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[GOLD] PowerPC tls_get_addr_optimize
- From: Alan Modra <amodra at gmail dot com>
- To: binutils at sourceware dot org
- Cc: Cary Coutant <ccoutant at gmail dot com>
- Date: Wed, 2 Aug 2017 00:41:00 +0930
- Subject: [GOLD] PowerPC tls_get_addr_optimize
- Authentication-results: sourceware.org; auth=none
>From 10cd12ba1510ea3317b9f2724946ba4e904f88e4 Mon Sep 17 00:00:00 2001
From: Alan Modra <amodra@gmail.com>
Date: Wed, 12 Jul 2017 20:54:13 +0930
Subject: [PATCH 4/4]
This implements the special __tls_get_addr_opt call stub for powerpc
gold that returns __thread variable addresses without actually making
a call to __tls_get_addr in most cases. Shared libraries that are
loaded at program load time (ie. dlopen is not used) have a known
layout for their __thread variables, and thus DTPMOD64/DPTREL64 pairs
describing those variables can be set up by ld.so for the
__tls_get_addr_opt fast exit.
Ref https://sourceware.org/ml/libc-alpha/2015-03/msg00626.html
I really, really wish I'd used a differently versioned __tls_get_addr
symbol than the base symbol to indicate glibc support for the
optimized call, rather than having glibc export __tls_get_addr_opt. A
lot of the messing around here, flipping symbols from __tls_get_addr
to __tls_get_addr_opt, is caused by that decision. About the only
benefit is that a user can see at a glance that their disassembled
code is calling __tls_get_addr via the fancy call stub.. Anyway, we
need references to __tls_get_addr to seem like they were to
__tls_get_addr_opt, and in cases like the tsan interceptor, a
definition of __tls_get_addr to seem like one of __tls_get_addr_opt
as well. That's the reason for Symbol::clear_in_reg and
Symbol_table::clone, and why symbols are substituted in Scan::global
and other places dealing with dynamic linking. I decided to not
template clone because treating its arguments as Sized_symbol isn't
correct given that mips derives its own symbol class. Passing in a
size at least gives a nod towards supporting clone on derived
classes.
OK?
elfcpp/
* elfcpp.h (DT_PPC_OPT): Define.
* powerpc.h (PPC_OPT_TLS): Define.
gold/
* options.h (tls_get_addr_optimize): New option.
* symtab.h (Symbol::clear_in_reg, clone): New functions.
(Symbol_table::clone): New function.
* resolve.cc (Symbol::clone): New function.
* powerpc.cc (Target_powerpc::has_tls_get_addr_opt_,
tls_get_addr_, tls_get_addr_opt_): New vars.
(Target_powerpc::tls_get_addr_opt, tls_get_addr,
is_tls_get_addr_opt, replace_tls_get_addr,
set_has_tls_get_addr_opt, stk_linker): New functions.
(Target_powerpc::Track_tls::maybe_skip_tls_get_addr_call): Add
target param. Update callers. Compare symbols rather than names.
(Target_powerpc::do_define_standard_symbols): Init tls_get_addr_
and tls_get_addr_opt_.
(Target_powerpc::Branch_info::mark_pltcall): Translate tls_get_addr
sym to tls_get_addr_opt.
(Target_powerpc::Branch_info::make_stub): Likewise.
(Stub_table::define_stub_syms): Likewise.
(Target_powerpc::Scan::global): Likewise.
(Target_powerpc::Relocate::relocate): Likewise.
(add_3_12_2, add_3_12_13, bctrl, beqlr, cmpdi_11_0, cmpwi_11_0,
ld_11_1, ld_11_3, ld_12_3, lwz_11_3, lwz_12_3, mr_0_3, mr_3_0,
mtlr_11, std_11_1): New constants.
(Stub_table::eh_frame_added_): Delete.
(Stub_table::tls_get_addr_opt_bctrl_, plt_fde_len_, plt_fde_): New vars.
(Stub_table::init_plt_fde): New functions.
(Stub_table::add_eh_frame, replace_eh_frame): Move definition out
of line. Init and use plt_fde_.
(Stub_table::plt_call_size): Return size for tls_get_addr stub.
Extract alignment code to..
(Stub_table::plt_call_align): ..this new function. Adjust all callers.
(Stub_table::add_plt_call_entry): Set has_tls_get_addr_opt and
tls_get_addr_opt_bctrl, and align after that.
(Stub_table::do_write): Write out tls_get_addr stub.
(Target_powerpc::do_finalize_sections): Emit DT_PPC_OPT
PPC_OPT_TLS/PPC64_OPT_TLS bit.
