered : 1;
MCDummyFragment DummyFragment;
@@ -137,6 +141,9 @@ public:
bool hasInstructions() const { return HasInstructions; }
void setHasInstructions(bool Value) { HasInstructions = Value; }
+ bool hasData() const { return HasData; }
+ void setHasData(bool Value) { HasData = Value; }
+
bool isRegistered() const { return IsRegistered; }
void setIsRegistered(bool Value) { IsRegistered = Value; }
diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp
index 358c036f2a7..5b8b013ad08 100644
--- a/lib/MC/ELFObjectWriter.cpp
+++ b/lib/MC/ELFObjectWriter.cpp
@@ -29,6 +29,7 @@
#include "llvm/MC/MCFixup.h"
#include "llvm/MC/MCFixupKindInfo.h"
#include "llvm/MC/MCFragment.h"
+#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSectionELF.h"
@@ -1107,6 +1108,8 @@ uint64_t ELFWriter::writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) {
SectionIndexMap[RelSection] = addToSectionTable(RelSection);
Relocations.push_back(RelSection);
}
+
+ OWriter.TargetObjectWriter->addTargetSectionFlags(Ctx, Section);
}
MCSectionELF *CGProfileSection = nullptr;
diff --git a/lib/MC/MCELFObjectTargetWriter.cpp b/lib/MC/MCELFObjectTargetWriter.cpp
index 483ee94c0db..ff53dd7299c 100644
--- a/lib/MC/MCELFObjectTargetWriter.cpp
+++ b/lib/MC/MCELFObjectTargetWriter.cpp
@@ -26,3 +26,6 @@ void
MCELFObjectTargetWriter::sortRelocs(const MCAssembler &Asm,
std::vector<ELFRelocationEntry> &Relocs) {
}
+
+void MCELFObjectTargetWriter::addTargetSectionFlags(MCContext &Ctx,
+ MCSectionELF &Sec) {}
diff --git a/lib/MC/MCObjectStreamer.cpp b/lib/MC/MCObjectStreamer.cpp
index 4b6dad5ce8f..a622be6d24c 100644
--- a/lib/MC/MCObjectStreamer.cpp
+++ b/lib/MC/MCObjectStreamer.cpp
@@ -493,6 +493,12 @@ void MCObjectStreamer::EmitBytes(StringRef Data) {
MCDataFragment *DF = getOrCreateDataFragment();
flushPendingLabels(DF, DF->getContents().size());
DF->getContents().append(Data.begin(), Data.end());
+
+ // EmitBytes might not cover all possible ways we emit data (or could be used
+ // to emit executable code in some cases), but is the best method we have
+ // right now for checking this.
+ MCSection *Sec = getCurrentSectionOnly();
+ Sec->setHasData(true);
}
void MCObjectStreamer::EmitValueToAlignment(unsigned ByteAlignment,
diff --git a/lib/MC/MCSection.cpp b/lib/MC/MCSection.cpp
index 97bc65387dd..d4f11d10136 100644
--- a/lib/MC/MCSection.cpp
+++ b/lib/MC/MCSection.cpp
@@ -23,7 +23,8 @@ using namespace llvm;
MCSection::MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin)
: Begin(Begin), BundleGroupBeforeFirstInst(false), HasInstructions(false),
- IsRegistered(false), DummyFragment(this), Variant(V), Kind(K) {}
+ HasData(false), IsRegistered(false), DummyFragment(this), Variant(V),
+ Kind(K) {}
MCSymbol *MCSection::getEndSymbol(MCContext &Ctx) {
if (!End)
diff --git a/lib/Target/ARM/ARMTargetObjectFile.cpp b/lib/Target/ARM/ARMTargetObjectFile.cpp
index d0620761ea9..9c13359cba7 100644
--- a/lib/Target/ARM/ARMTargetObjectFile.cpp
+++ b/lib/Target/ARM/ARMTargetObjectFile.cpp
@@ -32,7 +32,8 @@ void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
const TargetMachine &TM) {
const ARMBaseTargetMachine &ARM_TM = static_cast<const ARMBaseTargetMachine &>(TM);
