// reloc.cc -- relocate input files for gold.
-// Copyright 2006, 2007 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include "gold.h"
+#include <algorithm>
+
#include "workqueue.h"
#include "symtab.h"
#include "output.h"
#include "merge.h"
#include "object.h"
+#include "target-reloc.h"
#include "reloc.h"
namespace gold
{
Read_relocs_data *rd = new Read_relocs_data;
this->object_->read_relocs(rd);
+ this->object_->set_relocs_data(rd);
this->object_->release();
- workqueue->queue_front(new Scan_relocs(this->options_, this->symtab_,
- this->layout_, this->object_, rd,
- this->symtab_lock_, this->blocker_));
+ // If garbage collection or identical comdat folding is desired, we
+ // process the relocs first before scanning them. Scanning of relocs is
+ // done only after garbage or identical sections is identified.
+ if (parameters->options().gc_sections() || parameters->options().icf())
+ {
+ workqueue->queue_next(new Gc_process_relocs(this->options_,
+ this->symtab_,
+ this->layout_,
+ this->object_, rd,
+ this->symtab_lock_,
+ this->blocker_));
+ }
+ else
+ {
+ workqueue->queue_next(new Scan_relocs(this->options_, this->symtab_,
+ this->layout_, this->object_, rd,
+ this->symtab_lock_,
+ this->blocker_));
+ }
}
// Return a debugging name for the task.
return "Read_relocs " + this->object_->name();
}
+// Gc_process_relocs methods.
+
+// These tasks process the relocations read by Read_relocs and
+// determine which sections are referenced and which are garbage.
+// This task is done only when --gc-sections is used.
+
+Task_token*
+Gc_process_relocs::is_runnable()
+{
+ if (this->object_->is_locked())
+ return this->object_->token();
+ return NULL;
+}
+
+void
+Gc_process_relocs::locks(Task_locker* tl)
+{
+ tl->add(this, this->object_->token());
+ tl->add(this, this->blocker_);
+}
+
+void
+Gc_process_relocs::run(Workqueue*)
+{
+ this->object_->gc_process_relocs(this->options_, this->symtab_, this->layout_,
+ this->rd_);
+ this->object_->release();
+}
+
+// Return a debugging name for the task.
+
+std::string
+Gc_process_relocs::get_name() const
+{
+ return "Gc_process_relocs " + this->object_->name();
+}
+
// Scan_relocs methods.
// These tasks scan the relocations read by Read_relocs and mark up
{
this->object_->relocate(this->options_, this->symtab_, this->layout_,
this->of_);
+
+ // This is normally the last thing we will do with an object, so
+ // uncache all views.
+ this->object_->clear_view_cache_marks();
+
this->object_->release();
}
rd->relocs.reserve(shnum / 2);
- std::vector<Map_to_output>& map_sections(this->map_to_output());
+ const Output_sections& out_sections(this->output_sections());
+ const std::vector<Address>& out_offsets(this->section_offsets_);
const unsigned char *pshdrs = this->get_view(this->elf_file_.shoff(),
shnum * This::shdr_size,
- true);
+ true, true);
// Skip the first, dummy, section.
const unsigned char *ps = pshdrs + This::shdr_size;
for (unsigned int i = 1; i < shnum; ++i, ps += This::shdr_size)
if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
continue;
- unsigned int shndx = shdr.get_sh_info();
+ unsigned int shndx = this->adjust_shndx(shdr.get_sh_info());
if (shndx >= shnum)
{
this->error(_("relocation section %u has bad info %u"),
continue;
}
- Output_section* os = map_sections[shndx].output_section;
+ Output_section* os = out_sections[shndx];
if (os == NULL)
continue;
// We are scanning relocations in order to fill out the GOT and
// PLT sections. Relocations for sections which are not
// allocated (typically debugging sections) should not add new
- // GOT and PLT entries. So we skip them.
+ // GOT and PLT entries. So we skip them unless this is a
+ // relocatable link or we need to emit relocations. FIXME: What
+ // should we do if a linker script maps a section with SHF_ALLOC
+ // clear to a section with SHF_ALLOC set?
typename This::Shdr secshdr(pshdrs + shndx * This::shdr_size);
- if ((secshdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+ bool is_section_allocated = ((secshdr.get_sh_flags() & elfcpp::SHF_ALLOC)
+ != 0);
+ if (!is_section_allocated
+ && !parameters->options().relocatable()
+ && !parameters->options().emit_relocs())
continue;
- if (shdr.get_sh_link() != this->symtab_shndx_)
+ if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
{
this->error(_("relocation section %u uses unexpected "
"symbol table %u"),
- i, shdr.get_sh_link());
+ i, this->adjust_shndx(shdr.get_sh_link()));
continue;
}
sr.reloc_shndx = i;
sr.data_shndx = shndx;
sr.contents = this->get_lasting_view(shdr.get_sh_offset(), sh_size,
- true);
+ true, true);
sr.sh_type = sh_type;
sr.reloc_count = reloc_count;
sr.output_section = os;
- sr.needs_special_offset_handling = map_sections[shndx].offset == -1;
+ sr.needs_special_offset_handling = out_offsets[shndx] == invalid_address;
+ sr.is_data_section_allocated = is_section_allocated;
}
// Read the local symbols.
gold_assert(loccount == symtabshdr.get_sh_info());
off_t locsize = loccount * sym_size;
rd->local_symbols = this->get_lasting_view(symtabshdr.get_sh_offset(),
- locsize, true);
+ locsize, true, true);
+ }
+}
+
+// Process the relocs to generate mappings from source sections to referenced
+// sections. This is used during garbage colletion to determine garbage
+// sections.