(Target_powerpc::Relocate::relocate): Don't check for or modify
nop following bl for tls_get_addr stub.
diff --git a/elfcpp/elfcpp.h b/elfcpp/elfcpp.h
index cccec4c..1f629ce 100644
--- a/elfcpp/elfcpp.h
+++ b/elfcpp/elfcpp.h
@@ -768,6 +768,9 @@ enum DT
// Specify the value of _GLOBAL_OFFSET_TABLE_.
DT_PPC_GOT = 0x70000000,
+ // Specify whether various optimisations are possible.
+ DT_PPC_OPT = 0x70000001,
+
// Specify the start of the .glink section.
DT_PPC64_GLINK = 0x70000000,
diff --git a/elfcpp/powerpc.h b/elfcpp/powerpc.h
index 3dc0828..71cac5e 100644
--- a/elfcpp/powerpc.h
+++ b/elfcpp/powerpc.h
@@ -228,6 +228,12 @@ enum
EF_PPC64_ABI = 3
};
+// DT_PPC_OPT bits
+enum
+{
+ PPC_OPT_TLS = 1
+};
+
// DT_PPC64_OPT bits
enum
{
diff --git a/gold/options.h b/gold/options.h
index 7be15a5..2e2037d 100644
--- a/gold/options.h
+++ b/gold/options.h
@@ -1293,6 +1293,9 @@ class General_options
DEFINE_bool(tls_optimize, options::TWO_DASHES, '\0', true,
N_("(PowerPC/64 only) Optimize GD/LD/IE code to IE/LE"),
N_("(PowerPC/64 only) Don'\''t try to optimize TLS accesses"));
+ DEFINE_bool(tls_get_addr_optimize, options::TWO_DASHES, '\0', true,
+ N_("(PowerPC/64 only) Use a special __tls_get_addr call"),
+ N_("(PowerPC/64 only) Don't use a special __tls_get_addr call"));
DEFINE_bool(toc_optimize, options::TWO_DASHES, '\0', true,
N_("(PowerPC64 only) Optimize TOC code sequences"),
diff --git a/gold/powerpc.cc b/gold/powerpc.cc
index c29850b..b9f0012 100644
--- a/gold/powerpc.cc
+++ b/gold/powerpc.cc
@@ -613,8 +613,10 @@ class Target_powerpc : public Sized_target<size, big_endian>
stub_tables_(), branch_lookup_table_(), branch_info_(), tocsave_loc_(),
plt_thread_safe_(false), plt_localentry0_(false),
plt_localentry0_init_(false), has_localentry0_(false),
+ has_tls_get_addr_opt_(false),
relax_failed_(false), relax_fail_count_(0),
- stub_group_size_(0), savres_section_(0)
+ stub_group_size_(0), savres_section_(0),
+ tls_get_addr_(NULL), tls_get_addr_opt_(NULL)
{
}
@@ -1081,11 +1083,43 @@ class Target_powerpc : public Sized_target<size, big_endian>
this->set_processor_specific_flags(flags);
}
+ Symbol*
+ tls_get_addr_opt() const
+ { return this->tls_get_addr_opt_; }
+
+ Symbol*
+ tls_get_addr() const
+ { return this->tls_get_addr_; }
+
+ // If optimizing __tls_get_addr calls, whether this is the
+ // "__tls_get_addr" symbol.
+ bool
+ is_tls_get_addr_opt(const Symbol* gsym) const
+ {
+ return this->tls_get_addr_opt_ && (gsym == this->tls_get_addr_
+ || gsym == this->tls_get_addr_opt_);
+ }
+
+ bool
+ replace_tls_get_addr(const Symbol* gsym) const
+ { return this->tls_get_addr_opt_ && gsym == this->tls_get_addr_; }
+
+ void
+ set_has_tls_get_addr_opt()
+ { this->has_tls_get_addr_opt_ = true; }
+
// Offset to toc save stack slot
int
stk_toc() const
{ return this->abiversion() < 2 ? 40 : 24; }
+ // Offset to linker save stack slot. ELFv2 doesn't have a linker word,
+ // so use the CR save slot. Used only by __tls_get_addr call stub,
+ // relying on __tls_get_addr not saving CR itself.
