[PAC][CodeGen][ELF][AArch64] Support signed GOT #113811
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This re-applies #96164 after revert in #102434. Support the following relocations and assembly operators: - `R_AARCH64_AUTH_ADR_GOT_PAGE` (`:got_auth:` for `adrp`) - `R_AARCH64_AUTH_LD64_GOT_LO12_NC` (`:got_auth_lo12:` for `ldr`) - `R_AARCH64_AUTH_GOT_ADD_LO12_NC` (`:got_auth_lo12:` for `add`) `LOADgotAUTH` pseudo-instruction is introduced which is later expanded to actual instruction sequence like the following. ``` adrp x16, :got_auth:sym add x16, x16, :got_auth_lo12:sym ldr x0, [x16] autia x0, x16 ``` If a resign is requested, like below, `LOADgotPAC` pseudo is used, and GOT load is lowered similarly to `LOADgotAUTH`. ``` @var = global i32 0 define ptr @resign_globalvar() { ret ptr ptrauth (ptr @var, i32 3, i64 43) } ``` If FPAC bit is not set and resign is requested, a check+trap sequence similar to one used for `AUT` pseudo is emitted. Both SelectionDAG and GlobalISel are suppported. For FastISel, we fall back to SelectionDAG. Tests starting with 'ptrauth-' have corresponding variants w/o this prefix. See also specification https://github.com/ARM-software/abi-aa/blob/main/pauthabielf64/pauthabielf64.rst#appendix-signed-got
Before executing auth instruction on a signed address from a GOT slot, we must ensure that the address is not zero since zero addresses are not signed to preserve zero-checks working as expected. A GOT slot might be filled with zero when we have an undefined weak symbol.
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This was referenced Oct 27, 2024
kovdan01
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@llvm/pr-subscribers-backend-aarch64 @llvm/pr-subscribers-mc Author: Daniil Kovalev (kovdan01) Changes[PAC][CodeGen][ELF][AArch64] Support signed GOT This re-applies #96164 after revert in #102434. Support the following relocations and assembly operators:
If a resign is requested, like below, If FPAC bit is not set and auth instruction is emitted, a check+trap sequence Both SelectionDAG and GlobalISel are suppported. Tests starting with 'ptrauth-' have corresponding variants w/o this prefix. See also specification Patch is 49.48 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/113811.diff 21 Files Affected:
diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index 6d2dd0ecbccf31..e79457f925db66 100644
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -169,6 +169,11 @@ class AArch64AsmPrinter : public AsmPrinter {
// adrp-add followed by PAC sign)
void LowerMOVaddrPAC(const MachineInstr &MI);
+ // Emit the sequence for LOADgotAUTH (load signed pointer from signed ELF GOT
+ // and authenticate it with, if FPAC bit is not set, check+trap sequence after
+ // authenticating)
+ void LowerLOADgotAUTH(const MachineInstr &MI);
+
/// tblgen'erated driver function for lowering simple MI->MC
/// pseudo instructions.
bool lowerPseudoInstExpansion(const MachineInstr *MI, MCInst &Inst);
@@ -873,6 +878,22 @@ void AArch64AsmPrinter::emitEndOfAsmFile(Module &M) {
OutStreamer->addBlankLine();
}
+
+ // With signed ELF GOT enabled, the linker looks at the symbol type to
+ // choose between keys IA (for STT_FUNC) and DA (for other types). Symbols
+ // for functions not defined in the module have STT_NOTYPE type by default.
+ // This makes linker to emit signing schema with DA key (instead of IA) for
+ // corresponding R_AARCH64_AUTH_GLOB_DAT dynamic reloc. To avoid that, force
+ // all function symbols used in the module to have STT_FUNC type. See
+ // https://github.com/ARM-software/abi-aa/blob/main/pauthabielf64/pauthabielf64.rst#default-signing-schema
+ const auto *PtrAuthELFGOTFlag = mdconst::extract_or_null<ConstantInt>(
+ M.getModuleFlag("ptrauth-elf-got"));
+ if (PtrAuthELFGOTFlag && PtrAuthELFGOTFlag->getZExtValue() == 1)
+ for (const GlobalValue &GV : M.global_values())
+ if (!GV.use_empty() && isa<Function>(GV) &&
+ !GV.getName().starts_with("llvm."))
