// i386.cc -- i386 target support for gold.
-// Copyright (C) 2006-2014 Free Software Foundation, Inc.
+// Copyright (C) 2006-2015 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
static tls::Tls_optimization
optimize_tls_reloc(bool is_final, int r_type);
+ // Check if relocation against this symbol is a candidate for
+ // conversion from
+ // mov foo@GOT(%reg), %reg
+ // to
+ // lea foo@GOTOFF(%reg), %reg.
+ static bool
+ can_convert_mov_to_lea(const Symbol* gsym)
+ {
+ gold_assert(gsym != NULL);
+ return (gsym->type() != elfcpp::STT_GNU_IFUNC
+ && !gsym->is_undefined ()
+ && !gsym->is_from_dynobj()
+ && !gsym->is_preemptible()
+ && (!parameters->options().shared()
+ || (gsym->visibility() != elfcpp::STV_DEFAULT
+ && gsym->visibility() != elfcpp::STV_PROTECTED)
+ || parameters->options().Bsymbolic())
+ && strcmp(gsym->name(), "_DYNAMIC") != 0);
+ }
+
// Get the GOT section, creating it if necessary.
Output_data_got<32, false>*
got_section(Symbol_table*, Layout*);
case elfcpp::R_386_GOT32:
{
- // The symbol requires a GOT entry.
+ // We need GOT section.
Output_data_got<32, false>* got = target->got_section(symtab, layout);
+
+ // If the relocation symbol isn't IFUNC,
+ // and is local, then we will convert
+ // mov foo@GOT(%reg), %reg
+ // to
+ // lea foo@GOTOFF(%reg), %reg
+ // in Relocate::relocate.
+ if (reloc.get_r_offset() >= 2
+ && lsym.get_st_type() != elfcpp::STT_GNU_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;
+ }
+
+ // Otherwise, the symbol requires a GOT entry.
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
// For a STT_GNU_IFUNC symbol we want the PLT offset. That
// Make a dynamic relocation if necessary.
if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
{
- if (gsym->may_need_copy_reloc())
+ if (!parameters->options().output_is_position_independent()
+ && gsym->may_need_copy_reloc())
{
target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, reloc);
// Make a dynamic relocation if necessary.
if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
{
- if (gsym->may_need_copy_reloc())
+ if (parameters->options().output_is_executable()
+ && gsym->may_need_copy_reloc())
{
target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, reloc);
case elfcpp::R_386_GOT32:
{
- // The symbol requires a GOT entry.
+ // The symbol requires a GOT section.
Output_data_got<32, false>* got = target->got_section(symtab, layout);
+
+ // If we convert this from
+ // mov foo@GOT(%reg), %reg
+ // to
+ // lea foo@GOTOFF(%reg), %reg
+ // in Relocate::relocate, then there is nothing to do here.
+ if (reloc.get_r_offset() >= 2
+ && Target_i386::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.
}
}
- // Get the GOT offset if needed.
- // The GOT pointer points to the end of the GOT section.
- // We need to subtract the size of the GOT section to get
- // the actual offset to use in the relocation.
- bool have_got_offset = false;
- unsigned int got_offset = 0;
- switch (r_type)
- {
- case elfcpp::R_386_GOT32:
- if (gsym != NULL)
- {
- gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
- got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
- - target->got_size());
- }
- else
- {
- unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
- gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
- got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
- - target->got_size());
- }
- have_got_offset = true;
- break;
-
- default:
- break;
- }
-
switch (r_type)
{
case elfcpp::R_386_NONE:
break;
case elfcpp::R_386_GOT32:
- gold_assert(have_got_offset);
- Relocate_functions<32, false>::rel32(view, got_offset);
+ // Convert
+ // mov foo@GOT(%reg), %reg
+ // to
+ // lea foo@GOTOFF(%reg), %reg
+ // if possible.
+ if (rel.get_r_offset() >= 2
+ && view[-2] == 0x8b
+ && ((gsym == NULL && !psymval->is_ifunc_symbol())
+ || (gsym != NULL
+ && Target_i386::can_convert_mov_to_lea(gsym))))
+ {
+ view[-2] = 0x8d;
+ elfcpp::Elf_types<32>::Elf_Addr value;
+ value = (psymval->value(object, 0)
+ - target->got_plt_section()->address());
+ Relocate_functions<32, false>::rel32(view, value);
+ }
+ else
+ {
+ // The GOT pointer points to the end of the GOT section.
+ // We need to subtract the size of the GOT section to get
+ // the actual offset to use in the relocation.
+ unsigned int got_offset = 0;
+ if (gsym != NULL)
+ {
+ gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
+ got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
+ - target->got_size());
+ }
+ else
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
+ gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
+ got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
+ - target->got_size());
+ }
+ Relocate_functions<32, false>::rel32(view, got_offset);
+ }
break;
case elfcpp::R_386_GOTOFF:
{
// leal foo(,%ebx,1),%eax; call ___tls_get_addr
// ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
+ // leal foo(%ebx),%eax; call ___tls_get_addr; nop
+ // ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
op2 == 0x8d || op2 == 0x04);
tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
- int roff = 5;
-
- // FIXME: For now, support only the first (SIB) form.
- tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
+ int roff;
if (op2 == 0x04)
{
tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
- memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
+ roff = 5;
}
else
{
+ tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 10);
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
(op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
- if (rel.get_r_offset() + 9 < view_size
- && view[9] == 0x90)
- {
- // FIXME: This is not the right instruction sequence.
- // There is a trailing nop. Use the size byte subl.
- memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
- roff = 6;
- }
- else
- {
- // FIXME: This is not the right instruction sequence.
- // Use the five byte subl.
- memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
- }
+ tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[9] == 0x90);
+ roff = 6;
}
+ memcpy(view + roff - 8, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
Relocate_functions<32, false>::rel32(view + roff, value);
// The next reloc should be a PLT32 reloc against __tls_get_addr.
projects / binutils-gdb.git / blobdiff