From e16631979e847a6b39db3435bea7708b9f34b36d Mon Sep 17 00:00:00 2001 From: Cary Coutant Date: Mon, 9 Mar 2015 10:10:29 -0700 Subject: [PATCH] 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. --- gold/ChangeLog | 14 ++++++++++ gold/ehframe.cc | 18 ++++++------- gold/ehframe.h | 10 +++++++- gold/gold.cc | 3 +++ gold/layout.cc | 80 +++++++++++++++++++++++++++++++++++---------------------- gold/layout.h | 6 +++++ 6 files changed, 91 insertions(+), 40 deletions(-) diff --git a/gold/ChangeLog b/gold/ChangeLog index 24d3560..14a8610 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,17 @@ +2015-03-09 Cary Coutant + + 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 * output.cc (Relobj::initialize_input_to_output_map): diff --git a/gold/ehframe.cc b/gold/ehframe.cc index 711103b..262766e 100644 --- a/gold/ehframe.cc +++ b/gold/ehframe.cc @@ -567,7 +567,7 @@ Eh_frame::skip_leb128(const unsigned char** pp, const unsigned char* pend) // section. template -bool +Eh_frame::Eh_frame_section_disposition Eh_frame::add_ehframe_input_section( Sized_relobj_file* object, const unsigned char* symbols, @@ -584,7 +584,7 @@ Eh_frame::add_ehframe_input_section( &contents_len, false); if (contents_len == 0) - return false; + return EH_EMPTY_SECTION; // 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 @@ -592,7 +592,7 @@ Eh_frame::add_ehframe_input_section( // of unrecognized .eh_frame sections. if (contents_len == 4 && elfcpp::Swap<32, big_endian>::readval(pcontents) == 0) - return false; + return EH_END_MARKER_SECTION; New_cies new_cies; if (!this->do_add_ehframe_input_section(object, symbols, symbols_size, @@ -609,7 +609,7 @@ Eh_frame::add_ehframe_input_section( ++p) delete p->first; - return false; + return EH_UNRECOGNIZED_SECTION; } // 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); } - return true; + return EH_OPTIMIZABLE_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 template -bool +Eh_frame::Eh_frame_section_disposition Eh_frame::add_ehframe_input_section<32, false>( Sized_relobj_file<32, false>* object, const unsigned char* symbols, @@ -1220,7 +1220,7 @@ Eh_frame::add_ehframe_input_section<32, false>( #ifdef HAVE_TARGET_32_BIG template -bool +Eh_frame::Eh_frame_section_disposition Eh_frame::add_ehframe_input_section<32, true>( Sized_relobj_file<32, true>* object, const unsigned char* symbols, @@ -1234,7 +1234,7 @@ Eh_frame::add_ehframe_input_section<32, true>( #ifdef HAVE_TARGET_64_LITTLE template -bool +Eh_frame::Eh_frame_section_disposition Eh_frame::add_ehframe_input_section<64, false>( Sized_relobj_file<64, false>* object, const unsigned char* symbols, @@ -1248,7 +1248,7 @@ Eh_frame::add_ehframe_input_section<64, false>( #ifdef HAVE_TARGET_64_BIG template -bool +Eh_frame::Eh_frame_section_disposition Eh_frame::add_ehframe_input_section<64, true>( Sized_relobj_file<64, true>* object, const unsigned char* symbols, diff --git a/gold/ehframe.h b/gold/ehframe.h index bb47381..e6e21b2 100644 --- a/gold/ehframe.h +++ b/gold/ehframe.h @@ -359,6 +359,14 @@ extern bool operator==(const Cie&, const Cie&); class Eh_frame : public Output_section_data { public: + enum Eh_frame_section_disposition + { + EH_EMPTY_SECTION, + EH_UNRECOGNIZED_SECTION, + EH_OPTIMIZABLE_SECTION, + EH_END_MARKER_SECTION + }; + Eh_frame(); // 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 // data. template - bool + Eh_frame_section_disposition add_ehframe_input_section(Sized_relobj_file* object, const unsigned char* symbols, section_size_type symbols_size, diff --git a/gold/gold.cc b/gold/gold.cc index ab15980..e345887 100644 --- a/gold/gold.cc +++ b/gold/gold.cc @@ -492,6 +492,9 @@ queue_middle_tasks(const General_options& options, if (timer != NULL) timer->stamp(0); + // Finalize the .eh_frame section. + layout->finalize_eh_frame_section(); + // Add any symbols named with -u options to the symbol table. symtab->add_undefined_symbols_from_command_line(layout); diff --git a/gold/layout.cc b/gold/layout.cc index 7836640..14bfda0 100644 --- a/gold/layout.cc +++ b/gold/layout.cc @@ -1420,15 +1420,21 @@ Layout::layout_eh_frame(Sized_relobj_file* object, elfcpp::Elf_Xword orig_flags = os->flags(); - if (!parameters->incremental() - && this->eh_frame_data_->add_ehframe_input_section(object, - symbols, - symbols_size, - symbol_names, - symbol_names_size, - shndx, - reloc_shndx, - reloc_type)) + Eh_frame::Eh_frame_section_disposition disp = + Eh_frame::EH_UNRECOGNIZED_SECTION; + if (!parameters->incremental()) + { + disp = this->eh_frame_data_->add_ehframe_input_section(object, + symbols, + symbols_size, + symbol_names, + symbol_names_size, + shndx, + reloc_shndx, + reloc_type); + } + + if (disp == Eh_frame::EH_OPTIMIZABLE_SECTION) { os->update_flags_for_input_section(shdr.get_sh_flags()); @@ -1440,35 +1446,49 @@ Layout::layout_eh_frame(Sized_relobj_file* object, os->set_order(ORDER_RELRO); } - // We found a .eh_frame section we are going to optimize, 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 - // crtbegin.o winds up at the start of the output section. - if (!this->added_eh_frame_data_) - { - os->add_output_section_data(this->eh_frame_data_); - this->added_eh_frame_data_ = true; - } *off = -1; + return os; } - else + + if (disp == Eh_frame::EH_END_MARKER_SECTION && !this->added_eh_frame_data_) { - // We couldn't handle this .eh_frame section for some reason. - // Add it as a normal section. - bool saw_sections_clause = this->script_options_->saw_sections_clause(); - *off = os->add_input_section(this, object, shndx, ".eh_frame", shdr, - reloc_shndx, saw_sections_clause); - this->have_added_input_section_ = true; + // 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_); + this->added_eh_frame_data_ = true; + } - if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)) - != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))) - os->set_order(this->default_section_order(os, false)); - } + // We couldn't handle this .eh_frame section for some reason. + // Add it as a normal section. + bool saw_sections_clause = this->script_options_->saw_sections_clause(); + *off = os->add_input_section(this, object, shndx, ".eh_frame", shdr, + reloc_shndx, saw_sections_clause); + this->have_added_input_section_ = true; + + if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)) + != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))) + os->set_order(this->default_section_order(os, false)); 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 // .eh_frame_hdr also if appropriate. OBJECT is the object with the // input .eh_frame section; it may be NULL. diff --git a/gold/layout.h b/gold/layout.h index aec0c53..9039ee8 100644 --- a/gold/layout.h +++ b/gold/layout.h @@ -635,6 +635,12 @@ class Layout unsigned int reloc_shndx, unsigned int reloc_type, 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 // 4-byte PC-relative reference to the start of the PLT, followed by // a 4-byte size of PLT. -- 2.7.4