From 3ea0a085a6f439598edec3b67e7be8fd53d4a702 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Wed, 5 Sep 2012 02:54:26 +0000 Subject: [PATCH] * powerpc.cc (Powerpc_relobj::get_opd_ent): Make const. (Powerpc_relocate_functions::Status): New typedef. (Target_powerpc::Scan::get_reference_flags): Handle more relocs. (Target_powerpc::Scan::local): Handle REL64. (Target_powerpc::Scan::global): Likewise, and dynamic relocs for REL32 and REL64. (Target_powerpc::symval_for_branch): New function, extracted from.. (Target_powerpc::Relocate::relocate): ..here. Correct plt call checks. Report overflow errors. --- gold/ChangeLog | 12 +++ gold/powerpc.cc | 249 +++++++++++++++++++++++++++++++----------------- 2 files changed, 172 insertions(+), 89 deletions(-) diff --git a/gold/ChangeLog b/gold/ChangeLog index ea52ea21b7f..faa228ec364 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,15 @@ +2012-09-05 Alan Modra + + * powerpc.cc (Powerpc_relobj::get_opd_ent): Make const. + (Powerpc_relocate_functions::Status): New typedef. + (Target_powerpc::Scan::get_reference_flags): Handle more relocs. + (Target_powerpc::Scan::local): Handle REL64. + (Target_powerpc::Scan::global): Likewise, and dynamic relocs + for REL32 and REL64. + (Target_powerpc::symval_for_branch): New function, extracted from.. + (Target_powerpc::Relocate::relocate): ..here. Correct plt call + checks. Report overflow errors. + 2012-09-05 Alan Modra * object.h (Sized_relobj_file::emit_relocs): Delete. diff --git a/gold/powerpc.cc b/gold/powerpc.cc index c4b543d97a4..aa209c2b687 100644 --- a/gold/powerpc.cc +++ b/gold/powerpc.cc @@ -100,7 +100,7 @@ public: // Return section and offset of function entry for .opd + R_OFF. void - get_opd_ent(Address r_off, unsigned int* shndx, Address* value) + get_opd_ent(Address r_off, unsigned int* shndx, Address* value) const { size_t ndx = this->opd_ent_ndx(r_off); gold_assert(ndx < this->opd_ent_shndx_.size()); @@ -411,6 +411,11 @@ class Target_powerpc : public Sized_target bool issued_non_pic_error_; }; + Address + symval_for_branch(Address value, const Sized_symbol* gsym, + Powerpc_relobj* object, + unsigned int *dest_shndx); + // The class which implements relocation. class Relocate { @@ -847,11 +852,11 @@ public: check_bitfield }; - enum overflow_status + typedef enum overflow_status { status_ok, status_overflow - }; + } Status; private: typedef Powerpc_relocate_functions This; @@ -2190,6 +2195,7 @@ Target_powerpc::Scan::check_non_pic(Relobj* object, // and 64-bit powerpc. switch (r_type) { + case elfcpp::R_POWERPC_NONE: case elfcpp::R_POWERPC_RELATIVE: case elfcpp::R_POWERPC_GLOB_DAT: case elfcpp::R_POWERPC_DTPMOD: @@ -2197,9 +2203,24 @@ Target_powerpc::Scan::check_non_pic(Relobj* object, case elfcpp::R_POWERPC_TPREL: case elfcpp::R_POWERPC_JMP_SLOT: case elfcpp::R_POWERPC_COPY: + case elfcpp::R_POWERPC_IRELATIVE: case elfcpp::R_POWERPC_ADDR32: + case elfcpp::R_POWERPC_UADDR32: case elfcpp::R_POWERPC_ADDR24: + case elfcpp::R_POWERPC_ADDR16: + case elfcpp::R_POWERPC_UADDR16: + case elfcpp::R_POWERPC_ADDR16_LO: + case elfcpp::R_POWERPC_ADDR16_HI: + case elfcpp::R_POWERPC_ADDR16_HA: + case elfcpp::R_POWERPC_ADDR14: + case elfcpp::R_POWERPC_ADDR14_BRTAKEN: + case elfcpp::R_POWERPC_ADDR14_BRNTAKEN: + case elfcpp::R_POWERPC_REL32: case elfcpp::R_POWERPC_REL24: + case elfcpp::R_POWERPC_TPREL16: + case elfcpp::R_POWERPC_TPREL16_LO: + case elfcpp::R_POWERPC_TPREL16_HI: + case elfcpp::R_POWERPC_TPREL16_HA: return; default: @@ -2212,34 +2233,22 @@ Target_powerpc::Scan::check_non_pic(Relobj* object, { // These are the relocation types supported only