x86: Propery check PC16 reloc overflow in 16-bit mode instructions

commit a7664973b24a242cd9ea17deb5eaf503065fc0bd
Author: Jan Beulich <jbeulich@suse.com>
Date:   Mon Apr 26 10:41:35 2021 +0200

    x86: correct overflow checking for 16-bit PC-relative relocs

caused linker failure when building 16-bit program in a 32-bit ELF
container.  Update GNU_PROPERTY_X86_FEATURE_2_USED with

 #define GNU_PROPERTY_X86_FEATURE_2_CODE16 (1U << 12)

to indicate that 16-bit mode instructions are used in the input object:

https://groups.google.com/g/x86-64-abi/c/UvvXWeHIGMA

to indicate that 16-bit mode instructions are used in the object to
allow linker to properly perform relocation overflow check for 16-bit
PC-relative relocations in 16-bit mode instructions.

1. Update x86 assembler to always generate the GNU property note with
GNU_PROPERTY_X86_FEATURE_2_CODE16 for .code16 in ELF object.
2. Update i386 and x86-64 linkers to use 16-bit PC16 relocations if
input object is marked with GNU_PROPERTY_X86_FEATURE_2_CODE16.

bfd/

	PR ld/27905
	* elf32-i386.c: Include "libiberty.h".
	(elf_howto_table): Add 16-bit R_386_PC16 entry.
	(elf_i386_rtype_to_howto): Add a BFD argument.  Use 16-bit
	R_386_PC16 if input has 16-bit mode instructions.
	(elf_i386_info_to_howto_rel): Update elf_i386_rtype_to_howto
	call.
	(elf_i386_tls_transition): Likewise.
	(elf_i386_relocate_section): Likewise.
	* elf64-x86-64.c (x86_64_elf_howto_table): Add 16-bit
	R_X86_64_PC16 entry.
	(elf_x86_64_rtype_to_howto): Use 16-bit R_X86_64_PC16 if input
	has 16-bit mode instructions.
	* elfxx-x86.c (_bfd_x86_elf_parse_gnu_properties): Set
	elf_x86_has_code16 if relocatable input is marked with
	GNU_PROPERTY_X86_FEATURE_2_CODE16.
	* elfxx-x86.h (elf_x86_obj_tdata): Add has_code16.
	(elf_x86_has_code16): New.

binutils/

	PR ld/27905
	* readelf.c (decode_x86_feature_2): Support
	GNU_PROPERTY_X86_FEATURE_2_CODE16.

gas/

	PR ld/27905
	* config/tc-i386.c (set_code_flag): Update x86_feature_2_used
	with GNU_PROPERTY_X86_FEATURE_2_CODE16 for .code16 in ELF
	object.
	(set_16bit_gcc_code_flag): Likewise.
	(x86_cleanup): Always generate the GNU property note if
	x86_feature_2_used isn't 0.
	* testsuite/gas/i386/code16-2.d: New file.
	* testsuite/gas/i386/code16-2.s: Likewise.
	* testsuite/gas/i386/x86-64-code16-2.d: Likewise.
	* testsuite/gas/i386/i386.exp: Run code16-2 and x86-64-code16-2.

include/

	PR ld/27905
	* elf/common.h (GNU_PROPERTY_X86_FEATURE_2_CODE16): New.

ld/

	PR ld/27905
	* testsuite/ld-i386/code16.d: New file.
	* testsuite/ld-i386/code16.t: Likewise.
	* testsuite/ld-x86-64/code16.d: Likewise.
	* testsuite/ld-x86-64/code16.t: Likewise.
	* testsuite/ld-i386/i386.exp: Run code16.
	* testsuite/ld-x86-64/x86-64.exp: Likewise.

bfd/ChangeLog

@@ -1,3 +1,24 @@
+2021-05-26  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/27905
+	* elf32-i386.c: Include "libiberty.h".
+	(elf_howto_table): Add 16-bit R_386_PC16 entry.
+	(elf_i386_rtype_to_howto): Add a BFD argument.  Use 16-bit
+	R_386_PC16 if input has 16-bit mode instructions.
+	(elf_i386_info_to_howto_rel): Update elf_i386_rtype_to_howto
+	call.
+	(elf_i386_tls_transition): Likewise.
+	(elf_i386_relocate_section): Likewise.
+	* elf64-x86-64.c (x86_64_elf_howto_table): Add 16-bit
+	R_X86_64_PC16 entry.
+	(elf_x86_64_rtype_to_howto): Use 16-bit R_X86_64_PC16 if input
+	has 16-bit mode instructions.
+	* elfxx-x86.c (_bfd_x86_elf_parse_gnu_properties): Set
+	elf_x86_has_code16 if relocatable input is marked with
+	GNU_PROPERTY_X86_FEATURE_2_CODE16.
+	* elfxx-x86.h (elf_x86_obj_tdata): Add has_code16.
+	(elf_x86_has_code16): New.
+
 2021-05-26  Nelson Chu  <nelson.chu@sifive.com>
 
