Fix failure in exception_static_test.

Because the __EH_FRAME_BEGIN__ symbol is provided in an empty .eh_frame
section in crtbeginT.o, if crt1.o has a non-empty .eh_frame section,
we place all optimized .eh_frame sections into the output section ahead
of the __EH_FRAME_BEGIN__ symbol, which breaks EH for statically-linked
binaries.

This patch fixes the problem by delaying the attachment of the optimized
.eh_frame sections to the output section until we see the end marker
section (or to the end of pass 1 if we never see an end marker).

gold/
	PR gold/14675
	* ehframe.cc (Eh_frame::add_ehframe_input_section): Change return type;
	return enum indicating whether .eh_frame section is empty, optimizable,
	unrecognized, or an end marker. Adjust explicit instantiations.
	* ehframe.h (Eh_frame::Eh_frame_section_disposition): New enum type.
	(Eh_frame::add_ehframe_input_section): Change return type.
	* gold.cc (queue_middle_tasks): Call Layout::finalize_eh_frame_section.
	* layout.cc (Layout::layout_eh_frame): Don't add optimized sections
	to the .eh_frame output section until we see the end marker.
	(Layout::finalize_eh_frame_section): New.
	* layout.h: (Layout::finalize_eh_frame_section): New.
This commit is contained in:
Cary Coutant 2015-03-09 10:10:29 -07:00
parent 9a9df97001
commit e16631979e
6 changed files with 92 additions and 41 deletions

View file

@ -1,3 +1,17 @@
2015-03-09 Cary Coutant <ccoutant@google.com>
PR gold/14675
* ehframe.cc (Eh_frame::add_ehframe_input_section): Change return type;
return enum indicating whether .eh_frame section is empty, optimizable,
unrecognized, or an end marker. Adjust explicit instantiations.
* ehframe.h (Eh_frame::Eh_frame_section_disposition): New enum type.
(Eh_frame::add_ehframe_input_section): Change return type.
* gold.cc (queue_middle_tasks): Call Layout::finalize_eh_frame_section.
* layout.cc (Layout::layout_eh_frame): Don't add optimized sections
to the .eh_frame output section until we see the end marker.
(Layout::finalize_eh_frame_section): New.
* layout.h: (Layout::finalize_eh_frame_section): New.
2015-03-05 H.J. Lu <hongjiu.lu@intel.com> 2015-03-05 H.J. Lu <hongjiu.lu@intel.com>
* output.cc (Relobj::initialize_input_to_output_map<size>): * output.cc (Relobj::initialize_input_to_output_map<size>):

