unsigned int, Output_section*,
Target_arm<big_endian>*);
+ // Find the linked text section of an EXIDX section by looking at the
+ // first reloction of the EXIDX section. PSHDR points to the section
+ // headers of a relocation section and PSYMS points to the local symbols.
+ // PSHNDX points to a location storing the text section index if found.
+ // Return whether we can find the linked section.
+ bool
+ find_linked_text_section(const unsigned char* pshdr,
+ const unsigned char* psyms, unsigned int* pshndx);
+
+ //
// Make a new Arm_exidx_input_section object for EXIDX section with
- // index SHNDX and section header SHDR.
+ // index SHNDX and section header SHDR. TEXT_SHNDX is the section
+ // index of the linked text section.
void
make_exidx_input_section(unsigned int shndx,
- const elfcpp::Shdr<32, big_endian>& shdr);
+ const elfcpp::Shdr<32, big_endian>& shdr,
+ unsigned int text_shndx);
// Return the output address of either a plain input section or a
// relaxed input section. SHNDX is the section index.
do_is_defined_by_abi(Symbol* sym) const
{ return strcmp(sym->name(), "__tls_get_addr") == 0; }
+ // Return whether there is a GOT section.
+ bool
+ has_got_section() const
+ { return this->got_ != NULL; }
+
// Return the size of the GOT section.
section_size_type
got_size()
Output_section* os,
Target_arm<big_endian>* arm_target)
{
+ // Look for the first mapping symbol in this section. It should be
+ // at (shndx, 0).
+ Mapping_symbol_position section_start(shndx, 0);
+ typename Mapping_symbols_info::const_iterator p =
+ this->mapping_symbols_info_.lower_bound(section_start);
+
+ // There are no mapping symbols for this section. Treat it as a data-only
+ // section.
+ if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
+ return;
+
Arm_address output_address =
this->simple_input_section_output_address(shndx, os);
// THUMB code only. Second, we only want to look at the 4K-page boundary
// to speed up the scanning.
- // Look for the first mapping symbol in this section. It should be
- // at (shndx, 0).
- Mapping_symbol_position section_start(shndx, 0);
- typename Mapping_symbols_info::const_iterator p =
- this->mapping_symbols_info_.lower_bound(section_start);
-
- if (p == this->mapping_symbols_info_.end()
- || p->first != section_start)
- {
- gold_warning(_("Cortex-A8 erratum scanning failed because there "
- "is no mapping symbols for section %u of %s"),
- shndx, this->name().c_str());
- return;
- }
-
while (p != this->mapping_symbols_info_.end()
&& p->first.first == shndx)
{
}
}
-// Create a new EXIDX input section object for EXIDX section SHNDX with
-// header SHDR.
+// Find the linked text section of an EXIDX section by looking the the first
+// relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
+// must be linked to to its associated code section via the sh_link field of
+// its section header. However, some tools are broken and the link is not
+// always set. LD just drops such an EXIDX section silently, causing the
+// associated code not unwindabled. Here we try a little bit harder to
+// discover the linked code section.
+//
+// PSHDR points to the section header of a relocation section of an EXIDX
+// section. If we can find a linked text section, return true and
+// store the text section index in the location PSHNDX. Otherwise
+// return false.
template<bool big_endian>
-void
-Arm_relobj<big_endian>::make_exidx_input_section(
- unsigned int shndx,
- const elfcpp::Shdr<32, big_endian>& shdr)
+bool
+Arm_relobj<big_endian>::find_linked_text_section(
+ const unsigned char* pshdr,
+ const unsigned char* psyms,
+ unsigned int* pshndx)
{
- // Link .text section to its .ARM.exidx section in the same object.
- unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
+ elfcpp::Shdr<32, big_endian> shdr(pshdr);
+
+ // If there is no relocation, we cannot find the linked text section.
+ size_t reloc_size;
+ if (shdr.get_sh_type() == elfcpp::SHT_REL)
+ reloc_size = elfcpp::Elf_sizes<32>::rel_size;
+ else
+ reloc_size = elfcpp::Elf_sizes<32>::rela_size;
+ size_t reloc_count = shdr.get_sh_size() / reloc_size;
+
+ // Get the relocations.
+ const unsigned char* prelocs =
+ this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
- // Issue an error and ignore this EXIDX section if it does not point
- // to any text section.
- if (text_shndx == elfcpp::SHN_UNDEF)
+ // Find the REL31 relocation for the first word of the first EXIDX entry.
+ for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
{
- gold_error(_("EXIDX section %u in %s has no linked text section"),
- shndx, this->name().c_str());
- return;
+ Arm_address r_offset;
+ typename elfcpp::Elf_types<32>::Elf_WXword r_info;
+ if (shdr.get_sh_type() == elfcpp::SHT_REL)
+ {
+ typename elfcpp::Rel<32, big_endian> reloc(prelocs);
+ r_info = reloc.get_r_info();
+ r_offset = reloc.get_r_offset();
+ }
+ else
+ {
+ typename elfcpp::Rela<32, big_endian> reloc(prelocs);
+ r_info = reloc.get_r_info();
+ r_offset = reloc.get_r_offset();
+ }
+
+ unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
+ if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
+ continue;
+
+ unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
+ if (r_sym == 0
+ || r_sym >= this->local_symbol_count()
+ || r_offset != 0)
+ continue;
+
+ // This is the relocation for the first word of the first EXIDX entry.