+ int
+ stk_linker() const
+ { return this->abiversion() < 2 ? 32 : 8; }
+
private:
class Track_tls
@@ -1139,12 +1173,14 @@ class Target_powerpc : public Sized_target<size, big_endian>
{this->tls_get_addr_state_ = SKIP; }
Tls_get_addr
- maybe_skip_tls_get_addr_call(unsigned int r_type, const Symbol* gsym)
+ maybe_skip_tls_get_addr_call(Target_powerpc<size, big_endian>* target,
+ unsigned int r_type, const Symbol* gsym)
{
bool is_tls_call = ((r_type == elfcpp::R_POWERPC_REL24
|| r_type == elfcpp::R_PPC_PLTREL24)
&& gsym != NULL
- && strcmp(gsym->name(), "__tls_get_addr") == 0);
+ && (gsym == target->tls_get_addr()
+ || gsym == target->tls_get_addr_opt()));
Tls_get_addr last_tls = this->tls_get_addr_state_;
this->tls_get_addr_state_ = NOT_EXPECTED;
if (is_tls_call && last_tls != EXPECTED)
@@ -1549,12 +1585,18 @@ class Target_powerpc : public Sized_target<size, big_endian>
bool plt_localentry0_;
bool plt_localentry0_init_;
bool has_localentry0_;
+ bool has_tls_get_addr_opt_;
bool relax_failed_;
int relax_fail_count_;
int32_t stub_group_size_;
Output_data_save_res<size, big_endian> *savres_section_;
+
+ // The "__tls_get_addr" symbol, if present
+ Symbol* tls_get_addr_;
+ // If optimizing __tls_get_addr calls, the "__tls_get_addr_opt" symbol.
+ Symbol* tls_get_addr_opt_;
};
template<>
@@ -2459,6 +2501,31 @@ Target_powerpc<size, big_endian>::do_define_standard_symbols(
false, false);
}
}
+
+ this->tls_get_addr_ = symtab->lookup("__tls_get_addr");
+ if (parameters->options().tls_get_addr_optimize()
+ && this->tls_get_addr_ != NULL
+ && this->tls_get_addr_->in_reg())
+ this->tls_get_addr_opt_ = symtab->lookup("__tls_get_addr_opt");
+ if (this->tls_get_addr_opt_ != NULL)
+ {
+ if (this->tls_get_addr_->is_undefined()
+ || this->tls_get_addr_->is_from_dynobj())
+ {
+ // Make it seem as if references to __tls_get_addr are
+ // really to __tls_get_addr_opt, so the latter symbol is
+ // made dynamic, not the former.
+ this->tls_get_addr_->clear_in_reg();
+ this->tls_get_addr_opt_->set_in_reg();
+ }
+ // We have a non-dynamic definition for __tls_get_addr.
+ // Make __tls_get_addr_opt the same, if it does not already have
+ // a non-dynamic definition.
+ else if (this->tls_get_addr_opt_->is_undefined()
+ || this->tls_get_addr_opt_->is_from_dynobj())
+ symtab->clone(this->tls_get_addr_opt_, this->tls_get_addr_,
+ sizeof (Sized_symbol<size>));
+ }
}
// Set up PowerPC target specific relobj.
@@ -3030,6 +3097,8 @@ Target_powerpc<size, big_endian>::Branch_info::mark_pltcall(
return false;
Symbol* sym = this->object_->global_symbol(this->r_sym_);
+ if (target->replace_tls_get_addr(sym))
+ sym = target->tls_get_addr_opt();
if (sym != NULL && sym->is_forwarder())
sym = symtab->resolve_forwards(sym);
const Sized_symbol<size>* gsym = static_cast<const Sized_symbol<size>*>(sym);
@@ -3055,12 +3124,14 @@ Target_powerpc<size, big_endian>::Branch_info::make_stub(
Symbol_table* symtab) const
{
Symbol* sym = this->object_->global_symbol(this->r_sym_);
- if (sym != NULL && sym->is_forwarder())
- sym = symtab->resolve_forwards(sym);
- const Sized_symbol<size>* gsym = static_cast<const Sized_symbol<size>*>(sym);
Target_powerpc<size, big_endian>* target =
static_cast<Target_powerpc<size, big_endian>*>(
parameters->sized_target<size, big_endian>());
+ if (target->replace_tls_get_addr(sym))
+ sym = target->tls_get_addr_opt();
+ if (sym != NULL && sym->is_forwarder())
+ sym = symtab->resolve_forwards(sym);
+ const Sized_symbol<size>* gsym = static_cast<const Sized_symbol<size>*>(sym);
bool ok = true;
if (gsym != NULL
@@ -3675,6 +3746,8 @@ static const uint32_t add_2_2_11 = 0x7c425a14;
static const uint32_t add_2_2_12 = 0x7c426214;
static const uint32_t add_3_3_2 = 0x7c631214;
