[GOLD] handle more ppc relocs
Alan Modra
amodra@gmail.com
Wed Sep 5 02:57:00 GMT 2012
..and fix ppc64 plt call checks. Committed.
* powerpc.cc (Powerpc_relobj::get_opd_ent): Make const.
(Powerpc_relocate_functions::Status): New typedef.
(Target_powerpc::Scan::get_reference_flags): Handle more relocs.
(Target_powerpc::Scan::local): Handle REL64.
(Target_powerpc::Scan::global): Likewise, and dynamic relocs
for REL32 and REL64.
(Target_powerpc::symval_for_branch): New function, extracted from..
(Target_powerpc::Relocate::relocate): ..here. Correct plt call
checks. Report overflow errors.
Index: gold/powerpc.cc
===================================================================
RCS file: /cvs/src/src/gold/powerpc.cc,v
retrieving revision 1.53
diff -u -p -r1.53 powerpc.cc
--- gold/powerpc.cc 5 Sep 2012 00:34:20 -0000 1.53
+++ gold/powerpc.cc 5 Sep 2012 01:32:05 -0000
@@ -100,7 +100,7 @@ public:
// Return section and offset of function entry for .opd + R_OFF.
void
- get_opd_ent(Address r_off, unsigned int* shndx, Address* value)
+ get_opd_ent(Address r_off, unsigned int* shndx, Address* value) const
{
size_t ndx = this->opd_ent_ndx(r_off);
gold_assert(ndx < this->opd_ent_shndx_.size());
@@ -411,6 +411,11 @@ class Target_powerpc : public Sized_targ
bool issued_non_pic_error_;
};
+ Address
+ symval_for_branch(Address value, const Sized_symbol<size>* gsym,
+ Powerpc_relobj<size, big_endian>* object,
+ unsigned int *dest_shndx);
+
// The class which implements relocation.
class Relocate
{
@@ -847,11 +852,11 @@ public:
check_bitfield
};
- enum overflow_status
+ typedef enum overflow_status
{
status_ok,
status_overflow
- };
+ } Status;
private:
typedef Powerpc_relocate_functions<size, big_endian> This;
@@ -2190,6 +2195,7 @@ Target_powerpc<size, big_endian>::Scan::
// and 64-bit powerpc.
switch (r_type)
{
+ case elfcpp::R_POWERPC_NONE:
case elfcpp::R_POWERPC_RELATIVE:
case elfcpp::R_POWERPC_GLOB_DAT:
case elfcpp::R_POWERPC_DTPMOD:
@@ -2197,9 +2203,24 @@ Target_powerpc<size, big_endian>::Scan::
case elfcpp::R_POWERPC_TPREL:
case elfcpp::R_POWERPC_JMP_SLOT:
case elfcpp::R_POWERPC_COPY:
+ case elfcpp::R_POWERPC_IRELATIVE:
case elfcpp::R_POWERPC_ADDR32:
+ case elfcpp::R_POWERPC_UADDR32:
case elfcpp::R_POWERPC_ADDR24:
+ case elfcpp::R_POWERPC_ADDR16:
+ case elfcpp::R_POWERPC_UADDR16:
+ case elfcpp::R_POWERPC_ADDR16_LO:
+ case elfcpp::R_POWERPC_ADDR16_HI:
+ case elfcpp::R_POWERPC_ADDR16_HA:
+ case elfcpp::R_POWERPC_ADDR14:
+ case elfcpp::R_POWERPC_ADDR14_BRTAKEN:
+ case elfcpp::R_POWERPC_ADDR14_BRNTAKEN:
+ case elfcpp::R_POWERPC_REL32:
case elfcpp::R_POWERPC_REL24:
+ case elfcpp::R_POWERPC_TPREL16:
+ case elfcpp::R_POWERPC_TPREL16_LO:
+ case elfcpp::R_POWERPC_TPREL16_HI:
+ case elfcpp::R_POWERPC_TPREL16_HA:
return;
default:
@@ -2212,34 +2233,22 @@ Target_powerpc<size, big_endian>::Scan::
{
// These are the relocation types supported only on 64-bit.
