[llvm] [PAC][CodeGen][ELF][AArch64] Support signed GOT (PR #96164)

via llvm-commits llvm-commits at lists.llvm.org
Thu Jun 20 04:24:46 PDT 2024


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-backend-aarch64

@llvm/pr-subscribers-mc

Author: Daniil Kovalev (kovdan01)

<details>
<summary>Changes</summary>

Depends on #<!-- -->96158 and #<!-- -->96159

Support the following relocations and assembly operators:

- `R_AARCH64_AUTH_ADR_GOT_PAGE` (`:got_auth:` for `adrp`)
- `R_AARCH64_AUTH_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
```

Both SelectionDAG and GlobalISel are suppported. For FastISel, we fall back to SelectionDAG.

Tests with 'auth' in name have corresponding variants w/o it.

---

Patch is 31.86 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/96164.diff


20 Files Affected:

- (modified) llvm/lib/Target/AArch64/AArch64ExpandPseudoInsts.cpp (+33) 
- (modified) llvm/lib/Target/AArch64/AArch64FastISel.cpp (+3) 
- (modified) llvm/lib/Target/AArch64/AArch64ISelLowering.cpp (+5) 
- (modified) llvm/lib/Target/AArch64/AArch64InstrInfo.td (+4) 
- (modified) llvm/lib/Target/AArch64/AArch64MCInstLower.cpp (+7-3) 
- (modified) llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp (+21) 
- (modified) llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h (+10) 
- (modified) llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp (+19-13) 
- (modified) llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp (+3-1) 
- (modified) llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp (+29-5) 
- (modified) llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp (+5) 
- (modified) llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.h (+5) 
- (added) llvm/test/CodeGen/AArch64/basic-pic-auth.ll (+39) 
- (added) llvm/test/CodeGen/AArch64/elf-globals-pic-auth.ll (+23) 
- (added) llvm/test/CodeGen/AArch64/extern-weak-auth.ll (+36) 
- (added) llvm/test/CodeGen/AArch64/got-abuse-auth.ll (+44) 
- (added) llvm/test/CodeGen/AArch64/tagged-globals-pic-auth.ll (+66) 
- (added) llvm/test/MC/AArch64/adrp-auth-relocation.s (+12) 
- (modified) llvm/test/MC/AArch64/arm64-elf-relocs.s (+17-3) 
- (modified) llvm/test/MC/AArch64/ilp32-diagnostics.s (+8) 


``````````diff
diff --git a/llvm/lib/Target/AArch64/AArch64ExpandPseudoInsts.cpp b/llvm/lib/Target/AArch64/AArch64ExpandPseudoInsts.cpp
index 9b7fc228d5de8..72c767200b380 100644
--- a/llvm/lib/Target/AArch64/AArch64ExpandPseudoInsts.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ExpandPseudoInsts.cpp
@@ -1291,7 +1291,40 @@ bool AArch64ExpandPseudo::expandMI(MachineBasicBlock &MBB,
     MI.eraseFromParent();
     return true;
   }
+  case AArch64::LOADgotAUTH: {
+    Register DstReg = MI.getOperand(0).getReg();
+    const MachineOperand &MO1 = MI.getOperand(1);
+
+    MachineOperand GAHiOp(MO1);
+    MachineOperand GALoOp(MO1);
+    GAHiOp.addTargetFlag(AArch64II::MO_PAGE);
+    GALoOp.addTargetFlag(AArch64II::MO_PAGEOFF | AArch64II::MO_NC);
+
+    DebugLoc DL = MI.getDebugLoc();
+    BuildMI(MBB, MBBI, MI.getDebugLoc(), TII->get(AArch64::ADRP), AArch64::X16)
+        .add(GAHiOp);
 