 	* elfxx-riscv.h (check_unknown_prefixed_ext): New bool.

bfd/elf32-i386.c

@@ -22,6 +22,7 @@
 #include "elf-vxworks.h"
 #include "dwarf2.h"
 #include "opcode/i386.h"
+#include "libiberty.h"
 
 /* 386 uses REL relocations instead of RELA.  */
 #define USE_REL	1
@@ -175,10 +176,14 @@ static reloc_howto_type elf_howto_table[]=
 	 false,			/* partial_inplace */
 	 0,			/* src_mask */
 	 0,			/* dst_mask */
-	 false)			/* pcrel_offset */
+	 false),		/* pcrel_offset */
 
 #define R_386_vt (R_386_GNU_VTENTRY + 1 - R_386_vt_offset)
 
+/* Use complain_overflow_bitfield on R_386_PC16 for code16.  */
+  HOWTO(R_386_PC16, 0, 1, 16, true, 0, complain_overflow_bitfield,
+	bfd_elf_generic_reloc, "R_386_PC16",
+	true, 0xffff, 0xffff, true)
 };
 
 #define X86_PCREL_TYPE_P(TYPE) ((TYPE) == R_386_PC32)
@@ -369,7 +374,7 @@ elf_i386_reloc_name_lookup (bfd *abfd ATTRIBUTE_UNUSED,
 }
 
 static reloc_howto_type *
-elf_i386_rtype_to_howto (unsigned r_type)
+elf_i386_rtype_to_howto (bfd *abfd, unsigned r_type)
 {
   unsigned int indx;
 
@@ -384,6 +389,11 @@ elf_i386_rtype_to_howto (unsigned r_type)
   /* PR 17512: file: 0f67f69d.  */
   if (elf_howto_table [indx].type != r_type)
     return NULL;
+
+  /* Use complain_overflow_bitfield on R_386_PC16 for code16.  */
+  if (r_type == (unsigned int) R_386_PC16 && elf_x86_has_code16 (abfd))
+    indx = ARRAY_SIZE (elf_howto_table) - 1;
+
   return &elf_howto_table[indx];
 }
 
@@ -394,7 +404,8 @@ elf_i386_info_to_howto_rel (bfd *abfd,
 {
   unsigned int r_type = ELF32_R_TYPE (dst->r_info);
 
-  if ((cache_ptr->howto = elf_i386_rtype_to_howto (r_type)) == NULL)
+  if ((cache_ptr->howto = elf_i386_rtype_to_howto (abfd, r_type))
+      == NULL)
     {
       /* xgettext:c-format */
       _bfd_error_handler (_("%pB: unsupported relocation type %#x"),
@@ -1142,8 +1153,8 @@ elf_i386_tls_transition (struct bfd_link_info *info, bfd *abfd,
       reloc_howto_type *from, *to;
       const char *name;
 
-      from = elf_i386_rtype_to_howto (from_type);
+      from = elf_i386_rtype_to_howto (abfd, from_type);
-      to = elf_i386_rtype_to_howto (to_type);
+      to = elf_i386_rtype_to_howto (abfd, to_type);
 
       if (h)
 	name = h->root.root.string;
@@ -2074,7 +2085,7 @@ elf_i386_relocate_section (bfd *output_bfd,
 	  continue;
 	}
 
-      howto = elf_i386_rtype_to_howto (r_type);
+      howto = elf_i386_rtype_to_howto (input_bfd, r_type);
       if (howto == NULL)
 	return _bfd_unrecognized_reloc (input_bfd, input_section, r_type);
 

bfd/elf64-x86-64.c

@@ -187,6 +187,10 @@ static reloc_howto_type x86_64_elf_howto_table[] =
 	 _bfd_elf_rel_vtable_reloc_fn, "R_X86_64_GNU_VTENTRY", false, 0, 0,
 	 false),
 
+/* Use complain_overflow_bitfield on R_X86_64_PC16 for code16.  */
+  HOWTO(R_X86_64_PC16, 0, 1, 16, true, 0, complain_overflow_bitfield,
+	bfd_elf_generic_reloc, "R_X86_64_PC16", false, 0, 0xffff, true),
+
 /* Use complain_overflow_bitfield on R_X86_64_32 for x32.  */
   HOWTO(R_X86_64_32, 0, 2, 32, false, 0, complain_overflow_bitfield,
 	bfd_elf_generic_reloc, "R_X86_64_32", false, 0, 0xffffffff,
@@ -270,6 +274,14 @@ elf_x86_64_rtype_to_howto (bfd *abfd, unsigned r_type)
       else
 	i = ARRAY_SIZE (x86_64_elf_howto_table) - 1;
     }
+  else if (r_type == (unsigned int) R_X86_64_PC16)
+    {
+      /* Use complain_overflow_bitfield on R_X86_64_PC16 for code16.  */
+      if (elf_x86_has_code16 (abfd))
+	i = ARRAY_SIZE (x86_64_elf_howto_table) - 2;
+      else
+	i = r_type;
+    }
   else if (r_type < (unsigned int) R_X86_64_GNU_VTINHERIT
 	   || r_type >= (unsigned int) R_X86_64_max)
     {