case elfcpp::R_PPC64_ADDR64:
- case elfcpp::R_PPC64_TPREL16_LO_DS:
- case elfcpp::R_PPC64_TPREL16_DS:
- case elfcpp::R_POWERPC_TPREL16:
- case elfcpp::R_POWERPC_TPREL16_LO:
- case elfcpp::R_POWERPC_TPREL16_HI:
- case elfcpp::R_POWERPC_TPREL16_HA:
- case elfcpp::R_PPC64_TPREL16_HIGHER:
- case elfcpp::R_PPC64_TPREL16_HIGHEST:
- case elfcpp::R_PPC64_TPREL16_HIGHERA:
- case elfcpp::R_PPC64_TPREL16_HIGHESTA:
- case elfcpp::R_PPC64_ADDR16_LO_DS:
- case elfcpp::R_POWERPC_ADDR16_LO:
- case elfcpp::R_POWERPC_ADDR16_HI:
- case elfcpp::R_POWERPC_ADDR16_HA:
- case elfcpp::R_POWERPC_ADDR30:
case elfcpp::R_PPC64_UADDR64:
- case elfcpp::R_POWERPC_UADDR32:
- case elfcpp::R_POWERPC_ADDR16:
- case elfcpp::R_POWERPC_UADDR16:
+ case elfcpp::R_PPC64_JMP_IREL:
case elfcpp::R_PPC64_ADDR16_DS:
+ case elfcpp::R_PPC64_ADDR16_LO_DS:
case elfcpp::R_PPC64_ADDR16_HIGHER:
case elfcpp::R_PPC64_ADDR16_HIGHEST:
case elfcpp::R_PPC64_ADDR16_HIGHERA:
case elfcpp::R_PPC64_ADDR16_HIGHESTA:
- case elfcpp::R_POWERPC_ADDR14_BRTAKEN:
- case elfcpp::R_POWERPC_ADDR14_BRNTAKEN:
- case elfcpp::R_POWERPC_REL32:
case elfcpp::R_PPC64_REL64:
+ case elfcpp::R_POWERPC_ADDR30:
+ case elfcpp::R_PPC64_TPREL16_DS:
+ case elfcpp::R_PPC64_TPREL16_LO_DS:
+ case elfcpp::R_PPC64_TPREL16_HIGHER:
+ case elfcpp::R_PPC64_TPREL16_HIGHEST:
+ case elfcpp::R_PPC64_TPREL16_HIGHERA:
+ case elfcpp::R_PPC64_TPREL16_HIGHESTA:
return;
default:
@@ -2251,6 +2260,12 @@ Target_powerpc<size, big_endian>::Scan::
switch (r_type)
{
// These are the relocation types supported only on 32-bit.
+ // ??? glibc ld.so doesn't need to support these.
+ case elfcpp::R_POWERPC_DTPREL16:
+ case elfcpp::R_POWERPC_DTPREL16_LO:
+ case elfcpp::R_POWERPC_DTPREL16_HI:
+ case elfcpp::R_POWERPC_DTPREL16_HA:
+ return;
default:
break;
@@ -2361,6 +2376,7 @@ Target_powerpc<size, big_endian>::Scan::
}
break;
+ case elfcpp::R_PPC64_REL64:
case elfcpp::R_POWERPC_REL32:
case elfcpp::R_POWERPC_REL24:
case elfcpp::R_PPC_LOCAL24PC:
@@ -2670,35 +2686,36 @@ Target_powerpc<size, big_endian>::Scan::
case elfcpp::R_PPC_PLTREL24:
case elfcpp::R_POWERPC_REL24:
- {
- if (gsym->needs_plt_entry()
- || (!gsym->final_value_is_known()
- && !(gsym->is_defined()
- && !gsym->is_from_dynobj()
- && !gsym->is_preemptible())))
- target->make_plt_entry(layout, gsym, reloc, object);
- // Make a dynamic relocation if necessary.
