[binutils-gdb/binutils-2_35-branch] [GOLD] Power10 segv due to wild r2
Alan Modra
amodra@sourceware.org
Fri Oct 9 13:47:04 GMT 2020
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=43fb3c78d42692620400eb76a6b6aa87b37f7693
commit 43fb3c78d42692620400eb76a6b6aa87b37f7693
Author: Alan Modra <amodra@gmail.com>
Date: Fri Oct 9 16:56:33 2020 +1030
[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.
(cherry picked from commit fa40fbe484954c560ab1c0ff4bc1b2eeb1511344)
Diff:
---
bfd/ChangeLog | 5 +++++
bfd/elf64-ppc.c | 2 --
gold/ChangeLog | 14 ++++++++++++++
gold/powerpc.cc | 47 +++++++++++++++++++++++++++++++----------------
4 files changed, 50 insertions(+), 18 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index ac66598c2d7..2bca0948f6e 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,8 @@
+2020-10-09 Alan Modra <amodra@gmail.com>
+
+ * elf64-ppc.c (write_plt_relocs_for_local_syms): Don't do local
+ entry offset optimisation.
+
2020-10-07 H.J. Lu <hongjiu.lu@intel.com>
PR ld/26711
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 0aeda47e572..ec8c85eba59 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -14255,8 +14255,6 @@ 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 0d7576bffc6..03d99a52fe8 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,17 @@
+2020-10-09 Alan Modra <amodra@gmail.com>
+
+ * 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 <amodra@gmail.com>
* 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<size, big_endian>::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<size, big_endian>::writeval(oview + off, value);
modified = true;
@@ -3539,6 +3537,7 @@ Target_powerpc<size, big_endian>::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<size, big_endian>::Branch_info::make_stub(
to = symtab->compute_final_value<size>(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<size, big_endian>::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<size, big_endian>::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<size, big_endian>::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<size>::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<size, big_endian>*,
- unsigned int, Address, Address, bool);
+ unsigned int, Address, Address, unsigned int, bool);
const Branch_stub_ent*
find_long_branch_entry(const Powerpc_relobj<size, big_endian>*,
@@ -5282,6 +5284,7 @@ Stub_table<size, big_endian>::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<size, big_endian>::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<size, big_endian>::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<size, big_endian>::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<size, big_endian>::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<size, big_endian>::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<size, big_endian>::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<size>(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<size, big_endian>::Relocate::relocate(
&value, &dest_shndx);
}
}
- Address max_branch_offset = max_branch_delta<size>(r_type);
- if (max_branch_offset != 0
- && (value - address + max_branch_offset >= 2 * max_branch_offset
+ Address max_branch = max_branch_delta<size>(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<size, big_endian>::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)
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