[PAC][CodeGen][ELF][AArch64] Support signed TLSDESC

Support the following relocations and assembly operators:

- `R_AARCH64_AUTH_TLSDESC_ADR_PAGE21` (`:tlsdesc_auth:` for `adrp`)
- `R_AARCH64_AUTH_TLSDESC_LD64_LO12` (`:tlsdesc_auth_lo12:` for `ldr`)
- `R_AARCH64_AUTH_TLSDESC_ADD_LO12` (`:tlsdesc_auth_lo12:` for `add`)

`TLSDESC_AUTH_CALLSEQ` pseudo-instruction is introduced which is later expanded
to actual instruction sequence like the following.

```
adrp  x0, :tlsdesc:var
ldr   x16, [x0, #:tlsdesc_lo12:var]
add   x0, x0, #:tlsdesc_lo12:var
autia x16, x0
.tlsdesccall var
blr   x16
(TPIDR_EL0 offset now in x0)
```

FIXME: use BLRAA instead of AUTIA + BLR. BLRAA is currently explicitly
unsupported in AArch64SLSHardening pass.

Only SelectionDAG ISel is supported.

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

llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp

@@ -1647,6 +1647,69 @@ void AArch64AsmPrinter::emitInstruction(const MachineInstr *MI) {
     EmitToStreamer(*OutStreamer, TmpInstSB);
     return;
   }
+  case AArch64::TLSDESC_AUTH_CALLSEQ: {
+    // FIXME: use BLRAA instead of AUTIA + BLR. BLRAA is currently explicitly
+    //        unsupported in AArch64SLSHardening pass.
+    /// lower this to:
+    ///    adrp  x0, :tlsdesc:var
+    ///    ldr   x16, [x0, #:tlsdesc_lo12:var]
+    ///    add   x0, x0, #:tlsdesc_lo12:var
+    ///    autia x16, x0
+    ///    .tlsdesccall var
+    ///    blr   x16
+    ///    (TPIDR_EL0 offset now in x0)
+    const MachineOperand &MO_Sym = MI->getOperand(0);
+    MachineOperand MO_TLSDESC_LO12(MO_Sym), MO_TLSDESC(MO_Sym);
+    MCOperand Sym, SymTLSDescLo12, SymTLSDesc;
+    MO_TLSDESC_LO12.setTargetFlags(AArch64II::MO_TLS | AArch64II::MO_PAGEOFF);
+    MO_TLSDESC.setTargetFlags(AArch64II::MO_TLS | AArch64II::MO_PAGE);
+    MCInstLowering.lowerOperand(MO_Sym, Sym);
+    MCInstLowering.lowerOperand(MO_TLSDESC_LO12, SymTLSDescLo12);
+    MCInstLowering.lowerOperand(MO_TLSDESC, SymTLSDesc);
+
+    MCInst Adrp;
+    Adrp.setOpcode(AArch64::ADRP);
+    Adrp.addOperand(MCOperand::createReg(AArch64::X0));
+    Adrp.addOperand(SymTLSDesc);
+    EmitToStreamer(*OutStreamer, Adrp);
+
+    MCInst Ldr;
+    Ldr.setOpcode(AArch64::LDRXui);
+    Ldr.addOperand(MCOperand::createReg(AArch64::X16));
+    Ldr.addOperand(MCOperand::createReg(AArch64::X0));
+    Ldr.addOperand(SymTLSDescLo12);
+    Ldr.addOperand(MCOperand::createImm(0));
+    EmitToStreamer(*OutStreamer, Ldr);
+
+    MCInst Add;
+    Add.setOpcode(AArch64::ADDXri);
+    Add.addOperand(MCOperand::createReg(AArch64::X0));
+    Add.addOperand(MCOperand::createReg(AArch64::X0));
+    Add.addOperand(SymTLSDescLo12);
+    Add.addOperand(MCOperand::createImm(AArch64_AM::getShiftValue(0)));
+    EmitToStreamer(*OutStreamer, Add);
+
+    MCInst Autia;
+    Autia.setOpcode(AArch64::AUTIA);
+    Autia.addOperand(MCOperand::createReg(AArch64::X16));
+    Autia.addOperand(MCOperand::createReg(AArch64::X16));
+    Autia.addOperand(MCOperand::createReg(AArch64::X0));
+    EmitToStreamer(*OutStreamer, Autia);
+
+    // Emit a relocation-annotation. This expands to no code, but requests
+    // the following instruction gets an R_AARCH64_TLSDESC_CALL.
+    MCInst TLSDescCall;
+    TLSDescCall.setOpcode(AArch64::TLSDESCCALL);
+    TLSDescCall.addOperand(Sym);
+    EmitToStreamer(*OutStreamer, TLSDescCall);
+
+    MCInst Blr;
+    Blr.setOpcode(AArch64::BLR);
+    Blr.addOperand(MCOperand::createReg(AArch64::X16));
+    EmitToStreamer(*OutStreamer, Blr);
+
+    return;
+  }
   case AArch64::TLSDESC_CALLSEQ: {
     /// lower this to:
     ///    adrp  x0, :tlsdesc:var

