2009-06-02 Doug Kwan <dougkwan@google.com>
* gold/arm.cc (Target_arm::Scan::Scan): Initialize issued_non_pic_error_. (class Target_arm::Scan): Declare new method check_non_pic. Define new method symbol_needs_plt_entry. Declare new data member issued_non_pic_error_. (class Target_arm::Relocate): Declare new method should_apply_static_reloc. (Target_arm::may_need_copy_reloc): Handle STT_ARM_TFUNC. (Target_arm::Scan::check_non_pic): Define new method. (Target_arm::Scan::local): Handle a small subset of reloc types used by Android. (Target_arm::Scan::local): Same. (Target_arm::Relocate::should_apply_statci_reloc): Define new method.
This commit is contained in:
Doug Kwan
parent
05b48798fb
commit
bec53400ce
369
gold/arm.cc
369
gold/arm.cc
|
|
@ -75,8 +75,6 @@ class Output_data_plt_arm;
|
|||
// R_ARM_PREL31
|
||||
//
|
||||
// Coming soon (pending patches):
|
||||
// - Local scanner
|
||||
// - Global scanner
|
||||
// - Relocation
|
||||
// - Defining section symbols __exidx_start and __exidx_stop.
|
||||
// - Support interworking.
|
||||
|
|
@ -209,6 +207,7 @@ class Target_arm : public Sized_target<32, big_endian>
|
|||
{
|
||||
public:
|
||||
Scan()
|
||||
: issued_non_pic_error_(false)
|
||||
{ }
|
||||
|
||||
inline void
|
||||
|
|
@ -237,6 +236,29 @@ class Target_arm : public Sized_target<32, big_endian>
|
|||
static void
|
||||
unsupported_reloc_global(Sized_relobj<32, big_endian>*,
|
||||
unsigned int r_type, Symbol*);
|
||||
|
||||
void
|
||||
check_non_pic(Relobj*, unsigned int r_type);
|
||||
|
||||
// Almost identical to Symbol::needs_plt_entry except that it also
|
||||
// handles STT_ARM_TFUNC.
|
||||
static bool
|
||||
symbol_needs_plt_entry(const Symbol* sym)
|
||||
{
|
||||
// An undefined symbol from an executable does not need a PLT entry.
|
||||
if (sym->is_undefined() && !parameters->options().shared())
|
||||
return false;
|
||||
|
||||
return (!parameters->doing_static_link()
|
||||
&& (sym->type() == elfcpp::STT_FUNC
|
||||
|| sym->type() == elfcpp::STT_ARM_TFUNC)
|
||||
&& (sym->is_from_dynobj()
|
||||
|| sym->is_undefined()
|
||||
|| sym->is_preemptible()));
|
||||
}
|
||||
|
||||
// Whether we have issued an error about a non-PIC compilation.
|
||||
bool issued_non_pic_error_;
|
||||
};
|
||||
|
||||
// The class which implements relocation.
|
||||
|
|
@ -249,6 +271,13 @@ class Target_arm : public Sized_target<32, big_endian>
|
|||
~Relocate()
|
||||
{ }
|
||||
|
||||
// Return whether the static relocation needs to be applied.
|
||||
inline bool
|
||||
should_apply_static_reloc(const Sized_symbol<32>* gsym,
|
||||
int ref_flags,
|
||||
bool is_32bit,
|
||||
Output_section* output_section);
|
||||
|
||||
// Do a relocation. Return false if the caller should not issue
|
||||
// any warnings about this relocation.
|
||||
inline bool
|
||||
|
|
@ -306,7 +335,8 @@ class Target_arm : public Sized_target<32, big_endian>
|
|||
{
|
||||
return (!parameters->options().shared()
|
||||
&& gsym->is_from_dynobj()
|
||||
&& gsym->type() != elfcpp::STT_FUNC);
|
||||
&& gsym->type() != elfcpp::STT_FUNC
|
||||
&& gsym->type() != elfcpp::STT_ARM_TFUNC);
|
||||
}
|
||||
|
||||
// Add a potential copy relocation.
