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[GOLD] powerpc ifunc support
- From: Alan Modra <amodra at gmail dot com>
- To: binutils at sourceware dot org
- Date: Sat, 29 Sep 2012 19:58:37 +0930
- Subject: [GOLD] powerpc ifunc support
This adds ifunc support to powerpc gold, and fixes errors with dynamic
function symbols on ppc32. The code supporting IFUNC and normal
dynamic calls looks a little different to other targets due to some
quirks of the powerpc ABIs. What others call .plt, the executable
part of a dynamic call, we call .glink. What others call .got.plt,
the address lookup table, we call .plt. Also, there may be more than
one .glink stub per .plt entry for -m32 -fPIC code in a shared library
or PIE.
* powerpc.cc (Target_powerpc::iplt_): New output section.
(Target_powerpc::iplt_section, make_iplt_section,
reloc_needs_plt_for_ifunc, make_local_ifunc_plt_entry): New functions.
(Target_powerpc::make_plt_entry): Handle ifunc syms.
Target_powerpc::plt_entry_count): Count iplt entries too.
(Output_data_plt_powerpc::Output_data_plt_powerpc): Don't create
reloc section in constructor. New params.
(Target_powerpc::make_plt_section): Create reloc section here instead.
(Output_data_plt_powerpc::add_ifunc_entry, add_local_ifunc_entry): New
functions.
(Output_data_plt_powerpc::initial_plt_entry_size_, name_): New vars.
(Output_data_glink::add_entry, find_entry): New functions to
deal with local syms.
(Glink_sym_ent): Add support for local syms.
(Output_data_glink::do_write): Handle ifunc plt entries.
(Target_powerpc::Scan::get_reference_flags): Handle more relocs.
(Target_powerpc::Scan::local, global): Handle ifunc syms.
(Target_powerpc::Relocate::relocate): Likewise.
(Target_powerpc::do_dynsym_value): Use glink stub, not plt entry.
Index: gold/powerpc.cc
===================================================================
RCS file: /cvs/src/src/gold/powerpc.cc,v
retrieving revision 1.59
diff -u -p -r1.59 powerpc.cc
--- gold/powerpc.cc 25 Sep 2012 00:59:25 -0000 1.59
+++ gold/powerpc.cc 29 Sep 2012 01:53:14 -0000
@@ -255,7 +255,7 @@ class Target_powerpc : public Sized_targ
Target_powerpc()
: Sized_target<size, big_endian>(&powerpc_info),
- got_(NULL), plt_(NULL), glink_(NULL), rela_dyn_(NULL),
+ got_(NULL), plt_(NULL), iplt_(NULL), glink_(NULL), rela_dyn_(NULL),
copy_relocs_(elfcpp::R_POWERPC_COPY),
dynbss_(NULL), tlsld_got_offset_(-1U)
{
@@ -389,6 +389,14 @@ class Target_powerpc : public Sized_targ
return this->plt_;
}
+ // Get the IPLT section.
+ const Output_data_plt_powerpc<size, big_endian>*
+ iplt_section() const
+ {
+ gold_assert(this->iplt_ != NULL);
+ return this->iplt_;
+ }
+
// Get the .glink section.
const Output_data_glink<size, big_endian>*
glink_section() const
@@ -518,6 +526,10 @@ class Target_powerpc : public Sized_targ
void
check_non_pic(Relobj*, unsigned int r_type);
+ bool
+ reloc_needs_plt_for_ifunc(Sized_relobj_file<size, big_endian>* object,
+ unsigned int r_type);
+
// Whether we have issued an error about a non-PIC compilation.
bool issued_non_pic_error_;
};
@@ -632,11 +644,20 @@ class Target_powerpc : public Sized_targ
void
make_plt_section(Layout*);
+ void
+ make_iplt_section(Layout*, Symbol_table*);
+
// Create a PLT entry for a global symbol.
void
- make_plt_entry(Layout*, Symbol*,
+ make_plt_entry(Layout*, Symbol_table*, Symbol*,
const elfcpp::Rela<size, big_endian>&,
- const Sized_relobj<size, big_endian>* object);
+ const Sized_relobj_file<size, big_endian>* object);
+
+ // Create a PLT entry for a local IFUNC symbol.
+ void
+ make_local_ifunc_plt_entry(Layout*, Symbol_table*,
+ const elfcpp::Rela<size, big_endian>&,
+ Sized_relobj_file<size, big_endian>*);
// Create a GOT entry for local dynamic __tls_get_addr.
unsigned int
@@ -686,6 +707,8 @@ class Target_powerpc : public Sized_targ
Output_data_got_powerpc<size, big_endian>* got_;
// The PLT output section.
