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author | Ian Lance Taylor <ian@airs.com> | 2009-10-06 22:58:27 +0000 |
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committer | Ian Lance Taylor <ian@airs.com> | 2009-10-06 22:58:27 +0000 |
commit | 364c7fa5c98a7e2d75fe33ecb1ec4f7260849731 (patch) | |
tree | 2cfca9a55836527ac65fea760844754fe93f01a9 /gold/reloc.cc | |
parent | 5aafa1cc49c9a87aeb3e0aeaede8155fdf9f1645 (diff) | |
download | gdb-364c7fa5c98a7e2d75fe33ecb1ec4f7260849731.zip gdb-364c7fa5c98a7e2d75fe33ecb1ec4f7260849731.tar.gz gdb-364c7fa5c98a7e2d75fe33ecb1ec4f7260849731.tar.bz2 |
* 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.cc | 283 |
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> |