llvm/lib/Target/AArch64/AArch64ISelLowering.cpp

@@ -2428,6 +2428,7 @@ const char *AArch64TargetLowering::getTargetNodeName(unsigned Opcode) const {
     MAKE_CASE(AArch64ISD::CSINC)
     MAKE_CASE(AArch64ISD::THREAD_POINTER)
     MAKE_CASE(AArch64ISD::TLSDESC_CALLSEQ)
+    MAKE_CASE(AArch64ISD::TLSDESC_AUTH_CALLSEQ)
     MAKE_CASE(AArch64ISD::PROBED_ALLOCA)
     MAKE_CASE(AArch64ISD::ABDS_PRED)
     MAKE_CASE(AArch64ISD::ABDU_PRED)
@@ -8984,8 +8985,11 @@ SDValue AArch64TargetLowering::LowerELFTLSDescCallSeq(SDValue SymAddr,
   SDValue Chain = DAG.getEntryNode();
   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
 
-  Chain =
-      DAG.getNode(AArch64ISD::TLSDESC_CALLSEQ, DL, NodeTys, {Chain, SymAddr});
+  unsigned Opcode =
+      DAG.getMachineFunction().getFunction().getParent()->hasELFSignedGOT()
+          ? AArch64ISD::TLSDESC_AUTH_CALLSEQ
+          : AArch64ISD::TLSDESC_CALLSEQ;
+  Chain = DAG.getNode(Opcode, DL, NodeTys, {Chain, SymAddr});
   SDValue Glue = Chain.getValue(1);
 
   return DAG.getCopyFromReg(Chain, DL, AArch64::X0, PtrVT, Glue);

llvm/lib/Target/AArch64/AArch64ISelLowering.h

@@ -72,6 +72,7 @@ enum NodeType : unsigned {
   // Produces the full sequence of instructions for getting the thread pointer
   // offset of a variable into X0, using the TLSDesc model.
   TLSDESC_CALLSEQ,
+  TLSDESC_AUTH_CALLSEQ,
   ADRP,     // Page address of a TargetGlobalAddress operand.
   ADR,      // ADR
   ADDlow,   // Add the low 12 bits of a TargetGlobalAddress operand.

llvm/lib/Target/AArch64/AArch64InstrInfo.td

@@ -431,6 +431,8 @@ def SDT_AArch64stnp : SDTypeProfile<0, 3, [SDTCisVT<0, v4i32>, SDTCisSameAs<0, 1
 // number of operands (the variable)
 def SDT_AArch64TLSDescCallSeq : SDTypeProfile<0,1,
                                           [SDTCisPtrTy<0>]>;
+def SDT_AArch64TLSDescAuthCallSeq : SDTypeProfile<0,1,
+                                          [SDTCisPtrTy<0>]>;
 
 def SDT_AArch64WrapperLarge : SDTypeProfile<1, 4,
                                         [SDTCisVT<0, i64>, SDTCisVT<1, i32>,
@@ -785,6 +787,10 @@ def AArch64tlsdesc_callseq : SDNode<"AArch64ISD::TLSDESC_CALLSEQ",
                                     [SDNPInGlue, SDNPOutGlue, SDNPHasChain,
                                      SDNPVariadic]>;
 