|
||||
|
|
@ -669,18 +699,65 @@ Target_arm<big_endian>::Scan::unsupported_reloc_local(
|
|||
object->name().c_str(), r_type);
|
||||
}
|
||||
|
||||
// We are about to emit a dynamic relocation of type R_TYPE. If the
|
||||
// dynamic linker does not support it, issue an error. The GNU linker
|
||||
// only issues a non-PIC error for an allocated read-only section.
|
||||
// Here we know the section is allocated, but we don't know that it is
|
||||
// read-only. But we check for all the relocation types which the
|
||||
// glibc dynamic linker supports, so it seems appropriate to issue an
|
||||
// error even if the section is not read-only.
|
||||
|
||||
template<bool big_endian>
|
||||
void
|
||||
Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
|
||||
unsigned int r_type)
|
||||
{
|
||||
switch (r_type)
|
||||
{
|
||||
// These are the relocation types supported by glibc for ARM.
|
||||
case elfcpp::R_ARM_RELATIVE:
|
||||
case elfcpp::R_ARM_COPY:
|
||||
case elfcpp::R_ARM_GLOB_DAT:
|
||||
case elfcpp::R_ARM_JUMP_SLOT:
|
||||
case elfcpp::R_ARM_ABS32:
|
||||
case elfcpp::R_ARM_PC24:
|
||||
// FIXME: The following 3 types are not supported by Android's dynamic
|
||||
// linker.
|
||||
case elfcpp::R_ARM_TLS_DTPMOD32:
|
||||
case elfcpp::R_ARM_TLS_DTPOFF32:
|
||||
case elfcpp::R_ARM_TLS_TPOFF32:
|
||||
return;
|
||||
|
||||
default:
|
||||
// This prevents us from issuing more than one error per reloc
|
||||
// section. But we can still wind up issuing more than one
|
||||
// error per object file.
|
||||
if (this->issued_non_pic_error_)
|
||||
return;
|
||||
object->error(_("requires unsupported dynamic reloc; "
|
||||
"recompile with -fPIC"));
|
||||
this->issued_non_pic_error_ = true;
|
||||
return;
|
||||
|
||||
case elfcpp::R_ARM_NONE:
|
||||
gold_unreachable();
|
||||
}
|
||||
}
|
||||
|
||||
// Scan a relocation for a local symbol.
|
||||
// FIXME: This only handles a subset of relocation types used by Android
|
||||
// on ARM v5te devices.
|
||||
|
||||
template<bool big_endian>
|
||||
inline void
|
||||
Target_arm<big_endian>::Scan::local(const General_options&,
|
||||
Symbol_table* /* symtab */,
|
||||
Layout* /* layout */,
|
||||
Target_arm* /* target */,
|
||||
Symbol_table* symtab,
|
||||
Layout* layout,
|
||||
Target_arm* target,
|
||||
Sized_relobj<32, big_endian>* object,
|
||||
unsigned int /* data_shndx */,
|
||||
Output_section* /* output_section */,
|
||||
const elfcpp::Rel<32, big_endian>& /* reloc */,
|
||||
unsigned int data_shndx,
|
||||
Output_section* output_section,
|
||||
const elfcpp::Rel<32, big_endian>& reloc,
|
||||
unsigned int r_type,
|
||||
const elfcpp::Sym<32, big_endian>&)
|
||||
{
|
||||
|
|
@ -690,6 +767,77 @@ Target_arm<big_endian>::Scan::local(const General_options&,
|
|||
case elfcpp::R_ARM_NONE:
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_ABS32:
|
||||
// If building a shared library (or a position-independent
|
||||
// executable), we need to create a dynamic relocation for
|
||||
// this location. The relocation applied at link time will
|
||||
// apply the link-time value, so we flag the location with
|
||||
// an R_ARM_RELATIVE relocation so the dynamic loader can
|
||||
// relocate it easily.