+ OutStreamer->emitSymbolAttribute(getSymbol(&GV),
+ MCSA_ELF_TypeFunction);
}
// Emit stack and fault map information.
@@ -2068,6 +2089,10 @@ void AArch64AsmPrinter::LowerLOADauthptrstatic(const MachineInstr &MI) {
void AArch64AsmPrinter::LowerMOVaddrPAC(const MachineInstr &MI) {
const bool IsGOTLoad = MI.getOpcode() == AArch64::LOADgotPAC;
+ const bool IsELFSignedGOT = MI.getParent()
+ ->getParent()
+ ->getInfo<AArch64FunctionInfo>()
+ ->hasELFSignedGOT();
MachineOperand GAOp = MI.getOperand(0);
const uint64_t KeyC = MI.getOperand(1).getImm();
assert(KeyC <= AArch64PACKey::LAST &&
@@ -2084,9 +2109,17 @@ void AArch64AsmPrinter::LowerMOVaddrPAC(const MachineInstr &MI) {
// Emit:
// target materialization:
// - via GOT:
- // adrp x16, :got:target
- // ldr x16, [x16, :got_lo12:target]
- // add offset to x16 if offset != 0
+ // - unsigned GOT:
+ // adrp x16, :got:target
+ // ldr x16, [x16, :got_lo12:target]
+ // add offset to x16 if offset != 0
+ // - ELF signed GOT:
+ // adrp x17, :got:target
+ // add x17, x17, :got_auth_lo12:target
+ // ldr x16, [x17]
+ // aut{i|d}a x16, x17
+ // check+trap sequence (if no FPAC)
+ // add offset to x16 if offset != 0
//
// - direct:
// adrp x16, target
@@ -2129,13 +2162,48 @@ void AArch64AsmPrinter::LowerMOVaddrPAC(const MachineInstr &MI) {
MCInstLowering.lowerOperand(GAMOLo, GAMCLo);
EmitToStreamer(
- MCInstBuilder(AArch64::ADRP).addReg(AArch64::X16).addOperand(GAMCHi));
+ MCInstBuilder(AArch64::ADRP)
+ .addReg(IsGOTLoad && IsELFSignedGOT ? AArch64::X17 : AArch64::X16)
+ .addOperand(GAMCHi));
if (IsGOTLoad) {
- EmitToStreamer(MCInstBuilder(AArch64::LDRXui)
- .addReg(AArch64::X16)
- .addReg(AArch64::X16)
- .addOperand(GAMCLo));
+ if (IsELFSignedGOT) {
+ EmitToStreamer(MCInstBuilder(AArch64::ADDXri)
+ .addReg(AArch64::X17)
+ .addReg(AArch64::X17)
+ .addOperand(GAMCLo)
+ .addImm(0));
+
+ EmitToStreamer(MCInstBuilder(AArch64::LDRXui)
+ .addReg(AArch64::X16)
+ .addReg(AArch64::X17)
+ .addImm(0));
+
+ assert(GAOp.isGlobal());
+ assert(GAOp.getGlobal()->getValueType() != nullptr);
+ unsigned AuthOpcode = GAOp.getGlobal()->getValueType()->isFunctionTy()
+ ? AArch64::AUTIA
+ : AArch64::AUTDA;
+
+ EmitToStreamer(MCInstBuilder(AuthOpcode)
+ .addReg(AArch64::X16)
+ .addReg(AArch64::X16)
+ .addReg(AArch64::X17));
+
+ if (!STI->hasFPAC()) {
+ auto AuthKey = (AuthOpcode == AArch64::AUTIA ? AArch64PACKey::IA
+ : AArch64PACKey::DA);
+
+ emitPtrauthCheckAuthenticatedValue(AArch64::X16, AArch64::X17, AuthKey,
+ /*ShouldTrap=*/true,
+ /*OnFailure=*/nullptr);
+ }
+ } else {
+ EmitToStreamer(MCInstBuilder(AArch64::LDRXui)
+ .addReg(AArch64::X16)
+ .addReg(AArch64::X16)
+ .addOperand(GAMCLo));
+ }
} else {
EmitToStreamer(MCInstBuilder(AArch64::ADDXri)
.addReg(AArch64::X16)
@@ -2203,6 +2271,69 @@ void AArch64AsmPrinter::LowerMOVaddrPAC(const MachineInstr &MI) {
EmitToStreamer(MIB);
}
+void AArch64AsmPrinter::LowerLOADgotAUTH(const MachineInstr &MI) {
+ Register DstReg = MI.getOperand(0).getReg();
+ Register AuthResultReg = STI->hasFPAC() ? DstReg : AArch64::X16;
+ const MachineOperand &GAMO = MI.getOperand(1);
+ assert(GAMO.getOffset() == 0);