static const uint32_t add_3_3_13 = 0x7c636a14;
+static const uint32_t add_3_12_2 = 0x7c6c1214;
+static const uint32_t add_3_12_13 = 0x7c6c6a14;
static const uint32_t add_11_0_11 = 0x7d605a14;
static const uint32_t add_11_2_11 = 0x7d625a14;
static const uint32_t add_11_11_2 = 0x7d6b1214;
@@ -3696,10 +3769,14 @@ static const uint32_t addis_12_12 = 0x3d8c0000;
static const uint32_t b = 0x48000000;
static const uint32_t bcl_20_31 = 0x429f0005;
static const uint32_t bctr = 0x4e800420;
+static const uint32_t bctrl = 0x4e800421;
+static const uint32_t beqlr = 0x4d820020;
static const uint32_t blr = 0x4e800020;
static const uint32_t bnectr_p4 = 0x4ce20420;
static const uint32_t cmpld_7_12_0 = 0x7fac0040;
static const uint32_t cmpldi_2_0 = 0x28220000;
+static const uint32_t cmpdi_11_0 = 0x2c2b0000;
+static const uint32_t cmpwi_11_0 = 0x2c0b0000;
static const uint32_t cror_15_15_15 = 0x4def7b82;
static const uint32_t cror_31_31_31 = 0x4ffffb82;
static const uint32_t ld_0_1 = 0xe8010000;
@@ -3708,9 +3785,12 @@ static const uint32_t ld_2_1 = 0xe8410000;
static const uint32_t ld_2_2 = 0xe8420000;
static const uint32_t ld_2_11 = 0xe84b0000;
static const uint32_t ld_2_12 = 0xe84c0000;
+static const uint32_t ld_11_1 = 0xe9610000;
static const uint32_t ld_11_2 = 0xe9620000;
+static const uint32_t ld_11_3 = 0xe9630000;
static const uint32_t ld_11_11 = 0xe96b0000;
static const uint32_t ld_12_2 = 0xe9820000;
+static const uint32_t ld_12_3 = 0xe9830000;
static const uint32_t ld_12_11 = 0xe98b0000;
static const uint32_t ld_12_12 = 0xe98c0000;
static const uint32_t lfd_0_1 = 0xc8010000;
@@ -3722,17 +3802,22 @@ static const uint32_t lis_11 = 0x3d600000;
static const uint32_t lis_12 = 0x3d800000;
static const uint32_t lvx_0_12_0 = 0x7c0c00ce;
static const uint32_t lwz_0_12 = 0x800c0000;
+static const uint32_t lwz_11_3 = 0x81630000;
static const uint32_t lwz_11_11 = 0x816b0000;
static const uint32_t lwz_11_30 = 0x817e0000;
+static const uint32_t lwz_12_3 = 0x81830000;
static const uint32_t lwz_12_12 = 0x818c0000;
static const uint32_t lwzu_0_12 = 0x840c0000;
static const uint32_t mflr_0 = 0x7c0802a6;
static const uint32_t mflr_11 = 0x7d6802a6;
static const uint32_t mflr_12 = 0x7d8802a6;
+static const uint32_t mr_0_3 = 0x7c601b78;
+static const uint32_t mr_3_0 = 0x7c030378;
static const uint32_t mtctr_0 = 0x7c0903a6;
static const uint32_t mtctr_11 = 0x7d6903a6;
static const uint32_t mtctr_12 = 0x7d8903a6;
static const uint32_t mtlr_0 = 0x7c0803a6;
+static const uint32_t mtlr_11 = 0x7d6803a6;
static const uint32_t mtlr_12 = 0x7d8803a6;
static const uint32_t nop = 0x60000000;
static const uint32_t ori_0_0_0 = 0x60000000;
@@ -3740,6 +3825,7 @@ static const uint32_t srdi_0_0_2 = 0x7800f082;
static const uint32_t std_0_1 = 0xf8010000;
static const uint32_t std_0_12 = 0xf80c0000;
static const uint32_t std_2_1 = 0xf8410000;
+static const uint32_t std_11_1 = 0xf9610000;
static const uint32_t stfd_0_1 = 0xd8010000;
static const uint32_t stvx_0_12_0 = 0x7c0c01ce;
static const uint32_t sub_11_11_12 = 0x7d6c5850;
@@ -4102,7 +4188,8 @@ class Stub_table : public Output_relaxed_input_section
orig_data_size_(owner->current_data_size()),
plt_size_(0), last_plt_size_(0),
branch_size_(0), last_branch_size_(0), min_size_threshold_(0),
- eh_frame_added_(false), need_save_res_(false), uniq_(id)
+ need_save_res_(false), uniq_(id), tls_get_addr_opt_bctrl_(-1u),
+ plt_fde_len_(0)
{
this->set_output_section(output_section);
@@ -4263,48 +4350,17 @@ class Stub_table : public Output_relaxed_input_section
return false;
}
- // Add .eh_frame info for this stub section. Unlike other linker
- // generated .eh_frame this is added late in the link, because we
- // only want the .eh_frame info if this particular stub section is
- // non-empty.