|
||||
if (parameters->options().output_is_position_independent())
|
||||
{
|
||||
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
||||
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
||||
// If we are to add more other reloc types than R_ARM_ABS32,
|
||||
// we need to add check_non_pic(object, r_type) here.
|
||||
rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
|
||||
output_section, data_shndx,
|
||||
reloc.get_r_offset());
|
||||
}
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_REL32:
|
||||
case elfcpp::R_ARM_THM_CALL:
|
||||
case elfcpp::R_ARM_CALL:
|
||||
case elfcpp::R_ARM_PREL31:
|
||||
case elfcpp::R_ARM_JUMP24:
|
||||
case elfcpp::R_ARM_PLT32:
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_GOTOFF32:
|
||||
// We need a GOT section:
|
||||
target->got_section(symtab, layout);
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_BASE_PREL:
|
||||
// FIXME: What about this?
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_GOT_BREL:
|
||||
{
|
||||
// The symbol requires a GOT entry.
|
||||
Output_data_got<32, big_endian>* got =
|
||||
target->got_section(symtab, layout);
|
||||
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
||||
if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
|
||||
{
|
||||
// If we are generating a shared object, we need to add a
|
||||
// dynamic RELATIVE relocation for this symbol's GOT entry.
|
||||
if (parameters->options().output_is_position_independent())
|
||||
{
|
||||
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
||||
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
||||
rel_dyn->add_local_relative(
|
||||
object, r_sym, elfcpp::R_ARM_RELATIVE, got,
|
||||
object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
|
||||
}
|
||||
}
|
||||
}
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_TARGET1:
|
||||
// This should have been mapped to another type already.
|
||||
// Fall through.
|
||||
case elfcpp::R_ARM_COPY:
|
||||
case elfcpp::R_ARM_GLOB_DAT:
|
||||
case elfcpp::R_ARM_JUMP_SLOT:
|
||||
case elfcpp::R_ARM_RELATIVE:
|
||||
// These are relocations which should only be seen by the
|
||||
// dynamic linker, and should never be seen here.
|
||||
gold_error(_("%s: unexpected reloc %u in object file"),
|
||||
object->name().c_str(), r_type);
|
||||
break;
|
||||
|
||||
default:
|
||||
unsupported_reloc_local(object, r_type);
|
||||
break;
|
||||
|
|
@ -710,17 +858,19 @@ Target_arm<big_endian>::Scan::unsupported_reloc_global(
|
|||
}
|
||||
|
||||
// Scan a relocation for a global symbol.
|
||||
// FIXME: This only handles a subset of relocation types used by Android
|
||||
// on ARM v5te devices.
|
||||
|
||||
template<bool big_endian>
|
||||
inline void
|
||||
Target_arm<big_endian>::Scan::global(const General_options&,
|
||||
Symbol_table* /* symtab */,
|
||||
Layout* /* layout */,
|
||||
Target_arm* /* target */,
|
||||
Symbol_table* symtab,
|
||||
Layout* layout,
|
||||
Target_arm* target,
|
||||
Sized_relobj<32, big_endian>* object,
|
||||
unsigned int /* data_shndx */,
|
||||
Output_section* /* output_section */,
|
||||
const elfcpp::Rel<32, big_endian>& /* reloc */,
|
||||
unsigned int data_shndx,
|
||||
Output_section* output_section,
|
||||
const elfcpp::Rel<32, big_endian>& reloc,
|
||||
unsigned int r_type,
|
||||
Symbol* gsym)
|
||||
{
|
||||
|
|
@ -730,6 +880,155 @@ Target_arm<big_endian>::Scan::global(const General_options&,
|
|||
case elfcpp::R_ARM_NONE:
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_ABS32:
|
||||
{
|
||||
// Make a dynamic relocation if necessary.