+
+ MachineOperand GAHiOp(GAMO);
+ MachineOperand GALoOp(GAMO);
+ GAHiOp.addTargetFlag(AArch64II::MO_PAGE);
+ GALoOp.addTargetFlag(AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
+
+ MCOperand GAMCHi, GAMCLo;
+ MCInstLowering.lowerOperand(GAHiOp, GAMCHi);
+ MCInstLowering.lowerOperand(GALoOp, GAMCLo);
+
+ EmitToStreamer(
+ MCInstBuilder(AArch64::ADRP).addReg(AArch64::X17).addOperand(GAMCHi));
+
+ EmitToStreamer(MCInstBuilder(AArch64::ADDXri)
+ .addReg(AArch64::X17)
+ .addReg(AArch64::X17)
+ .addOperand(GAMCLo)
+ .addImm(0));
+
+ EmitToStreamer(MCInstBuilder(AArch64::LDRXui)
+ .addReg(AuthResultReg)
+ .addReg(AArch64::X17)
+ .addImm(0));
+
+ assert(GAMO.isGlobal());
+ MCSymbol *UndefWeakSym;
+ if (GAMO.getGlobal()->hasExternalWeakLinkage()) {
+ UndefWeakSym = createTempSymbol("undef_weak");
+ EmitToStreamer(
+ MCInstBuilder(AArch64::CBZX)
+ .addReg(AuthResultReg)
+ .addExpr(MCSymbolRefExpr::create(UndefWeakSym, OutContext)));
+ }
+
+ assert(GAMO.getGlobal()->getValueType() != nullptr);
+ unsigned AuthOpcode = GAMO.getGlobal()->getValueType()->isFunctionTy()
+ ? AArch64::AUTIA
+ : AArch64::AUTDA;
+ EmitToStreamer(MCInstBuilder(AuthOpcode)
+ .addReg(AuthResultReg)
+ .addReg(AuthResultReg)
+ .addReg(AArch64::X17));
+
+ if (GAMO.getGlobal()->hasExternalWeakLinkage())
+ OutStreamer->emitLabel(UndefWeakSym);
+
+ if (!STI->hasFPAC()) {
+ auto AuthKey =
+ (AuthOpcode == AArch64::AUTIA ? AArch64PACKey::IA : AArch64PACKey::DA);
+
+ emitPtrauthCheckAuthenticatedValue(AuthResultReg, AArch64::X17, AuthKey,
+ /*ShouldTrap=*/true,
+ /*OnFailure=*/nullptr);
+
+ emitMovXReg(DstReg, AuthResultReg);
+ }
+}
+
const MCExpr *
AArch64AsmPrinter::lowerBlockAddressConstant(const BlockAddress &BA) {
const MCExpr *BAE = AsmPrinter::lowerBlockAddressConstant(BA);
@@ -2381,6 +2512,10 @@ void AArch64AsmPrinter::emitInstruction(const MachineInstr *MI) {
LowerMOVaddrPAC(*MI);
return;
+ case AArch64::LOADgotAUTH:
+ LowerLOADgotAUTH(*MI);
+ return;
+
case AArch64::BRA:
case AArch64::BLRA:
emitPtrauthBranch(MI);
diff --git a/llvm/lib/Target/AArch64/AArch64FastISel.cpp b/llvm/lib/Target/AArch64/AArch64FastISel.cpp
index cbf38f2c57a35e..4487d34a936c4d 100644
--- a/llvm/lib/Target/AArch64/AArch64FastISel.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FastISel.cpp
@@ -453,6 +453,9 @@ unsigned AArch64FastISel::materializeGV(const GlobalValue *GV) {
if (!Subtarget->useSmallAddressing() && !Subtarget->isTargetMachO())
return 0;
+ if (FuncInfo.MF->getInfo<AArch64FunctionInfo>()->hasELFSignedGOT())
+ return 0;
+
unsigned OpFlags = Subtarget->ClassifyGlobalReference(GV, TM);
EVT DestEVT = TLI.getValueType(DL, GV->getType(), true);
diff --git a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
index 4c0cd1ac3d4512..884e5fe9f60040 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -9598,6 +9598,11 @@ SDValue AArch64TargetLowering::getGOT(NodeTy *N, SelectionDAG &DAG,
SDValue GotAddr = getTargetNode(N, Ty, DAG, AArch64II::MO_GOT | Flags);
// FIXME: Once remat is capable of dealing with instructions with register
// operands, expand this into two nodes instead of using a wrapper node.