+
+template<int size, bool big_endian>
+void
+Sized_relobj<size, big_endian>::do_gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Read_relocs_data* rd)
+{
+ Sized_target<size, big_endian>* target =
+ parameters->sized_target<size, big_endian>();
+
+ const unsigned char* local_symbols;
+ if (rd->local_symbols == NULL)
+ local_symbols = NULL;
+ else
+ local_symbols = rd->local_symbols->data();
+
+ for (Read_relocs_data::Relocs_list::iterator p = rd->relocs.begin();
+ p != rd->relocs.end();
+ ++p)
+ {
+ if (!parameters->options().relocatable())
+ {
+ // As noted above, when not generating an object file, we
+ // only scan allocated sections. We may see a non-allocated
+ // section here if we are emitting relocs.
+ if (p->is_data_section_allocated)
+ target->gc_process_relocs(options, symtab, layout, this,
+ p->data_shndx, p->sh_type,
+ p->contents->data(), p->reloc_count,
+ p->output_section,
+ p->needs_special_offset_handling,
+ this->local_symbol_count_,
+ local_symbols);
+ }
}
}
+
// Scan the relocs and adjust the symbol table. This looks for
// relocations which require GOT/PLT/COPY relocations.
Layout* layout,
Read_relocs_data* rd)
{
- Sized_target<size, big_endian>* target = this->sized_target();
+ Sized_target<size, big_endian>* target =
+ parameters->sized_target<size, big_endian>();
const unsigned char* local_symbols;
if (rd->local_symbols == NULL)
p != rd->relocs.end();
++p)
{
- target->scan_relocs(options, symtab, layout, this, p->data_shndx,
- p->sh_type, p->contents->data(), p->reloc_count,
- p->output_section, p->needs_special_offset_handling,
- this->local_symbol_count_,
- local_symbols);
+ // When garbage collection is on, unreferenced sections are not included
+ // in the link that would have been included normally. This is known only
+ // after Read_relocs hence this check has to be done again.
+ if (parameters->options().gc_sections() || parameters->options().icf())
+ {
+ if (p->output_section == NULL)
+ continue;
+ }
+ if (!parameters->options().relocatable())
+ {
+ // As noted above, when not generating an object file, we
+ // only scan allocated sections. We may see a non-allocated
+ // section here if we are emitting relocs.
+ if (p->is_data_section_allocated)
+ target->scan_relocs(options, symtab, layout, this, p->data_shndx,
+ p->sh_type, p->contents->data(),
+ p->reloc_count, p->output_section,
+ p->needs_special_offset_handling,
+ this->local_symbol_count_,
+ local_symbols);
+ if (parameters->options().emit_relocs())
+ this->emit_relocs_scan(options, symtab, layout, local_symbols, p);
+ }
+ else
+ {
+ Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
+ gold_assert(rr != NULL);
+ rr->set_reloc_count(p->reloc_count);
+ target->scan_relocatable_relocs(options, symtab, layout, this,
+ p->data_shndx, p->sh_type,
+ p->contents->data(),
+ p->reloc_count,
+ p->output_section,
+ p->needs_special_offset_handling,
+ this->local_symbol_count_,
+ local_symbols,
+ rr);
+ }
+
delete p->contents;
p->contents = NULL;
}
}
}
+// This is a strategy class we use when scanning for --emit-relocs.
+
+template<int sh_type>
+class Emit_relocs_strategy
+{
+ public:
+ // A local non-section symbol.
+ inline Relocatable_relocs::Reloc_strategy
+ local_non_section_strategy(unsigned int, Relobj*, unsigned int)
+ { return Relocatable_relocs::RELOC_COPY; }
+
+ // A local section symbol.
+ inline Relocatable_relocs::Reloc_strategy
+ local_section_strategy(unsigned int, Relobj*)
+ {
+ if (sh_type == elfcpp::SHT_RELA)
+ return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
+ else
+ {
+ // The addend is stored in the section contents. Since this
+ // is not a relocatable link, we are going to apply the
+ // relocation contents to the section as usual. This means
+ // that we have no way to record the original addend. If the
+ // original addend is not zero, there is basically no way for
+ // the user to handle this correctly. Caveat emptor.
+ return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
+ }
+ }
+
+ // A global symbol.
+ inline Relocatable_relocs::Reloc_strategy
+ global_strategy(unsigned int, Relobj*, unsigned int)
+ { return Relocatable_relocs::RELOC_COPY; }
+};
+
+// Scan the input relocations for --emit-relocs.