|
||||
if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
|
||||
{
|
||||
if (target->may_need_copy_reloc(gsym))
|
||||
{
|
||||
target->copy_reloc(symtab, layout, object,
|
||||
data_shndx, output_section, gsym, reloc);
|
||||
}
|
||||
else if (gsym->can_use_relative_reloc(false))
|
||||
{
|
||||
// If we are to add more other reloc types than R_ARM_ABS32,
|
||||
// we need to add check_non_pic(object, r_type) here.
|
||||
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
||||
rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
|
||||
output_section, object,
|
||||
data_shndx, reloc.get_r_offset());
|
||||
}
|
||||
else
|
||||
{
|
||||
// If we are to add more other reloc types than R_ARM_ABS32,
|
||||
// we need to add check_non_pic(object, r_type) here.
|
||||
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
||||
rel_dyn->add_global(gsym, r_type, output_section, object,
|
||||
data_shndx, reloc.get_r_offset());
|
||||
}
|
||||
}
|
||||
}
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_REL32:
|
||||
case elfcpp::R_ARM_PREL31:
|
||||
{
|
||||
// Make a dynamic relocation if necessary.
|
||||
int flags = Symbol::NON_PIC_REF;
|
||||
if (gsym->needs_dynamic_reloc(flags))
|
||||
{
|
||||
if (target->may_need_copy_reloc(gsym))
|
||||
{
|
||||
target->copy_reloc(symtab, layout, object,
|
||||
data_shndx, output_section, gsym, reloc);
|
||||
}
|
||||
else
|
||||
{
|
||||
check_non_pic(object, r_type);
|
||||
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
||||
rel_dyn->add_global(gsym, r_type, output_section, object,
|
||||
data_shndx, reloc.get_r_offset());
|
||||
}
|
||||
}
|
||||
}
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_JUMP24:
|
||||
case elfcpp::R_ARM_THM_CALL:
|
||||
case elfcpp::R_ARM_CALL:
|
||||
{
|
||||
if (Target_arm<big_endian>::Scan::symbol_needs_plt_entry(gsym))
|
||||
target->make_plt_entry(symtab, layout, gsym);
|
||||
// Make a dynamic relocation if necessary.
|
||||
int flags = Symbol::NON_PIC_REF;
|
||||
if (gsym->type() == elfcpp::STT_FUNC
|
||||
| gsym->type() == elfcpp::STT_ARM_TFUNC)
|
||||
flags |= Symbol::FUNCTION_CALL;
|
||||
if (gsym->needs_dynamic_reloc(flags))
|
||||
{
|
||||
if (target->may_need_copy_reloc(gsym))
|
||||
{
|
||||
target->copy_reloc(symtab, layout, object,
|
||||
data_shndx, output_section, gsym,
|
||||
reloc);
|
||||
}
|
||||
else
|
||||
{
|
||||
check_non_pic(object, r_type);
|
||||
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
||||
rel_dyn->add_global(gsym, r_type, output_section, object,
|
||||
data_shndx, reloc.get_r_offset());
|
||||
}
|
||||
}
|
||||
}
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_PLT32:
|
||||
// If the symbol is fully resolved, this is just a relative
|
||||
// local reloc. Otherwise we need a PLT entry.
|
||||
if (gsym->final_value_is_known())
|
||||
break;
|
||||
// If building a shared library, we can also skip the PLT entry
|
||||
// if the symbol is defined in the output file and is protected
|
||||
// or hidden.
|
||||
if (gsym->is_defined()
|
||||
&& !gsym->is_from_dynobj()
|
||||
&& !gsym->is_preemptible())
|
||||
break;
|
||||
target->make_plt_entry(symtab, layout, gsym);
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_GOTOFF32:
|
||||
// We need a GOT section.
|
||||
target->got_section(symtab, layout);
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_BASE_PREL:
|
||||
// FIXME: What about this?