bool isAAPCS_ABI = ARM_TM.TargetABI == ARMBaseTargetMachine::ARMABI::ARM_ABI_AAPCS;
- // genExecuteOnly = ARM_TM.getSubtargetImpl()->genExecuteOnly();
+ bool genExecuteOnly =
+ ARM_TM.getMCSubtargetInfo()->hasFeature(ARM::FeatureExecuteOnly);
TargetLoweringObjectFileELF::Initialize(Ctx, TM);
InitializeELF(isAAPCS_ABI);
@@ -40,6 +41,17 @@ void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
if (isAAPCS_ABI) {
LSDASection = nullptr;
}
+
+ // Make code section unreadable when in execute-only mode
+ if (genExecuteOnly) {
+ unsigned Type = ELF::SHT_PROGBITS;
+ unsigned Flags =
+ ELF::SHF_EXECINSTR | ELF::SHF_ALLOC | ELF::SHF_ARM_PURECODE;
+ // Since we cannot modify flags for an existing section, we create a new
+ // section with the right flags, and use 0 as the unique ID for
+ // execute-only text
+ TextSection = Ctx.getELFSection(".text", Type, Flags, 0, "", 0U);
+ }
}
const MCExpr *ARMElfTargetObjectFile::getTTypeGlobalReference(
diff --git a/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp b/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp
index 7d04c73fb3f..b8ba7584911 100644
--- a/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp
+++ b/lib/Target/ARM/MCTargetDesc/ARMELFObjectWriter.cpp
@@ -14,6 +14,7 @@
#include "llvm/MC/MCELFObjectWriter.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCFixup.h"
+#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/ErrorHandling.h"
@@ -40,6 +41,8 @@ namespace {
bool needsRelocateWithSymbol(const MCSymbol &Sym,
unsigned Type) const override;
+
+ void addTargetSectionFlags(MCContext &Ctx, MCSectionELF &Sec) override;
};
} // end anonymous namespace
@@ -236,6 +239,21 @@ unsigned ARMELFObjectWriter::GetRelocTypeInner(const MCValue &Target,
}
}
+void ARMELFObjectWriter::addTargetSectionFlags(MCContext &Ctx,
+ MCSectionELF &Sec) {
+ // The mix of execute-only and non-execute-only at link time is
+ // non-execute-only. To avoid the empty implicitly created .text
+ // section from making the whole .text section non-execute-only, we
+ // mark it execute-only if it is empty and there is at least one
+ // execute-only section in the object.
+ MCSectionELF *TextSection =
+ static_cast<MCSectionELF *>(Ctx.getObjectFileInfo()->getTextSection());
+ if (Sec.getKind().isExecuteOnly() && !TextSection->hasInstructions() &&
+ !TextSection->hasData()) {
+ TextSection->setFlags(TextSection->getFlags() | ELF::SHF_ARM_PURECODE);
+ }
+}
+
std::unique_ptr<MCObjectTargetWriter>
llvm::createARMELFObjectWriter(uint8_t OSABI) {
return llvm::make_unique<ARMELFObjectWriter>(OSABI);
diff --git a/test/CodeGen/ARM/execute-only.ll b/test/CodeGen/ARM/execute-only.ll
index b5d9d89f1f7..3f42ca3b5f4 100644
--- a/test/CodeGen/ARM/execute-only.ll
+++ b/test/CodeGen/ARM/execute-only.ll
@@ -2,6 +2,9 @@
; RUN: llc -mtriple=thumbv7m-eabi -mattr=+execute-only %s -o - | FileCheck --check-prefix=CHECK --check-prefix=CHECK-T2 %s
; RUN: llc -mtriple=thumbv8m.main-eabi -mattr=+execute-only %s -o - | FileCheck --check-prefix=CHECK --check-prefix=CHECK-T2 %s
+; CHECK-NOT: {{^ *}}.text{{$}}
+; CHECK: .section .text,"axy",%progbits,unique,0
+
@var = global i32 0
define i32 @global() minsize {
diff --git a/test/MC/ARM/elf-execute-only-section.ll b/test/MC/ARM/elf-execute-only-section.ll