Output_data_plt_powerpc<size, big_endian>* plt_;
+ // The IPLT output section.
+ Output_data_plt_powerpc<size, big_endian>* iplt_;
// The .glink output section.
Output_data_glink<size, big_endian>* glink_;
// The dynamic reloc output section.
@@ -1500,14 +1523,29 @@ class Output_data_plt_powerpc : public O
typedef Output_data_reloc<elfcpp::SHT_RELA, true,
size, big_endian> Reloc_section;
- Output_data_plt_powerpc(Layout*, Target_powerpc<size, big_endian>*);
+ Output_data_plt_powerpc(Target_powerpc<size, big_endian>* targ,
+ Reloc_section* plt_rel,
+ unsigned int reserved_size,
+ const char* name)
+ : Output_section_data_build(size == 32 ? 4 : 8),
+ rel_(plt_rel),
+ targ_(targ),
+ initial_plt_entry_size_(reserved_size),
+ name_(name)
+ { }
// Add an entry to the PLT.
void
add_entry(Symbol*);
+ void
+ add_ifunc_entry(Symbol*);
+
+ void
+ add_local_ifunc_entry(Sized_relobj_file<size, big_endian>*, unsigned int);
+
// Return the .rela.plt section data.
- const Reloc_section*
+ Reloc_section*
rel_plt() const
{
return this->rel_;
@@ -1517,14 +1555,14 @@ class Output_data_plt_powerpc : public O
unsigned int
entry_count() const
{
- return ((this->current_data_size() - initial_plt_entry_size)
+ return ((this->current_data_size() - this->initial_plt_entry_size_)
/ plt_entry_size);
}
// Return the offset of the first non-reserved PLT entry.
- static unsigned int
+ unsigned int
first_plt_entry_offset()
- { return initial_plt_entry_size; }
+ { return this->initial_plt_entry_size_; }
// Return the size of a PLT entry.
static unsigned int
@@ -1541,13 +1579,11 @@ class Output_data_plt_powerpc : public O
// Write to a map file.
void
do_print_to_mapfile(Mapfile* mapfile) const
- { mapfile->print_output_data(this, _("** PLT")); }
+ { mapfile->print_output_data(this, this->name_); }
private:
// The size of an entry in the PLT.
static const int plt_entry_size = size == 32 ? 4 : 24;
- // The size of the first reserved entry.
- static const int initial_plt_entry_size = size == 32 ? 0 : 24;
// Write out the PLT data.
void
@@ -1557,38 +1593,68 @@ class Output_data_plt_powerpc : public O
Reloc_section* rel_;
// Allows access to .glink for do_write.
Target_powerpc<size, big_endian>* targ_;
+ // The size of the first reserved entry.
+ int initial_plt_entry_size_;
+ // What to report in map file.
+ const char *name_;
};
-// Create the PLT section.
+// Add an entry to the PLT.
template<int size, bool big_endian>
-Output_data_plt_powerpc<size, big_endian>::Output_data_plt_powerpc(
- Layout* layout,
- Target_powerpc<size, big_endian>* targ)
- : Output_section_data_build(size == 32 ? 4 : 8),
- targ_(targ)
+void
+Output_data_plt_powerpc<size, big_endian>::add_entry(Symbol* gsym)
{
- this->rel_ = new Reloc_section(false);
- layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
- elfcpp::SHF_ALLOC, this->rel_,
- ORDER_DYNAMIC_PLT_RELOCS, false);
+ if (!gsym->has_plt_offset())
+ {
+ off_t off = this->current_data_size();
+ if (off == 0)
+ off += this->first_plt_entry_offset();
+ gsym->set_plt_offset(off);
+ gsym->set_needs_dynsym_entry();
+ unsigned int dynrel = elfcpp::R_POWERPC_JMP_SLOT;
+ this->rel_->add_global(gsym, dynrel, this, off, 0);
+ off += plt_entry_size;
+ this->set_current_data_size(off);
+ }
}
-// Add an entry to the PLT.
+// Add an entry for a global ifunc symbol that resolves locally, to the IPLT.
template<int size, bool big_endian>
void
-Output_data_plt_powerpc<size, big_endian>::add_entry(Symbol* gsym)
+Output_data_plt_powerpc<size, big_endian>::add_ifunc_entry(Symbol* gsym)
{
if (!gsym->has_plt_offset())
{
off_t off = this->current_data_size();
-
- if (off == 0)
- off += initial_plt_entry_size;
gsym->set_plt_offset(off);
- gsym->set_needs_dynsym_entry();
- this->rel_->add_global(gsym, elfcpp::R_POWERPC_JMP_SLOT, this, off, 0);
+ unsigned int dynrel = elfcpp::R_POWERPC_IRELATIVE;
+ if (size == 64)
+ dynrel = elfcpp::R_PPC64_JMP_IREL;
+ this->rel_->add_symbolless_global_addend(gsym, dynrel, this, off, 0);
+ off += plt_entry_size;
+ this->set_current_data_size(off);
+ }
+}
+
+// Add an entry for a local ifunc symbol to the IPLT.