+ // Generate a suitable FDE to describe code in this stub group.
void
- add_eh_frame(Layout* layout)
- {
- if (!parameters->options().ld_generated_unwind_info())
- return;
-
- // Since we add stub .eh_frame info late, it must be placed
- // after all other linker generated .eh_frame info so that
- // merge mapping need not be updated for input sections.
- // There is no provision to use a different CIE to that used
- // by .glink.
- if (!this->targ_->has_glink())
- return;
+ init_plt_fde();
- if (this->plt_size_ + this->branch_size_ + this->need_save_res_ == 0)
- return;
-
- layout->add_eh_frame_for_plt(this,
- Eh_cie<size>::eh_frame_cie,
- sizeof (Eh_cie<size>::eh_frame_cie),
- default_fde,
- sizeof (default_fde));
- this->eh_frame_added_ = true;
- }
+ // Add .eh_frame info for this stub section.
+ void
+ add_eh_frame(Layout* layout);
+ // Remove .eh_frame info for this stub section.
void
- remove_eh_frame(Layout* layout)
- {
- if (this->eh_frame_added_)
- {
- layout->remove_eh_frame_for_plt(this,
- Eh_cie<size>::eh_frame_cie,
- sizeof (Eh_cie<size>::eh_frame_cie),
- default_fde,
- sizeof (default_fde));
- this->eh_frame_added_ = false;
- }
- }
+ remove_eh_frame(Layout* layout);
Target_powerpc<size, big_endian>*
targ() const
@@ -4356,7 +4412,12 @@ class Stub_table : public Output_relaxed_input_section
plt_call_size(typename Plt_stub_entries::const_iterator p) const
{
if (size == 32)
- return 16;
+ {
+ const Symbol* gsym = p->first.sym_;
+ if (this->targ_->is_tls_get_addr_opt(gsym))
+ return 12 * 4;
+ return 4 * 4;
+ }
bool is_iplt;
Address plt_addr = this->plt_off(p, &is_iplt);
@@ -4370,6 +4431,9 @@ class Stub_table : public Output_relaxed_input_section
got_addr += ppcobj->toc_base_offset();
Address off = plt_addr - got_addr;
unsigned int bytes = 4 * 4 + 4 * (ha(off) != 0);
+ const Symbol* gsym = p->first.sym_;
+ if (this->targ_->is_tls_get_addr_opt(gsym))
+ bytes += 13 * 4;
if (this->targ_->abiversion() < 2)
{
bool static_chain = parameters->options().plt_static_chain();
@@ -4379,6 +4443,12 @@ class Stub_table : public Output_relaxed_input_section
+ 8 * thread_safe
+ 4 * (ha(off + 8 + 8 * static_chain) != ha(off)));
}
+ return bytes;
+ }
+
+ unsigned int
+ plt_call_align(unsigned int bytes) const
+ {
unsigned int align = 1 << parameters->options().plt_align();
if (align > 1)
bytes = (bytes + align - 1) & -align;
@@ -4518,13 +4588,16 @@ class Stub_table : public Output_relaxed_input_section
// a stub table, it is zero for the first few iterations, then
// increases monotonically.
Address min_size_threshold_;
- // Whether .eh_frame info has been created for this stub section.
- bool eh_frame_added_;
// Set if this stub group needs a copy of out-of-line register
// save/restore functions.
bool need_save_res_;
// Per stub table unique identifier.
uint32_t uniq_;
+ // The bctrl in the __tls_get_addr_opt stub, if present.
+ unsigned int tls_get_addr_opt_bctrl_;
+ // FDE unwind info for this stub group.
+ unsigned int plt_fde_len_;
+ unsigned char plt_fde_[20];
};
// Add a plt call stub, if we do not already have one for this
@@ -4553,6 +4626,12 @@ Stub_table<size, big_endian>::add_plt_call_entry(
p.first->second.localentry0_ = 1;
this->targ_->set_has_localentry0();
}
+ if (this->targ_->is_tls_get_addr_opt(gsym))
+ {
+ this->targ_->set_has_tls_get_addr_opt();
+ this->tls_get_addr_opt_bctrl_ = this->plt_size_ - 5 * 4;
+ }
+ this->plt_size_ = this->plt_call_align(this->plt_size_);
}
if (size == 64
&& !tocsave
@@ -4578,6 +4657,7 @@ Stub_table<size, big_endian>::add_plt_call_entry(
if (p.second)
{
this->plt_size_ = ent.off_ + this->plt_call_size(p.first);
+ this->plt_size_ = this->plt_call_align(this->plt_size_);
if (size == 64
&& this->targ_->is_elfv2_localentry0(object, locsym_index))
{
@@ -4697,6 +4777,94 @@ Stub_table<size, big_endian>::find_long_branch_entry(
return p->second;
}
+// Generate a suitable FDE to describe code in this stub group.