+
+template<int size, bool big_endian>
+void
+Sized_relobj<size, big_endian>::emit_relocs_scan(
+ const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ const unsigned char* plocal_syms,
+ const Read_relocs_data::Relocs_list::iterator& p)
+{
+ Relocatable_relocs* rr = this->relocatable_relocs(p->reloc_shndx);
+ gold_assert(rr != NULL);
+ rr->set_reloc_count(p->reloc_count);
+
+ if (p->sh_type == elfcpp::SHT_REL)
+ this->emit_relocs_scan_reltype<elfcpp::SHT_REL>(options, symtab, layout,
+ plocal_syms, p, rr);
+ else
+ {
+ gold_assert(p->sh_type == elfcpp::SHT_RELA);
+ this->emit_relocs_scan_reltype<elfcpp::SHT_RELA>(options, symtab,
+ layout, plocal_syms, p,
+ rr);
+ }
+}
+
+// Scan the input relocation for --emit-relocs, templatized on the
+// type of the relocation section.
+
+template<int size, bool big_endian>
+template<int sh_type>
+void
+Sized_relobj<size, big_endian>::emit_relocs_scan_reltype(
+ const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ const unsigned char* plocal_syms,
+ const Read_relocs_data::Relocs_list::iterator& p,
+ Relocatable_relocs* rr)
+{
+ scan_relocatable_relocs<size, big_endian, sh_type,
+ Emit_relocs_strategy<sh_type> >(
+ options,
+ symtab,
+ layout,
+ this,
+ p->data_shndx,
+ p->contents->data(),
+ p->reloc_count,
+ p->output_section,
+ p->needs_special_offset_handling,
+ this->local_symbol_count_,
+ plocal_syms,
+ rr);
+}
+
// Relocate the input sections and write out the local symbols.
template<int size, bool big_endian>
// Read the section headers.
const unsigned char* pshdrs = this->get_view(this->elf_file_.shoff(),
shnum * This::shdr_size,
- true);
+ true, true);
Views views;
views.resize(shnum);
}
// Write out the local symbols.
- this->write_local_symbols(of, layout->sympool(), layout->dynpool());
+ this->write_local_symbols(of, layout->sympool(), layout->dynpool(),
+ layout->symtab_xindex(), layout->dynsym_xindex());
+
+ // We should no longer need the local symbol values.
+ this->clear_local_symbols();
}
+// Sort a Read_multiple vector by file offset.
+struct Read_multiple_compare
+{
+ inline bool
+ operator()(const File_read::Read_multiple_entry& rme1,
+ const File_read::Read_multiple_entry& rme2) const
+ { return rme1.file_offset < rme2.file_offset; }
+};
+
// Write section data to the output file. PSHDRS points to the
// section headers. Record the views in *PVIEWS for use when
// relocating.
void
Sized_relobj<size, big_endian>::write_sections(const unsigned char* pshdrs,
Output_file* of,
- Views* pviews) const
+ Views* pviews)
{
unsigned int shnum = this->shnum();
- const std::vector<Map_to_output>& map_sections(this->map_to_output());
+ const Output_sections& out_sections(this->output_sections());
+ const std::vector<Address>& out_offsets(this->section_offsets_);
+
+ File_read::Read_multiple rm;
+ bool is_sorted = true;
const unsigned char* p = pshdrs + This::shdr_size;
for (unsigned int i = 1; i < shnum; ++i, p += This::shdr_size)
pvs->view = NULL;
- const Output_section* os = map_sections[i].output_section;
+ const Output_section* os = out_sections[i];
if (os == NULL)
continue;
- off_t output_offset = map_sections[i].offset;
+ Address output_offset = out_offsets[i];
typename This::Shdr shdr(p);
if (shdr.get_sh_type() == elfcpp::SHT_NOBITS)
continue;
+ if ((parameters->options().relocatable()
+ || parameters->options().emit_relocs())
+ && (shdr.get_sh_type() == elfcpp::SHT_REL
+ || shdr.get_sh_type() == elfcpp::SHT_RELA)
+ && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+ {
+ // This is a reloc section in a relocatable link or when
+ // emitting relocs. We don't need to read the input file.
+ // The size and file offset are stored in the
+ // Relocatable_relocs structure.
+ Relocatable_relocs* rr = this->relocatable_relocs(i);
+ gold_assert(rr != NULL);
+ Output_data* posd = rr->output_data();
+ gold_assert(posd != NULL);
+
+ pvs->offset = posd->offset();
+ pvs->view_size = posd->data_size();
+ pvs->view = of->get_output_view(pvs->offset, pvs->view_size);
+ pvs->address = posd->address();
+ pvs->is_input_output_view = false;
+ pvs->is_postprocessing_view = false;
+
+ continue;
+ }
+
// In the normal case, this input section is simply mapped to
// the output section at offset OUTPUT_OFFSET.