+def AArch64tlsdesc_auth_callseq : SDNode<"AArch64ISD::TLSDESC_AUTH_CALLSEQ",
+                                    SDT_AArch64TLSDescAuthCallSeq,
+                                    [SDNPInGlue, SDNPOutGlue, SDNPHasChain,
+                                     SDNPVariadic]>;
 
 def AArch64WrapperLarge : SDNode<"AArch64ISD::WrapperLarge",
                                  SDT_AArch64WrapperLarge>;
@@ -2920,8 +2926,16 @@ def TLSDESC_CALLSEQ
     : Pseudo<(outs), (ins i64imm:$sym),
              [(AArch64tlsdesc_callseq tglobaltlsaddr:$sym)]>,
       Sched<[WriteI, WriteLD, WriteI, WriteBrReg]>;
+let isCall = 1, Defs = [NZCV, LR, X0, X16], hasSideEffects = 1, Size = 20,
+    isCodeGenOnly = 1 in
+def TLSDESC_AUTH_CALLSEQ
+    : Pseudo<(outs), (ins i64imm:$sym),
+             [(AArch64tlsdesc_auth_callseq tglobaltlsaddr:$sym)]>,
+      Sched<[WriteI, WriteLD, WriteI, WriteBrReg]>;
 def : Pat<(AArch64tlsdesc_callseq texternalsym:$sym),
           (TLSDESC_CALLSEQ texternalsym:$sym)>;
+def : Pat<(AArch64tlsdesc_auth_callseq texternalsym:$sym),
+          (TLSDESC_AUTH_CALLSEQ texternalsym:$sym)>;
 
 //===----------------------------------------------------------------------===//
 // Conditional branch (immediate) instruction.

llvm/lib/Target/AArch64/AArch64MCInstLower.cpp

@@ -220,10 +220,18 @@ MCOperand AArch64MCInstLower::lowerSymbolOperandELF(const MachineOperand &MO,
     case TLSModel::LocalDynamic:
       RefFlags |= AArch64MCExpr::VK_DTPREL;
       break;
-    case TLSModel::GeneralDynamic:
-      RefFlags |= AArch64MCExpr::VK_TLSDESC;
+    case TLSModel::GeneralDynamic: {
+      // TODO: it's probably better to introduce MO_TLS_AUTH or smth and avoid
+      // running M->hasELFSignedGOT() every time, but existing flags already
+      // cover all 12 bits of SubReg_TargetFlags field in MachineOperand, and
+      // making the field wider breaks static assertions.
+      const Module *M =
+          MO.getParent()->getParent()->getParent()->getFunction().getParent();
+      RefFlags |= M->hasELFSignedGOT() ? AArch64MCExpr::VK_TLSDESC_AUTH
+                                       : AArch64MCExpr::VK_TLSDESC;
       break;
     }
+    }
   } else if (MO.getTargetFlags() & AArch64II::MO_PREL) {
     RefFlags |= AArch64MCExpr::VK_PREL;
   } else {

llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp

@@ -880,6 +880,7 @@ class AArch64Operand : public MCParsedAsmOperand {
         ELFRefKind == AArch64MCExpr::VK_TPREL_LO12_NC ||
         ELFRefKind == AArch64MCExpr::VK_GOTTPREL_LO12_NC ||
         ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12 ||
+        ELFRefKind == AArch64MCExpr::VK_TLSDESC_AUTH_LO12 ||
         ELFRefKind == AArch64MCExpr::VK_SECREL_LO12 ||
         ELFRefKind == AArch64MCExpr::VK_SECREL_HI12 ||
         ELFRefKind == AArch64MCExpr::VK_GOT_PAGE_LO15) {
@@ -997,6 +998,7 @@ class AArch64Operand : public MCParsedAsmOperand {
              ELFRefKind == AArch64MCExpr::VK_TPREL_LO12 ||
              ELFRefKind == AArch64MCExpr::VK_TPREL_LO12_NC ||
              ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12 ||
+             ELFRefKind == AArch64MCExpr::VK_TLSDESC_AUTH_LO12 ||
              ELFRefKind == AArch64MCExpr::VK_SECREL_HI12 ||
              ELFRefKind == AArch64MCExpr::VK_SECREL_LO12;
     }
@@ -3253,7 +3255,8 @@ ParseStatus AArch64AsmParser::tryParseAdrpLabel(OperandVector &Operands) {
                ELFRefKind != AArch64MCExpr::VK_GOT_AUTH_PAGE &&
                ELFRefKind != AArch64MCExpr::VK_GOT_PAGE_LO15 &&
                ELFRefKind != AArch64MCExpr::VK_GOTTPREL_PAGE &&
-               ELFRefKind != AArch64MCExpr::VK_TLSDESC_PAGE) {
+               ELFRefKind != AArch64MCExpr::VK_TLSDESC_PAGE &&
+               ELFRefKind != AArch64MCExpr::VK_TLSDESC_AUTH_PAGE) {
       // The operand must be an @page or @gotpage qualified symbolref.
       return Error(S, "page or gotpage label reference expected");
     }
@@ -4302,56 +4305,59 @@ bool AArch64AsmParser::parseSymbolicImmVal(const MCExpr *&ImmVal) {
       return TokError("expect relocation specifier in operand after ':'");
 