- if (needs_dynamic_reloc<size>(gsym, Scan::get_reference_flags(r_type)))
- {
- if (gsym->may_need_copy_reloc())
- {
- target->copy_reloc(symtab, layout, object,
- data_shndx, output_section, gsym,
- reloc);
- }
- else
- {
- Reloc_section* rela_dyn = target->rela_dyn_section(layout);
- check_non_pic(object, r_type);
- rela_dyn->add_global(gsym, r_type, output_section, object,
- data_shndx, reloc.get_r_offset(),
- reloc.get_r_addend());
- }
- }
- }
- break;
+ if (gsym->needs_plt_entry()
+ || (!gsym->final_value_is_known()
+ && (gsym->is_undefined()
+ || gsym->is_from_dynobj()
+ || gsym->is_preemptible())))
+ target->make_plt_entry(layout, gsym, reloc, object);
+ // Fall thru
+ case elfcpp::R_PPC64_REL64:
case elfcpp::R_POWERPC_REL32:
+ // Make a dynamic relocation if necessary.
+ if (needs_dynamic_reloc<size>(gsym, Scan::get_reference_flags(r_type)))
+ {
+ if (gsym->may_need_copy_reloc())
+ {
+ target->copy_reloc(symtab, layout, object,
+ data_shndx, output_section, gsym,
+ reloc);
+ }
+ else
+ {
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ check_non_pic(object, r_type);
+ rela_dyn->add_global(gsym, r_type, output_section, object,
+ data_shndx, reloc.get_r_offset(),
+ reloc.get_r_addend());
+ }
+ }
+ break;
+
case elfcpp::R_POWERPC_REL16:
case elfcpp::R_POWERPC_REL16_LO:
case elfcpp::R_POWERPC_REL16_HI:
@@ -3022,6 +3039,43 @@ Target_powerpc<size, big_endian>::do_fin
this->copy_relocs_.emit(this->rela_dyn_section(layout));
}
+// Return the value to use for a branch relocation.
+
+template<int size, bool big_endian>
+typename elfcpp::Elf_types<size>::Elf_Addr
+Target_powerpc<size, big_endian>::symval_for_branch(
+ Address value,
+ const Sized_symbol<size>* gsym,
+ Powerpc_relobj<size, big_endian>* object,
+ unsigned int *dest_shndx)
+{
+ *dest_shndx = 0;
+ if (size == 32)
+ return value;
+
+ // If the symbol is defined in an opd section, ie. is a function
+ // descriptor, use the function descriptor code entry address
+ Powerpc_relobj<size, big_endian>* symobj = object;
+ if (gsym != NULL)
+ symobj = static_cast<Powerpc_relobj<size, big_endian>*>(gsym->object());
+ unsigned int shndx = symobj->opd_shndx();
+ if (shndx == 0)
+ return value;
+ Address opd_addr = symobj->get_output_section_offset(shndx);
+ gold_assert(opd_addr != invalid_address);
+ opd_addr += symobj->output_section(shndx)->address();
+ if (value >= opd_addr && value < opd_addr + symobj->section_size(shndx))
+ {
+ Address sec_off;
+ symobj->get_opd_ent(value - opd_addr, dest_shndx, &sec_off);
+ Address sec_addr = symobj->get_output_section_offset(*dest_shndx);
+ gold_assert(sec_addr != invalid_address);
+ sec_addr += symobj->output_section(*dest_shndx)->address();
+ value = sec_addr + sec_off;
+ }
+ return value;
+}
+
// Perform a relocation.