on 64-bit. case elfcpp::R_PPC64_ADDR64: - case elfcpp::R_PPC64_TPREL16_LO_DS: - case elfcpp::R_PPC64_TPREL16_DS: - case elfcpp::R_POWERPC_TPREL16: - case elfcpp::R_POWERPC_TPREL16_LO: - case elfcpp::R_POWERPC_TPREL16_HI: - case elfcpp::R_POWERPC_TPREL16_HA: - case elfcpp::R_PPC64_TPREL16_HIGHER: - case elfcpp::R_PPC64_TPREL16_HIGHEST: - case elfcpp::R_PPC64_TPREL16_HIGHERA: - case elfcpp::R_PPC64_TPREL16_HIGHESTA: - case elfcpp::R_PPC64_ADDR16_LO_DS: - case elfcpp::R_POWERPC_ADDR16_LO: - case elfcpp::R_POWERPC_ADDR16_HI: - case elfcpp::R_POWERPC_ADDR16_HA: - case elfcpp::R_POWERPC_ADDR30: case elfcpp::R_PPC64_UADDR64: - case elfcpp::R_POWERPC_UADDR32: - case elfcpp::R_POWERPC_ADDR16: - case elfcpp::R_POWERPC_UADDR16: + case elfcpp::R_PPC64_JMP_IREL: case elfcpp::R_PPC64_ADDR16_DS: + case elfcpp::R_PPC64_ADDR16_LO_DS: case elfcpp::R_PPC64_ADDR16_HIGHER: case elfcpp::R_PPC64_ADDR16_HIGHEST: case elfcpp::R_PPC64_ADDR16_HIGHERA: case elfcpp::R_PPC64_ADDR16_HIGHESTA: - case elfcpp::R_POWERPC_ADDR14_BRTAKEN: - case elfcpp::R_POWERPC_ADDR14_BRNTAKEN: - case elfcpp::R_POWERPC_REL32: case elfcpp::R_PPC64_REL64: + case elfcpp::R_POWERPC_ADDR30: + case elfcpp::R_PPC64_TPREL16_DS: + case elfcpp::R_PPC64_TPREL16_LO_DS: + case elfcpp::R_PPC64_TPREL16_HIGHER: + case elfcpp::R_PPC64_TPREL16_HIGHEST: + case elfcpp::R_PPC64_TPREL16_HIGHERA: + case elfcpp::R_PPC64_TPREL16_HIGHESTA: return; default: @@ -2251,6 +2260,12 @@ Target_powerpc::Scan::check_non_pic(Relobj* object, switch (r_type) { // These are the relocation types supported only on 32-bit. + // ??? glibc ld.so doesn't need to support these. + case elfcpp::R_POWERPC_DTPREL16: + case elfcpp::R_POWERPC_DTPREL16_LO: + case elfcpp::R_POWERPC_DTPREL16_HI: + case elfcpp::R_POWERPC_DTPREL16_HA: + return; default: break; @@ -2361,6 +2376,7 @@ Target_powerpc::Scan::local( } break; + case elfcpp::R_PPC64_REL64: case elfcpp::R_POWERPC_REL32: case elfcpp::R_POWERPC_REL24: case elfcpp::R_PPC_LOCAL24PC: @@ -2670,35 +2686,36 @@ Target_powerpc::Scan::global( case elfcpp::R_PPC_PLTREL24: case elfcpp::R_POWERPC_REL24: - { - if (gsym->needs_plt_entry() - || (!gsym->final_value_is_known() - && !(gsym->is_defined() - && !gsym->is_from_dynobj() - && !gsym->is_preemptible()))) - target->make_plt_entry(layout, gsym, reloc, object); - // Make a dynamic relocation if necessary. - if (needs_dynamic_reloc(gsym, Scan::get_reference_flags(r_type))) - { - if (gsym->may_need_copy_reloc()) - { - target->copy_reloc(symtab, layout, object, - data_shndx, output_section, gsym, - reloc); - } - else - { - Reloc_section* rela_dyn = target->rela_dyn_section(layout); - check_non_pic(object, r_type); - rela_dyn->add_global(gsym, r_type, output_section, object, - data_shndx, reloc.get_r_offset(), - reloc.get_r_addend()); - } - } - } - break; + if (gsym->needs_plt_entry() + || (!gsym->final_value_is_known() + && (gsym->is_undefined() + || gsym->is_from_dynobj() + || gsym->is_preemptible()))) + target->make_plt_entry(layout, gsym, reloc, object); + // Fall thru + case elfcpp::R_PPC64_REL64: case elfcpp::R_POWERPC_REL32: + // Make a dynamic relocation if necessary. + if (needs_dynamic_reloc(gsym, Scan::get_reference_flags(r_type))) + { + if (gsym->may_need_copy_reloc()) + { + target->copy_reloc(symtab, layout, object, + data_shndx, output_section, gsym, + reloc); + } + else + { + Reloc_section* rela_dyn = target->rela_dyn_section(layout); + check_non_pic(object, r_type); + rela_dyn->add_global(gsym, r_type, output_section, object, + data_shndx, reloc.get_r_offset(), + reloc.get_r_addend()); + } + } + break; + case elfcpp::R_POWERPC_REL16: case elfcpp::R_POWERPC_REL16_LO: case elfcpp::R_POWERPC_REL16_HI: @@ -3022,6 +3039,43 @@ Target_powerpc::do_finalize_sections( this->copy_relocs_.emit(this->rela_dyn_section(layout)); } +// Return the value to use for a branch relocation. + +template +typename elfcpp::Elf_types::Elf_Addr +Target_powerpc::symval_for_branch( + Address value, + const Sized_symbol* gsym, + Powerpc_relobj* object, + unsigned int *dest_shndx) +{ + *dest_shndx = 0; + if (size == 32) + return value; + + // If the symbol is defined in an opd section, ie. is a function + // descriptor, use the function descriptor code entry address + Powerpc_relobj* symobj = object; + if (gsym != NULL) + symobj = static_cast*>(gsym->object()); + unsigned int shndx = symobj->opd_shndx(); + if (shndx == 0) + return value; + Address opd_addr = symobj->get_output_section_offset(shndx); + gold_assert(opd_addr != invalid_address); + opd_addr += symobj->output_section(shndx)->address(); + if (value >= opd_addr && value < opd_addr + symobj->section_size(shndx)) + { + Address sec_off; + symobj->get_opd_ent(value - opd_addr, dest_shndx, &sec_off); + Address sec_addr = symobj->get_output_section_offset(*dest_shndx); + gold_assert(sec_addr != invalid_address); + sec_addr += symobj->output_section(*dest_shndx)->address(); + value = sec_addr + sec_off; + } + return value; +} + // Perform a relocation. template @@ -3060,8 +3114,8 @@ Target_powerpc::Relocate::relocate( typedef Powerpc_relocate_functions Reloc; typedef typename elfcpp::Swap<32, big_endian>::Valtype Insn; - const Powerpc_relobj* const object - = static_cast*>(relinfo->object); + Powerpc_relobj* const object + = static_cast*>(relinfo->object); Address value = 0; bool has_plt_value = false; if (gsym != NULL @@ -3111,17 +3165,50 @@ Target_powerpc::Relocate::relocate( bool can_plt_call = false; if (rela.get_r_offset() + 8 <= view_size) { + Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv); Valtype insn2 = elfcpp::Swap<32, big_endian>::readval(wv + 1); - if (insn2 == nop - || insn2 == cror_15_15_15 || insn2 == cror_31_31_31) + if ((insn & 1) != 0 + && (insn2 == nop + || insn2 == cror_15_15_15 || insn2 == cror_31_31_31)) { elfcpp::Swap<32, big_endian>::writeval(wv + 1, ld_2_1 + 40); can_plt_call = true; } } if (!can_plt_call) - gold_error_at_location(relinfo, relnum, rela.get_r_offset(), - _("call lacks nop, can't restore toc")); + { + // If we don't have a branch and link followed by a nop, + // we can't go via the plt because there is no place to + // put a toc restoring instruction. + // Unless we know we won't be returning. + if (strcmp(gsym->name(), "__libc_start_main") == 0) + can_plt_call = true; + } + if (!can_plt_call) + { + // This is not an error in one special case: A self + // call. It isn't possible to cheaply verify we have + // such a call so just check for a call to the same + // section. + bool ok = false; + if (gsym->source() == Symbol::FROM_OBJECT + && gsym->object() == object) + { + Address addend = rela.get_r_addend(); + unsigned int dest_shndx; + value = psymval->value(object, addend); + value = target->symval_for_branch(value, gsym, object, + &dest_shndx); + bool is_ordinary; + if (dest_shndx == 0) + dest_shndx = gsym->shndx(&is_ordinary); + ok = dest_shndx == relinfo->data_shndx; + } + if (!ok) + gold_error_at_location(relinfo, relnum, rela.get_r_offset(), + _("call lacks nop, can't restore toc; " + "recompile with -fPIC")); + } } } else if (r_type == elfcpp::R_POWERPC_GOT_TLSGD16 @@ -3365,34 +3452,13 @@ Target_powerpc::Relocate::relocate( else { Address addend = 0; + unsigned int dest_shndx; if (r_type != elfcpp::R_PPC_PLTREL24) addend = rela.get_r_addend(); if (size == 64 || !has_plt_value) value = psymval->value(object, addend); if (size == 64 && is_branch_reloc(r_type)) - { - // If the symbol is defined in an opd section, ie. is a function - // descriptor, use the function descriptor code entry address - Powerpc_relobj* symobj = const_cast - *>(object); - if (gsym != NULL) - symobj = static_cast - *>(gsym->object()); - unsigned int shndx = symobj->opd_shndx(); - Address opd_addr = symobj->get_output_section_offset(shndx); - gold_assert(opd_addr != invalid_address); - opd_addr += symobj->output_section(shndx)->address(); - if (value >= opd_addr - && value < opd_addr + symobj->section_size(shndx)) - { - Address sec_off; - symobj->get_opd_ent(value - opd_addr, &shndx, &sec_off); - Address sec_addr = symobj->get_output_section_offset(shndx); - gold_assert(sec_addr != invalid_address); - sec_addr += symobj->output_section(shndx)->address(); - value = sec_addr + sec_off; - } - } + value = target->symval_for_branch(value, gsym, object, &dest_shndx); } switch (r_type) @@ -3562,6 +3628,8 @@ Target_powerpc::Relocate::relocate( break; } + typename Powerpc_relocate_functions::Status status + = Powerpc_relocate_functions::status_ok; switch (r_type) { case elfcpp::R_POWERPC_NONE: @@ -3582,7 +3650,7 @@ Target_powerpc::Relocate::relocate( if (size == 64) Reloc::addr64(view, value); else - Reloc::addr32(view, value, overflow); + status = Reloc::addr32(view, value, overflow); break; case elfcpp::R_PPC64_UADDR64: @@ -3591,25 +3659,25 @@ Target_powerpc::Relocate::relocate( case elfcpp::R_POWERPC_ADDR32: case elfcpp::R_POWERPC_REL32: - Reloc::addr32(view, value, overflow); + status = Reloc::addr32(view, value, overflow); break; case elfcpp::R_POWERPC_UADDR32: - Reloc::addr32_u(view, value, overflow); + status = Reloc::addr32_u(view, value, overflow); break; case elfcpp::R_POWERPC_ADDR24: case elfcpp::R_POWERPC_REL24: case elfcpp::R_PPC_PLTREL24: case elfcpp::R_PPC_LOCAL24PC: - Reloc::addr24(view, value, overflow); + status = Reloc::addr24(view, value, overflow); break; case elfcpp::R_POWERPC_GOT_DTPREL16: case elfcpp::R_POWERPC_GOT_DTPREL16_LO: if (size == 64) { - Reloc::addr16_ds(view, value, overflow); + status = Reloc::addr16_ds(view, value, overflow); break; } case elfcpp::R_POWERPC_ADDR16: @@ -3632,11 +3700,11 @@ Target_powerpc::Relocate::relocate( case elfcpp::R_POWERPC_GOT_TLSGD16_LO: case elfcpp::R_POWERPC_GOT_TLSLD16_LO: case elfcpp::R_POWERPC_GOT_TPREL16_LO: - Reloc::addr16(view, value, overflow); + status = Reloc::addr16(view, value, overflow); break; case elfcpp::R_POWERPC_UADDR16: - Reloc::addr16_u(view, value, overflow); + status = Reloc::addr16_u(view, value, overflow); break; case elfcpp::R_POWERPC_ADDR16_HI: @@ -3721,7 +3789,7 @@ Target_powerpc::Relocate::relocate( case elfcpp::R_PPC64_GOT16_LO_DS: case elfcpp::R_PPC64_SECTOFF_DS: case elfcpp::R_PPC64_SECTOFF_LO_DS: - Reloc::addr16_ds(view, value, overflow); + status = Reloc::addr16_ds(view, value, overflow); break; case elfcpp::R_POWERPC_ADDR14: @@ -3730,7 +3798,7 @@ Target_powerpc::Relocate::relocate( case elfcpp::R_POWERPC_REL14: case elfcpp::R_POWERPC_REL14_BRTAKEN: case elfcpp::R_POWERPC_REL14_BRNTAKEN: - Reloc::addr14(view, value, overflow); + status = Reloc::addr14(view, value, overflow); break; case elfcpp::R_POWERPC_COPY: @@ -3791,6 +3859,9 @@ Target_powerpc::Relocate::relocate( r_type); break; } + if (status != Powerpc_relocate_functions::status_ok) + gold_error_at_location(relinfo, relnum, rela.get_r_offset(), + _("relocation overflow")); return true; } -- 2.30.2