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gold: Handle R_X86_64_CODE_4_GOTPCRELX

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Handle R_X86_64_CODE_4_GOTPCRELX and convert

	mov	name@GOTPCREL(%rip), %r31

to

	lea	name@GOTPCREL(%rip), %r31

if the instruction is encoded with the REX2 prefix when possible.

elfcpp/

	* x86_64.h (R_X86_64_CODE_4_GOTPCRELX): New.

gold/

	* x86_64.cc (Target_x86_64::can_convert_mov_to_lea): Handle
	R_X86_64_CODE_4_GOTPCRELX.
	(Target_x86_64::Scan::get_reference_flags): Likewise.
	(Target_x86_64::Scan::local): Likewise.
	(Target_x86_64::Scan::possible_function_pointer_reloc): Likewise.
	(Target_x86_64::Scan::global): Likewise.
	(Target_x86_64::Relocate::relocate): Likewise.
	* testsuite/x86_64_mov_to_lea1.s: Add a test for
	R_X86_64_CODE_4_GOTPCRELX.
	* testsuite/x86_64_mov_to_lea2.s: Likewise.
	* testsuite/x86_64_mov_to_lea3.s: Likewise.
	* testsuite/x86_64_mov_to_lea4.s: Likewise.
	* testsuite/x86_64_mov_to_lea5.s: Likewise.
	* testsuite/x86_64_mov_to_lea.sh: Updated.
This commit is contained in:
H.J. Lu 2023-06-08 12:12:48 -07:00
parent 3d5a60de52
commit 4a54cb0658
8 changed files with 54 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
elfcpp/x86_64.h
View file

@ -95,9 +95,13 @@ enum
R_X86_64_PC32_BND = 39, // PC relative 32 bit signed with BND prefix
R_X86_64_PLT32_BND = 40, // 32 bit PLT address with BND prefix
R_X86_64_GOTPCRELX = 41, // 32 bit signed PC relative offset to GOT
// without REX prefix, relaxable.
// without REX nor REX2 prefixes, relaxable.
R_X86_64_REX_GOTPCRELX = 42, // 32 bit signed PC relative offset to GOT
// with REX prefix, relaxable.
R_X86_64_CODE_4_GOTPCRELX = 43, // 32 bit signed PC relative offset to
// GOT if the instruction starts at 4
// bytes before the relocation offset,
// relaxable.
// GNU vtable garbage collection extensions.
R_X86_64_GNU_VTINHERIT = 250,
R_X86_64_GNU_VTENTRY = 251

16
gold/testsuite/x86_64_mov_to_lea.sh
View file

@ -25,20 +25,36 @@
set -e
grep -q "lea -0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea1.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea1.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea2.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea2.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea3.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea3.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea4.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea4.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea5.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea5.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea6.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea6.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea7.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea7.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea8.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea8.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea9.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea9.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea10.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea10.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea11.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea11.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea12.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea12.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea13.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea13.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%rax" x86_64_mov_to_lea14.stdout
grep -q "lea -0x[a-f0-9]\+(%rip),%r26" x86_64_mov_to_lea14.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%eax" x86_64_mov_to_lea15.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%r26d" x86_64_mov_to_lea15.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%eax" x86_64_mov_to_lea16.stdout
grep -q "mov 0x[a-f0-9]\+(%rip),%r26d" x86_64_mov_to_lea16.stdout
exit 0

1
gold/testsuite/x86_64_mov_to_lea1.s
View file

@ -8,4 +8,5 @@ foo:
.type _start, @function
_start:
movq foo@GOTPCREL(%rip), %rax
movq foo@GOTPCREL(%rip), %r26
.size _start, .-_start

1
gold/testsuite/x86_64_mov_to_lea2.s
View file

@ -3,4 +3,5 @@
.type _start, @function
_start:
movq _DYNAMIC@GOTPCREL(%rip), %rax
movq _DYNAMIC@GOTPCREL(%rip), %r26
.size _start, .-_start

1
gold/testsuite/x86_64_mov_to_lea3.s
View file

@ -7,4 +7,5 @@ foo:
.type _start, @function
_start:
movq foo@GOTPCREL(%rip), %rax
movq foo@GOTPCREL(%rip), %r26
.size _start, .-_start

1
gold/testsuite/x86_64_mov_to_lea4.s
View file

@ -9,4 +9,5 @@ foo:
.type _start, @function
_start:
movq foo@GOTPCREL(%rip), %rax
movq foo@GOTPCREL(%rip), %r26
.size _start, .-_start

1
gold/testsuite/x86_64_mov_to_lea5.s
View file

@ -9,4 +9,5 @@ foo:
.type _start, @function
_start:
movl foo@GOTPCREL+4(%rip), %eax
movl foo@GOTPCREL+4(%rip), %r26d
.size _start, .-_start