- // However, if OUTPUT_OFFSET == -1, then input data is handled
- // specially--e.g., a .eh_frame section. The relocation
+ // However, if OUTPUT_OFFSET == INVALID_ADDRESS, then input data is
+ // handled specially--e.g., a .eh_frame section. The relocation
// routines need to check for each reloc where it should be
// applied. For this case, we need an input/output view for the
// entire contents of the section in the output file. We don't
// final data to the output file.
off_t output_section_offset;
- off_t output_section_size;
+ Address output_section_size;
if (!os->requires_postprocessing())
{
output_section_offset = os->offset();
- output_section_size = os->data_size();
+ output_section_size = convert_types<Address, off_t>(os->data_size());
}
else
{
output_section_offset = 0;
- output_section_size = os->postprocessing_buffer_size();
+ output_section_size =
+ convert_types<Address, off_t>(os->postprocessing_buffer_size());
}
off_t view_start;
section_size_type view_size;
- if (output_offset != -1)
+ if (output_offset != invalid_address)
{
view_start = output_section_offset + output_offset;
view_size = convert_to_section_size_type(shdr.get_sh_size());
if (view_size == 0)
continue;
- gold_assert(output_offset == -1
- || (output_offset >= 0
- && output_offset + view_size <= output_section_size));
+ gold_assert(output_offset == invalid_address
+ || output_offset + view_size <= output_section_size);
unsigned char* view;
if (os->requires_postprocessing())
{
unsigned char* buffer = os->postprocessing_buffer();
view = buffer + view_start;
- if (output_offset != -1)
- this->read(shdr.get_sh_offset(), view_size, view);
+ if (output_offset != invalid_address)
+ {
+ off_t sh_offset = shdr.get_sh_offset();
+ if (!rm.empty() && rm.back().file_offset > sh_offset)
+ is_sorted = false;
+ rm.push_back(File_read::Read_multiple_entry(sh_offset,
+ view_size, view));
+ }
}
else
{
- if (output_offset == -1)
+ if (output_offset == invalid_address)
view = of->get_input_output_view(view_start, view_size);
else
{
view = of->get_output_view(view_start, view_size);
- this->read(shdr.get_sh_offset(), view_size, view);
+ off_t sh_offset = shdr.get_sh_offset();
+ if (!rm.empty() && rm.back().file_offset > sh_offset)
+ is_sorted = false;
+ rm.push_back(File_read::Read_multiple_entry(sh_offset,
+ view_size, view));
}
}
pvs->view = view;
pvs->address = os->address();
- if (output_offset != -1)
+ if (output_offset != invalid_address)
pvs->address += output_offset;
pvs->offset = view_start;
pvs->view_size = view_size;
- pvs->is_input_output_view = output_offset == -1;
+ pvs->is_input_output_view = output_offset == invalid_address;
pvs->is_postprocessing_view = os->requires_postprocessing();
}
+
+ // Actually read the data.
+ if (!rm.empty())
+ {
+ if (!is_sorted)
+ std::sort(rm.begin(), rm.end(), Read_multiple_compare());
+ this->read_multiple(rm);
+ }
}
// Relocate section data. VIEWS points to the section data as views
Views* pviews)
{
unsigned int shnum = this->shnum();
- Sized_target<size, big_endian>* target = this->sized_target();
+ Sized_target<size, big_endian>* target =
+ parameters->sized_target<size, big_endian>();
- const std::vector<Map_to_output>& map_sections(this->map_to_output());
+ const Output_sections& out_sections(this->output_sections());
+ const std::vector<Address>& out_offsets(this->section_offsets_);
Relocate_info<size, big_endian> relinfo;
relinfo.options = &options;
if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
continue;
- unsigned int index = shdr.get_sh_info();
+ off_t sh_size = shdr.get_sh_size();
+ if (sh_size == 0)
+ continue;
+
+ unsigned int index = this->adjust_shndx(shdr.get_sh_info());
if (index >= this->shnum())
{
this->error(_("relocation section %u has bad info %u"),
continue;
}
- Output_section* os = map_sections[index].output_section;
+ Output_section* os = out_sections[index];
if (os == NULL)
{
// This relocation section is against a section which we
// discarded.
continue;
}
- off_t output_offset = map_sections[index].offset;
+ Address output_offset = out_offsets[index];
gold_assert((*pviews)[index].view != NULL);
+ if (parameters->options().relocatable())
+ gold_assert((*pviews)[i].view != NULL);
- if (shdr.get_sh_link() != this->symtab_shndx_)
+ if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx_)
{
gold_error(_("relocation section %u uses unexpected "
"symbol table %u"),
- i, shdr.get_sh_link());
+ i, this->adjust_shndx(shdr.get_sh_link()));
continue;
}
- off_t sh_size = shdr.get_sh_size();
const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
- sh_size, false);
+ sh_size, true, false);
unsigned int reloc_size;
if (sh_type == elfcpp::SHT_REL)
continue;
}
- gold_assert(output_offset != -1
+ gold_assert(output_offset != invalid_address
|| this->relocs_must_follow_section_writes());
relinfo.reloc_shndx = i;
relinfo.data_shndx = index;
- target->relocate_section(&relinfo,
- sh_type,
- prelocs,
- reloc_count,
- os,
- output_offset == -1,
- (*pviews)[index].view,
- (*pviews)[index].address,
- (*pviews)[index].view_size);
+ unsigned char* view = (*pviews)[index].view;
+ Address address = (*pviews)[index].address;
+ section_size_type view_size = (*pviews)[index].view_size;
+
+ Reloc_symbol_changes* reloc_map = NULL;
+ if (this->uses_split_stack() && output_offset != invalid_address)
+ {
+ typename This::Shdr data_shdr(pshdrs + index * This::shdr_size);
+ if ((data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0)
+ this->split_stack_adjust(symtab, pshdrs, sh_type, index,
+ prelocs, reloc_count, view, view_size,
+ &reloc_map);
+ }
+
+ if (!parameters->options().relocatable())
+ {
+ target->relocate_section(&relinfo, sh_type, prelocs, reloc_count, os,
+ output_offset == invalid_address,
+ view, address, view_size, reloc_map);
+ if (parameters->options().emit_relocs())
+ this->emit_relocs(&relinfo, i, sh_type, prelocs, reloc_count,
+ os, output_offset, view, address, view_size,
+ (*pviews)[i].view, (*pviews)[i].view_size);
+ }
+ else
+ {
+ Relocatable_relocs* rr = this->relocatable_relocs(i);
+ target->relocate_for_relocatable(&relinfo, sh_type, prelocs,
+ reloc_count, os, output_offset, rr,
+ view, address, view_size,
+ (*pviews)[i].view,
+ (*pviews)[i].view_size);
+ }
}
}
+// Emit the relocs for --emit-relocs.