+ if (DAG.getMachineFunction()
+ .getInfo<AArch64FunctionInfo>()
+ ->hasELFSignedGOT())
+ return SDValue(DAG.getMachineNode(AArch64::LOADgotAUTH, DL, Ty, GotAddr),
+ 0);
return DAG.getNode(AArch64ISD::LOADgot, DL, Ty, GotAddr);
}
diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.td b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
index fe3c8578b52aa4..fdaa01598dcba5 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -1937,8 +1937,15 @@ let Predicates = [HasPAuth] in {
Sched<[WriteI, ReadI]> {
let isReMaterializable = 1;
let isCodeGenOnly = 1;
- let Size = 40; // 12 fixed + 28 variable, for pointer offset, and discriminator
- let Defs = [X16,X17];
+ let Size = 68; // 12 fixed + 56 variable, for pointer offset, discriminator and
+ // ELF signed GOT signed pointer authentication (if no FPAC)
+ let Defs = [X16,X17,NZCV];
+ }
+
+ def LOADgotAUTH : Pseudo<(outs GPR64common:$dst), (ins i64imm:$addr), []>,
+ Sched<[WriteI, ReadI]> {
+ let Defs = [X16,X17,NZCV];
+ let Size = 44;
}
// Load a signed global address from a special $auth_ptr$ stub slot.
diff --git a/llvm/lib/Target/AArch64/AArch64MCInstLower.cpp b/llvm/lib/Target/AArch64/AArch64MCInstLower.cpp
index 48672241f905d5..9f234b0f917058 100644
--- a/llvm/lib/Target/AArch64/AArch64MCInstLower.cpp
+++ b/llvm/lib/Target/AArch64/AArch64MCInstLower.cpp
@@ -12,6 +12,7 @@
//===----------------------------------------------------------------------===//
#include "AArch64MCInstLower.h"
+#include "AArch64MachineFunctionInfo.h"
#include "MCTargetDesc/AArch64MCExpr.h"
#include "Utils/AArch64BaseInfo.h"
#include "llvm/CodeGen/AsmPrinter.h"
@@ -185,9 +186,12 @@ MCOperand AArch64MCInstLower::lowerSymbolOperandELF(const MachineOperand &MO,
MCSymbol *Sym) const {
uint32_t RefFlags = 0;
- if (MO.getTargetFlags() & AArch64II::MO_GOT)
- RefFlags |= AArch64MCExpr::VK_GOT;
- else if (MO.getTargetFlags() & AArch64II::MO_TLS) {
+ if (MO.getTargetFlags() & AArch64II::MO_GOT) {
+ const MachineFunction *MF = MO.getParent()->getParent()->getParent();
+ RefFlags |= (MF->getInfo<AArch64FunctionInfo>()->hasELFSignedGOT()
+ ? AArch64MCExpr::VK_GOT_AUTH
+ : AArch64MCExpr::VK_GOT);
+ } else if (MO.getTargetFlags() & AArch64II::MO_TLS) {
TLSModel::Model Model;
if (MO.isGlobal()) {
const GlobalValue *GV = MO.getGlobal();
diff --git a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
index e96c5a953ff2bb..56a38bc6d4023a 100644
--- a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
@@ -72,6 +72,18 @@ static bool ShouldSignWithBKey(const Function &F, const AArch64Subtarget &STI) {
return Key == "b_key";
}
+static bool HasELFSignedGOTHelper(const Function &F,
+ const AArch64Subtarget *STI) {
+ if (!Triple(STI->getTargetTriple()).isOSBinFormatELF())
+ return false;
+ const Module *M = F.getParent();
+ const auto *Flag = mdconst::extract_or_null<ConstantInt>(
+ M->getModuleFlag("ptrauth-elf-got"));
+ if (Flag && Flag->getZExtValue() == 1)
+ return true;
+ return false;
+}
+
AArch64FunctionInfo::AArch64FunctionInfo(const Function &F,
const AArch64Subtarget *STI) {
// If we already know that the function doesn't have a redzone, set
@@ -80,6 +92,7 @@ AArch64FunctionInfo::AArch64FunctionInfo(const Function &F,
HasRedZone = false;
std::tie(SignReturnAddress, SignReturnAddressAll) = GetSignReturnAddress(F);
SignWithBKey = ShouldSignWithBKey(F, *STI);
+ HasELFSignedGOT = HasELFSignedGOTHelper(F, STI);
// TODO: skip functions that have no instrumented allocas for optimization
IsMTETagged = F.hasFnAttribute(Attribute::SanitizeMemTag);
diff --git a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h
index 85b9733e95c529..a77fdaf19bcf5f 100644
--- a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h
+++ b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h
@@ -177,6 +177,11 @@ class AArch64FunctionInfo final : public MachineFunctionInfo {
/// SignWithBKey modifies the default PAC-RET mode to signing with the B key.
