[PATCH] D58102: Support X86 Control-flow Enforcement Technology (CET) in LLD

[Xiang Zhang via Phabricator via llvm-commits]

xiangzhangllvm added a comment.

The update:

   1 diff --git a/ELF/SyntheticSections.cpp b/ELF/SyntheticSections.cpp
   2 index 9066a84..a55ca1b 100644
   3 --- a/ELF/SyntheticSections.cpp
   4 +++ b/ELF/SyntheticSections.cpp
   5 @@ -304,6 +304,9 @@ void GnuPropertySection::writeTo(uint8_t *Buf) {
   6    uint8_t *DescBuf = Buf + 16;
   7    write32(DescBuf, GNU_PROPERTY_X86_FEATURE_1_AND); // Feature type
   8    write32(DescBuf + 4, 4);                          // Feature size
   9 +  // We need remove this if code when we supported IFUNC+CET.
  10 +  if (!Config->SPltSectionEnable)
  11 +    Feature1AND &= ~GNU_PROPERTY_X86_FEATURE_1_IBT;
  12    write32(DescBuf + 8, Feature1AND);                // Feature flags
  13  }
  14
  15 diff --git a/ELF/SyntheticSections.h b/ELF/SyntheticSections.h
  16 index 626a76d..51c3515 100644
  17 --- a/ELF/SyntheticSections.h
  18 +++ b/ELF/SyntheticSections.h
  19 @@ -697,7 +697,8 @@ public:
  20    SPltSection();
  21    void writeTo(uint8_t *Buf) override;
  22    size_t getSize() const override;
  23 -  bool empty() const override { return Entries.empty(); }
  24 +  bool empty() const override {
  25 +    return !Config->SPltSectionEnable || Entries.empty(); }
  26
  27    template <class ELFT> void addEntry(Symbol &Sym);
  28  private:
  29 diff --git a/ELF/Writer.cpp b/ELF/Writer.cpp
  30 index 11639e5..341a557 100644
  31 --- a/ELF/Writer.cpp
  32 +++ b/ELF/Writer.cpp
  33 @@ -421,10 +421,8 @@ template <class ELFT> static void createSyntheticSections() {
  34      Add(In.Splt);
  35    }
  36
  37 -  if (Config->X86Feature1AND) {
  38 -    In.GnuProperty = make<GnuPropertySection>();
  39 -    Add(In.GnuProperty);
  40 -  }
  41 +  if (Config->X86Feature1AND)
  42 +    Add(make<GnuPropertySection>());
  43
  44    // .note.GNU-stack is always added when we are creating a re-linkable
  45    // object file. Other linkers are using the presence of this marker
  46 @@ -1669,8 +1667,6 @@ template <class ELFT> void Writer<ELFT>::finalizeSections() {
  47    // earlier.
  48    finalizeSynthetic(In.EhFrame);
  49
  50 -  finalizeSynthetic(In.GnuProperty);
  51 -
  52    for (Symbol *S : Symtab->getSymbols())
  53      if (!S->IsPreemptible)


Repository:
  rLLD LLVM Linker

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D58102/new/

https://reviews.llvm.org/D58102