+
+template<int size, bool big_endian>
+void
+Output_data_plt_powerpc<size, big_endian>::add_local_ifunc_entry(
+ Sized_relobj_file<size, big_endian>* relobj,
+ unsigned int local_sym_index)
+{
+ if (!relobj->local_has_plt_offset(local_sym_index))
+ {
+ off_t off = this->current_data_size();
+ relobj->set_local_plt_offset(local_sym_index, off);
+ unsigned int dynrel = elfcpp::R_POWERPC_IRELATIVE;
+ if (size == 64)
+ dynrel = elfcpp::R_PPC64_JMP_IREL;
+ this->rel_->add_symbolless_local_addend(relobj, local_sym_index, dynrel,
+ this, off, 0);
off += plt_entry_size;
this->set_current_data_size(off);
}
@@ -1660,7 +1726,7 @@ Output_data_plt_powerpc<size, big_endian
unsigned char* pov = oview;
unsigned char* endpov = oview + oview_size;
- // The address the .glink branch table
+ // The address of the .glink branch table
const Output_data_glink<size, big_endian>* glink
= this->targ_->glink_section();
elfcpp::Elf_types<32>::Elf_Addr branch_tab
@@ -1693,7 +1759,14 @@ Target_powerpc<size, big_endian>::make_p
// needs to include .rela.plt in it's range.
this->rela_dyn_section(layout);
- this->plt_ = new Output_data_plt_powerpc<size, big_endian>(layout, this);
+ Reloc_section* plt_rel = new Reloc_section(false);
+ layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
+ elfcpp::SHF_ALLOC, plt_rel,
+ ORDER_DYNAMIC_PLT_RELOCS, false);
+ this->plt_
+ = new Output_data_plt_powerpc<size, big_endian>(this, plt_rel,
+ size == 32 ? 0 : 24,
+ "** PLT");
layout->add_output_section_data(".plt",
(size == 32
? elfcpp::SHT_PROGBITS
@@ -1707,6 +1780,39 @@ Target_powerpc<size, big_endian>::make_p
}
}
+// Create the IPLT section.
+
+template<int size, bool big_endian>
+void
+Target_powerpc<size, big_endian>::make_iplt_section(Layout* layout,
+ Symbol_table* symtab)
+{
+ if (this->iplt_ == NULL)
+ {
+ this->make_plt_section(layout);
+
+ Reloc_section* iplt_rel = new Reloc_section(false);
+ this->rela_dyn_->output_section()->add_output_section_data(iplt_rel);
+ this->iplt_
+ = new Output_data_plt_powerpc<size, big_endian>(this, iplt_rel,
+ 0, "** IPLT");
+ this->plt_->output_section()->add_output_section_data(this->iplt_);
+ if (parameters->doing_static_link())
+ {
+ symtab->define_in_output_data("__rela_iplt_start", NULL,
+ Symbol_table::PREDEFINED,
+ iplt_rel, 0, 0,
+ elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
+ elfcpp::STV_HIDDEN, 0, false, true);
+ symtab->define_in_output_data("__rela_iplt_end", NULL,
+ Symbol_table::PREDEFINED,
+ iplt_rel, 0, 0,
+ elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
+ elfcpp::STV_HIDDEN, 0, true, true);
+ }
+ }
+}
+
// A class to handle .glink.
