From ae6c7d2be3c39179a93f89df0c1e819a753b7d32 Mon Sep 17 00:00:00 2001
From: "A. Wilcox" <AWilcox@Wilcox-Tech.com>
Date: Sat, 6 Oct 2018 02:28:40 +0000
Subject: user/llvm6: even more Secure PLT work on PPC32

---
 user/llvm6/even-more-secure-plt.patch | 101 ++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 user/llvm6/even-more-secure-plt.patch

(limited to 'user/llvm6/even-more-secure-plt.patch')

diff --git a/user/llvm6/even-more-secure-plt.patch b/user/llvm6/even-more-secure-plt.patch
new file mode 100644
index 000000000..112e111b8
--- /dev/null
+++ b/user/llvm6/even-more-secure-plt.patch
@@ -0,0 +1,101 @@
+Index: lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
+===================================================================
+--- a/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
++++ b/lib/Target/PowerPC/InstPrinter/PPCInstPrinter.cpp
+@@ -442,13 +442,22 @@
+   // 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
+Index: lib/Target/PowerPC/PPCAsmPrinter.cpp
+===================================================================
+--- a/lib/Target/PowerPC/PPCAsmPrinter.cpp
++++ b/lib/Target/PowerPC/PPCAsmPrinter.cpp
+@@ -487,8 +487,14 @@
+   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);
+Index: lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+===================================================================
+--- a/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
++++ b/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+@@ -4054,7 +4054,20 @@
+     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();
+ 
+Index: test/CodeGen/PowerPC/ppc32-secure-plt-tls.ll
+===================================================================
+--- a/test/CodeGen/PowerPC/ppc32-secure-plt-tls.ll
++++ b/test/CodeGen/PowerPC/ppc32-secure-plt-tls.ll
+@@ -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
++
++@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$pb@ha
++; SECURE-PLT-TLS-NEXT:  addi 30, 30, .LTOC-.L0$pb@l
++; SECURE-PLT-TLS-NEXT:  bl .L{{.*}}
++; SECURE-PLT-TLS:       bl __tls_get_addr(a@tlsgd)@PLT+32768
+\ No newline at end of file
-- 
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