new file mode 100644
index 00000000000..2be3f4c7038
--- /dev/null
+++ b/test/MC/ARM/elf-execute-only-section.ll
@@ -0,0 +1,13 @@
+; RUN: llc < %s -mtriple=thumbv8m.base-eabi -mattr=+execute-only -filetype=obj %s -o - | \
+; RUN: llvm-readelf -s | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv8m.main-eabi -mattr=+execute-only -filetype=obj %s -o - | \
+; RUN: llvm-readelf -s | FileCheck %s
+; RUN: llc < %s -mtriple=thumbv7m-eabi -mattr=+execute-only -filetype=obj %s -o - | \
+; RUN: llvm-readelf -s | FileCheck %s
+
+; CHECK-NOT: {{.text[ ]+PROGBITS[ ]+[0-9]+ [0-9]+ [0-9]+ [0-9]+ AX[^p]}}
+; CHECK: {{.text[ ]+PROGBITS[ ]+[0-9]+ [0-9]+ [0-9]+ [0-9]+ AXp}}
+define void @test_func() {
+entry:
+ ret void
+}
diff --git a/test/MC/ELF/ARM/execute-only-populated-text-section.s b/test/MC/ELF/ARM/execute-only-populated-text-section.s
new file mode 100644
index 00000000000..26a9c499f89
--- /dev/null
+++ b/test/MC/ELF/ARM/execute-only-populated-text-section.s
@@ -0,0 +1,27 @@
+// RUN: llvm-mc -filetype=obj -triple thumbv7m-arm-linux-gnu %s -o - \
+// RUN: | llvm-readobj -s -t | FileCheck %s
+
+ .text
+ bx lr
+
+ .section .text.foo,"axy"
+ bx lr
+
+// CHECK: Section {
+// CHECK: Name: .text
+// CHECK-NEXT: Type: SHT_PROGBITS (0x1)
+// CHECK-NEXT: Flags [ (0x6)
+// CHECK-NEXT: SHF_ALLOC (0x2)
+// CHECK-NEXT: SHF_EXECINSTR (0x4)
+// CHECK-NEXT: ]
+// CHECK: }
+
+// CHECK: Section {
+// CHECK: Name: .text.foo
+// CHECK-NEXT: Type: SHT_PROGBITS (0x1)
+// CHECK-NEXT: Flags [ (0x20000006)
+// CHECK-NEXT: SHF_ALLOC (0x2)
+// CHECK-NEXT: SHF_ARM_PURECODE (0x20000000)
+// CHECK-NEXT: SHF_EXECINSTR (0x4)
+// CHECK-NEXT: ]
+// CHECK: }
diff --git a/test/MC/ELF/ARM/execute-only-section.s b/test/MC/ELF/ARM/execute-only-section.s
index 600ef5a41fd..524ba8ac687 100644
--- a/test/MC/ELF/ARM/execute-only-section.s
+++ b/test/MC/ELF/ARM/execute-only-section.s
@@ -20,8 +20,9 @@ foo:
// CHECK: Section {
// CHECK: Name: .text (16)
// CHECK-NEXT: Type: SHT_PROGBITS (0x1)
-// CHECK-NEXT: Flags [ (0x6)
+// CHECK-NEXT: Flags [ (0x20000006)
// CHECK-NEXT: SHF_ALLOC (0x2)
+// CHECK-NEXT: SHF_ARM_PURECODE (0x20000000)
// CHECK-NEXT: SHF_EXECINSTR (0x4)
// CHECK-NEXT: ]
// CHECK: Size: 0
diff --git a/test/MC/ELF/ARM/execute-only-text-section-data.s b/test/MC/ELF/ARM/execute-only-text-section-data.s
new file mode 100644
index 00000000000..3e9abca34a2
--- /dev/null
+++ b/test/MC/ELF/ARM/execute-only-text-section-data.s
@@ -0,0 +1,27 @@
+// RUN: llvm-mc -filetype=obj -triple thumbv7m-arm-linux-gnu %s -o - \
+// RUN: | llvm-readobj -s -t | FileCheck %s
+
+ .text
+ .ascii "test"
+
+ .section .text.foo,"axy"
+ bx lr
+
+// CHECK: Section {
+// CHECK: Name: .text
+// CHECK-NEXT: Type: SHT_PROGBITS (0x1)
+// CHECK-NEXT: Flags [ (0x6)
+// CHECK-NEXT: SHF_ALLOC (0x2)
+// CHECK-NEXT: SHF_EXECINSTR (0x4)
+// CHECK-NEXT: ]
+// CHECK: }
+
+// CHECK: Section {
+// CHECK: Name: .text.foo
+// CHECK-NEXT: Type: SHT_PROGBITS (0x1)
+// CHECK-NEXT: Flags [ (0x20000006)
+// CHECK-NEXT: SHF_ALLOC (0x2)
+// CHECK-NEXT: SHF_ARM_PURECODE (0x20000000)
+// CHECK-NEXT: SHF_EXECINSTR (0x4)
+// CHECK-NEXT: ]
+// CHECK: }
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-27 17:00:20 +0000