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authorIan Lance Taylor <ian@airs.com>2009-10-06 22:58:27 +0000
committerIan Lance Taylor <ian@airs.com>2009-10-06 22:58:27 +0000
commit364c7fa5c98a7e2d75fe33ecb1ec4f7260849731 (patch)
tree2cfca9a55836527ac65fea760844754fe93f01a9 /gold/reloc.cc
parent5aafa1cc49c9a87aeb3e0aeaede8155fdf9f1645 (diff)
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* options.h (class General_options): Define
split_stack_adjust_size parameter. * object.h (class Object): Add uses_split_stack_ and has_no_split_stack_ fields. Add uses_split_stack and has_no_split_stack accessor functions. Declare handle_split_stack_section. (class Reloc_symbol_changes): Define. (class Sized_relobj): Define Function_offsets. Declare split_stack_adjust, split_stack_adjust_reltype, and find_functions. * object.cc (Object::handle_split_stack_section): New function. (Sized_relobj::do_layout): Call handle_split_stack_section. * dynobj.cc (Sized_dynobj::do_layout): Call handle_split_stack_section. * reloc.cc (Sized_relobj::relocate_sections): Call split_stack_adjust for executable sections in split_stack objects. Pass reloc_map to relocate_section. (Sized_relobj::split_stack_adjust): New function. (Sized_relobj::split_stack_adjust_reltype): New function. (Sized_relobj::find_functions): New function. * target-reloc.h: Include "object.h". (relocate_section): Add reloc_symbol_changes parameter. Change all callers. * target.h (class Target): Add calls_non_split method. Declare do_calls_non_split virtual method. Declare match_view and set_view_to_nop. * target.cc: Include "elfcpp.h". (Target::do_calls_non_split): New function. (Target::match_view): New function. (Target::set_view_to_nop): New function. * gold.cc (queue_middle_tasks): Give an error if mixing split-stack and non-split-stack objects with -r. * i386.cc (Target_i386::relocate_section): Add reloc_symbol_changes parameter. (Target_i386::do_calls_non_split): New function. * x86_64.cc (Target_x86_64::relocate_section): Add reloc_symbol_changes parameter. (Target_x86_64::do_calls_non_split): New function. * arm.cc (Target_arm::relocate_section): Add reloc_symbol_changes parameter. * powerpc.cc (Target_powerpc::relocate_section): Add reloc_symbol_changes parameter. * sparc.cc (Target_sparc::relocate_section): Add reloc_symbol_changes parameter. * configure.ac: Call AM_CONDITIONAL for the default target. * configure: Rebuild. * testsuite/Makefile.am (TEST_AS): New variable. (check_SCRIPTS): Add split_i386.sh and split_x86_64.sh. (check_DATA): Add split_i386 and split_x86_64 files. (SPLIT_DEFSYMS): Define. (split_i386_[1234n].o): New targets. (split_i386_[124]): New targets. (split_i386_[1234r].stdout): New targets. (split_x86_64_[1234n].o): New targets. (split_x86_64_[124]): New targets. (split_x86_64_[1234r].stdout): New targets. (MOSTLYCLEANFILES): Add new executables. * testsuite/split_i386.sh: New file. * testsuite/split_x86_64.sh: New file. * testsuite/split_i386_1.s: New file. * testsuite/split_i386_2.s: New file. * testsuite/split_i386_3.s: New file. * testsuite/split_i386_4.s: New file. * testsuite/split_i386_n.s: New file. * testsuite/split_x86_64_1.s: New file. * testsuite/split_x86_64_2.s: New file. * testsuite/split_x86_64_3.s: New file. * testsuite/split_x86_64_4.s: New file. * testsuite/split_x86_64_n.s: New file. * testsuite/testfile.cc (Target_test): Update relocation_section function. * testsuite/Makefile.in: Rebuild.
Diffstat (limited to 'gold/reloc.cc')
-rw-r--r--gold/reloc.cc283
1 files changed, 259 insertions, 24 deletions
diff --git a/gold/reloc.cc b/gold/reloc.cc
index bfa2f1c..7fb5cea 100644
--- a/gold/reloc.cc
+++ b/gold/reloc.cc
@@ -888,39 +888,36 @@ Sized_relobj<size, big_endian>::relocate_sections(
relinfo.reloc_shndx = i;
relinfo.data_shndx = index;
+ 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,
+ target->relocate_section(&relinfo, sh_type, prelocs, reloc_count, os,
output_offset == invalid_address,
- (*pviews)[index].view,
- (*pviews)[index].address,
- (*pviews)[index].view_size);
+ view, address, view_size, reloc_map);
if (parameters->options().emit_relocs())
this->emit_relocs(&relinfo, i, sh_type, prelocs, reloc_count,
- os, output_offset,
- (*pviews)[index].view,
- (*pviews)[index].address,
- (*pviews)[index].view_size,
- (*pviews)[i].view,
- (*pviews)[i].view_size);
+ 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,
- (*pviews)[index].view,
- (*pviews)[index].address,
- (*pviews)[index].view_size,
+ 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);
}
@@ -1025,6 +1022,244 @@ Sized_relobj<size, big_endian>::free_input_to_output_maps()
}
}
+// 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, bool big_endian>
+void
+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)
+{
+ 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);
+ }
+}
+
+// Adjust for -fsplit-stack, templatized on the type of the relocation
+// section.
+
+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)
+{
+ typedef typename Reloc_types<sh_type, size, big_endian>::Reloc Reltype;
+ const int reloc_size = Reloc_types<sh_type, size, big_endian>::reloc_size;
+
+ size_t local_count = this->local_symbol_count();
+
+ std::vector<section_offset_type> non_split_refs;
+
+ const unsigned char* 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;
+
+ 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);
+ }
+ }
+
+ if (non_split_refs.empty())
+ return;
+
+ // 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.
+
+ Function_offsets function_offsets;
+ this->find_functions(pshdrs, shndx, &function_offsets);
+ if (function_offsets.empty())
+ return;
+
+ // Now get a list of the function with references to non split-stack
+ // code.
+
+ 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;
+
+ calls_non_split.insert(*low);
+ }
+ if (calls_non_split.empty())
+ return;
+
+ // 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.
+
+ 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;
+
+ // 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);
+ }
+ }
+ }
+ }
+}
+
+// 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
+Sized_relobj<size, big_endian>::find_functions(
+ const unsigned char* pshdrs,
+ unsigned int shndx,
+ Sized_relobj<size, big_endian>::Function_offsets* function_offsets)
+{
+ // 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;
+ }
+}
+
// Class Merged_symbol_value.
template<int size>