From: Alan Modra Date: Fri, 9 Oct 2020 06:26:33 +0000 (+1030) Subject: [GOLD] Power10 segv due to wild r2 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=fa40fbe484954c560ab1c0ff4bc1b2eeb1511344;p=binutils-gdb.git [GOLD] Power10 segv due to wild r2 Calling non-pcrel functions from pcrel code requires a stub to set up r2. Gold created the stub, but an "optimisation" made the stub jump to the function local entry, ie. r2 was not initialised. This patch fixes that long branch stub problem, and another that might occur for plt call stubs to local functions. bfd/ * elf64-ppc.c (write_plt_relocs_for_local_syms): Don't do local entry offset optimisation. gold/ * powerpc.cc (Powerpc_relobj::do_relocate_sections): Don't do local entry offset optimisation for lplt_section. (Target_powerpc::Branch_info::make_stub): Don't add local entry offset to long branch dest passed to add_long_branch_entry. Do pass st_other bits. (Stub_table::Branch_stub_ent): Add "other_" field. (Stub_table::add_long_branch_entry): Add "other" param, and save. (Stub_table::branch_stub_size): Adjust long branch offset. (Stub_table::do_write): Likewise. (Target_powerpc::Relocate::relocate): Likewise. --- diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 9650b3d827c..3ff3b1e2395 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,8 @@ +2020-10-09 Alan Modra + + * elf64-ppc.c (write_plt_relocs_for_local_syms): Don't do local + entry offset optimisation. + 2020-10-09 H.J. Lu PR gas/26703 diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c index fa0c7f96e79..c30215b5507 100644 --- a/bfd/elf64-ppc.c +++ b/bfd/elf64-ppc.c @@ -14259,8 +14259,6 @@ write_plt_relocs_for_local_syms (struct bfd_link_info *info) } val = sym->st_value + ent->addend; - if (ELF_ST_TYPE (sym->st_info) != STT_GNU_IFUNC) - val += PPC64_LOCAL_ENTRY_OFFSET (sym->st_other); if (sym_sec != NULL && sym_sec->output_section != NULL) val += sym_sec->output_offset + sym_sec->output_section->vma; diff --git a/gold/ChangeLog b/gold/ChangeLog index 0c00d96f4eb..25248a6267a 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,17 @@ +2020-10-09 Alan Modra + + * powerpc.cc (Powerpc_relobj::do_relocate_sections): Don't do + local entry offset optimisation for lplt_section. + (Target_powerpc::Branch_info::make_stub): Don't add local + entry offset to long branch dest passed to + add_long_branch_entry. Do pass st_other bits. + (Stub_table::Branch_stub_ent): Add "other_" field. + (Stub_table::add_long_branch_entry): Add "other" param, and + save. + (Stub_table::branch_stub_size): Adjust long branch offset. + (Stub_table::do_write): Likewise. + (Target_powerpc::Relocate::relocate): Likewise. + 2020-10-09 Alan Modra * powerpc.cc (is_got_reloc): New function. diff --git a/gold/powerpc.cc b/gold/powerpc.cc index f9eb4f98bda..476fb4e588d 100644 --- a/gold/powerpc.cc +++ b/gold/powerpc.cc @@ -2767,8 +2767,6 @@ Powerpc_relobj::do_relocate_sections( if (this->local_has_plt_offset(i)) { Address value = this->local_symbol_value(i, 0); - if (size == 64) - value += ppc64_local_entry_offset(i); size_t off = this->local_plt_offset(i); elfcpp::Swap::writeval(oview + off, value); modified = true; @@ -3539,6 +3537,7 @@ Target_powerpc::Branch_info::make_stub( from += (this->object_->output_section(this->shndx_)->address() + this->offset_); Address to; + unsigned int other; if (gsym != NULL) { switch (gsym->source()) @@ -3566,8 +3565,7 @@ Target_powerpc::Branch_info::make_stub( to = symtab->compute_final_value(gsym, &status); if (status != Symbol_table::CFVS_OK) return true; - if (size == 64) - to += this->object_->ppc64_local_entry_offset(gsym); + other = gsym->nonvis() >> 3; } else { @@ -3584,8 +3582,7 @@ Target_powerpc::Branch_info::make_stub( || !symval.has_output_value()) return true; to = symval.value(this->object_, 0); - if (size == 64) - to += this->object_->ppc64_local_entry_offset(this->r_sym_); + other = this->object_->st_other(this->r_sym_) >> 5; } if (!