template<int size, bool big_endian>
@@ -1720,11 +1826,19 @@ class Output_data_glink : public Output_
// Add an entry
void
add_entry(const Symbol*, const elfcpp::Rela<size, big_endian>&,
- const Sized_relobj<size, big_endian>*);
+ const Sized_relobj_file<size, big_endian>*);
+
+ void
+ add_entry(unsigned int, const elfcpp::Rela<size, big_endian>&,
+ const Sized_relobj_file<size, big_endian>*);
unsigned int
find_entry(const Symbol*, const elfcpp::Rela<size, big_endian>&,
- const Sized_relobj<size, big_endian>*) const;
+ const Sized_relobj_file<size, big_endian>*) const;
+
+ unsigned int
+ find_entry(unsigned int, const elfcpp::Rela<size, big_endian>&,
+ const Sized_relobj_file<size, big_endian>*) const;
unsigned int
glink_entry_size() const
@@ -1762,8 +1876,8 @@ class Output_data_glink : public Output_
public:
Glink_sym_ent(const Symbol* sym,
const elfcpp::Rela<size, big_endian>& reloc,
- const Sized_relobj<size, big_endian>* object)
- : sym_(sym), addend_(0), object_(0)
+ const Sized_relobj_file<size, big_endian>* object)
+ : sym_(sym), object_(0), addend_(0), locsym_(0)
{
if (size != 32)
this->addend_ = reloc.get_r_addend();
@@ -1772,21 +1886,36 @@ class Output_data_glink : public Output_
== elfcpp::R_PPC_PLTREL24))
{
this->addend_ = reloc.get_r_addend();
- if (this->addend_ != 0)
+ if (this->addend_ >= 32768)
this->object_ = object;
}
}
+ Glink_sym_ent(unsigned int locsym_index,
+ const elfcpp::Rela<size, big_endian>& reloc,
+ const Sized_relobj_file<size, big_endian>* object)
+ : sym_(NULL), object_(object), addend_(0), locsym_(locsym_index)
+ {
+ if (size != 32)
+ this->addend_ = reloc.get_r_addend();
+ else if (parameters->options().output_is_position_independent()
+ && (elfcpp::elf_r_type<size>(reloc.get_r_info())
+ == elfcpp::R_PPC_PLTREL24))
+ this->addend_ = reloc.get_r_addend();
+ }
+
bool operator==(const Glink_sym_ent& that) const
{
return (this->sym_ == that.sym_
&& this->object_ == that.object_
- && this->addend_ == that.addend_);
+ && this->addend_ == that.addend_
+ && this->locsym_ == that.locsym_);
}
const Symbol* sym_;
- unsigned int addend_;
- const Sized_relobj<size, big_endian>* object_;
+ const Sized_relobj_file<size, big_endian>* object_;
+ typename elfcpp::Elf_types<size>::Elf_Addr addend_;
+ unsigned int locsym_;
};
class Glink_sym_ent_hash
@@ -1796,7 +1925,8 @@ class Output_data_glink : public Output_
{
return (reinterpret_cast<uintptr_t>(ent.sym_)
^ reinterpret_cast<uintptr_t>(ent.object_)
- ^ ent.addend_);
+ ^ ent.addend_
+ ^ ent.locsym_);
}
};
@@ -1830,7 +1960,7 @@ void
Output_data_glink<size, big_endian>::add_entry(
const Symbol* gsym,
const elfcpp::Rela<size, big_endian>& reloc,
- const Sized_relobj<size, big_endian>* object)
+ const Sized_relobj_file<size, big_endian>* object)
{
Glink_sym_ent ent(gsym, reloc, object);
unsigned int indx = this->glink_entries_.size();
@@ -1838,11 +1968,23 @@ Output_data_glink<size, big_endian>::add
}
template<int size, bool big_endian>
+void
+Output_data_glink<size, big_endian>::add_entry(
+ unsigned int locsym_index,
+ const elfcpp::Rela<size, big_endian>& reloc,
+ const Sized_relobj_file<size, big_endian>* object)
+{
+ Glink_sym_ent ent(locsym_index, reloc, object);
+ unsigned int indx = this->glink_entries_.size();
+ this->glink_entries_.insert(std::make_pair(ent, indx));
+}
+
+template<int size, bool big_endian>
unsigned int
Output_data_glink<size, big_endian>::find_entry(
const Symbol* gsym,
const elfcpp::Rela<size, big_endian>& reloc,
- const Sized_relobj<size, big_endian>* object) const
+ const Sized_relobj_file<size, big_endian>* object) const
{
Glink_sym_ent ent(gsym, reloc, object);
typename Glink_entries::const_iterator p = this->glink_entries_.find(ent);
@@ -1851,6 +1993,19 @@ Output_data_glink<size, big_endian>::fin
}
template<int size, bool big_endian>
+unsigned int
+Output_data_glink<size, big_endian>::find_entry(
+ unsigned int locsym_index,
+ const elfcpp::Rela<size, big_endian>& reloc,
+ const Sized_relobj_file<size, big_endian>* object) const
+{
+ Glink_sym_ent ent(locsym_index, reloc, object);
+ typename Glink_entries::const_iterator p = this->glink_entries_.find(ent);
+ gold_assert(p != this->glink_entries_.end());
+ return p->second;
+}
+
+template<int size, bool big_endian>
void
Output_data_glink<size, big_endian>::set_final_data_size()
{
@@ -1925,7 +2080,9 @@ Output_data_glink<size, big_endian>::do_
// The base address of the .plt section.
typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
+ static const Address invalid_address = static_cast<Address>(0) - 1;
Address plt_base = this->targ_->plt_section()->address();
+ Address iplt_base = invalid_address;
const Output_data_got_powerpc<size, big_endian>* got
= this->targ_->got_section();
@@ -1940,7 +2097,31 @@ Output_data_glink<size, big_endian>::do_
g != this->glink_entries_.end();
++g)
{
- Address plt_addr = plt_base + g->first.sym_->plt_offset();
+ Address plt_addr;
+ bool is_ifunc;
+ const Symbol* gsym = g->first.sym_;
+ if (gsym != NULL)
+ {
+ is_ifunc = (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false));
+ plt_addr = gsym->plt_offset();
+ }
+ else
+ {
+ is_ifunc = true;
+ const Sized_relobj_file<size, big_endian>* relobj
+ = g->first.object_;
+ unsigned int local_sym_index = g->first.locsym_;
+ plt_addr = relobj->local_plt_offset(local_sym_index);
+ }
+ if (is_ifunc)
+ {
+ if (iplt_base == invalid_address)
+ iplt_base = this->targ_->iplt_section()->address();
+ plt_addr += iplt_base;
+ }
+ else
+ plt_addr += plt_base;
const Powerpc_relobj<size, big_endian>* ppcobj = static_cast
<const Powerpc_relobj<size, big_endian>*>(g->first.object_);
Address got_addr = got_os_addr + ppcobj->toc_base_offset();
@@ -2033,16 +2214,39 @@ Output_data_glink<size, big_endian>::do_
g != this->glink_entries_.end();
++g)
{
- Address plt_addr = plt_base + g->first.sym_->plt_offset();
- Address got_addr;
- const Address invalid_address = static_cast<Address>(-1);
+ Address plt_addr;
+ bool is_ifunc;
+ const Symbol* gsym = g->first.sym_;
+ if (gsym != NULL)
+ {
+ is_ifunc = (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false));
+ plt_addr = gsym->plt_offset();
+ }
+ else
+ {
+ is_ifunc = true;
+ const Sized_relobj_file<size, big_endian>* relobj
+ = g->first.object_;
+ unsigned int local_sym_index = g->first.locsym_;
+ plt_addr = relobj->local_plt_offset(local_sym_index);
+ }
+ if (is_ifunc)
+ {
+ if (iplt_base == invalid_address)
+ iplt_base = this->targ_->iplt_section()->address();
+ plt_addr += iplt_base;
+ }
+ else
+ plt_addr += plt_base;
p = oview + g->second * this->glink_entry_size();
if (parameters->options().output_is_position_independent())
{
+ Address got_addr;
const Powerpc_relobj<size, big_endian>* object = static_cast
<const Powerpc_relobj<size, big_endian>*>(g->first.object_);
- if (object != NULL)
+ if (object != NULL && g->first.addend_ >= 32768)
{
unsigned int got2 = object->got2_shndx();
got_addr = g->first.object_->get_output_section_offset(got2);
@@ -2175,16 +2379,42 @@ template<int size, bool big_endian>
void
Target_powerpc<size, big_endian>::make_plt_entry(
Layout* layout,
+ Symbol_table* symtab,
Symbol* gsym,
const elfcpp::Rela<size, big_endian>& reloc,
- const Sized_relobj<size, big_endian>* object)
+ const Sized_relobj_file<size, big_endian>* object)
{
- if (this->plt_ == NULL)
- this->make_plt_section(layout);
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false))
+ {
+ if (this->iplt_ == NULL)
+ this->make_iplt_section(layout, symtab);
+ this->iplt_->add_ifunc_entry(gsym);
+ }
+ else
+ {
+ if (this->plt_ == NULL)
+ this->make_plt_section(layout);
+ this->plt_->add_entry(gsym);
+ }
+ this->glink_->add_entry(gsym, reloc, object);
+}
- this->plt_->add_entry(gsym);
+// Make a PLT entry for a local STT_GNU_IFUNC symbol.
- this->glink_->add_entry(gsym, reloc, object);
+template<int size, bool big_endian>
+void
+Target_powerpc<size, big_endian>::make_local_ifunc_plt_entry(
+ Layout* layout,
+ Symbol_table* symtab,
+ const elfcpp::Rela<size, big_endian>& reloc,
+ Sized_relobj_file<size, big_endian>* relobj)
+{
+ if (this->iplt_ == NULL)
+ this->make_iplt_section(layout, symtab);
+ unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
+ this->iplt_->add_local_ifunc_entry(relobj, r_sym);
+ this->glink_->add_entry(r_sym, reloc, relobj);
}
// Return the number of entries in the PLT.