+    BuildMI(MBB, MBBI, DL, TII->get(AArch64::ADDXri), AArch64::X16)
+        .addReg(AArch64::X16)
+        .add(GALoOp)
+        .addImm(0);
+
+    BuildMI(MBB, MBBI, DL, TII->get(AArch64::LDRXui), DstReg)
+        .addReg(AArch64::X16)
+        .addImm(0);
+
+    assert(MO1.isGlobal());
+    assert(MO1.getGlobal()->getValueType() != nullptr);
+    unsigned AuthOpcode = MO1.getGlobal()->getValueType()->isFunctionTy()
+                              ? AArch64::AUTIA
+                              : AArch64::AUTDA;
+    BuildMI(MBB, MBBI, DL, TII->get(AuthOpcode), DstReg)
+        .addReg(DstReg)
+        .addReg(AArch64::X16);
+
+    MI.eraseFromParent();
+    return true;
+  }
   case AArch64::LOADgot: {
     MachineFunction *MF = MBB.getParent();
     Register DstReg = MI.getOperand(0).getReg();
diff --git a/llvm/lib/Target/AArch64/AArch64FastISel.cpp b/llvm/lib/Target/AArch64/AArch64FastISel.cpp
index 56fd15f23363d..0729a63cf11f1 100644
--- a/llvm/lib/Target/AArch64/AArch64FastISel.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FastISel.cpp
@@ -452,6 +452,9 @@ 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 c790209cc221f..a37fc580af5ce 100644
--- a/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64ISelLowering.cpp
@@ -9044,6 +9044,11 @@ 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 6afee9bd388a6..a0206e0af44a7 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -1785,6 +1785,10 @@ let Predicates = [HasPAuth] in {
               (AUTH_TCRETURN_BTI tcGPRx16x17:$dst, imm:$FPDiff, imm:$Key,
                                  imm:$Disc, tcGPR64:$AddrDisc)>;
 
+  def LOADgotAUTH : Pseudo<(outs GPR64common:$dst), (ins i64imm:$addr), []>,
+               Sched<[WriteI, ReadI]> {
+    let Defs = [X16];
+  }
 }
 
 // v9.5-A pointer authentication extensions
diff --git a/llvm/lib/Target/AArch64/AArch64MCInstLower.cpp b/llvm/lib/Target/AArch64/AArch64MCInstLower.cpp
index 37d621cd2f658..1dc7b37e09caa 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"
@@ -184,9 +185,12 @@ 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 957d7bc79b187..61e5d9b35209f 100644
--- a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
@@ -16,6 +16,7 @@
 #include "AArch64MachineFunctionInfo.h"
 #include "AArch64InstrInfo.h"
 #include "AArch64Subtarget.h"
+#include "llvm/BinaryFormat/ELF.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/Metadata.h"
 #include "llvm/IR/Module.h"
@@ -82,6 +83,25 @@ 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();
+  uint64_t PAuthABIPlatform = -1;
+  if (const auto *PAP = mdconst::extract_or_null<ConstantInt>(
+          M->getModuleFlag("aarch64-elf-pauthabi-platform")))
+    PAuthABIPlatform = PAP->getZExtValue();
+  if (PAuthABIPlatform != ELF::AARCH64_PAUTH_PLATFORM_LLVM_LINUX)
+    return false;
+  uint64_t PAuthABIVersion = -1;
+  if (const auto *PAV = mdconst::extract_or_null<ConstantInt>(
+          M->getModuleFlag("aarch64-elf-pauthabi-version")))
+    PAuthABIVersion = PAV->getZExtValue();
+  return (PAuthABIVersion &
+          (1 << ELF::AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_GOT)) != 0;
+}
+
 AArch64FunctionInfo::AArch64FunctionInfo(const Function &F,
                                          const AArch64Subtarget *STI) {
   // If we already know that the function doesn't have a redzone, set
@@ -90,6 +110,7 @@ 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 001521d1101eb..d89ed5f8e56bf 100644
--- a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h
+++ b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.h
@@ -171,6 +171,14 @@ 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 the following flags:
+  /// - aarch64-elf-pauthabi-platform flag equal to
+  ///   AARCH64_PAUTH_PLATFORM_LLVM_LINUX;
+  /// - aarch64-elf-pauthabi-version flag with
+  ///   AARCH64_PAUTH_PLATFORM_LLVM_LINUX_VERSION_GOT bit set.
+  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)
@@ -482,6 +490,8 @@ 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 57e4f6d298d8d..7f9d115b865da 100644
--- a/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
+++ b/llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
@@ -875,6 +875,7 @@ 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 ||
@@ -986,19 +987,20 @@ 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.
@@ -3250,6 +3252,7 @@ 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) {
@@ -4334,6 +4337,8 @@ 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)
@@ -5708,6 +5713,7 @@ 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 d32007ec45fb6..accecd7b27446 100644
--- a/llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
+++ b/llvm/lib/Target/AArch64/GISel/AArch64InstructionSelector.cpp
@@ -2827,7 +2827,9 @@ 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 b4c5cde5fd888..d21408ddf844a 100644
--- a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
+++ b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp
@@ -167,6 +167,15 @@ unsigned AArch64ELFObjectWriter::getRelocType(MCContext &Ctx,
       }
       if (SymLoc == AArch64MCExpr::VK_GOT && !IsNC)
         return R_CLS(ADR_GOT_PAGE);
+      if (SymLoc == AArch64MCExpr::VK_GOT_AUTH && !IsNC) {
+        if (IsILP32) {
+          Ctx.reportError(Fixup.getLoc(),
+                          "ILP32 ADRP AUTH relocation not supported "
+                          "(LP64 eqv: AUTH_ADR_GOT_PAGE)");
+          return ELF::R_AARCH64_NONE;
+        }
+        return ELF::R_AARCH64_AUTH_ADR_GOT_PAGE;
+      }
       if (SymLoc == AArch64MCExpr::VK_GOTTPREL && !IsNC)
         return R_CLS(TLSIE_ADR_GOTTPREL_PAGE21);
       if (SymLoc == AArch64MCExpr::VK_TLSDESC && !IsNC)
@@ -237,6 +246,15 @@ unsigned AArch64ELFObjectWriter::getRelocType(MCContext &Ctx,
         return R_CLS(TLSLE_ADD_TPREL_LO12);
       if (RefKind == AArch64MCExpr::VK_TLSDESC_LO12)
         return R_CLS(TLSDESC_ADD_LO12);
+      if (RefKind == AArch64MCExpr::VK_GOT_AUTH_LO12 && IsNC) {
+        if (IsILP32) {
+          Ctx.reportError(Fixup.getLoc(),
+                          "ILP32 ADD AUTH relocation not supported "
+                          "(LP64 eqv: AUTH_GOT_ADD_LO12_NC)");
+          return ELF::R_AARCH64_NONE;
+        }
+        return ELF::R_AARCH64_AUTH_GOT_ADD_LO12_NC;
+      }
       if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
         return R_CLS(ADD_ABS_LO12_NC);
 
