[Bug gold/25872] Gold doesn't properly support CET PLT

[hjl.tools at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=25872

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|ifuncmain7.c:47: error:     |Gold doesn't properly
                   |relocation overflow:        |support CET PLT
                   |reference to local symbol 5 |
                   |in ifuncmain7.o             |

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> ---
template<int size>
uint64_t
Output_data_plt_x86_64_ibt<size>::do_address_for_global(const Symbol* gsym)
{
  uint64_t offset = this->aplt_offset_;
  // Convert the PLT offset into an APLT offset.
  unsigned int plt_offset = gsym->plt_offset();
  if (gsym->type() == elfcpp::STT_GNU_IFUNC
      && gsym->can_use_relative_reloc(false))
    offset += this->regular_count() * aplt_entry_size;
  else 
    plt_offset -= plt_entry_size;
  plt_offset = plt_offset / (plt_entry_size / aplt_entry_size);
  return this->address() + offset + plt_offset;
}

checks STT_GNU_IFUNC.  But do_address_for_local doesn't.  Even with

diff --git a/gold/x86_64.cc b/gold/x86_64.cc
index 1442a009d7..284809c719 100644
--- a/gold/x86_64.cc
+++ b/gold/x86_64.cc
@@ -2288,7 +2288,12 @@
Output_data_plt_x86_64_ibt<size>::do_address_for_local(const Relobj* object,
                   unsigned int r_sym)
 {
   // Convert the PLT offset into an APLT offset.
-  unsigned int plt_offset = ((object->local_plt_offset(r_sym) -
plt_entry_size)
+  const Sized_relobj_file<size, false>* sized_relobj =
+    static_cast<const Sized_relobj_file<size, false>*>(object);
+  const Symbol_value<size>* psymval = sized_relobj->local_symbol(r_sym);
+  unsigned int plt_offset = ((object->local_plt_offset(r_sym)
+              - (psymval->is_ifunc_symbol()
+            ? 0 : plt_entry_size))
              / (plt_entry_size / aplt_entry_size));
   return (this->address()
     + this->aplt_offset_

I got

/export/gnu/import/git/gitlab/x86-binutils/gold/../test-driver: line 107:
299279 Segmentation fault      (core dumped) "$@" > $log_file 2>&1
FAIL: tls_shared_gnu2_test

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