(size == 32 && this->r_type_ == elfcpp::R_PPC_PLTREL24)) to += this->addend_; @@ -3598,7 +3595,11 @@ Target_powerpc::Branch_info::make_stub( &to, &dest_shndx)) return true; } - Address delta = to - from; + unsigned int local_ent = 0; + if (size == 64 + && this->r_type_ != elfcpp::R_PPC64_REL24_NOTOC) + local_ent = elfcpp::ppc64_decode_local_entry(other); + Address delta = to + local_ent - from; if (delta + max_branch_offset >= 2 * max_branch_offset || (size == 64 && this->r_type_ == elfcpp::R_PPC64_REL24_NOTOC @@ -3620,7 +3621,7 @@ Target_powerpc::Branch_info::make_stub( && gsym->output_data() == target->savres_section()); ok = stub_table->add_long_branch_entry(this->object_, this->r_type_, - from, to, save_res); + from, to, other, save_res); } } if (!ok) @@ -4688,7 +4689,7 @@ class Stub_table : public Output_relaxed_input_section { Branch_stub_ent(unsigned int off, bool notoc, bool save_res) : off_(off), iter_(0), notoc_(notoc), toc_(0), save_res_(save_res), - tocoff_(0) + other_(0), tocoff_(0) { } unsigned int off_; @@ -4696,6 +4697,7 @@ class Stub_table : public Output_relaxed_input_section unsigned int notoc_ : 1; unsigned int toc_ : 1; unsigned int save_res_ : 1; + unsigned int other_ : 3; unsigned int tocoff_ : 8; }; typedef typename elfcpp::Elf_types::Elf_Addr Address; @@ -4762,7 +4764,7 @@ class Stub_table : public Output_relaxed_input_section // Add a long branch stub. bool add_long_branch_entry(const Powerpc_relobj*, - unsigned int, Address, Address, bool); + unsigned int, Address, Address, unsigned int, bool); const Branch_stub_ent* find_long_branch_entry(const Powerpc_relobj*, @@ -5282,6 +5284,7 @@ Stub_table::add_long_branch_entry( unsigned int r_type, Address from, Address to, + unsigned int other, bool save_res) { Branch_stub_key key(object, to); @@ -5301,6 +5304,8 @@ Stub_table::add_long_branch_entry( this->need_resize_ = true; p.first->second.toc_ = true; } + if (p.first->second.other_ == 0) + p.first->second.other_ = other; gold_assert(save_res == p.first->second.save_res_); if (p.second || (this->resizing_ && !p.first->second.iter_)) { @@ -6198,6 +6203,7 @@ Stub_table::branch_stub_size( } } + off += elfcpp::ppc64_decode_local_entry(p->second.other_); if (off + (1 << 25) < 2 << 25) return bytes + 4; if (!this->targ_->power10_stubs() @@ -6377,6 +6383,7 @@ Stub_table::do_write(Output_file* of) } if (bs->second.toc_) { + delta += elfcpp::ppc64_decode_local_entry(bs->second.other_); if (delta + (1 << 25) >= 2 << 25) { Address brlt_addr @@ -6410,6 +6417,8 @@ Stub_table::do_write(Output_file* of) } else { + if (!bs->second.notoc_) + delta += elfcpp::ppc64_decode_local_entry(bs->second.other_); if (bs->second.notoc_ || delta + (1 << 25) >= 2 << 25) { unsigned char* startp = p; @@ -6640,6 +6649,8 @@ Stub_table::do_write(Output_file* of) p = oview + off; Address loc = this->stub_address() + off; Address delta = bs->first.dest_ - loc; + if (!bs->second.notoc_) + delta += elfcpp::ppc64_decode_local_entry(bs->second.other_); if (bs->second.notoc_) { unsigned char* startp = p; @@ -11039,14 +11050,15 @@ Target_powerpc::Relocate::relocate( || r_type == elfcpp::R_POWERPC_PLT16_HA))) addend = rela.get_r_addend(); value = psymval->value(object, addend); + unsigned int local_ent = 0; if (size == 64 && is_branch_reloc(r_type)) { if (target->abiversion() >= 2) { if (gsym != NULL) - value += object->ppc64_local_entry_offset(gsym); + local_ent = object->ppc64_local_entry_offset(gsym); else - value += object->ppc64_local_entry_offset(r_sym); + local_ent = object->ppc64_local_entry_offset(r_sym); } else { @@ -11055,9 +11067,9 @@ Target_powerpc::Relocate::relocate( &value, &dest_shndx); } } - Address max_branch_offset = max_branch_delta(r_type); - if (max_branch_offset != 0 - && (value - address + max_branch_offset >= 2 * max_branch_offset + Address max_branch = max_branch_delta(r_type); + if (max_branch != 0 + && (value + local_ent - address + max_branch >= 2 * max_branch || (size == 64 && r_type == elfcpp::R_PPC64_REL24_NOTOC && (gsym != NULL @@ -11082,12 +11094,15 @@ Target_powerpc::Relocate::relocate( + ent->off_); if (size == 64 && r_type != elfcpp::R_PPC64_REL24_NOTOC) - value += ent->tocoff_; + value += (elfcpp::ppc64_decode_local_entry(ent->other_) + + ent->tocoff_); } has_stub_value = true; } } } + if (!has_stub_value) + value += local_ent; } switch (r_type)