[llvm] r355513 - [PowerPC] Add secure plt support for TLS symbols

[Strahinja Petrovic via llvm-commits]

Author: spetrovic
Date: Wed Mar  6 07:00:10 2019
New Revision: 355513

URL: http://llvm.org/viewvc/llvm-project?rev=355513&view=rev
Log:
[PowerPC] Add secure plt support for TLS symbols

This patch supports secure plt mode for TLS symbols.

Differential Revision: https://reviews.llvm.org/D45520

Added:
    llvm/trunk/test/CodeGen/PowerPC/ppc32-secure-plt-tls.ll
Modified:
    llvm/trunk/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
    llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
    llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp

Modified: llvm/trunk/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp?rev=355513&r1=355512&r2=355513&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp Wed Mar  6 07:00:10 2019
@@ -444,13 +444,22 @@ void PPCInstPrinter::printTLSCall(const
   // On PPC64, VariantKind is VK_None, but on PPC32, it's VK_PLT, and it must
   // come at the _end_ of the expression.
   const MCOperand &Op = MI->getOperand(OpNo);
-  const MCSymbolRefExpr &refExp = cast<MCSymbolRefExpr>(*Op.getExpr());
-  O << refExp.getSymbol().getName();
+  const MCSymbolRefExpr *RefExp = nullptr;
+  const MCConstantExpr *ConstExp = nullptr;
+  if (const MCBinaryExpr *BinExpr = dyn_cast<MCBinaryExpr>(Op.getExpr())) {
+    RefExp = cast<MCSymbolRefExpr>(BinExpr->getLHS());
+    ConstExp = cast<MCConstantExpr>(BinExpr->getRHS());
+  } else
+    RefExp = cast<MCSymbolRefExpr>(Op.getExpr());
+
+  O << RefExp->getSymbol().getName();
   O << '(';
   printOperand(MI, OpNo+1, O);
   O << ')';
-  if (refExp.getKind() != MCSymbolRefExpr::VK_None)
-    O << '@' << MCSymbolRefExpr::getVariantKindName(refExp.getKind());
+  if (RefExp->getKind() != MCSymbolRefExpr::VK_None)
+    O << '@' << MCSymbolRefExpr::getVariantKindName(RefExp->getKind());
+  if (ConstExp != nullptr)
+    O << '+' << ConstExp->getValue();
 }
 
 /// showRegistersWithPercentPrefix - Check if this register name should be

Modified: llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp?rev=355513&r1=355512&r2=355513&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCAsmPrinter.cpp Wed Mar  6 07:00:10 2019
@@ -472,8 +472,14 @@ void PPCAsmPrinter::EmitTlsCall(const Ma
   if (!Subtarget->isPPC64() && !Subtarget->isDarwin() &&
       isPositionIndependent())
     Kind = MCSymbolRefExpr::VK_PLT;
-  const MCSymbolRefExpr *TlsRef =
+  const MCExpr *TlsRef =
     MCSymbolRefExpr::create(TlsGetAddr, Kind, OutContext);
+
+  // Add 32768 offset to the symbol so we follow up the latest GOT/PLT ABI.
+  if (Kind == MCSymbolRefExpr::VK_PLT && Subtarget->isSecurePlt())
+    TlsRef = MCBinaryExpr::createAdd(TlsRef,
+                                     MCConstantExpr::create(32768, OutContext),
+                                     OutContext);
   const MachineOperand &MO = MI->getOperand(2);
   const GlobalValue *GValue = MO.getGlobal();
   MCSymbol *MOSymbol = getSymbol(GValue);

Modified: llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp?rev=355513&r1=355512&r2=355513&view=diff
==============================================================================
--- llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp (original)
+++ llvm/trunk/lib/Target/PowerPC/PPCISelDAGToDAG.cpp Wed Mar  6 07:00:10 2019
@@ -4353,7 +4353,20 @@ void PPCDAGToDAGISel::Select(SDNode *N)
     if (trySETCC(N))
       return;
     break;
-
+  // These nodes will be transformed into GETtlsADDR32 node, which
+  // later becomes BL_TLS __tls_get_addr(sym at tlsgd)@PLT
+  case PPCISD::ADDI_TLSLD_L_ADDR:
+  case PPCISD::ADDI_TLSGD_L_ADDR: {
+    const Module *Mod = MF->getFunction().getParent();
+    if (PPCLowering->getPointerTy(CurDAG->getDataLayout()) != MVT::i32 ||
+        !PPCSubTarget->isSecurePlt() || !PPCSubTarget->isTargetELF() ||
+        Mod->getPICLevel() == PICLevel::SmallPIC)
+      break;
+      // Attach global base pointer on GETtlsADDR32 node in order to
+      // generate secure plt code for TLS symbols.
+      getGlobalBaseReg();
+  }
+    break;
   case PPCISD::CALL: {
     const Module *M = MF->getFunction().getParent();
 

Added: llvm/trunk/test/CodeGen/PowerPC/ppc32-secure-plt-tls.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/PowerPC/ppc32-secure-plt-tls.ll?rev=355513&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/PowerPC/ppc32-secure-plt-tls.ll (added)
+++ llvm/trunk/test/CodeGen/PowerPC/ppc32-secure-plt-tls.ll Wed Mar  6 07:00:10 2019
@@ -0,0 +1,18 @@
+; RUN: llc < %s -mtriple=powerpc-unknown-linux-gnu -mattr=+secure-plt -relocation-model=pic | FileCheck -check-prefix=SECURE-PLT-TLS %s
+
+ at a = thread_local local_unnamed_addr global i32 6, align 4
+define i32 @main() local_unnamed_addr #0 {
+entry:
+  %0 = load i32, i32* @a, align 4
+  ret i32 %0
+}
+
+
+!llvm.module.flags = !{!0}
+!0 = !{i32 7, !"PIC Level", i32 2}
+
+; SECURE-PLT-TLS:       mflr 30
+; SECURE-PLT-TLS-NEXT:  addis 30, 30, .LTOC-.L0$pb at ha
+; SECURE-PLT-TLS-NEXT:  addi 30, 30, .LTOC-.L0$pb at l
+; SECURE-PLT-TLS-NEXT:  bl .L{{.*}}
+; SECURE-PLT-TLS:       bl __tls_get_addr(a at tlsgd)@PLT+32768
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