     std::string LowerCase = getTok().getIdentifier().lower();
-    RefKind = StringSwitch<AArch64MCExpr::VariantKind>(LowerCase)
-                  .Case("lo12", AArch64MCExpr::VK_LO12)
-                  .Case("abs_g3", AArch64MCExpr::VK_ABS_G3)
-                  .Case("abs_g2", AArch64MCExpr::VK_ABS_G2)
-                  .Case("abs_g2_s", AArch64MCExpr::VK_ABS_G2_S)
-                  .Case("abs_g2_nc", AArch64MCExpr::VK_ABS_G2_NC)
-                  .Case("abs_g1", AArch64MCExpr::VK_ABS_G1)
-                  .Case("abs_g1_s", AArch64MCExpr::VK_ABS_G1_S)
-                  .Case("abs_g1_nc", AArch64MCExpr::VK_ABS_G1_NC)
-                  .Case("abs_g0", AArch64MCExpr::VK_ABS_G0)
-                  .Case("abs_g0_s", AArch64MCExpr::VK_ABS_G0_S)
-                  .Case("abs_g0_nc", AArch64MCExpr::VK_ABS_G0_NC)
-                  .Case("prel_g3", AArch64MCExpr::VK_PREL_G3)
-                  .Case("prel_g2", AArch64MCExpr::VK_PREL_G2)
-                  .Case("prel_g2_nc", AArch64MCExpr::VK_PREL_G2_NC)
-                  .Case("prel_g1", AArch64MCExpr::VK_PREL_G1)
-                  .Case("prel_g1_nc", AArch64MCExpr::VK_PREL_G1_NC)
-                  .Case("prel_g0", AArch64MCExpr::VK_PREL_G0)
-                  .Case("prel_g0_nc", AArch64MCExpr::VK_PREL_G0_NC)
-                  .Case("dtprel_g2", AArch64MCExpr::VK_DTPREL_G2)
-                  .Case("dtprel_g1", AArch64MCExpr::VK_DTPREL_G1)
-                  .Case("dtprel_g1_nc", AArch64MCExpr::VK_DTPREL_G1_NC)
-                  .Case("dtprel_g0", AArch64MCExpr::VK_DTPREL_G0)
-                  .Case("dtprel_g0_nc", AArch64MCExpr::VK_DTPREL_G0_NC)
-                  .Case("dtprel_hi12", AArch64MCExpr::VK_DTPREL_HI12)
-                  .Case("dtprel_lo12", AArch64MCExpr::VK_DTPREL_LO12)
-                  .Case("dtprel_lo12_nc", AArch64MCExpr::VK_DTPREL_LO12_NC)
-                  .Case("pg_hi21_nc", AArch64MCExpr::VK_ABS_PAGE_NC)
-                  .Case("tprel_g2", AArch64MCExpr::VK_TPREL_G2)
-                  .Case("tprel_g1", AArch64MCExpr::VK_TPREL_G1)
-                  .Case("tprel_g1_nc", AArch64MCExpr::VK_TPREL_G1_NC)
-                  .Case("tprel_g0", AArch64MCExpr::VK_TPREL_G0)
-                  .Case("tprel_g0_nc", AArch64MCExpr::VK_TPREL_G0_NC)
-                  .Case("tprel_hi12", AArch64MCExpr::VK_TPREL_HI12)
-                  .Case("tprel_lo12", AArch64MCExpr::VK_TPREL_LO12)
-                  .Case("tprel_lo12_nc", AArch64MCExpr::VK_TPREL_LO12_NC)
-                  .Case("tlsdesc_lo12", AArch64MCExpr::VK_TLSDESC_LO12)
-                  .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)
-                  .Case("gottprel_g0_nc", AArch64MCExpr::VK_GOTTPREL_G0_NC)
-                  .Case("tlsdesc", AArch64MCExpr::VK_TLSDESC_PAGE)
-                  .Case("secrel_lo12", AArch64MCExpr::VK_SECREL_LO12)
-                  .Case("secrel_hi12", AArch64MCExpr::VK_SECREL_HI12)