+// The __tls_get_addr_opt call stub needs to describe where it saves
+// LR, to support exceptions that might be thrown from __tls_get_addr.
+
+template<int size, bool big_endian>
+void
+Stub_table<size, big_endian>::init_plt_fde()
+{
+ unsigned char* p = this->plt_fde_;
+ // offset pcrel sdata4, size udata4, and augmentation size byte.
+ memset (p, 0, 9);
+ p += 9;
+ if (this->tls_get_addr_opt_bctrl_ != -1u)
+ {
+ unsigned int to_bctrl = this->tls_get_addr_opt_bctrl_ / 4;
+ if (to_bctrl < 64)
+ *p++ = elfcpp::DW_CFA_advance_loc + to_bctrl;
+ else if (to_bctrl < 256)
+ {
+ *p++ = elfcpp::DW_CFA_advance_loc1;
+ *p++ = to_bctrl;
+ }
+ else if (to_bctrl < 65536)
+ {
+ *p++ = elfcpp::DW_CFA_advance_loc2;
+ elfcpp::Swap<16, big_endian>::writeval(p, to_bctrl);
+ p += 2;
+ }
+ else
+ {
+ *p++ = elfcpp::DW_CFA_advance_loc4;
+ elfcpp::Swap<32, big_endian>::writeval(p, to_bctrl);
+ p += 4;
+ }
+ *p++ = elfcpp::DW_CFA_offset_extended_sf;
+ *p++ = 65;
+ *p++ = -(this->targ_->stk_linker() / 8) & 0x7f;
+ *p++ = elfcpp::DW_CFA_advance_loc + 4;
+ *p++ = elfcpp::DW_CFA_restore_extended;
+ *p++ = 65;
+ }
+ this->plt_fde_len_ = p - this->plt_fde_;
+}
+
+// Add .eh_frame info for this stub section. Unlike other linker
+// generated .eh_frame this is added late in the link, because we
+// only want the .eh_frame info if this particular stub section is
+// non-empty.
+
+template<int size, bool big_endian>
+void
+Stub_table<size, big_endian>::add_eh_frame(Layout* layout)
+{
+ if (!parameters->options().ld_generated_unwind_info())
+ return;
+
+ // Since we add stub .eh_frame info late, it must be placed
+ // after all other linker generated .eh_frame info so that
+ // merge mapping need not be updated for input sections.
+ // There is no provision to use a different CIE to that used
+ // by .glink.
+ if (!this->targ_->has_glink())
+ return;
+
+ if (this->plt_size_ + this->branch_size_ + this->need_save_res_ == 0)
+ return;
+
+ this->init_plt_fde();
+ layout->add_eh_frame_for_plt(this,
+ Eh_cie<size>::eh_frame_cie,
+ sizeof (Eh_cie<size>::eh_frame_cie),
+ this->plt_fde_, this->plt_fde_len_);
+}
+
+template<int size, bool big_endian>
+void
+Stub_table<size, big_endian>::remove_eh_frame(Layout* layout)
+{
+ if (this->plt_fde_len_ != 0)
+ {
+ layout->remove_eh_frame_for_plt(this,
+ Eh_cie<size>::eh_frame_cie,
+ sizeof (Eh_cie<size>::eh_frame_cie),
+ this->plt_fde_, this->plt_fde_len_);
+ this->plt_fde_len_ = 0;
+ }
+}
+
// A class to handle .glink.