@@ -329,17 +347,23 @@ unsigned AArch64ELFObjectWriter::getRelocType(MCContext &Ctx,
     case AArch64::fixup_aarch64_ldst_imm12_scale8:
       if (SymLoc == AArch64MCExpr::VK_ABS && IsNC)
         return R_CLS(LDST64_ABS_LO12_NC);
-      if (SymLoc == AArch64MCExpr::VK_GOT && IsNC) {
+      if ((SymLoc == AArch64MCExpr::VK_GOT ||
+           SymLoc == AArch64MCExpr::VK_GOT_AUTH) &&
+          IsNC) {
         AArch64MCExpr::VariantKind AddressLoc =
             AArch64MCExpr::getAddressFrag(RefKind);
+        bool IsAuth = (SymLoc == AArch64MCExpr::VK_GOT_AUTH);
         if (!IsILP32) {
           if (AddressLoc == AArch64MCExpr::VK_LO15)
             return ELF::R_AARCH64_LD64_GOTPAGE_LO15;
-          return ELF::R_AARCH64_LD64_GOT_LO12_NC;
+          return (IsAuth ? ELF::R_AARCH64_AUTH_GOT_LO12_NC
+                         : ELF::R_AARCH64_LD64_GOT_LO12_NC);
         }
-        Ctx.reportError(Fixup.getLoc(), "ILP32 64-bit load/store "
-                                        "relocation not supported (LP64 eqv: "
-                                        "LD64_GOT_LO12_NC)");
+        Ctx.reportError(Fixup.getLoc(),
+                        Twine("ILP32 64-bit load/store "
+                              "relocation not supported (LP64 eqv: ") +
+                            (IsAuth ? "AUTH_GOT_LO12_NC" : "LD64_GOT_LO12_NC") +
+                            Twine(')'));
         return ELF::R_AARCH64_NONE;
       }
       if (SymLoc == AArch64MCExpr::VK_DTPREL && !IsNC)
diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp
index 0c5a9d79f6cbc..768170281a05f 100644
--- a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp
+++ b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp
@@ -30,6 +30,7 @@ const AArch64MCExpr *AArch64MCExpr::create(const MCExpr *Expr, VariantKind Kind,
 }
 