-                  .Default(AArch64MCExpr::VK_INVALID);
+    RefKind =
+        StringSwitch<AArch64MCExpr::VariantKind>(LowerCase)
+            .Case("lo12", AArch64MCExpr::VK_LO12)
+            .Case("abs_g3", AArch64MCExpr::VK_ABS_G3)
+            .Case("abs_g2", AArch64MCExpr::VK_ABS_G2)
+            .Case("abs_g2_s", AArch64MCExpr::VK_ABS_G2_S)
+            .Case("abs_g2_nc", AArch64MCExpr::VK_ABS_G2_NC)
+            .Case("abs_g1", AArch64MCExpr::VK_ABS_G1)
+            .Case("abs_g1_s", AArch64MCExpr::VK_ABS_G1_S)
+            .Case("abs_g1_nc", AArch64MCExpr::VK_ABS_G1_NC)
+            .Case("abs_g0", AArch64MCExpr::VK_ABS_G0)
+            .Case("abs_g0_s", AArch64MCExpr::VK_ABS_G0_S)
+            .Case("abs_g0_nc", AArch64MCExpr::VK_ABS_G0_NC)
+            .Case("prel_g3", AArch64MCExpr::VK_PREL_G3)
+            .Case("prel_g2", AArch64MCExpr::VK_PREL_G2)
+            .Case("prel_g2_nc", AArch64MCExpr::VK_PREL_G2_NC)
+            .Case("prel_g1", AArch64MCExpr::VK_PREL_G1)
+            .Case("prel_g1_nc", AArch64MCExpr::VK_PREL_G1_NC)
+            .Case("prel_g0", AArch64MCExpr::VK_PREL_G0)
+            .Case("prel_g0_nc", AArch64MCExpr::VK_PREL_G0_NC)
+            .Case("dtprel_g2", AArch64MCExpr::VK_DTPREL_G2)
+            .Case("dtprel_g1", AArch64MCExpr::VK_DTPREL_G1)
+            .Case("dtprel_g1_nc", AArch64MCExpr::VK_DTPREL_G1_NC)
+            .Case("dtprel_g0", AArch64MCExpr::VK_DTPREL_G0)
+            .Case("dtprel_g0_nc", AArch64MCExpr::VK_DTPREL_G0_NC)
+            .Case("dtprel_hi12", AArch64MCExpr::VK_DTPREL_HI12)
+            .Case("dtprel_lo12", AArch64MCExpr::VK_DTPREL_LO12)
+            .Case("dtprel_lo12_nc", AArch64MCExpr::VK_DTPREL_LO12_NC)
+            .Case("pg_hi21_nc", AArch64MCExpr::VK_ABS_PAGE_NC)
+            .Case("tprel_g2", AArch64MCExpr::VK_TPREL_G2)
+            .Case("tprel_g1", AArch64MCExpr::VK_TPREL_G1)
+            .Case("tprel_g1_nc", AArch64MCExpr::VK_TPREL_G1_NC)
+            .Case("tprel_g0", AArch64MCExpr::VK_TPREL_G0)
+            .Case("tprel_g0_nc", AArch64MCExpr::VK_TPREL_G0_NC)
+            .Case("tprel_hi12", AArch64MCExpr::VK_TPREL_HI12)
+            .Case("tprel_lo12", AArch64MCExpr::VK_TPREL_LO12)
+            .Case("tprel_lo12_nc", AArch64MCExpr::VK_TPREL_LO12_NC)
+            .Case("tlsdesc_lo12", AArch64MCExpr::VK_TLSDESC_LO12)
+            .Case("tlsdesc_auth_lo12", AArch64MCExpr::VK_TLSDESC_AUTH_LO12)
+            .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)
+            .Case("gottprel_g0_nc", AArch64MCExpr::VK_GOTTPREL_G0_NC)
+            .Case("tlsdesc", AArch64MCExpr::VK_TLSDESC_PAGE)
+            .Case("tlsdesc_auth", AArch64MCExpr::VK_TLSDESC_AUTH_PAGE)
+            .Case("secrel_lo12", AArch64MCExpr::VK_SECREL_LO12)
+            .Case("secrel_hi12", AArch64MCExpr::VK_SECREL_HI12)
+            .Default(AArch64MCExpr::VK_INVALID);
 