bool SignWithBKey = false;
+ /// HasELFSignedGOT is true if the target binary format is ELF and the IR
+ /// module containing the corresponding function has "ptrauth-elf-got" flag
+ /// set to 1.
+ bool HasELFSignedGOT = false;
+
/// SigningInstrOffset captures the offset of the PAC-RET signing instruction
/// within the prologue, so it can be re-used for authentication in the
/// epilogue when using PC as a second salt (FEAT_PAuth_LR)
@@ -509,6 +514,8 @@ class AArch64FunctionInfo final : public MachineFunctionInfo {
bool shouldSignWithBKey() const { return SignWithBKey; }
+ bool hasELFSignedGOT() const { return HasELFSignedGOT; }
+
MCSymbol *getSigningInstrLabel() const { return SignInstrLabel; }
void setSigningInstrLabel(MCSymbol *Label) { SignInstrLabel = Label; }
diff --git a/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp b/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
index dfc5e04110cf57..b83ca3f7e52db4 100644
--- a/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
+++ b/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
@@ -896,6 +896,7 @@ class AArch64Operand : public MCParsedAsmOperand {
if (DarwinRefKind == MCSymbolRefExpr::VK_PAGEOFF ||
ELFRefKind == AArch64MCExpr::VK_LO12 ||
ELFRefKind == AArch64MCExpr::VK_GOT_LO12 ||
+ ELFRefKind == AArch64MCExpr::VK_GOT_AUTH_LO12 ||
ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12 ||
ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12_NC ||
ELFRefKind == AArch64MCExpr::VK_TPREL_LO12 ||
@@ -1007,19 +1008,20 @@ class AArch64Operand : public MCParsedAsmOperand {
int64_t Addend;
if (AArch64AsmParser::classifySymbolRef(Expr, ELFRefKind,
DarwinRefKind, Addend)) {
- return DarwinRefKind == MCSymbolRefExpr::VK_PAGEOFF
- || DarwinRefKind == MCSymbolRefExpr::VK_TLVPPAGEOFF
- || (DarwinRefKind == MCSymbolRefExpr::VK_GOTPAGEOFF && Addend == 0)
- || ELFRefKind == AArch64MCExpr::VK_LO12
- || ELFRefKind == AArch64MCExpr::VK_DTPREL_HI12
- || ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12
- || ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12_NC
- || ELFRefKind == AArch64MCExpr::VK_TPREL_HI12
- || ELFRefKind == AArch64MCExpr::VK_TPREL_LO12
- || ELFRefKind == AArch64MCExpr::VK_TPREL_LO12_NC
- || ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12
- || ELFRefKind == AArch64MCExpr::VK_SECREL_HI12
- || ELFRefKind == AArch64MCExpr::VK_SECREL_LO12;
+ return DarwinRefKind == MCSymbolRefExpr::VK_PAGEOFF ||
+ DarwinRefKind == MCSymbolRefExpr::VK_TLVPPAGEOFF ||
+ (DarwinRefKind == MCSymbolRefExpr::VK_GOTPAGEOFF && Addend == 0) ||
+ ELFRefKind == AArch64MCExpr::VK_LO12 ||
+ ELFRefKind == AArch64MCExpr::VK_GOT_AUTH_LO12 ||
+ ELFRefKind == AArch64MCExpr::VK_DTPREL_HI12 ||
+ ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12 ||
+ ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12_NC ||
+ ELFRefKind == AArch64MCExpr::VK_TPREL_HI12 ||
+ ELFRefKind == AArch64MCExpr::VK_TPREL_LO12 ||
+ ELFRefKind == AArch64MCExpr::VK_TPREL_LO12_NC ||
+ ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12 ||
+ ELFRefKind == AArch64MCExpr::VK_SECREL_HI12 ||
+ ELFRefKind == AArch64MCExpr::VK_SECREL_LO12;
}
// If it's a constant, it should be a real immediate in range.