View file

@ -567,7 +567,7 @@ Eh_frame::skip_leb128(const unsigned char** pp, const unsigned char* pend)
// section. // section.
template<int size, bool big_endian> template<int size, bool big_endian>
bool Eh_frame::Eh_frame_section_disposition
Eh_frame::add_ehframe_input_section( Eh_frame::add_ehframe_input_section(
Sized_relobj_file<size, big_endian>* object, Sized_relobj_file<size, big_endian>* object,
const unsigned char* symbols, const unsigned char* symbols,
@ -584,7 +584,7 @@ Eh_frame::add_ehframe_input_section(
&contents_len, &contents_len,
false); false);
if (contents_len == 0) if (contents_len == 0)
return false; return EH_EMPTY_SECTION;
// If this is the marker section for the end of the data, then // If this is the marker section for the end of the data, then
// return false to force it to be handled as an ordinary input // return false to force it to be handled as an ordinary input
@ -592,7 +592,7 @@ Eh_frame::add_ehframe_input_section(
// of unrecognized .eh_frame sections. // of unrecognized .eh_frame sections.
if (contents_len == 4 if (contents_len == 4
&& elfcpp::Swap<32, big_endian>::readval(pcontents) == 0) && elfcpp::Swap<32, big_endian>::readval(pcontents) == 0)
return false; return EH_END_MARKER_SECTION;
New_cies new_cies; New_cies new_cies;
if (!this->do_add_ehframe_input_section(object, symbols, symbols_size, if (!this->do_add_ehframe_input_section(object, symbols, symbols_size,
@ -609,7 +609,7 @@ Eh_frame::add_ehframe_input_section(
++p) ++p)
delete p->first; delete p->first;
return false; return EH_UNRECOGNIZED_SECTION;
} }
// Now that we know we are using this section, record any new CIEs // Now that we know we are using this section, record any new CIEs
@ -624,7 +624,7 @@ Eh_frame::add_ehframe_input_section(
this->unmergeable_cie_offsets_.push_back(p->first); this->unmergeable_cie_offsets_.push_back(p->first);
} }
return true; return EH_OPTIMIZABLE_SECTION;
} }
// The bulk of the implementation of add_ehframe_input_section. // The bulk of the implementation of add_ehframe_input_section.
@ -1206,7 +1206,7 @@ Eh_frame::do_sized_write(unsigned char* oview)
#ifdef HAVE_TARGET_32_LITTLE #ifdef HAVE_TARGET_32_LITTLE
template template
bool Eh_frame::Eh_frame_section_disposition
Eh_frame::add_ehframe_input_section<32, false>( Eh_frame::add_ehframe_input_section<32, false>(
Sized_relobj_file<32, false>* object, Sized_relobj_file<32, false>* object,
const unsigned char* symbols, const unsigned char* symbols,
@ -1220,7 +1220,7 @@ Eh_frame::add_ehframe_input_section<32, false>(
#ifdef HAVE_TARGET_32_BIG #ifdef HAVE_TARGET_32_BIG
template template
bool Eh_frame::Eh_frame_section_disposition
Eh_frame::add_ehframe_input_section<32, true>( Eh_frame::add_ehframe_input_section<32, true>(
Sized_relobj_file<32, true>* object, Sized_relobj_file<32, true>* object,
const unsigned char* symbols, const unsigned char* symbols,
@ -1234,7 +1234,7 @@ Eh_frame::add_ehframe_input_section<32, true>(
#ifdef HAVE_TARGET_64_LITTLE #ifdef HAVE_TARGET_64_LITTLE
template template
bool Eh_frame::Eh_frame_section_disposition
Eh_frame::add_ehframe_input_section<64, false>( Eh_frame::add_ehframe_input_section<64, false>(
Sized_relobj_file<64, false>* object, Sized_relobj_file<64, false>* object,
const unsigned char* symbols, const unsigned char* symbols,
@ -1248,7 +1248,7 @@ Eh_frame::add_ehframe_input_section<64, false>(
#ifdef HAVE_TARGET_64_BIG #ifdef HAVE_TARGET_64_BIG
template template
bool Eh_frame::Eh_frame_section_disposition
Eh_frame::add_ehframe_input_section<64, true>( Eh_frame::add_ehframe_input_section<64, true>(
Sized_relobj_file<64, true>* object, Sized_relobj_file<64, true>* object,
const unsigned char* symbols, const unsigned char* symbols,

View file

@ -359,6 +359,14 @@ extern bool operator==(const Cie&, const Cie&);
class Eh_frame : public Output_section_data class Eh_frame : public Output_section_data
{ {
public: public:
enum Eh_frame_section_disposition
{
EH_EMPTY_SECTION,
EH_UNRECOGNIZED_SECTION,
EH_OPTIMIZABLE_SECTION,
EH_END_MARKER_SECTION
};
Eh_frame(); Eh_frame();
// Record the associated Eh_frame_hdr, if any. // Record the associated Eh_frame_hdr, if any.
@ -374,7 +382,7 @@ class Eh_frame : public Output_section_data
// returns whether the section was incorporated into the .eh_frame // returns whether the section was incorporated into the .eh_frame
// data. // data.
template<int size, bool big_endian> template<int size, bool big_endian>
bool Eh_frame_section_disposition
add_ehframe_input_section(Sized_relobj_file<size, big_endian>* object, add_ehframe_input_section(Sized_relobj_file<size, big_endian>* object,
const unsigned char* symbols, const unsigned char* symbols,
section_size_type symbols_size, section_size_type symbols_size,

View file

@ -492,6 +492,9 @@ queue_middle_tasks(const General_options& options,
if (timer != NULL) if (timer != NULL)
timer->stamp(0); timer->stamp(0);
// Finalize the .eh_frame section.
layout->finalize_eh_frame_section();
// Add any symbols named with -u options to the symbol table. // Add any symbols named with -u options to the symbol table.
symtab->add_undefined_symbols_from_command_line(layout); symtab->add_undefined_symbols_from_command_line(layout);

