[BOLT] Add .relr.dyn section support

Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei

Differential Revision: https://reviews.llvm.org/D146085

3 files changed, 15 insertions, 0 deletions

diff --git a/bolt/include/bolt/Core/BinarySection.h b/bolt/include/bolt/Core/BinarySection.h
index 20b4b5c92576..d3c3ba485c75 100644
--- a/bolt/include/bolt/Core/BinarySection.h
+++ b/bolt/include/bolt/Core/BinarySection.h
@@ -275,6 +275,7 @@ public:
   bool isTBSS() const { return isBSS() && isTLS(); }
   bool isVirtual() const { return ELFType == ELF::SHT_NOBITS; }
   bool isRela() const { return ELFType == ELF::SHT_RELA; }
+  bool isRelr() const { return ELFType == ELF::SHT_RELR; }
   bool isWritable() const { return (ELFFlags & ELF::SHF_WRITE); }
   bool isAllocatable() const {
     if (isELF()) {
diff --git a/bolt/include/bolt/Core/Relocation.h b/bolt/include/bolt/Core/Relocation.h
index ed56d41beb05..51dd76938756 100644
--- a/bolt/include/bolt/Core/Relocation.h
+++ b/bolt/include/bolt/Core/Relocation.h
@@ -109,6 +109,9 @@ struct Relocation {
   /// Return code for a ABS 8-byte relocation
   static uint64_t getAbs64();
 
+  /// Return code for a RELATIVE relocation
+  static uint64_t getRelative();
+
   /// Return true if this relocation is PC-relative. Return false otherwise.
   bool isPCRelative() const { return isPCRelative(Type); }
 
diff --git a/bolt/include/bolt/Rewrite/RewriteInstance.h b/bolt/include/bolt/Rewrite/RewriteInstance.h
index 54837aaccee3..7e4f7c3e2187 100644
--- a/bolt/include/bolt/Rewrite/RewriteInstance.h
+++ b/bolt/include/bolt/Rewrite/RewriteInstance.h
@@ -138,6 +138,9 @@ private:
   /// Read relocations from a given section.
   void readDynamicRelocations(const object::SectionRef &Section, bool IsJmpRel);
 
+  /// Read relocations from a given RELR section.
+  void readDynamicRelrRelocations(BinarySection &Section);
+
   /// Print relocation information.
   void printRelocationInfo(const RelocationRef &Rel, StringRef SymbolName,
                            uint64_t SymbolAddress, uint64_t Addend,
@@ -312,6 +315,9 @@ private:
   /// Patch allocatable relocation sections.
   ELF_FUNCTION(void, patchELFAllocatableRelaSections);
 
+  /// Patch allocatable relr section.
+  ELF_FUNCTION(void, patchELFAllocatableRelrSection);
+
   /// Finalize memory image of section header string table.
   ELF_FUNCTION(void, finalizeSectionStringTable);
 
@@ -486,6 +492,11 @@ private:
   uint64_t DynamicRelocationsSize{0};
   uint64_t DynamicRelativeRelocationsCount{0};
 
+  // Location and size of .relr.dyn relocations.
+  std::optional<uint64_t> DynamicRelrAddress;
+  uint64_t DynamicRelrSize{0};
+  uint64_t DynamicRelrEntrySize{0};
+
   /// PLT relocations are special kind of dynamic relocations stored separately.
   std::optional<uint64_t> PLTRelocationsAddress;
   uint64_t PLTRelocationsSize{0};