+
+template<int size, bool big_endian>
+void
+Sized_relobj<size, big_endian>::emit_relocs(
+ const Relocate_info<size, big_endian>* relinfo,
+ unsigned int i,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
+ unsigned char* view,
+ typename elfcpp::Elf_types<size>::Elf_Addr address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size)
+{
+ if (sh_type == elfcpp::SHT_REL)
+ this->emit_relocs_reltype<elfcpp::SHT_REL>(relinfo, i, prelocs,
+ reloc_count, output_section,
+ offset_in_output_section,
+ view, address, view_size,
+ reloc_view, reloc_view_size);
+ else
+ {
+ gold_assert(sh_type == elfcpp::SHT_RELA);
+ this->emit_relocs_reltype<elfcpp::SHT_RELA>(relinfo, i, prelocs,
+ reloc_count, output_section,
+ offset_in_output_section,
+ view, address, view_size,
+ reloc_view, reloc_view_size);
+ }
+}
+
+// Emit the relocs for --emit-relocs, templatized on the type of the
+// relocation section.
+
+template<int size, bool big_endian>
+template<int sh_type>
+void
+Sized_relobj<size, big_endian>::emit_relocs_reltype(
+ const Relocate_info<size, big_endian>* relinfo,
+ unsigned int i,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ typename elfcpp::Elf_types<size>::Elf_Addr offset_in_output_section,
+ unsigned char* view,
+ typename elfcpp::Elf_types<size>::Elf_Addr address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size)
+{
+ const Relocatable_relocs* rr = this->relocatable_relocs(i);
+ relocate_for_relocatable<size, big_endian, sh_type>(
+ relinfo,
+ prelocs,
+ reloc_count,
+ output_section,
+ offset_in_output_section,
+ rr,
+ view,
+ address,
+ view_size,
+ reloc_view,
+ reloc_view_size);
+}
+
// Create merge hash tables for the local symbols. These are used to
// speed up relocations.
}
}
-// Class Merged_symbol_value.
+// If an object was compiled with -fsplit-stack, this is called to
+// check whether any relocations refer to functions defined in objects
+// which were not compiled with -fsplit-stack. If they were, then we
+// need to apply some target-specific adjustments to request
+// additional stack space.
-template<int size>
+template<int size, bool big_endian>
void
-Merged_symbol_value<size>::initialize_input_to_output_map(
- const Relobj* object,
- unsigned int input_shndx)
+Sized_relobj<size, big_endian>::split_stack_adjust(
+ const Symbol_table* symtab,
+ const unsigned char* pshdrs,
+ unsigned int sh_type,
+ unsigned int shndx,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ unsigned char* view,
+ section_size_type view_size,
+ Reloc_symbol_changes** reloc_map)
{
- Object_merge_map* map = object->merge_map();
- map->initialize_input_to_output_map<size>(input_shndx,
- this->output_start_address_,
- &this->output_addresses_);
+ if (sh_type == elfcpp::SHT_REL)
+ this->split_stack_adjust_reltype<elfcpp::SHT_REL>(symtab, pshdrs, shndx,
+ prelocs, reloc_count,
+ view, view_size,
+ reloc_map);
+ else
+ {
+ gold_assert(sh_type == elfcpp::SHT_RELA);
+ this->split_stack_adjust_reltype<elfcpp::SHT_RELA>(symtab, pshdrs, shndx,
+ prelocs, reloc_count,
+ view, view_size,
+ reloc_map);
+ }
}
-// Get the output value corresponding to an input offset if we
-// couldn't find it in the hash table.
+// Adjust for -fsplit-stack, templatized on the type of the relocation
+// section.