template<int size, bool big_endian>
@@ -4896,13 +5064,15 @@ Stub_table<size, big_endian>::define_stub_syms(Symbol_table* symtab)
sprintf(localname, "%x", cs->first.locsym_);
symname = localname;
}
+ else if (this->targ_->is_tls_get_addr_opt(cs->first.sym_))
+ symname = this->targ_->tls_get_addr_opt()->name();
else
symname = cs->first.sym_->name();
char* name = new char[8 + 10 + strlen(obj) + strlen(symname) + strlen(add) + 1];
sprintf(name, "%08x.plt_call.%s%s%s", this->uniq_, obj, symname, add);
Address value
= this->stub_address() - this->address() + cs->second.off_;
- unsigned int stub_size = this->plt_call_size(cs);
+ unsigned int stub_size = this->plt_call_align(this->plt_call_size(cs));
this->targ_->define_local(symtab, name, this, value, stub_size);
}
}
@@ -5011,6 +5181,33 @@ Stub_table<size, big_endian>::do_write(Output_file* of)
}
p = oview + cs->second.off_;
+ const Symbol* gsym = cs->first.sym_;
+ if (this->targ_->is_tls_get_addr_opt(gsym))
+ {
+ write_insn<big_endian>(p, ld_11_3 + 0);
+ p += 4;
+ write_insn<big_endian>(p, ld_12_3 + 8);
+ p += 4;
+ write_insn<big_endian>(p, mr_0_3);
+ p += 4;
+ write_insn<big_endian>(p, cmpdi_11_0);
+ p += 4;
+ write_insn<big_endian>(p, add_3_12_13);
+ p += 4;
+ write_insn<big_endian>(p, beqlr);
+ p += 4;
+ write_insn<big_endian>(p, mr_3_0);
+ p += 4;
+ if (!cs->second.localentry0_)
+ {
+ write_insn<big_endian>(p, mflr_11);
+ p += 4;
+ write_insn<big_endian>(p, (std_11_1
+ + this->targ_->stk_linker()));
+ p += 4;
+ }
+ use_fake_dep = thread_safe;
+ }
if (ha(off) != 0)
{
if (cs->second.r2save_)
@@ -5097,7 +5294,20 @@ Stub_table<size, big_endian>::do_write(Output_file* of)
p += 4;
}
}
- if (thread_safe && !use_fake_dep)
+ if (!cs->second.localentry0_
+ && this->targ_->is_tls_get_addr_opt(gsym))
+ {
+ write_insn<big_endian>(p, bctrl);
+ p += 4;
+ write_insn<big_endian>(p, ld_2_1 + this->targ_->stk_toc());
+ p += 4;
+ write_insn<big_endian>(p, ld_11_1 + this->targ_->stk_linker());
+ p += 4;
+ write_insn<big_endian>(p, mtlr_11);
+ p += 4;
+ write_insn<big_endian>(p, blr);
+ }
+ else if (thread_safe && !use_fake_dep)
{
write_insn<big_endian>(p, cmpldi_2_0);
p += 4;
@@ -5173,6 +5383,26 @@ Stub_table<size, big_endian>::do_write(Output_file* of)
plt_addr += plt_base;
p = oview + cs->second.off_;
+ const Symbol* gsym = cs->first.sym_;
+ if (this->targ_->is_tls_get_addr_opt(gsym))
+ {
+ write_insn<big_endian>(p, lwz_11_3 + 0);
+ p += 4;
+ write_insn<big_endian>(p, lwz_12_3 + 4);
+ p += 4;
+ write_insn<big_endian>(p, mr_0_3);
+ p += 4;
+ write_insn<big_endian>(p, cmpwi_11_0);
+ p += 4;
+ write_insn<big_endian>(p, add_3_12_2);
+ p += 4;
+ write_insn<big_endian>(p, beqlr);
+ p += 4;
+ write_insn<big_endian>(p, mr_3_0);
+ p += 4;
+ write_insn<big_endian>(p, nop);
+ p += 4;
+ }
if (parameters->options().output_is_position_independent())
{
Address got_addr;
@@ -6225,7 +6455,7 @@ Target_powerpc<size, big_endian>::Scan::local(
const elfcpp::Sym<size, big_endian>& lsym,
bool is_discarded)
{
- this->maybe_skip_tls_get_addr_call(r_type, NULL);
+ this->maybe_skip_tls_get_addr_call(target, r_type, NULL);
if ((size == 64 && r_type == elfcpp::R_PPC64_TLSGD)
|| (size == 32 && r_type == elfcpp::R_PPC_TLSGD))
@@ -6772,9 +7002,15 @@ Target_powerpc<size, big_endian>::Scan::global(
unsigned int r_type,
Symbol* gsym)
{
- if (this->maybe_skip_tls_get_addr_call(r_type, gsym) == Track_tls::SKIP)
+ if (this->maybe_skip_tls_get_addr_call(target, r_type, gsym)
+ == Track_tls::SKIP)
return;
+ if (target->replace_tls_get_addr(gsym))
+ // Change a __tls_get_addr reference to __tls_get_addr_opt
+ // so dynamic relocs are emitted against the latter symbol.
