Revert "[MC] Move ELFWriter::createMemtagRelocs to AArch64ELFStreamer::finishImpl"

This reverts commit 9d63506ddc6d60e220d967eb11779114075d401d.

There is a heap-use-after-free.

1 files changed, 21 insertions, 0 deletions

diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index 5724c5c..b8ef265 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -193,6 +193,8 @@ public:
   MCSectionELF *createRelocationSection(MCContext &Ctx,
                                         const MCSectionELF &Sec);
 
+  void createMemtagRelocs(MCAssembler &Asm);
+
   void writeSectionHeader(const MCAsmLayout &Layout,
                           const SectionIndexMapTy &SectionIndexMap,
                           const SectionOffsetsTy &SectionOffsets);
@@ -614,6 +616,23 @@ bool ELFWriter::isInSymtab(const MCAsmLayout &Layout, const MCSymbolELF &Symbol,
   return true;
 }
 
+void ELFWriter::createMemtagRelocs(MCAssembler &Asm) {
+  MCSectionELF *MemtagRelocs = nullptr;
+  for (const MCSymbol &Sym : Asm.symbols()) {
+    const auto &SymE = cast<MCSymbolELF>(Sym);
+    if (!SymE.isMemtag())
+      continue;
+    if (MemtagRelocs == nullptr) {
+      MemtagRelocs = OWriter.TargetObjectWriter->getMemtagRelocsSection(Asm.getContext());
+      if (MemtagRelocs == nullptr)
+        report_fatal_error("Tagged globals are not available on this architecture.");
+      Asm.registerSection(*MemtagRelocs);
+    }
+    ELFRelocationEntry Rec(0, &SymE, ELF::R_AARCH64_NONE, 0, nullptr, 0);
+    OWriter.Relocations[MemtagRelocs].push_back(Rec);
+  }
+}
+
 void ELFWriter::computeSymbolTable(
     MCAssembler &Asm, const MCAsmLayout &Layout,
     const SectionIndexMapTy &SectionIndexMap, const RevGroupMapTy &RevGroupMap,
@@ -1075,6 +1094,8 @@ uint64_t ELFWriter::writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) {
       Ctx.getELFSection(".strtab", ELF::SHT_STRTAB, 0);
   StringTableIndex = addToSectionTable(StrtabSection);
 
+  createMemtagRelocs(Asm);
+
   RevGroupMapTy RevGroupMap;
   SectionIndexMapTy SectionIndexMap;