-template<int size>
-typename elfcpp::Elf_types<size>::Elf_Addr
-Merged_symbol_value<size>::value_from_output_section(
- const Relobj* object,
- unsigned int input_shndx,
- typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
+template<int size, bool big_endian>
+template<int sh_type>
+void
+Sized_relobj<size, big_endian>::split_stack_adjust_reltype(
+ const Symbol_table* symtab,
+ const unsigned char* pshdrs,
+ unsigned int shndx,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ unsigned char* view,
+ section_size_type view_size,
+ Reloc_symbol_changes** reloc_map)
{
- section_offset_type output_offset;
- bool found = object->merge_map()->get_output_offset(NULL, input_shndx,
- input_offset,
- &output_offset);
-
- // If this assertion fails, it means that some relocation was
- // against a portion of an input merge section which we didn't map
- // to the output file and we didn't explicitly discard. We should
- // always map all portions of input merge sections.
- gold_assert(found);
+ typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
+ const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
- if (output_offset == -1)
- return 0;
- else
- return this->output_start_address_ + output_offset;
-}
+ size_t local_count = this->local_symbol_count();
-// Copy_relocs::Copy_reloc_entry methods.
+ std::vector<section_offset_type> non_split_refs;
-// Return whether we should emit this reloc. We should emit it if the
-// symbol is still defined in a dynamic object. If we should not emit
-// it, we clear it, to save ourselves the test next time.
+ const unsigned char* pr = prelocs;
+ for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
+ {
+ Reltype reloc(pr);
-template<int size, bool big_endian>
-bool
-Copy_relocs<size, big_endian>::Copy_reloc_entry::should_emit()
-{
- if (this->sym_ == NULL)
- return false;
- if (this->sym_->is_from_dynobj())
- return true;
- this->sym_ = NULL;
- return false;
-}
+ typename elfcpp::Elf_types<size>::Elf_WXword r_info = reloc.get_r_info();
+ unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
+ if (r_sym < local_count)
+ continue;
-// Emit a reloc into a SHT_REL section.
+ const Symbol* gsym = this->global_symbol(r_sym);
+ gold_assert(gsym != NULL);
+ if (gsym->is_forwarder())
+ gsym = symtab->resolve_forwards(gsym);
+
+ // See if this relocation refers to a function defined in an
+ // object compiled without -fsplit-stack. Note that we don't
+ // care about the type of relocation--this means that in some
+ // cases we will ask for a large stack unnecessarily, but this
+ // is not fatal. FIXME: Some targets have symbols which are
+ // functions but are not type STT_FUNC, e.g., STT_ARM_TFUNC.
+ if (gsym->type() == elfcpp::STT_FUNC
+ && !gsym->is_undefined()
+ && gsym->source() == Symbol::FROM_OBJECT
+ && !gsym->object()->uses_split_stack())
+ {
+ section_offset_type offset =
+ convert_to_section_size_type(reloc.get_r_offset());
+ non_split_refs.push_back(offset);
+ }
+ }
-template<int size, bool big_endian>
-void
-Copy_relocs<size, big_endian>::Copy_reloc_entry::emit(
- Output_data_reloc<elfcpp::SHT_REL, true, size, big_endian>* reloc_data)
-{
- this->sym_->set_needs_dynsym_entry();
- reloc_data->add_global(this->sym_, this->reloc_type_, this->output_section_,
- this->relobj_, this->shndx_, this->address_);
-}
+ if (non_split_refs.empty())
+ return;
-// Emit a reloc into a SHT_RELA section.
+ // At this point, every entry in NON_SPLIT_REFS indicates a
+ // relocation which refers to a function in an object compiled
+ // without -fsplit-stack. We now have to convert that list into a
+ // set of offsets to functions. First, we find all the functions.
-template<int size, bool big_endian>
-void
-Copy_relocs<size, big_endian>::Copy_reloc_entry::emit(
- Output_data_reloc<elfcpp::SHT_RELA, true, size, big_endian>* reloc_data)
-{
- this->sym_->set_needs_dynsym_entry();
- reloc_data->add_global(this->sym_, this->reloc_type_, this->output_section_,
- this->relobj_, this->shndx_, this->address_,
- this->addend_);
-}
+ Function_offsets function_offsets;
+ this->find_functions(pshdrs, shndx, &function_offsets);
+ if (function_offsets.empty())
+ return;
-// Copy_relocs methods.
+ // Now get a list of the function with references to non split-stack
+ // code.
-// Return whether we need a COPY reloc for a relocation against GSYM.
-// The relocation is being applied to section SHNDX in OBJECT.
+ Function_offsets calls_non_split;
+ for (std::vector<section_offset_type>::const_iterator p
+ = non_split_refs.begin();
+ p != non_split_refs.end();
+ ++p)
+ {
+ Function_offsets::const_iterator low = function_offsets.lower_bound(*p);
+ if (low == function_offsets.end())
+ --low;
+ else if (low->first == *p)
+ ;
+ else if (low == function_offsets.begin())
+ continue;
+ else
+ --low;
-template<int size, bool big_endian>
-bool
-Copy_relocs<size, big_endian>::need_copy_reloc(
- const General_options*,
- Relobj* object,
- unsigned int shndx,
- Sized_symbol<size>* sym)
-{
- // FIXME: Handle -z nocopyrelocs.
+ calls_non_split.insert(*low);
+ }
+ if (calls_non_split.empty())
+ return;
- if (sym->symsize() == 0)
- return false;
+ // Now we have a set of functions to adjust. The adjustments are
+ // target specific. Besides changing the output section view
+ // however, it likes, the target may request a relocation change
+ // from one global symbol name to another.