     if (RefKind == AArch64MCExpr::VK_INVALID)
       return TokError("expect relocation specifier in operand after ':'");
@@ -5701,6 +5707,7 @@ bool AArch64AsmParser::validateInstruction(MCInst &Inst, SMLoc &IDLoc,
              ELFRefKind == AArch64MCExpr::VK_TPREL_LO12 ||
              ELFRefKind == AArch64MCExpr::VK_TPREL_LO12_NC ||
              ELFRefKind == AArch64MCExpr::VK_TLSDESC_LO12 ||
+             ELFRefKind == AArch64MCExpr::VK_TLSDESC_AUTH_LO12 ||
              ELFRefKind == AArch64MCExpr::VK_SECREL_LO12 ||
              ELFRefKind == AArch64MCExpr::VK_SECREL_HI12) &&
             (Inst.getOpcode() == AArch64::ADDXri ||

llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp

@@ -190,6 +190,15 @@ unsigned AArch64ELFObjectWriter::getRelocType(MCContext &Ctx,
         return R_CLS(TLSIE_ADR_GOTTPREL_PAGE21);
       if (SymLoc == AArch64MCExpr::VK_TLSDESC && !IsNC)
         return R_CLS(TLSDESC_ADR_PAGE21);
+      if (SymLoc == AArch64MCExpr::VK_TLSDESC_AUTH && !IsNC) {
+        if (IsILP32) {
+          Ctx.reportError(Fixup.getLoc(),
+                          "ILP32 ADRP AUTH relocation not supported "
+                          "(LP64 eqv: AUTH_TLSDESC_ADR_PAGE21)");
+          return ELF::R_AARCH64_NONE;
+        }
+        return ELF::R_AARCH64_AUTH_TLSDESC_ADR_PAGE21;
+      }
       Ctx.reportError(Fixup.getLoc(),
                       "invalid symbol kind for ADRP relocation");
       return ELF::R_AARCH64_NONE;
@@ -265,6 +274,15 @@ 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_TLSDESC_AUTH_LO12) {
+        if (IsILP32) {
+          Ctx.reportError(Fixup.getLoc(),
+                          "ILP32 ADD AUTH relocation not supported "
+                          "(LP64 eqv: AUTH_TLSDESC_ADD_LO12)");
+          return ELF::R_AARCH64_NONE;
+        }
+        return ELF::R_AARCH64_AUTH_TLSDESC_ADD_LO12;
+      }
       if (RefKind == AArch64MCExpr::VK_GOT_AUTH_LO12 && IsNC) {
         if (IsILP32) {
           Ctx.reportError(Fixup.getLoc(),
@@ -420,6 +438,14 @@ unsigned AArch64ELFObjectWriter::getRelocType(MCContext &Ctx,
           return ELF::R_AARCH64_NONE;
         }
       }
+      if (SymLoc == AArch64MCExpr::VK_TLSDESC_AUTH) {
+        if (!IsILP32)
+          return ELF::R_AARCH64_AUTH_TLSDESC_LD64_LO12;
+        Ctx.reportError(Fixup.getLoc(), "ILP32 64-bit load/store AUTH "
+                                        "relocation not supported (LP64 eqv: "
+                                        "AUTH_TLSDESC_LD64_LO12)");
+        return ELF::R_AARCH64_NONE;
+      }
       Ctx.reportError(Fixup.getLoc(),
                       "invalid fixup for 64-bit load/store instruction");
       return ELF::R_AARCH64_NONE;

llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCExpr.cpp

@@ -68,6 +68,7 @@ StringRef AArch64MCExpr::getVariantKindName() const {
   case VK_TPREL_LO12:          return ":tprel_lo12:";
   case VK_TPREL_LO12_NC:       return ":tprel_lo12_nc:";
   case VK_TLSDESC_LO12:        return ":tlsdesc_lo12:";
+  case VK_TLSDESC_AUTH_LO12:   return ":tlsdesc_auth_lo12:";
   case VK_ABS_PAGE:            return "";
   case VK_ABS_PAGE_NC:         return ":pg_hi21_nc:";
   case VK_GOT:                 return ":got:";
@@ -81,6 +82,8 @@ StringRef AArch64MCExpr::getVariantKindName() const {
   case VK_GOTTPREL_G0_NC:      return ":gottprel_g0_nc:";
   case VK_TLSDESC:             return "";
   case VK_TLSDESC_PAGE:        return ":tlsdesc:";
+  case VK_TLSDESC_AUTH:        return "";
+  case VK_TLSDESC_AUTH_PAGE:   return ":tlsdesc_auth:";
   case VK_SECREL_LO12:         return ":secrel_lo12:";
   case VK_SECREL_HI12:         return ":secrel_hi12:";
   case VK_GOT_AUTH:            return ":got_auth:";