 StringRef AArch64MCExpr::getVariantKindName() const {
+  // clang-format off
   switch (static_cast<uint32_t>(getKind())) {
   case VK_CALL:                return "";
   case VK_LO12:                return ":lo12:";
@@ -82,9 +83,13 @@ StringRef AArch64MCExpr::getVariantKindName() const {
   case VK_TLSDESC_PAGE:        return ":tlsdesc:";
   case VK_SECREL_LO12:         return ":secrel_lo12:";
   case VK_SECREL_HI12:         return ":secrel_hi12:";
+  case VK_GOT_AUTH:            return ":got_auth:";
+  case VK_GOT_AUTH_PAGE:       return ":got_auth:";
+  case VK_GOT_AUTH_LO12:       return ":got_auth_lo12:";
   default:
     llvm_unreachable("Invalid ELF symbol kind");
   }
+  // clang-format on
 }
 
 void AArch64MCExpr::printImpl(raw_ostream &OS, const MCAsmInfo *MAI) const {
diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.h b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.h
index 48235988869ca..780ae39c15a73 100644
--- a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.h
+++ b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.h
@@ -24,6 +24,7 @@ namespace llvm {
 class AArch64MCExpr : public MCTargetExpr {
 public:
   enum VariantKind {
+    // clang-format off
     // Symbol locations specifying (roughly speaking) what calculation should be
     // performed to construct the final address for the relocated
     // symbol. E.g. direct, via the GOT, ...
@@ -38,6 +39,7 @@ class AArch64MCExpr : public MCTargetExpr {
     VK_SECREL   = 0x009,
     VK_AUTH     = 0x00a,
     VK_AUTHADDR = 0x00b,
+    VK_GOT_AUTH = 0x00c,
     VK_SymLocBits = 0x00f,
 
     // Variants specifying which part of the final address calculation is
@@ -88,6 +90,8 @@ class AArch64MCExpr : public MCTargetExpr {
     VK_GOT_LO12          = VK_GOT      | VK_PAGEOFF | VK_NC,
     VK_GOT_PAGE          = VK_GOT      | VK_PAGE,
     VK_GOT_PAGE_LO15     = VK_GOT      | VK_LO15    | VK_NC,
+    VK_GOT_AUTH_LO12     = VK_GOT_AUTH | VK_PAGEOFF | VK_NC,
+    VK_GOT_AUTH_PAGE     = VK_GOT_AUTH | VK_PAGE,
     VK_DTPREL_G2         = VK_DTPREL   | VK_G2,
     VK_DTPREL_G1         = VK_DTPREL   | VK_G1,
     VK_DTPREL_G1_NC      = VK_DTPREL   | VK_G1      | VK_NC,
@@ -114,6 +118,7 @@ class AArch64MCExpr : public MCTargetExpr {
     VK_SECREL_HI12       = VK_SECREL   | VK_HI12,
 
     VK_INVALID  = 0xfff
+    // clang-format on
   };
 
 private:
diff --git a/llvm/test/CodeGen/AArch64/basic-pic-auth.ll b/llvm/test/CodeGen/AArch64/basic-pic-auth.ll
new file mode 100644
index 0000000000000..32d2098ee63cc
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/basic-pic-auth.ll
@@ -0,0 +1,39 @@
+; RUN: llc -mtriple=aarch64-linux-gnu -global-isel=0 -fast-isel=0 -verify-machineinstrs \
+; RUN:   -relocation-model=pic -mattr=+pauth %s -o - | FileCheck %s
+; RUN: llc -mtriple=aarch64-linux-gnu -global-isel=0 -fast-isel=1 -verify-machineinstrs \
+; RUN:   -relocation-model=pic -mattr=+pauth %s -o - | FileCheck %s
+; RUN...
[truncated]

``````````

</details>


https://github.com/llvm/llvm-project/pull/96164


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