[PATCH] PR gold/18609

[Andrew Senkevich]

Hi,

this patch fixes https://sourceware.org/bugzilla/show_bug.cgi?id=18609

Is it ok?

2015-07-09  Andrew Senkevich  <andrew.senkevich@intel.com>

        * gold/x86_64.cc: Added overflow check for converting
        R_X86_64_GOTPCREL to R_X86_64_PC32.

diff --git a/gold/x86_64.cc b/gold/x86_64.cc
index 007af1d..0c66525 100644
--- a/gold/x86_64.cc
+++ b/gold/x86_64.cc
@@ -2480,23 +2480,6 @@ Target_x86_64<size>::Scan::local(Symbol_table* symtab,
        // The symbol requires a GOT section.
        Output_data_got<64, false>* got = target->got_section(symtab, layout);

-       // If the relocation symbol isn't IFUNC,
-       // and is local, then we will convert
-       // mov foo@GOTPCREL(%rip), %reg
-       // to lea foo(%rip), %reg.
-       // in Relocate::relocate.
-       if (r_type == elfcpp::R_X86_64_GOTPCREL
-           && reloc.get_r_offset() >= 2
-           && !is_ifunc)
-         {
-           section_size_type stype;
-           const unsigned char* view = object->section_contents(data_shndx,
-                                                                &stype, true);
-           if (view[reloc.get_r_offset() - 2] == 0x8b)
-             break;
-         }
-
-
        // The symbol requires a GOT entry.
        unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());

@@ -2906,21 +2889,6 @@ Target_x86_64<size>::Scan::global(Symbol_table* symtab,
        // The symbol requires a GOT entry.
        Output_data_got<64, false>* got = target->got_section(symtab, layout);

-       // If we convert this from
-       // mov foo@GOTPCREL(%rip), %reg
-       // to lea foo(%rip), %reg.
-       // in Relocate::relocate, then there is nothing to do here.
-       if (r_type == elfcpp::R_X86_64_GOTPCREL
-           && reloc.get_r_offset() >= 2
-           && Target_x86_64<size>::can_convert_mov_to_lea(gsym))
-         {
-           section_size_type stype;
-           const unsigned char* view = object->section_contents(data_shndx,
-                                                                &stype, true);
-           if (view[reloc.get_r_offset() - 2] == 0x8b)
-             break;
-         }
-
        if (gsym->final_value_is_known())
          {
            // For a STT_GNU_IFUNC symbol we want the PLT address.
@@ -3543,7 +3511,9 @@ Target_x86_64<size>::Relocate::relocate(
       // mov foo@GOTPCREL(%rip), %reg
       // to lea foo(%rip), %reg.
       // if possible.
-      if (rela.get_r_offset() >= 2
+      int64_t x = psymval->value(object, addend) - address;
+      if (x == static_cast<int64_t>(static_cast<int32_t>(x))
+         && rela.get_r_offset() >= 2
          && view[-2] == 0x8b
          && ((gsym == NULL && !psymval->is_ifunc_symbol())
              || (gsym != NULL


--
WBR,
Andrew