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path: root/user/llvm6/secure-plt.patch
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Index: llvm/lib/Target/PowerPC/PPC.td
===================================================================
--- llvm/lib/Target/PowerPC/PPC.td
+++ llvm/lib/Target/PowerPC/PPC.td
@@ -119,6 +119,8 @@
                               [FeatureBookE]>;
 def FeatureE500      : SubtargetFeature<"e500", "IsE500", "true",
                                         "Enable E500/E500mc instructions">;
+def FeatureSecurePlt : SubtargetFeature<"secure-plt","SecurePlt", "true",
+                                        "Enable secure plt mode">;
 def FeaturePPC4xx    : SubtargetFeature<"ppc4xx", "IsPPC4xx", "true",
                                         "Enable PPC 4xx instructions">;
 def FeaturePPC6xx    : SubtargetFeature<"ppc6xx", "IsPPC6xx", "true",
Index: llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
===================================================================
--- llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -563,33 +563,63 @@
     // Transform %rd = UpdateGBR(%rt, %ri)
     // Into: lwz %rt, .L0$poff - .L0$pb(%ri)
     //       add %rd, %rt, %ri
+    // or into (if secure plt mode is on):
+    //       addis r30, r30, .LTOC - .L0$pb@ha
+    //       addi r30, r30, .LTOC - .L0$pb@l
     // Get the offset from the GOT Base Register to the GOT
     LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
-    MCSymbol *PICOffset =
-      MF->getInfo<PPCFunctionInfo>()->getPICOffsetSymbol();
-    TmpInst.setOpcode(PPC::LWZ);
-    const MCExpr *Exp =
-      MCSymbolRefExpr::create(PICOffset, MCSymbolRefExpr::VK_None, OutContext);
-    const MCExpr *PB =
-      MCSymbolRefExpr::create(MF->getPICBaseSymbol(),
-                              MCSymbolRefExpr::VK_None,
-                              OutContext);
-    const MCOperand TR = TmpInst.getOperand(1);
-    const MCOperand PICR = TmpInst.getOperand(0);
+    if (Subtarget->isSecurePlt() && isPositionIndependent() ) {
+      unsigned PICR = TmpInst.getOperand(0).getReg();
+      MCSymbol *LTOCSymbol = OutContext.getOrCreateSymbol(StringRef(".LTOC"));
+      const MCExpr *PB =
+        MCSymbolRefExpr::create(MF->getPICBaseSymbol(),
+                                OutContext);
 
-    // Step 1: lwz %rt, .L$poff - .L$pb(%ri)
-    TmpInst.getOperand(1) =
-        MCOperand::createExpr(MCBinaryExpr::createSub(Exp, PB, OutContext));
-    TmpInst.getOperand(0) = TR;
-    TmpInst.getOperand(2) = PICR;
-    EmitToStreamer(*OutStreamer, TmpInst);
+      const MCExpr *LTOCDeltaExpr =
+        MCBinaryExpr::createSub(MCSymbolRefExpr::create(LTOCSymbol, OutContext),
+                                PB, OutContext);
 
-    TmpInst.setOpcode(PPC::ADD4);
-    TmpInst.getOperand(0) = PICR;
-    TmpInst.getOperand(1) = TR;
-    TmpInst.getOperand(2) = PICR;
-    EmitToStreamer(*OutStreamer, TmpInst);
-    return;
+      const MCExpr *LTOCDeltaHi =
+        PPCMCExpr::createHa(LTOCDeltaExpr, false, OutContext);
+      EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::ADDIS)
+                                   .addReg(PICR)
+                                   .addReg(PICR)
+                                   .addExpr(LTOCDeltaHi));
+
+      const MCExpr *LTOCDeltaLo =
+        PPCMCExpr::createLo(LTOCDeltaExpr, false, OutContext);
+      EmitToStreamer(*OutStreamer, MCInstBuilder(PPC::ADDI)
+                                   .addReg(PICR)
+                                   .addReg(PICR)
+                                   .addExpr(LTOCDeltaLo));
+      return;
+    } else {
+      MCSymbol *PICOffset =
+        MF->getInfo<PPCFunctionInfo>()->getPICOffsetSymbol();
+      TmpInst.setOpcode(PPC::LWZ);
+      const MCExpr *Exp =
+        MCSymbolRefExpr::create(PICOffset, MCSymbolRefExpr::VK_None, OutContext);
+      const MCExpr *PB =
+        MCSymbolRefExpr::create(MF->getPICBaseSymbol(),
+                                MCSymbolRefExpr::VK_None,
+                                OutContext);
+      const MCOperand TR = TmpInst.getOperand(1);
+      const MCOperand PICR = TmpInst.getOperand(0);
+
+      // Step 1: lwz %rt, .L$poff - .L$pb(%ri)
+      TmpInst.getOperand(1) =
+          MCOperand::createExpr(MCBinaryExpr::createSub(Exp, PB, OutContext));
+      TmpInst.getOperand(0) = TR;
+      TmpInst.getOperand(2) = PICR;
+      EmitToStreamer(*OutStreamer, TmpInst);
+
+      TmpInst.setOpcode(PPC::ADD4);
+      TmpInst.getOperand(0) = PICR;
+      TmpInst.getOperand(1) = TR;
+      TmpInst.getOperand(2) = PICR;
+      EmitToStreamer(*OutStreamer, TmpInst);
+      return;
+    }
   }
   case PPC::LWZtoc: {
     // Transform %r3 = LWZtoc @min1, %r2
@@ -1233,7 +1263,7 @@
 