- // If this is a readonly section, then we need a COPY reloc.
- // Otherwise we can use a dynamic reloc.
- if ((object->section_flags(shndx) & elfcpp::SHF_WRITE) == 0)
- return true;
+ for (Function_offsets::const_iterator p = calls_non_split.begin();
+ p != calls_non_split.end();
+ ++p)
+ {
+ std::string from;
+ std::string to;
+ parameters->target().calls_non_split(this, shndx, p->first, p->second,
+ view, view_size, &from, &to);
+ if (!from.empty())
+ {
+ gold_assert(!to.empty());
+ Symbol* tosym = NULL;
- return false;
+ // Find relocations in the relevant function which are for
+ // FROM.
+ pr = prelocs;
+ for (size_t i = 0; i < reloc_count; ++i, pr += reloc_size)
+ {
+ Reltype reloc(pr);
+
+ typename elfcpp::Elf_types<size>::Elf_WXword r_info =
+ reloc.get_r_info();
+ unsigned int r_sym = elfcpp::elf_r_sym<size>(r_info);
+ if (r_sym < local_count)
+ continue;
+
+ section_offset_type offset =
+ convert_to_section_size_type(reloc.get_r_offset());
+ if (offset < p->first
+ || (offset
+ >= (p->first
+ + static_cast<section_offset_type>(p->second))))
+ continue;
+
+ const Symbol* gsym = this->global_symbol(r_sym);
+ if (from == gsym->name())
+ {
+ if (tosym == NULL)
+ {
+ tosym = symtab->lookup(to.c_str());
+ if (tosym == NULL)
+ {
+ this->error(_("could not convert call "
+ "to '%s' to '%s'"),
+ from.c_str(), to.c_str());
+ break;
+ }
+ }
+
+ if (*reloc_map == NULL)
+ *reloc_map = new Reloc_symbol_changes(reloc_count);
+ (*reloc_map)->set(i, tosym);
+ }
+ }
+ }
+ }
}
-// Save a Rel reloc.
+// Find all the function in this object defined in section SHNDX.
+// Store their offsets in the section in FUNCTION_OFFSETS.
template<int size, bool big_endian>
void
-Copy_relocs<size, big_endian>::save(
- Symbol* sym,
- Relobj* relobj,
+Sized_relobj<size, big_endian>::find_functions(
+ const unsigned char* pshdrs,
unsigned int shndx,
- Output_section* output_section,
- const elfcpp::Rel<size, big_endian>& rel)
+ Sized_relobj<size, big_endian>::Function_offsets* function_offsets)
{
- unsigned int reloc_type = elfcpp::elf_r_type<size>(rel.get_r_info());
- this->entries_.push_back(Copy_reloc_entry(sym, reloc_type, relobj, shndx,
- output_section,
- rel.get_r_offset(), 0));
+ // We need to read the symbols to find the functions. If we wanted
+ // to, we could cache reading the symbols across all sections in the
+ // object.
+ const unsigned int symtab_shndx = this->symtab_shndx_;
+ typename This::Shdr symtabshdr(pshdrs + symtab_shndx * This::shdr_size);
+ gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
+
+ typename elfcpp::Elf_types<size>::Elf_WXword sh_size =
+ symtabshdr.get_sh_size();
+ const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
+ sh_size, true, true);
+
+ const int sym_size = This::sym_size;
+ const unsigned int symcount = sh_size / sym_size;
+ for (unsigned int i = 0; i < symcount; ++i, psyms += sym_size)
+ {
+ typename elfcpp::Sym<size, big_endian> isym(psyms);
+
+ // FIXME: Some targets can have functions which do not have type
+ // STT_FUNC, e.g., STT_ARM_TFUNC.
+ if (isym.get_st_type() != elfcpp::STT_FUNC
+ || isym.get_st_size() == 0)
+ continue;
+
+ bool is_ordinary;
+ unsigned int sym_shndx = this->adjust_sym_shndx(i, isym.get_st_shndx(),
+ &is_ordinary);
+ if (!is_ordinary || sym_shndx != shndx)
+ continue;
+
+ section_offset_type value =
+ convert_to_section_size_type(isym.get_st_value());
+ section_size_type fnsize =
+ convert_to_section_size_type(isym.get_st_size());
+
+ (*function_offsets)[value] = fnsize;
+ }
}
-// Save a Rela reloc.
+// Class Merged_symbol_value.
-template<int size, bool big_endian>
+template<int size>
void
-Copy_relocs<size, big_endian>::save(
- Symbol* sym,
- Relobj* relobj,
- unsigned int shndx,
- Output_section* output_section,
- const elfcpp::Rela<size, big_endian>& rela)
+Merged_symbol_value<size>::initialize_input_to_output_map(
+ const Relobj* object,
+ unsigned int input_shndx)
{
- unsigned int reloc_type = elfcpp::elf_r_type<size>(rela.get_r_info());
- this->entries_.push_back(Copy_reloc_entry(sym, reloc_type, relobj, shndx,
- output_section,
- rela.get_r_offset(),
- rela.get_r_addend()));
+ Object_merge_map* map = object->merge_map();
+ map->initialize_input_to_output_map<size>(input_shndx,
+ this->output_start_address_,
+ &this->output_addresses_);
}
-// Return whether there are any relocs to emit. We don't want to emit
-// a reloc if the symbol is no longer defined in a dynamic object.
