Re: [gold commit] PR 20216: Fix extraneous complaints about missing expected TLS relocation

["H.J. Lu" <hjl.tools@gmail.com>]

On Wed, Aug 10, 2016 at 10:59 AM, Cary Coutant <ccoutant@gmail.com> wrote:
> With some versions of gas, the call to tls_get_addr uses a GOTPCREL
> relocation instead of a GOTPCRELX relocation. We should allow for that
> when skip_call_tls_get_addr_ is true. We should also build the test
> objects with the in-tree assembler.
>
> This patch also fixes some cascading error messages caused by not
> resetting the skip_call_tls_get_addr_ flag after printing the error.
>
> -cary
>
>
> 2016-08-10  Cary Coutant  <ccoutant@gmail.com>
>
> gold/
>         PR gold/20216
>         * x86_64.cc (Target_x86_64::Relocate::relocate): Add check for
>         R_X86_64_GOTPCREL. Reset skip_call_tls_get_addr_ after printing
>         error message.
>         * testsuite/Makefile.am (pr20216_gd.o): Add -Bgcctestdir/.
>         (pr20216_ld.o): Likewise.
>         * testsuite/Makefile.in: Regenerate.
>
> diff --git a/gold/testsuite/Makefile.am b/gold/testsuite/Makefile.am
> index 39f9e9e..739458c 100644
> --- a/gold/testsuite/Makefile.am
> +++ b/gold/testsuite/Makefile.am
> @@ -1193,10 +1193,10 @@ pr20216b.so: pr20216_def.o gcctestdir/ld
>         $(LINK) -Bgcctestdir/ -shared pr20216_def.o
>
>  pr20216_gd.o: pr20216_gd.S
> -       $(COMPILE) -c -o $@ $<
> +       $(COMPILE) -Bgcctestdir/ -c -o $@ $<
>
>  pr20216_ld.o: pr20216_ld.S
> -       $(COMPILE) -c -o $@ $<
> +       $(COMPILE) -Bgcctestdir/ -c -o $@ $<
>
>  endif DEFAULT_TARGET_X86_64_OR_X32
>
> diff --git a/gold/x86_64.cc b/gold/x86_64.cc
> index 6aa489a..8d494ea 100644
> --- a/gold/x86_64.cc
> +++ b/gold/x86_64.cc
> @@ -3505,6 +3505,7 @@ Target_x86_64<size>::Relocate::relocate(
>    if (this->skip_call_tls_get_addr_)
>      {
>        if ((r_type != elfcpp::R_X86_64_PLT32
> +          && r_type != elfcpp::R_X86_64_GOTPCREL

There are

 // Convert
  // callq *foo@GOTPCRELX(%rip) to
  // addr32 callq foo
  // and jmpq *foo@GOTPCRELX(%rip) to
  // jmpq foo
  // nop
  template<class View_type>
  static inline bool
  can_convert_callq_to_direct(const Symbol* gsym, unsigned int r_type,
                              size_t r_offset, View_type* view)
  {
    gold_assert(gsym != NULL);
    // We cannot do the conversion unless it's a GOTPCRELX relocation.
    if (r_type != elfcpp::R_X86_64_GOTPCRELX)
      return false;

I don't think checking R_X86_64_GOTPCREL is needed.   GCC
generates x86-64 TLS code sequences without PLT only if
R_X86_64_GOTPCRELX is supported.

>            && r_type != elfcpp::R_X86_64_GOTPCRELX
>            && r_type != elfcpp::R_X86_64_PLT32_BND
>            && r_type != elfcpp::R_X86_64_PC32_BND
> @@ -3514,6 +3515,7 @@ Target_x86_64<size>::Relocate::relocate(
>         {
>           gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
>                                  _("missing expected TLS relocation"));
> +         this->skip_call_tls_get_addr_ = false;
>         }
>        else
>         {



-- 
H.J.