+ gsym = target->tls_get_addr_opt();
+
if ((size == 64 && r_type == elfcpp::R_PPC64_TLSGD)
|| (size == 32 && r_type == elfcpp::R_PPC_TLSGD))
{
@@ -7904,6 +8140,8 @@ Target_powerpc<size, big_endian>::do_finalize_sections(
odyn->add_section_plus_offset(elfcpp::DT_PPC_GOT,
this->got_, this->got_->g_o_t());
}
+ if (this->has_tls_get_addr_opt_)
+ odyn->add_constant(elfcpp::DT_PPC_OPT, elfcpp::PPC_OPT_TLS);
}
else
{
@@ -7915,9 +8153,12 @@ Target_powerpc<size, big_endian>::do_finalize_sections(
(this->glink_->pltresolve_size
- 32));
}
- if (this->has_localentry0_)
+ if (this->has_localentry0_ || this->has_tls_get_addr_opt_)
odyn->add_constant(elfcpp::DT_PPC64_OPT,
- elfcpp::PPC64_OPT_LOCALENTRY);
+ ((this->has_localentry0_
+ ? elfcpp::PPC64_OPT_LOCALENTRY : 0)
+ | (this->has_tls_get_addr_opt_
+ ? elfcpp::PPC64_OPT_TLS : 0)));
}
}
@@ -8035,9 +8276,12 @@ Target_powerpc<size, big_endian>::Relocate::relocate(
if (view == NULL)
return true;
+ if (target->replace_tls_get_addr(gsym))
+ gsym = static_cast<const Sized_symbol<size>*>(target->tls_get_addr_opt());
+
const elfcpp::Rela<size, big_endian> rela(preloc);
unsigned int r_type = elfcpp::elf_r_type<size>(rela.get_r_info());
- switch (this->maybe_skip_tls_get_addr_call(r_type, gsym))
+ switch (this->maybe_skip_tls_get_addr_call(target, r_type, gsym))
{
case Track_tls::NOT_EXPECTED:
gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
@@ -8162,8 +8406,8 @@ Target_powerpc<size, big_endian>::Relocate::relocate(
{
typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
Valtype* wv = reinterpret_cast<Valtype*>(view);
- bool can_plt_call = localentry0;
- if (!localentry0 && rela.get_r_offset() + 8 <= view_size)
+ bool can_plt_call = localentry0 || target->is_tls_get_addr_opt(gsym);
+ if (!can_plt_call && 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);
diff --git a/gold/resolve.cc b/gold/resolve.cc
index 7c22606..5a35f34 100644
--- a/gold/resolve.cc
+++ b/gold/resolve.cc
@@ -917,6 +917,31 @@ Symbol_table::report_resolve_problem(bool is_error, const char* msg,
gold_info("%s: %s: previous definition here", program_name, objname);
}
+// Completely override existing symbol. Everything bar name_,
+// version_, and is_forced_local_ flag are copied. version_ is
+// cleared if from->version_ is clear. Returns true if this symbol
+// should be forced local.
+bool
+Symbol::clone(const Symbol* from, size_t symbol_size)
+{
+ // Don't allow cloning after dynamic linking info is attached to symbols.
+ // We aren't prepared to merge such.
+ gold_assert(!this->has_symtab_index() && !from->has_symtab_index());
+ gold_assert(!this->has_dynsym_index() && !from->has_dynsym_index());
+ gold_assert(this->got_offsets_.get_list() == NULL
+ && from->got_offsets_.get_list() == NULL);
+ gold_assert(!this->has_plt_offset() && !from->has_plt_offset());
+ const char* name = this->name_;
+ const char* version = this->version_;
+ bool was_forced_local = this->is_forced_local_;
+ memcpy (this, from, symbol_size);
+ this->name_ = name;
+ if (from->version_)
+ this->version_ = version;
+ this->is_forced_local_ = was_forced_local;
+ return !was_forced_local && from->is_forced_local_;
+}
+
// A special case of should_override which is only called for a strong
// defined symbol from a regular object file. This is used when
// defining special symbols.
diff --git a/gold/symtab.h b/gold/symtab.h
index 853c9fe..635405a 100644
--- a/gold/symtab.h
+++ b/gold/symtab.h
@@ -329,6 +329,11 @@ class Symbol
set_in_reg()
{ this->in_reg_ = true; }
+ // Forget this symbol was seen in a regular object.
+ void
+ clear_in_reg()
+ { this->in_reg_ = false; }
+
// Return whether this symbol has been seen in a dynamic object.
bool
in_dyn() const
@@ -893,6 +898,13 @@ class Symbol
set_non_zero_localentry()
{ this->non_zero_localentry_ = true; }
+ // Completely override existing symbol. Everything bar name_,
+ // version_, and is_forced_local_ flag are copied. version_ is
+ // cleared if from->version_ is clear. Returns true if this symbol
+ // should be forced local.
+ bool
+ clone(const Symbol* from, size_t symbol_size);
+
protected:
// Instances of this class should always be created at a specific
// size.
@@ -1690,6 +1702,14 @@ class Symbol_table
version_script() const
{ return version_script_; }
+ // Completely override existing symbol.
+ void
+ clone(Symbol* to, const Symbol* from, size_t symbol_size)
+ {
+ if (to->clone(from, symbol_size))
+ this->force_local(to);
+ }
+
private:
Symbol_table(const Symbol_table&);
Symbol_table& operator=(const Symbol_table&);
--
Alan Modra
Australia Development Lab, IBM