View file

@ -1420,15 +1420,21 @@ Layout::layout_eh_frame(Sized_relobj_file<size, big_endian>* object,
elfcpp::Elf_Xword orig_flags = os->flags(); elfcpp::Elf_Xword orig_flags = os->flags();
if (!parameters->incremental() Eh_frame::Eh_frame_section_disposition disp =
&& this->eh_frame_data_->add_ehframe_input_section(object, Eh_frame::EH_UNRECOGNIZED_SECTION;
if (!parameters->incremental())
{
disp = this->eh_frame_data_->add_ehframe_input_section(object,
symbols, symbols,
symbols_size, symbols_size,
symbol_names, symbol_names,
symbol_names_size, symbol_names_size,
shndx, shndx,
reloc_shndx, reloc_shndx,
reloc_type)) reloc_type);
}
if (disp == Eh_frame::EH_OPTIMIZABLE_SECTION)
{ {
os->update_flags_for_input_section(shdr.get_sh_flags()); os->update_flags_for_input_section(shdr.get_sh_flags());
@ -1440,20 +1446,21 @@ Layout::layout_eh_frame(Sized_relobj_file<size, big_endian>* object,
os->set_order(ORDER_RELRO); os->set_order(ORDER_RELRO);
} }
// We found a .eh_frame section we are going to optimize, so now *off = -1;
// we can add the set of optimized sections to the output return os;
// section. We need to postpone adding this until we've found a }
// section we can optimize so that the .eh_frame section in
// crtbegin.o winds up at the start of the output section. if (disp == Eh_frame::EH_END_MARKER_SECTION && !this->added_eh_frame_data_)
if (!this->added_eh_frame_data_)
{ {
// We found the end marker section, so now we can add the set of
// optimized sections to the output section. We need to postpone
// adding this until we've found a section we can optimize so that
// the .eh_frame section in crtbeginT.o winds up at the start of
// the output section.
os->add_output_section_data(this->eh_frame_data_); os->add_output_section_data(this->eh_frame_data_);
this->added_eh_frame_data_ = true; this->added_eh_frame_data_ = true;
} }
*off = -1;
}
else
{
// We couldn't handle this .eh_frame section for some reason. // We couldn't handle this .eh_frame section for some reason.
// Add it as a normal section. // Add it as a normal section.
bool saw_sections_clause = this->script_options_->saw_sections_clause(); bool saw_sections_clause = this->script_options_->saw_sections_clause();
@ -1464,11 +1471,24 @@ Layout::layout_eh_frame(Sized_relobj_file<size, big_endian>* object,
if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)) if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))
!= (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))) != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)))
os->set_order(this->default_section_order(os, false)); os->set_order(this->default_section_order(os, false));
}
return os; return os;
} }
void
Layout::finalize_eh_frame_section()
{
// If we never found an end marker section, we need to add the
// optimized eh sections to the output section now.
if (!parameters->incremental()
&& this->eh_frame_section_ != NULL
&& !this->added_eh_frame_data_)
{
this->eh_frame_section_->add_output_section_data(this->eh_frame_data_);
this->added_eh_frame_data_ = true;
}
}
// Create and return the magic .eh_frame section. Create // Create and return the magic .eh_frame section. Create
// .eh_frame_hdr also if appropriate. OBJECT is the object with the // .eh_frame_hdr also if appropriate. OBJECT is the object with the
// input .eh_frame section; it may be NULL. // input .eh_frame section; it may be NULL.

View file

@ -635,6 +635,12 @@ class Layout
unsigned int reloc_shndx, unsigned int reloc_type, unsigned int reloc_shndx, unsigned int reloc_type,
off_t* offset); off_t* offset);
// After processing all input files, we call this to make sure that
// the optimized .eh_frame sections have been added to the output
// section.
void
finalize_eh_frame_section();
// Add .eh_frame information for a PLT. The FDE must start with a // Add .eh_frame information for a PLT. The FDE must start with a
// 4-byte PC-relative reference to the start of the PLT, followed by // 4-byte PC-relative reference to the start of the PLT, followed by
// a 4-byte size of PLT. // a 4-byte size of PLT.