37
gold/x86_64.cc
View file

@ -1053,8 +1053,9 @@ class Target_x86_64 : public Sized_target<size, false>
gold_assert(gsym != NULL);
// We cannot do the conversion unless it's one of these relocations.
if (r_type != elfcpp::R_X86_64_GOTPCREL
&& r_type != elfcpp::R_X86_64_GOTPCRELX
&& r_type != elfcpp::R_X86_64_REX_GOTPCRELX)
&& r_type != elfcpp::R_X86_64_GOTPCRELX
&& r_type != elfcpp::R_X86_64_REX_GOTPCRELX
&& r_type != elfcpp::R_X86_64_CODE_4_GOTPCRELX)
return false;
// We cannot convert references to IFUNC symbols, or to symbols that
// are not local to the current module.
@ -2971,6 +2972,7 @@ Target_x86_64<size>::Scan::get_reference_flags(unsigned int r_type)
case elfcpp::R_X86_64_GOTPCREL:
case elfcpp::R_X86_64_GOTPCRELX:
case elfcpp::R_X86_64_REX_GOTPCRELX:
case elfcpp::R_X86_64_CODE_4_GOTPCRELX:
case elfcpp::R_X86_64_GOTPLT64:
// Absolute in GOT.
return Symbol::ABSOLUTE_REF;
@ -3251,6 +3253,7 @@ Target_x86_64<size>::Scan::local(Symbol_table* symtab,
case elfcpp::R_X86_64_GOTPCREL:
case elfcpp::R_X86_64_GOTPCRELX:
case elfcpp::R_X86_64_REX_GOTPCRELX:
case elfcpp::R_X86_64_CODE_4_GOTPCRELX:
case elfcpp::R_X86_64_GOTPLT64:
{
// The symbol requires a GOT section.
@ -3261,21 +3264,30 @@ Target_x86_64<size>::Scan::local(Symbol_table* symtab,
// mov foo@GOTPCREL(%rip), %reg
// to lea foo(%rip), %reg.
// in Relocate::relocate.
size_t r_offset = reloc.get_r_offset();
if (!parameters->incremental()
&& (r_type == elfcpp::R_X86_64_GOTPCREL
|| r_type == elfcpp::R_X86_64_GOTPCRELX
|| r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
&& (((r_type == elfcpp::R_X86_64_GOTPCREL
|| r_type == elfcpp::R_X86_64_GOTPCRELX
|| r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
&& r_offset >= 2)
|| (r_type == elfcpp::R_X86_64_CODE_4_GOTPCRELX
&& r_offset >= 4))
&& reloc.get_r_addend() == -4
&& reloc.get_r_offset() >= 2
&& !is_ifunc)
{
section_size_type stype;
const unsigned char* view = object->section_contents(data_shndx,
&stype, true);
if (view[reloc.get_r_offset() - 2] == 0x8b)
if (r_type == elfcpp::R_X86_64_CODE_4_GOTPCRELX
&& view[r_offset - 4] != 0xd5)
goto need_got;
if (view[r_offset - 2] == 0x8b)
break;
}
need_got:
// The symbol requires a GOT entry.
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
@ -3498,6 +3510,7 @@ Target_x86_64<size>::Scan::possible_function_pointer_reloc(
case elfcpp::R_X86_64_GOTPCREL:
case elfcpp::R_X86_64_GOTPCRELX:
case elfcpp::R_X86_64_REX_GOTPCRELX:
case elfcpp::R_X86_64_CODE_4_GOTPCRELX:
case elfcpp::R_X86_64_GOTPLT64:
{
return true;
@ -3714,6 +3727,7 @@ Target_x86_64<size>::Scan::global(Symbol_table* symtab,
case elfcpp::R_X86_64_GOTPCREL:
case elfcpp::R_X86_64_GOTPCRELX:
case elfcpp::R_X86_64_REX_GOTPCRELX:
case elfcpp::R_X86_64_CODE_4_GOTPCRELX:
case elfcpp::R_X86_64_GOTPLT64:
{
// The symbol requires a GOT entry.
@ -3736,8 +3750,12 @@ Target_x86_64<size>::Scan::global(Symbol_table* symtab,
size_t r_offset = reloc.get_r_offset();
if (!parameters->incremental()
&& reloc.get_r_addend() == -4
&& r_offset >= 2
&& Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
&& ((r_type != elfcpp::R_X86_64_CODE_4_GOTPCRELX
&& r_offset >= 2)
|| (r_type == elfcpp::R_X86_64_CODE_4_GOTPCRELX
&& r_offset >= 4
&& view[r_offset - 4] == 0xd5))
&& Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
r_offset, &view))
break;
@ -4420,6 +4438,7 @@ Target_x86_64<size>::Relocate::relocate(
case elfcpp::R_X86_64_GOTPCREL:
case elfcpp::R_X86_64_GOTPCRELX:
case elfcpp::R_X86_64_REX_GOTPCRELX:
case elfcpp::R_X86_64_CODE_4_GOTPCRELX:
{
bool converted_p = false;