@@ -3308,6 +3310,7 @@ ParseStatus AArch64AsmParser::tryParseAdrpLabel(OperandVector &Operands) {
DarwinRefKind != MCSymbolRefExpr::VK_TLVPPAGE &&
ELFRefKind != AArch64MCExpr::VK_ABS_PAGE_NC &&
ELFRefKind != AArch64MCExpr::VK_GOT_PAGE &&
+ ELFRefKind != AArch64MCExpr::VK_GOT_AUTH_PAGE &&
ELFRefKind != AArch64MCExpr::VK_GOT_PAGE_LO15 &&
ELFRefKind != AArch64MCExpr::VK_GOTTPREL_PAGE &&
ELFRefKind != AArch64MCExpr::VK_TLSDESC_PAGE) {
@@ -4427,6 +4430,8 @@ bool AArch64AsmParser::parseSymbolicImmVal(const MCExpr *&ImmVal) {
.Case("got", AArch64MCExpr::VK_GOT_PAGE)
.Case("gotpage_lo15", AArch64MCExpr::VK_GOT_PAGE_LO15)
.Case("got_lo12", AArch64MCExpr::VK_GOT_LO12)
+ .Case("got_auth", AArch64MCExpr::VK_GOT_AUTH_PAGE)
+ .Case("got_auth_lo12", AArch64MCExpr::VK_GOT_AUTH_LO12)
.Case("gottprel", AArch64MCExpr::VK_GOTTPREL_PAGE)
.Case("gottprel_lo12", AArch64MCExpr::VK_GOTTPREL_LO12_NC)
.Case("gottprel_g1", AArch64MCExpr::VK_GOTTPREL_G1)
@@ -5800,6 +5805,7 @@ bool AArch64AsmParser::validateInstruction(MCInst &Inst, SMLoc &IDLoc,
// Only allow these with ADDXri/ADDWri
if ((ELFRefKind == AArch64MCExpr::VK_LO12 ||
+ ELFRefKind == AArch64MCExpr::VK_GOT_AUTH_LO12 ||
ELFRefKind == AArch64MCExpr::VK_DTPREL_HI12 ||
ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12 ||
ELFRefKind == AArch64MCExpr::VK_DTPREL_LO12_NC ||
diff --git a/llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp b/llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
index df0c09d32c074a..1c75868645a947 100644
--- a/llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
@@ -2959,7 +2959,9 @@ bool AArch64InstructionSelector::select(MachineInstr &I) {
}
if (OpFlags & AArch64II::MO_GOT) {
- I.setDesc(TII.get(AArch64::LOADgot));
+ I.setDesc(TII.get(MF.getInfo<AArch64FunctionInfo>()->hasELFSignedGOT()
+ ? AArch64::LOADgotAUTH
+ : AArch64::LOADgot));
I.getOperand(1).setTargetFlags(OpFlags);
} else if (TM.getCodeModel() == CodeModel::Large &&
!TM.isPositionIndependent()) {
diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
index 83aac6fdae7290..b5f5a58d96288e 100644
--- a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
+++ b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObj...