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_GOT_BREL:
|
||||
{
|
||||
// The symbol requires a GOT entry.
|
||||
Output_data_got<32, big_endian>* 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
|
||||
// GOT entry with a dynamic relocation.
|
||||
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
||||
if (gsym->is_from_dynobj()
|
||||
|| gsym->is_undefined()
|
||||
|| gsym->is_preemptible())
|
||||
got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
|
||||
rel_dyn, elfcpp::R_ARM_GLOB_DAT);
|
||||
else
|
||||
{
|
||||
if (got->add_global(gsym, GOT_TYPE_STANDARD))
|
||||
rel_dyn->add_global_relative(
|
||||
gsym, elfcpp::R_ARM_RELATIVE, got,
|
||||
gsym->got_offset(GOT_TYPE_STANDARD));
|
||||
}
|
||||
}
|
||||
}
|
||||
break;
|
||||
|
||||
case elfcpp::R_ARM_TARGET1:
|
||||
// This should have been mapped to another type already.
|
||||
// Fall through.
|
||||
case elfcpp::R_ARM_COPY:
|
||||
case elfcpp::R_ARM_GLOB_DAT:
|
||||
case elfcpp::R_ARM_JUMP_SLOT:
|
||||
case elfcpp::R_ARM_RELATIVE:
|
||||
// These are relocations which should only be seen by the
|
||||
// dynamic linker, and should never be seen here.
|
||||
gold_error(_("%s: unexpected reloc %u in object file"),
|
||||
object->name().c_str(), r_type);
|
||||
break;
|
||||
|
||||
default:
|
||||
unsupported_reloc_global(object, r_type, gsym);
|
||||
break;
|
||||
|
|
@ -855,6 +1154,46 @@ Target_arm<big_endian>::do_finalize_sections(Layout* layout)
|
|||
this->copy_relocs_.emit(this->rel_dyn_section(layout));
|
||||
}
|
||||
|
||||
// Return whether a direct absolute static relocation needs to be applied.
|
||||
// In cases where Scan::local() or Scan::global() has created
|
||||
// a dynamic relocation other than R_ARM_RELATIVE, the addend
|
||||
// of the relocation is carried in the data, and we must not
|
||||
// apply the static relocation.
|
||||
|
||||
template<bool big_endian>
|
||||
inline bool
|
||||
Target_arm<big_endian>::Relocate::should_apply_static_reloc(
|
||||
const Sized_symbol<32>* gsym,
|
||||
int ref_flags,
|
||||
bool is_32bit,
|
||||
Output_section* output_section)
|
||||
{
|
||||
// If the output section is not allocated, then we didn't call
|
||||
// scan_relocs, we didn't create a dynamic reloc, and we must apply
|
||||
// the reloc here.
|
||||
if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
|
||||
return true;
|
||||
|
||||
// For local symbols, we will have created a non-RELATIVE dynamic
|
||||
// relocation only if (a) the output is position independent,
|
||||
// (b) the relocation is absolute (not pc- or segment-relative), and
|
||||
// (c) the relocation is not 32 bits wide.
|
||||
if (gsym == NULL)
|
||||
return !(parameters->options().output_is_position_independent()
|
||||
&& (ref_flags & Symbol::ABSOLUTE_REF)
|
||||
&& !is_32bit);
|
||||
|
||||
// For global symbols, we use the same helper routines used in the
|
||||
// scan pass. If we did not create a dynamic relocation, or if we
|
||||
// created a RELATIVE dynamic relocation, we should apply the static
|
||||
// relocation.
|
||||
bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
|
||||
bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
|
||||
&& gsym->can_use_relative_reloc(ref_flags
|
||||
& Symbol::FUNCTION_CALL);
|
||||
return !has_dyn || is_rel;
|
||||
}
|
||||
|
||||
// Perform a relocation.
|
||||
|
||||
template<bool big_endian>
|
||||
|
|
|
|||
Loading…
Reference in New Issue