+// Get the output value corresponding to an input offset if we
+// couldn't find it in the hash table.
-template<int size, bool big_endian>
-bool
-Copy_relocs<size, big_endian>::any_to_emit()
+template<int size>
+typename elfcpp::Elf_types<size>::Elf_Addr
+Merged_symbol_value<size>::value_from_output_section(
+ const Relobj* object,
+ unsigned int input_shndx,
+ typename elfcpp::Elf_types<size>::Elf_Addr input_offset) const
{
- for (typename Copy_reloc_entries::iterator p = this->entries_.begin();
- p != this->entries_.end();
- ++p)
- {
- if (p->should_emit())
- return true;
- }
- return false;
-}
+ section_offset_type output_offset;
+ bool found = object->merge_map()->get_output_offset(NULL, input_shndx,
+ input_offset,
+ &output_offset);
-// Emit relocs.
+ // If this assertion fails, it means that some relocation was
+ // against a portion of an input merge section which we didn't map
+ // to the output file and we didn't explicitly discard. We should
+ // always map all portions of input merge sections.
+ gold_assert(found);
-template<int size, bool big_endian>
-template<int sh_type>
-void
-Copy_relocs<size, big_endian>::emit(
- Output_data_reloc<sh_type, true, size, big_endian>* reloc_data)
-{
- for (typename Copy_reloc_entries::iterator p = this->entries_.begin();
- p != this->entries_.end();
- ++p)
- {
- if (p->should_emit())
- p->emit(reloc_data);
- }
+ if (output_offset == -1)
+ return 0;
+ else
+ return this->output_start_address_ + output_offset;
}
// Track_relocs methods.
return ret;
}
-// Instantiate the templates we need. We could use the configure
-// script to restrict this to only the ones for implemented targets.
+// Instantiate the templates we need.
#ifdef HAVE_TARGET_32_LITTLE
template
Sized_relobj<64, true>::do_read_relocs(Read_relocs_data* rd);
#endif
+#ifdef HAVE_TARGET_32_LITTLE
+template
+void
+Sized_relobj<32, false>::do_gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Read_relocs_data* rd);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+void
+Sized_relobj<32, true>::do_gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Read_relocs_data* rd);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+void
+Sized_relobj<64, false>::do_gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Read_relocs_data* rd);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+void
+Sized_relobj<64, true>::do_gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Read_relocs_data* rd);
+#endif
+
#ifdef HAVE_TARGET_32_LITTLE
template
void
class Symbol_value<64>;
#endif
-#ifdef HAVE_TARGET_32_LITTLE
-template
-class Copy_relocs<32, false>;
-#endif
-
-#ifdef HAVE_TARGET_32_BIG
-template
-class Copy_relocs<32, true>;
-#endif
-
-#ifdef HAVE_TARGET_64_LITTLE
-template
-class Copy_relocs<64, false>;
-#endif
-
-#ifdef HAVE_TARGET_64_BIG
-template
-class Copy_relocs<64, true>;
-#endif
-
-#ifdef HAVE_TARGET_32_LITTLE
-template
-void
-Copy_relocs<32, false>::emit<elfcpp::SHT_REL>(
- Output_data_reloc<elfcpp::SHT_REL, true, 32, false>*);
-#endif
-
-#ifdef HAVE_TARGET_32_BIG
-template
-void
-Copy_relocs<32, true>::emit<elfcpp::SHT_REL>(
- Output_data_reloc<elfcpp::SHT_REL, true, 32, true>*);
-#endif
-
-#ifdef HAVE_TARGET_64_LITTLE
-template
-void
-Copy_relocs<64, false>::emit<elfcpp::SHT_REL>(
- Output_data_reloc<elfcpp::SHT_REL, true, 64, false>*);
-#endif
-
-#ifdef HAVE_TARGET_64_BIG
-template
-void
-Copy_relocs<64, true>::emit<elfcpp::SHT_REL>(
- Output_data_reloc<elfcpp::SHT_REL, true, 64, true>*);
-#endif
-
-#ifdef HAVE_TARGET_32_LITTLE
-template
-void
-Copy_relocs<32, false>::emit<elfcpp::SHT_RELA>(
- Output_data_reloc<elfcpp::SHT_RELA , true, 32, false>*);
-#endif
-
-#ifdef HAVE_TARGET_32_BIG
-template
-void
-Copy_relocs<32, true>::emit<elfcpp::SHT_RELA>(
- Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>*);
-#endif
-
-#ifdef HAVE_TARGET_64_LITTLE
-template
-void
-Copy_relocs<64, false>::emit<elfcpp::SHT_RELA>(
- Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>*);
-#endif
-
-#ifdef HAVE_TARGET_64_BIG
-template
-void
-Copy_relocs<64, true>::emit<elfcpp::SHT_RELA>(
- Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>*);
-#endif
-
#ifdef HAVE_TARGET_32_LITTLE
template
class Track_relocs<32, false>;