+ // We expect to see a local section symbol.
+ const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
+ elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
+ if (sym.get_st_type() == elfcpp::STT_SECTION)
+ {
+ *pshndx = this->adjust_shndx(sym.get_st_shndx());
+ return true;
+ }
+ else
+ return false;
}
-
+
+ return false;
+}
+
+// Make an EXIDX input section object for an EXIDX section whose index is
+// SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
+// is the section index of the linked text section.
+
+template<bool big_endian>
+void
+Arm_relobj<big_endian>::make_exidx_input_section(
+ unsigned int shndx,
+ const elfcpp::Shdr<32, big_endian>& shdr,
+ unsigned int text_shndx)
+{
// Issue an error and ignore this EXIDX section if it points to a text
// section already has an EXIDX section.
if (this->exidx_section_map_[text_shndx] != NULL)
// Go over the section headers and look for .ARM.attributes and .ARM.exidx
// sections.
+ std::vector<unsigned int> deferred_exidx_sections;
const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
- const unsigned char *ps =
- sd->section_headers->data() + shdr_size;
+ const unsigned char* pshdrs = sd->section_headers->data();
+ const unsigned char *ps = pshdrs + shdr_size;
for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
{
elfcpp::Shdr<32, big_endian> shdr(ps);
new Attributes_section_data(view->data(), section_size);
}
else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
- this->make_exidx_input_section(i, shdr);
+ {
+ unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
+ if (text_shndx >= this->shnum())
+ gold_error(_("EXIDX section %u linked to invalid section %u"),
+ i, text_shndx);
+ else if (text_shndx == elfcpp::SHN_UNDEF)
+ deferred_exidx_sections.push_back(i);
+ else
+ this->make_exidx_input_section(i, shdr, text_shndx);
+ }
+ }
+
+ // Some tools are broken and they do not set the link of EXIDX sections.
+ // We look at the first relocation to figure out the linked sections.
+ if (!deferred_exidx_sections.empty())
+ {
+ // We need to go over the section headers again to find the mapping
+ // from sections being relocated to their relocation sections. This is
+ // a bit inefficient as we could do that in the loop above. However,
+ // we do not expect any deferred EXIDX sections normally. So we do not
+ // want to slow down the most common path.
+ typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
+ Reloc_map reloc_map;
+ ps = pshdrs + shdr_size;
+ for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
+ {
+ elfcpp::Shdr<32, big_endian> shdr(ps);
+ elfcpp::Elf_Word sh_type = shdr.get_sh_type();
+ if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
+ {
+ unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
+ if (info_shndx >= this->shnum())
+ gold_error(_("relocation section %u has invalid info %u"),
+ i, info_shndx);
+ Reloc_map::value_type value(info_shndx, i);
+ std::pair<Reloc_map::iterator, bool> result =
+ reloc_map.insert(value);
+ if (!result.second)
+ gold_error(_("section %u has multiple relocation sections "
+ "%u and %u"),
+ info_shndx, i, reloc_map[info_shndx]);
+ }
+ }
+
+ // Read the symbol table section header.
+ const unsigned int symtab_shndx = this->symtab_shndx();
+ elfcpp::Shdr<32, big_endian>
+ symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
+ gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
+
+ // Read the local symbols.
+ const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
+ const unsigned int loccount = this->local_symbol_count();
+ gold_assert(loccount == symtabshdr.get_sh_info());
+ off_t locsize = loccount * sym_size;
+ const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
+ locsize, true, true);
+
+ // Process the deferred EXIDX sections.
+ for(unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
+ {
+ unsigned int shndx = deferred_exidx_sections[i];
+ elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
+ unsigned int text_shndx;
+ Reloc_map::const_iterator it = reloc_map.find(shndx);
+ if (it != reloc_map.end()
+ && find_linked_text_section(pshdrs + it->second * shdr_size,
+ psyms, &text_shndx))
+ this->make_exidx_input_section(shndx, shdr, text_shndx);
+ else
+ gold_error(_("EXIDX section %u has no linked text section."),
+ shndx);
+ }
}
}
return;
default:
- // This prevents us from issuing more than one error per reloc
- // section. But we can still wind up issuing more than one
- // error per object file.
- if (this->issued_non_pic_error_)
+ {
+ // This prevents us from issuing more than one error per reloc
+ // section. But we can still wind up issuing more than one
+ // error per object file.
+ if (this->issued_non_pic_error_)
+ return;
+ const Arm_reloc_property* reloc_property =
+ arm_reloc_property_table->get_reloc_property(r_type);
+ gold_assert(reloc_property != NULL);
+ object->error(_("requires unsupported dynamic reloc %s; "
+ "recompile with -fPIC"),
+ reloc_property->name().c_str());
+ this->issued_non_pic_error_ = true;
return;
- object->error(_("requires unsupported dynamic reloc; "
- "recompile with -fPIC"));
- this->issued_non_pic_error_ = true;
- return;
+ }
case elfcpp::R_ARM_NONE:
gold_unreachable();
unsigned int r_type,
Symbol* gsym)
{
+ // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
+ // section. We check here to avoid creating a dynamic reloc against
+ // _GLOBAL_OFFSET_TABLE_.
+ if (!target->has_got_section()
+ && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
+ target->got_section(symtab, layout);
+
r_type = get_real_reloc_type(r_type);
switch (r_type)
{
projects / deliverable / binutils-gdb.git / commitdiff
