+2010-06-25 Doug Kwan <dougkwan@google.com>
+
+ * arm.cc (Target_arm::can_check_for_functions_pointers): Return true.
+ (Target_arm::section_may_have_icf_unsafe_pointers): New method
+ definition.
+ (Target_arm::Scan::local_reloc_may_be_function_pointer,
+ Target_arm::Scan::global_reloc_may_be_function_pointer): Implement
+ target hook to detect function points.
+ (Target_arm::Scan::possible_function_pointer_reloc): New method.
+ * icf.h (Icf::check_section_for_function_pointers): Change type of
+ parameter SECTION_NAME to const reference to std::string. Use
+ target hook to determine if section may have unsafe pointers.
+ * target.h (Target::section_may_have_icf_unsafe_pointers): New
+ method definition.
+
2010-06-21 Rafael Espindola <espindola@google.com>
* fileread.cc (Input_file::find_fie): New
fix_cortex_a8_(false), cortex_a8_relocs_info_()
{ }
+ // Virtual function which is set to return true by a target if
+ // it can use relocation types to determine if a function's
+ // pointer is taken.
+ virtual bool
+ can_check_for_function_pointers() const
+ { return true; }
+
+ // Whether a section called SECTION_NAME may have function pointers to
+ // sections not eligible for safe ICF folding.
+ virtual bool
+ section_may_have_icf_unsafe_pointers(const char* section_name) const
+ {
+ return (!is_prefix_of(".ARM.exidx", section_name)
+ && !is_prefix_of(".ARM.extab", section_name)
+ && Target::section_may_have_icf_unsafe_pointers(section_name));
+ }
+
// Whether we can use BLX.
bool
may_use_blx() const
Output_section* ,
const elfcpp::Rel<32, big_endian>& ,
unsigned int ,
- const elfcpp::Sym<32, big_endian>&)
- { return false; }
+ const elfcpp::Sym<32, big_endian>&);
inline bool
global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
unsigned int ,
Output_section* ,
const elfcpp::Rel<32, big_endian>& ,
- unsigned int , Symbol*)
- { return false; }
+ unsigned int , Symbol*);
private:
static void
|| sym->is_preemptible()));
}
+ inline bool
+ possible_function_pointer_reloc(unsigned int r_type);
+
// Whether we have issued an error about a non-PIC compilation.
bool issued_non_pic_error_;
};
object->name().c_str(), r_type, gsym->demangled_name().c_str());
}
+template<bool big_endian>
+inline bool
+Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
+ unsigned int r_type)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_ARM_PC24:
+ case elfcpp::R_ARM_THM_CALL:
+ case elfcpp::R_ARM_PLT32:
+ case elfcpp::R_ARM_CALL:
+ case elfcpp::R_ARM_JUMP24:
+ case elfcpp::R_ARM_THM_JUMP24:
+ case elfcpp::R_ARM_SBREL31:
+ case elfcpp::R_ARM_PREL31:
+ case elfcpp::R_ARM_THM_JUMP19:
+ case elfcpp::R_ARM_THM_JUMP6:
+ case elfcpp::R_ARM_THM_JUMP11:
+ case elfcpp::R_ARM_THM_JUMP8:
+ // All the relocations above are branches except SBREL31 and PREL31.
+ return false;
+
+ default:
+ // Be conservative and assume this is a function pointer.
+ return true;
+ }
+}
+
+template<bool big_endian>
+inline bool
+Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
+ Symbol_table*,
+ Layout*,
+ Target_arm<big_endian>* target,
+ Sized_relobj<32, big_endian>*,
+ unsigned int,
+ Output_section*,
+ const elfcpp::Rel<32, big_endian>&,
+ unsigned int r_type,
+ const elfcpp::Sym<32, big_endian>&)
+{
+ r_type = target->get_real_reloc_type(r_type);
+ return possible_function_pointer_reloc(r_type);
+}
+
+template<bool big_endian>
+inline bool
+Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
+ Symbol_table*,
+ Layout*,
+ Target_arm<big_endian>* target,
+ Sized_relobj<32, big_endian>*,
+ unsigned int,
+ Output_section*,
+ const elfcpp::Rel<32, big_endian>&,
+ unsigned int r_type,
+ Symbol* gsym)
+{
+ // GOT is not a function.
+ if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
+ return false;
+
+ r_type = target->get_real_reloc_type(r_type);
+ return possible_function_pointer_reloc(r_type);
+}
+
// Scan a relocation for a global symbol.
template<bool big_endian>
// corresponding to taken function pointers. Ignores eh_frame
// and vtable sections.
inline bool
- check_section_for_function_pointers(std::string section_name,
+ check_section_for_function_pointers(const std::string& section_name,
Target* target)
{
return (parameters->options().icf_safe_folding()
&& target->can_check_for_function_pointers()
- && !is_prefix_of(".rodata._ZTV", section_name.c_str())
- && !is_prefix_of(".data.rel.ro._ZTV", section_name.c_str())
- && !is_prefix_of(".eh_frame", section_name.c_str()));
+ && target->section_may_have_icf_unsafe_pointers(
+ section_name.c_str()));
}
// Returns a map of a section to info (Reloc_info) about its relocations.
can_check_for_function_pointers() const
{ return false; }
+ // Whether a section called SECTION_NAME may have function pointers to
+ // sections not eligible for safe ICF folding.
+ virtual bool
+ section_may_have_icf_unsafe_pointers(const char* section_name) const
+ {
+ // We recognize sections for normal vtables, construction vtables and
+ // EH frames.
+ return (!is_prefix_of(".rodata._ZTV", section_name)
+ && !is_prefix_of(".data.rel.ro._ZTV", section_name)
+ && !is_prefix_of(".rodata._ZTC", section_name)
+ && !is_prefix_of(".data.rel.ro._ZTC", section_name)
+ && !is_prefix_of(".eh_frame", section_name));
+ }
+
// Return the bit size that this target implements. This should
// return 32 or 64.
int
projects / binutils-gdb.git / commitdiff