@@ -2195,7 +2425,10 @@ Target_powerpc<size, big_endian>::plt_en
{
if (this->plt_ == NULL)
return 0;
- return this->plt_->entry_count();
+ unsigned int count = this->plt_->entry_count();
+ if (this->iplt_ != NULL)
+ count += this->iplt_->entry_count();
+ return count;
}
// Return the offset of the first non-reserved PLT entry.
@@ -2204,7 +2437,7 @@ template<int size, bool big_endian>
unsigned int
Target_powerpc<size, big_endian>::first_plt_entry_offset() const
{
- return Output_data_plt_powerpc<size, big_endian>::first_plt_entry_offset();
+ return this->plt_->first_plt_entry_offset();
}
// Return the size of each PLT entry.
@@ -2271,6 +2504,7 @@ Target_powerpc<size, big_endian>::Scan::
case elfcpp::R_POWERPC_ADDR14_BRNTAKEN:
return Symbol::FUNCTION_CALL | Symbol::ABSOLUTE_REF;
+ case elfcpp::R_PPC64_REL64:
case elfcpp::R_POWERPC_REL32:
case elfcpp::R_PPC_LOCAL24PC:
case elfcpp::R_POWERPC_REL16:
@@ -2290,6 +2524,8 @@ Target_powerpc<size, big_endian>::Scan::
case elfcpp::R_POWERPC_GOT16_LO:
case elfcpp::R_POWERPC_GOT16_HI:
case elfcpp::R_POWERPC_GOT16_HA:
+ case elfcpp::R_PPC64_GOT16_DS:
+ case elfcpp::R_PPC64_GOT16_LO_DS:
case elfcpp::R_PPC64_TOC16:
case elfcpp::R_PPC64_TOC16_LO:
case elfcpp::R_PPC64_TOC16_HI:
@@ -2429,6 +2665,69 @@ Target_powerpc<size, big_endian>::Scan::
return;
}
+// Return whether we need to make a PLT entry for a relocation of the
+// given type against a STT_GNU_IFUNC symbol.
+
+template<int size, bool big_endian>
+bool
+Target_powerpc<size, big_endian>::Scan::reloc_needs_plt_for_ifunc(
+ Sized_relobj_file<size, big_endian>* object,
+ unsigned int r_type)
+{
+ switch (r_type)
+ {
+ // Word size refs from data sections are OK.
+ case elfcpp::R_POWERPC_ADDR32:
+ case elfcpp::R_POWERPC_UADDR32:
+ if (size == 32)
+ return true;
+ break;
+
+ case elfcpp::R_PPC64_ADDR64:
+ case elfcpp::R_PPC64_UADDR64:
+ if (size == 64)
+ return true;
+ break;
+
+ // GOT refs are good.
+ case elfcpp::R_POWERPC_GOT16:
+ case elfcpp::R_POWERPC_GOT16_LO:
+ case elfcpp::R_POWERPC_GOT16_HI:
+ case elfcpp::R_POWERPC_GOT16_HA:
+ case elfcpp::R_PPC64_GOT16_DS:
+ case elfcpp::R_PPC64_GOT16_LO_DS:
+ return true;
+
+ // So are function calls.
+ case elfcpp::R_POWERPC_ADDR24:
+ case elfcpp::R_POWERPC_ADDR14:
+ case elfcpp::R_POWERPC_ADDR14_BRTAKEN:
+ case elfcpp::R_POWERPC_ADDR14_BRNTAKEN:
+ case elfcpp::R_POWERPC_REL24:
+ case elfcpp::R_PPC_PLTREL24:
+ case elfcpp::R_POWERPC_REL14:
+ case elfcpp::R_POWERPC_REL14_BRTAKEN:
+ case elfcpp::R_POWERPC_REL14_BRNTAKEN:
+ return true;
+
+ default:
+ break;
+ }
+
+ // Anything else is a problem.
+ // If we are building a static executable, the libc startup function
+ // responsible for applying indirect function relocations is going
+ // to complain about the reloc type.
+ // If we are building a dynamic executable, we will have a text
+ // relocation. The dynamic loader will set the text segment
+ // writable and non-executable to apply text relocations. So we'll
+ // segfault when trying to run the indirection function to resolve
+ // the reloc.
+ gold_error(_("%s: unsupported reloc %u for IFUNC symbol"),
+ object->name().c_str(), r_type);
+ return false;
+}
+
// Scan a relocation for a local symbol.
template<int size, bool big_endian>
@@ -2442,7 +2741,7 @@ Target_powerpc<size, big_endian>::Scan::
Output_section* output_section,
const elfcpp::Rela<size, big_endian>& reloc,
unsigned int r_type,
- const elfcpp::Sym<size, big_endian>& /* lsym */,
+ const elfcpp::Sym<size, big_endian>& lsym,
bool is_discarded)
{
Powerpc_relobj<size, big_endian>* ppc_object
@@ -2457,6 +2756,11 @@ Target_powerpc<size, big_endian>::Scan::
return;
}
+ // A local STT_GNU_IFUNC symbol may require a PLT entry.
+ bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
+ if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
+ target->make_local_ifunc_plt_entry(layout, symtab, reloc, object);
+
switch (r_type)
{
case elfcpp::R_POWERPC_NONE:
@@ -2520,11 +2824,16 @@ Target_powerpc<size, big_endian>::Scan::
|| (size == 64 && r_type == elfcpp::R_PPC64_ADDR64))
{
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
- rela_dyn->add_local_relative(object, r_sym,
- elfcpp::R_POWERPC_RELATIVE,
+ unsigned int dynrel = elfcpp::R_POWERPC_RELATIVE;
+ if (is_ifunc)
+ {
+ rela_dyn = target->iplt_section()->rel_plt();
+ dynrel = elfcpp::R_POWERPC_IRELATIVE;
+ }
+ rela_dyn->add_local_relative(object, r_sym, dynrel,
output_section, data_shndx,
reloc.get_r_offset(),
- reloc.get_r_addend(), false);
+ reloc.get_r_addend(), is_ifunc);
}
else
{
@@ -2590,24 +2899,31 @@ Target_powerpc<size, big_endian>::Scan::
= target->got_section(symtab, layout);
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
- // If we are generating a shared object, we need to add a
- // dynamic relocation for this symbol's GOT entry.
- if (parameters->options().output_is_position_independent())
+ if (!parameters->options().output_is_position_independent())
{
- if (!object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD))
- {
- Reloc_section* rela_dyn = target->rela_dyn_section(layout);
- unsigned int off;
+ if (size == 32 && is_ifunc)
+ got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
+ else
+ got->add_local(object, r_sym, GOT_TYPE_STANDARD);
+ }
+ else if (!object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD))
+ {
+ // If we are generating a shared object or a pie, this
+ // symbol's GOT entry will be set by a dynamic relocation.
+ unsigned int off;
+ off = got->add_constant(0);
+ object->set_local_got_offset(r_sym, GOT_TYPE_STANDARD, off);
- off = got->add_constant(0);
- object->set_local_got_offset(r_sym, GOT_TYPE_STANDARD, off);
- rela_dyn->add_local_relative(object, r_sym,
- elfcpp::R_POWERPC_RELATIVE,
- got, off, 0, false);
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ unsigned int dynrel = elfcpp::R_POWERPC_RELATIVE;
+ if (is_ifunc)
+ {
+ rela_dyn = target->iplt_section()->rel_plt();
+ dynrel = elfcpp::R_POWERPC_IRELATIVE;
}
+ rela_dyn->add_local_relative(object, r_sym, dynrel,
+ got, off, 0, is_ifunc);
}
- else
- got->add_local(object, r_sym, GOT_TYPE_STANDARD);
}
break;
@@ -2739,6 +3055,11 @@ Target_powerpc<size, big_endian>::Scan::
Powerpc_relobj<size, big_endian>* ppc_object
= static_cast<Powerpc_relobj<size, big_endian>*>(object);
+ // A STT_GNU_IFUNC symbol may require a PLT entry.
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && this->reloc_needs_plt_for_ifunc(object, r_type))
+ target->make_plt_entry(layout, symtab, gsym, reloc, object);
+
switch (r_type)
{
case elfcpp::R_POWERPC_NONE:
@@ -2807,13 +3128,14 @@ Target_powerpc<size, big_endian>::Scan::
// Make a PLT entry if necessary.
if (gsym->needs_plt_entry())
{
- target->make_plt_entry(layout, gsym, reloc, 0);
+ target->make_plt_entry(layout, symtab, gsym, reloc, 0);
// Since this is not a PC-relative relocation, we may be
// taking the address of a function. In that case we need to
// set the entry in the dynamic symbol table to the address of
- // the PLT entry.
+ // the PLT call stub.
if (size == 32
- && gsym->is_from_dynobj() && !parameters->options().shared())
+ && gsym->is_from_dynobj()
+ && !parameters->options().output_is_position_independent())
gsym->set_needs_dynsym_value();
}
// Make a dynamic relocation if necessary.