template<int size, bool big_endian>
@@ -3060,8 +3114,8 @@ Target_powerpc<size, big_endian>::Reloca
typedef Powerpc_relocate_functions<size, big_endian> Reloc;
typedef typename elfcpp::Swap<32, big_endian>::Valtype Insn;
- const Powerpc_relobj<size, big_endian>* const object
- = static_cast<const Powerpc_relobj<size, big_endian>*>(relinfo->object);
+ Powerpc_relobj<size, big_endian>* const object
+ = static_cast<Powerpc_relobj<size, big_endian>*>(relinfo->object);
Address value = 0;
bool has_plt_value = false;
if (gsym != NULL
@@ -3111,17 +3165,50 @@ Target_powerpc<size, big_endian>::Reloca
bool can_plt_call = false;
if (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);
- if (insn2 == nop
- || insn2 == cror_15_15_15 || insn2 == cror_31_31_31)
+ if ((insn & 1) != 0
+ && (insn2 == nop
+ || insn2 == cror_15_15_15 || insn2 == cror_31_31_31))
{
elfcpp::Swap<32, big_endian>::writeval(wv + 1, ld_2_1 + 40);
can_plt_call = true;
}
}
if (!can_plt_call)
- gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
- _("call lacks nop, can't restore toc"));
+ {
+ // If we don't have a branch and link followed by a nop,
+ // we can't go via the plt because there is no place to
+ // put a toc restoring instruction.
+ // Unless we know we won't be returning.
+ if (strcmp(gsym->name(), "__libc_start_main") == 0)
+ can_plt_call = true;
+ }
+ if (!can_plt_call)
+ {
+ // This is not an error in one special case: A self
+ // call. It isn't possible to cheaply verify we have
+ // such a call so just check for a call to the same
+ // section.
+ bool ok = false;
+ if (gsym->source() == Symbol::FROM_OBJECT
+ && gsym->object() == object)
+ {
+ Address addend = rela.get_r_addend();
+ unsigned int dest_shndx;
+ value = psymval->value(object, addend);
+ value = target->symval_for_branch(value, gsym, object,
+ &dest_shndx);
+ bool is_ordinary;
+ if (dest_shndx == 0)
+ dest_shndx = gsym->shndx(&is_ordinary);
+ ok = dest_shndx == relinfo->data_shndx;
+ }
+ if (!ok)
+ gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
+ _("call lacks nop, can't restore toc; "
+ "recompile with -fPIC"));
+ }
}
}
else if (r_type == elfcpp::R_POWERPC_GOT_TLSGD16
@@ -3365,34 +3452,13 @@ Target_powerpc<size, big_endian>::Reloca
else
{
Address addend = 0;
+ unsigned int dest_shndx;
if (r_type != elfcpp::R_PPC_PLTREL24)
addend = rela.get_r_addend();
if (size == 64 || !has_plt_value)
value = psymval->value(object, addend);
if (size == 64 && is_branch_reloc(r_type))
- {
- // If the symbol is defined in an opd section, ie. is a function
- // descriptor, use the function descriptor code entry address
- Powerpc_relobj<size, big_endian>* symobj = const_cast
- <Powerpc_relobj<size, big_endian>*>(object);
- if (gsym != NULL)
- symobj = static_cast
- <Powerpc_relobj<size, big_endian>*>(gsym->object());
- unsigned int shndx = symobj->opd_shndx();
- Address opd_addr = symobj->get_output_section_offset(shndx);
- gold_assert(opd_addr != invalid_address);
- opd_addr += symobj->output_section(shndx)->address();
- if (value >= opd_addr
- && value < opd_addr + symobj->section_size(shndx))