[truncated]
|
MaskRay
approved these changes
Oct 30, 2024
| @@ -72,6 +72,18 @@ static bool ShouldSignWithBKey(const Function &F, const AArch64Subtarget &STI) { | |||
| return Key == "b_key"; | |||
| } | |||
|
|
|||
| static bool HasELFSignedGOTHelper(const Function &F, | |||
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hasELF... (fix style when adding new functions)
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Fixed, thanks! See 48ce9aa
smallp-o-p
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Nov 3, 2024
This re-applies llvm#96164 after revert in llvm#102434. Support the following relocations and assembly operators: - `R_AARCH64_AUTH_ADR_GOT_PAGE` (`:got_auth:` for `adrp`) - `R_AARCH64_AUTH_LD64_GOT_LO12_NC` (`:got_auth_lo12:` for `ldr`) - `R_AARCH64_AUTH_GOT_ADD_LO12_NC` (`:got_auth_lo12:` for `add`) `LOADgotAUTH` pseudo-instruction is introduced which is later expanded to actual instruction sequence like the following. ``` adrp x16, :got_auth:sym add x16, x16, :got_auth_lo12:sym ldr x0, [x16] autia x0, x16 ``` If a resign is requested, like below, `LOADgotPAC` pseudo is used, and GOT load is lowered similarly to `LOADgotAUTH`. ``` @var = global i32 0 define ptr @resign_globalvar() { ret ptr ptrauth (ptr @var, i32 3, i64 43) } ``` If FPAC bit is not set and auth instruction is emitted, a check+trap sequence similar to one used for `AUT` pseudo is emitted to ensure auth success. Both SelectionDAG and GlobalISel are suppported. For FastISel, we fall back to SelectionDAG. Tests starting with 'ptrauth-' have corresponding variants w/o this prefix. See also specification https://github.com/ARM-software/abi-aa/blob/main/pauthabielf64/pauthabielf64.rst#appendix-signed-got
NoumanAmir657
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that referenced
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Nov 4, 2024
This re-applies llvm#96164 after revert in llvm#102434. Support the following relocations and assembly operators: - `R_AARCH64_AUTH_ADR_GOT_PAGE` (`:got_auth:` for `adrp`) - `R_AARCH64_AUTH_LD64_GOT_LO12_NC` (`:got_auth_lo12:` for `ldr`) - `R_AARCH64_AUTH_GOT_ADD_LO12_NC` (`:got_auth_lo12:` for `add`) `LOADgotAUTH` pseudo-instruction is introduced which is later expanded to actual instruction sequence like the following. ``` adrp x16, :got_auth:sym add x16, x16, :got_auth_lo12:sym ldr x0, [x16] autia x0, x16 ``` If a resign is requested, like below, `LOADgotPAC` pseudo is used, and GOT load is lowered similarly to `LOADgotAUTH`. ``` @var = global i32 0 define ptr @resign_globalvar() { ret ptr ptrauth (ptr @var, i32 3, i64 43) } ``` If FPAC bit is not set and auth instruction is emitted, a check+trap sequence similar to one used for `AUT` pseudo is emitted to ensure auth success. Both SelectionDAG and GlobalISel are suppported. For FastISel, we fall back to SelectionDAG. Tests starting with 'ptrauth-' have corresponding variants w/o this prefix. See also specification https://github.com/ARM-software/abi-aa/blob/main/pauthabielf64/pauthabielf64.rst#appendix-signed-got
kovdan01
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Dec 17, 2024
Depends on #113811 Support `R_AARCH64_AUTH_ADR_GOT_PAGE`, `R_AARCH64_AUTH_GOT_LO12_NC` and `R_AARCH64_AUTH_GOT_ADD_LO12_NC` GOT-generating relocations. For preemptible symbols, dynamic relocation `R_AARCH64_AUTH_GLOB_DAT` is emitted. Otherwise, we unconditionally emit `R_AARCH64_AUTH_RELATIVE` dynamic relocation since pointers in signed GOT needs to be signed during dynamic link time.
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This re-applies #96164 after revert in #102434.
Support the following relocations and assembly operators:
R_AARCH64_AUTH_ADR_GOT_PAGE(:got_auth:foradrp)R_AARCH64_AUTH_LD64_GOT_LO12_NC(:got_auth_lo12:forldr)R_AARCH64_AUTH_GOT_ADD_LO12_NC(:got_auth_lo12:foradd)LOADgotAUTHpseudo-instruction is introduced which is later expanded toactual instruction sequence like the following.
If a resign is requested, like below,
LOADgotPACpseudo is used, and GOTload is lowered similarly to
LOADgotAUTH.If FPAC bit is not set and auth instruction is emitted, a check+trap sequence
similar to one used for
AUTpseudo is emitted to ensure auth success.Both SelectionDAG and GlobalISel are suppported.
For FastISel, we fall back to SelectionDAG.
Tests starting with 'ptrauth-' have corresponding variants w/o this prefix.
See also specification
https://github.com/ARM-software/abi-aa/blob/main/pauthabielf64/pauthabielf64.rst#appendix-signed-got