@@ -2827,13 +3149,19 @@ Target_powerpc<size, big_endian>::Scan::
else if (((size == 32 && r_type == elfcpp::R_POWERPC_ADDR32)
|| (size == 64 && r_type == elfcpp::R_PPC64_ADDR64))
&& (gsym->can_use_relative_reloc(false)
- || data_shndx == ppc_object->opd_shndx()))
+ || (size == 64
+ && data_shndx == ppc_object->opd_shndx())))
{
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
- rela_dyn->add_global_relative(gsym, elfcpp::R_POWERPC_RELATIVE,
- output_section, object,
- data_shndx, reloc.get_r_offset(),
- reloc.get_r_addend(), false);
+ unsigned int dynrel = elfcpp::R_POWERPC_RELATIVE;
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC)
+ {
+ rela_dyn = target->iplt_section()->rel_plt();
+ dynrel = elfcpp::R_POWERPC_IRELATIVE;
+ }
+ rela_dyn->add_symbolless_global_addend(
+ gsym, dynrel, output_section, object, data_shndx,
+ reloc.get_r_offset(), reloc.get_r_addend());
}
else
{
@@ -2855,7 +3183,7 @@ Target_powerpc<size, big_endian>::Scan::
&& (gsym->is_undefined()
|| gsym->is_from_dynobj()
|| gsym->is_preemptible())))
- target->make_plt_entry(layout, gsym, reloc, object);
+ target->make_plt_entry(layout, symtab, gsym, reloc, object);
// Fall thru
case elfcpp::R_PPC64_REL64:
@@ -2929,24 +3257,37 @@ Target_powerpc<size, big_endian>::Scan::
got = target->got_section(symtab, layout);
if (gsym->final_value_is_known())
- got->add_global(gsym, GOT_TYPE_STANDARD);
- else
{
- // If this symbol is not fully resolved, we need to add a
- // dynamic relocation for it.
+ if (size == 32 && gsym->type() == elfcpp::STT_GNU_IFUNC)
+ got->add_global_plt(gsym, GOT_TYPE_STANDARD);
+ else
+ got->add_global(gsym, GOT_TYPE_STANDARD);
+ }
+ else if (!gsym->has_got_offset(GOT_TYPE_STANDARD))
+ {
+ // If we are generating a shared object or a pie, this
+ // symbol's GOT entry will be set by a dynamic relocation.
+ unsigned int off = got->add_constant(0);
+ gsym->set_got_offset(GOT_TYPE_STANDARD, off);
+
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
- if (gsym->is_from_dynobj()
- || gsym->is_undefined()
- || gsym->is_preemptible())
- got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn,
- elfcpp::R_POWERPC_GLOB_DAT);
- else if (!gsym->has_got_offset(GOT_TYPE_STANDARD))
+ if (gsym->can_use_relative_reloc(false)
+ && !(size == 32
+ && gsym->visibility() == elfcpp::STV_PROTECTED
+ && parameters->options().shared()))
{
- unsigned int off = got->add_constant(0);
-
- gsym->set_got_offset(GOT_TYPE_STANDARD, off);
- rela_dyn->add_global_relative(gsym, elfcpp::R_POWERPC_RELATIVE,
- got, off, 0, false);
+ unsigned int dynrel = elfcpp::R_POWERPC_RELATIVE;
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC)
+ {
+ rela_dyn = target->iplt_section()->rel_plt();
+ dynrel = elfcpp::R_POWERPC_IRELATIVE;
+ }
+ rela_dyn->add_global_relative(gsym, dynrel, got, off, 0, false);
+ }
+ else
+ {
+ unsigned int dynrel = elfcpp::R_POWERPC_GLOB_DAT;
+ rela_dyn->add_global(gsym, dynrel, got, off, 0);
}
}
}
@@ -3418,8 +3759,10 @@ Target_powerpc<size, big_endian>::Reloca
= static_cast<Powerpc_relobj<size, big_endian>*>(relinfo->object);
Address value = 0;
bool has_plt_value = false;
+ unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
if (gsym != NULL
- && use_plt_offset<size>(gsym, Scan::get_reference_flags(r_type)))
+ ? use_plt_offset<size>(gsym, Scan::get_reference_flags(r_type))
+ : object->local_has_plt_offset(r_sym))
{
const Output_data_glink<size, big_endian>* glink
= target->glink_section();
@@ -4617,7 +4960,11 @@ Target_powerpc<size, big_endian>::do_dyn
if (size == 32)
{
gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
- return this->plt_section()->address() + gsym->plt_offset();
+ const Output_data_glink<size, big_endian>* glink = this->glink_section();
+ static const unsigned char zeros[elfcpp::Elf_sizes<32>::rela_size] = {0};
+ const elfcpp::Rela<size, big_endian> zero_reloc(zeros);
+ unsigned int glink_index = glink->find_entry(gsym, zero_reloc, NULL);
+ return glink->address() + glink_index * glink->glink_entry_size();
}
else
gold_unreachable();
--
Alan Modra
Australia Development Lab, IBM