- {
- Address sec_off;
- symobj->get_opd_ent(value - opd_addr, &shndx, &sec_off);
- Address sec_addr = symobj->get_output_section_offset(shndx);
- gold_assert(sec_addr != invalid_address);
- sec_addr += symobj->output_section(shndx)->address();
- value = sec_addr + sec_off;
- }
- }
+ value = target->symval_for_branch(value, gsym, object, &dest_shndx);
}
switch (r_type)
@@ -3562,6 +3628,8 @@ Target_powerpc<size, big_endian>::Reloca
break;
}
+ typename Powerpc_relocate_functions<size, big_endian>::Status status
+ = Powerpc_relocate_functions<size, big_endian>::status_ok;
switch (r_type)
{
case elfcpp::R_POWERPC_NONE:
@@ -3582,7 +3650,7 @@ Target_powerpc<size, big_endian>::Reloca
if (size == 64)
Reloc::addr64(view, value);
else
- Reloc::addr32(view, value, overflow);
+ status = Reloc::addr32(view, value, overflow);
break;
case elfcpp::R_PPC64_UADDR64:
@@ -3591,25 +3659,25 @@ Target_powerpc<size, big_endian>::Reloca
case elfcpp::R_POWERPC_ADDR32:
case elfcpp::R_POWERPC_REL32:
- Reloc::addr32(view, value, overflow);
+ status = Reloc::addr32(view, value, overflow);
break;
case elfcpp::R_POWERPC_UADDR32:
- Reloc::addr32_u(view, value, overflow);
+ status = Reloc::addr32_u(view, value, overflow);
break;
case elfcpp::R_POWERPC_ADDR24:
case elfcpp::R_POWERPC_REL24:
case elfcpp::R_PPC_PLTREL24:
case elfcpp::R_PPC_LOCAL24PC:
- Reloc::addr24(view, value, overflow);
+ status = Reloc::addr24(view, value, overflow);
break;
case elfcpp::R_POWERPC_GOT_DTPREL16:
case elfcpp::R_POWERPC_GOT_DTPREL16_LO:
if (size == 64)
{
- Reloc::addr16_ds(view, value, overflow);
+ status = Reloc::addr16_ds(view, value, overflow);
break;
}
case elfcpp::R_POWERPC_ADDR16:
@@ -3632,11 +3700,11 @@ Target_powerpc<size, big_endian>::Reloca
case elfcpp::R_POWERPC_GOT_TLSGD16_LO:
case elfcpp::R_POWERPC_GOT_TLSLD16_LO:
case elfcpp::R_POWERPC_GOT_TPREL16_LO:
- Reloc::addr16(view, value, overflow);
+ status = Reloc::addr16(view, value, overflow);
break;
case elfcpp::R_POWERPC_UADDR16:
- Reloc::addr16_u(view, value, overflow);
+ status = Reloc::addr16_u(view, value, overflow);
break;
case elfcpp::R_POWERPC_ADDR16_HI:
@@ -3721,7 +3789,7 @@ Target_powerpc<size, big_endian>::Reloca
case elfcpp::R_PPC64_GOT16_LO_DS:
case elfcpp::R_PPC64_SECTOFF_DS:
case elfcpp::R_PPC64_SECTOFF_LO_DS:
- Reloc::addr16_ds(view, value, overflow);
+ status = Reloc::addr16_ds(view, value, overflow);
break;
case elfcpp::R_POWERPC_ADDR14:
@@ -3730,7 +3798,7 @@ Target_powerpc<size, big_endian>::Reloca
case elfcpp::R_POWERPC_REL14:
case elfcpp::R_POWERPC_REL14_BRTAKEN:
case elfcpp::R_POWERPC_REL14_BRNTAKEN:
- Reloc::addr14(view, value, overflow);
+ status = Reloc::addr14(view, value, overflow);
break;
case elfcpp::R_POWERPC_COPY:
@@ -3791,6 +3859,9 @@ Target_powerpc<size, big_endian>::Reloca
r_type);
break;
}
+ if (status != Powerpc_relocate_functions<size, big_endian>::status_ok)
+ gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
+ _("relocation overflow"));
return true;
}
--
Alan Modra
Australia Development Lab, IBM
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