   if (!Subtarget->isPPC64()) {
     const PPCFunctionInfo *PPCFI = MF->getInfo<PPCFunctionInfo>();
-    if (PPCFI->usesPICBase()) {
+    if (PPCFI->usesPICBase() && !Subtarget->isSecurePlt()) {
       MCSymbol *RelocSymbol = PPCFI->getPICOffsetSymbol();
       MCSymbol *PICBase = MF->getPICBaseSymbol();
       OutStreamer->EmitLabel(RelocSymbol);
Index: llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
===================================================================
--- llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -4001,6 +4001,27 @@
       return;
     break;
 
+  case PPCISD::CALL: {
+    const Module *M = MF->getFunction().getParent();
+
+    if (PPCLowering->getPointerTy(CurDAG->getDataLayout()) != MVT::i32 ||
+        !PPCSubTarget->isSecurePlt() || !PPCSubTarget->isTargetELF() ||
+        M->getPICLevel() == PICLevel::SmallPIC)
+      break;
+
+    SDValue Op = N->getOperand(1);
+
+    if (GlobalAddressSDNode *GA = dyn_cast<GlobalAddressSDNode>(Op)) {
+      if (GA->getTargetFlags() == PPCII::MO_PLT)
+        getGlobalBaseReg();
+    }
+    else if (ExternalSymbolSDNode *ES = dyn_cast<ExternalSymbolSDNode>(Op)) {
+      if (ES->getTargetFlags() == PPCII::MO_PLT)
+        getGlobalBaseReg();
+    }
+  }
+    break;
+
   case PPCISD::GlobalBaseReg:
     ReplaceNode(N, getGlobalBaseReg());
     return;
Index: llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
===================================================================
--- llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
+++ llvm/lib/Target/PowerPC/PPCMCInstLower.cpp
@@ -107,10 +107,20 @@
       break;
   }
 
-  if (MO.getTargetFlags() == PPCII::MO_PLT)
+ if (MO.getTargetFlags() == PPCII::MO_PLT)
     RefKind = MCSymbolRefExpr::VK_PLT;
 
+  const MachineFunction *MF = MO.getParent()->getParent()->getParent();
+  const PPCSubtarget *Subtarget = &(MF->getSubtarget<PPCSubtarget>());
+  const TargetMachine &TM = Printer.TM;
   const MCExpr *Expr = MCSymbolRefExpr::create(Symbol, RefKind, Ctx);
+  // -msecure-plt option works only in PIC mode. If secure plt mode
+  // is on add 32768 to symbol.
+  if (Subtarget->isSecurePlt() && TM.isPositionIndependent() &&
+      MO.getTargetFlags() == PPCII::MO_PLT)
+    Expr = MCBinaryExpr::createAdd(Expr,
+                                   MCConstantExpr::create(32768, Ctx),
+                                   Ctx);
 
   if (!MO.isJTI() && MO.getOffset())
     Expr = MCBinaryExpr::createAdd(Expr,
Index: llvm/lib/Target/PowerPC/PPCSubtarget.h
===================================================================
--- llvm/lib/Target/PowerPC/PPCSubtarget.h
+++ llvm/lib/Target/PowerPC/PPCSubtarget.h
@@ -133,6 +133,7 @@
   bool HasFloat128;
   bool IsISA3_0;
   bool UseLongCalls;
+  bool SecurePlt;
 
   POPCNTDKind HasPOPCNTD;
 
@@ -255,6 +256,7 @@
   bool hasOnlyMSYNC() const { return HasOnlyMSYNC; }
   bool isPPC4xx() const { return IsPPC4xx; }
   bool isPPC6xx() const { return IsPPC6xx; }
+  bool isSecurePlt() const {return SecurePlt; }
   bool isE500() const { return IsE500; }
   bool isFeatureMFTB() const { return FeatureMFTB; }
   bool isDeprecatedDST() const { return DeprecatedDST; }
Index: llvm/test/CodeGen/PowerPC/ppc32-pic-large.ll
===================================================================
--- llvm/test/CodeGen/PowerPC/ppc32-pic-large.ll
+++ llvm/test/CodeGen/PowerPC/ppc32-pic-large.ll
@@ -1,4 +1,5 @@
 ; RUN: llc < %s -mtriple=powerpc-unknown-linux-gnu -relocation-model=pic | FileCheck -check-prefix=LARGE-BSS %s
+; RUN: llc < %s -mtriple=powerpc-unknown-linux-gnu -mattr=+secure-plt -relocation-model=pic | FileCheck -check-prefix=LARGE-SECUREPLT %s
 @bar = common global i32 0, align 4
 
 declare i32 @call_foo(i32, ...)
@@ -29,3 +30,6 @@
 ; LARGE-BSS:       [[VREF]]:
 ; LARGE-BSS-NEXT:     .p2align 2
 ; LARGE-BSS-NEXT:    .long bar
+; LARGE-SECUREPLT:   addis 30, 30, .LTOC-.L0$pb@ha
+; LARGE-SECUREPLT:   addi 30, 30, .LTOC-.L0$pb@l
+; LARGE-SECUREPLT:   bl call_foo@PLT+32768