bfd/elfxx-x86.c

@@ -2353,6 +2353,7 @@ _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
       || (type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
 	  && type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
     {
+      unsigned int number;
       if (datasz != 4)
 	{
 	  _bfd_error_handler
@@ -2361,7 +2362,13 @@ _bfd_x86_elf_parse_gnu_properties (bfd *abfd, unsigned int type,
 	  return property_corrupt;
 	}
       prop = _bfd_elf_get_property (abfd, type, datasz);
-      prop->u.number |= bfd_h_get_32 (abfd, ptr);
+      number = bfd_h_get_32 (abfd, ptr);
+      if ((abfd->flags
+	   & (DYNAMIC | BFD_LINKER_CREATED | BFD_PLUGIN)) == 0
+	  && type == GNU_PROPERTY_X86_FEATURE_2_USED
+	  && (number & GNU_PROPERTY_X86_FEATURE_2_CODE16) != 0)
+	elf_x86_has_code16 (abfd) = 1;
+      prop->u.number |= number;
       prop->pr_kind = property_number;
       return property_number;
     }

bfd/elfxx-x86.h

@@ -549,6 +549,9 @@ struct elf_x86_obj_tdata
 
   /* GOTPLT entries for TLS descriptors.  */
   bfd_vma *local_tlsdesc_gotent;
+
+  /* Set if the objec file has 16-bit code.  */
+  unsigned int has_code16 : 1;
 };
 
 enum elf_x86_plt_type
@@ -584,6 +587,9 @@ struct elf_x86_plt
 #define elf_x86_local_tlsdesc_gotent(abfd) \
   (elf_x86_tdata (abfd)->local_tlsdesc_gotent)
 
+#define elf_x86_has_code16(abfd) \
+  (elf_x86_tdata (abfd)->has_code16)
+
 #define elf_x86_compute_jump_table_size(htab) \
   ((htab)->elf.srelplt->reloc_count * (htab)->got_entry_size)
 

binutils/ChangeLog

@@ -1,3 +1,9 @@
+2021-05-26  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/27905
+	* readelf.c (decode_x86_feature_2): Support
+	GNU_PROPERTY_X86_FEATURE_2_CODE16.
+
 2021-05-23  Tiezhu Yang  <yangtiezhu@loongson.cn>
 
 	* readelf.c (get_machine_name): Change Loongson Loongarch to

binutils/readelf.c

@@ -19140,6 +19140,9 @@ decode_x86_feature_2 (unsigned int bitmask)
 	case GNU_PROPERTY_X86_FEATURE_2_XSAVEC:
 	  printf ("XSAVEC");
 	  break;
+	case GNU_PROPERTY_X86_FEATURE_2_CODE16:
+	  printf ("CODE16");
+	  break;
 	default:
 	  printf (_("<unknown: %x>"), bit);
 	  break;

gas/ChangeLog

@@ -1,3 +1,17 @@
+2021-05-26  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/27905
+	* config/tc-i386.c (set_code_flag): Update x86_feature_2_used
+	with GNU_PROPERTY_X86_FEATURE_2_CODE16 for .code16 in ELF
+	object.
+	(set_16bit_gcc_code_flag): Likewise.
+	(x86_cleanup): Always generate the GNU property note if
+	x86_feature_2_used isn't 0.
+	* testsuite/gas/i386/code16-2.d: New file.
+	* testsuite/gas/i386/code16-2.s: Likewise.
+	* testsuite/gas/i386/x86-64-code16-2.d: Likewise.
+	* testsuite/gas/i386/i386.exp: Run code16-2 and x86-64-code16-2.
+
 2021-05-26  Sebastien Villemot  <sebastien@debian.org>
 
 	PR gas/27906

gas/config/tc-i386.c

@@ -2695,6 +2695,10 @@ static void
 set_code_flag (int value)
 {
   update_code_flag (value, 0);
+#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
+  if (value == CODE_16BIT)
+    x86_feature_2_used |= GNU_PROPERTY_X86_FEATURE_2_CODE16;
+#endif
 }
 
 static void
@@ -2706,6 +2710,10 @@ set_16bit_gcc_code_flag (int new_code_flag)
   cpu_arch_flags.bitfield.cpu64 = 0;
   cpu_arch_flags.bitfield.cpuno64 = 1;
   stackop_size = LONG_MNEM_SUFFIX;
+#if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
+  if (new_code_flag == CODE_16BIT)
+    x86_feature_2_used |= GNU_PROPERTY_X86_FEATURE_2_CODE16;
+#endif
 }
 
 static void
@@ -9032,7 +9040,7 @@ x86_cleanup (void)
   unsigned int isa_1_descsz_raw, feature_2_descsz_raw;
   unsigned int padding;
 
-  if (!IS_ELF || !x86_used_note)
+  if (!IS_ELF || (!x86_used_note && !x86_feature_2_used))
     return;
 
   x86_feature_2_used |= GNU_PROPERTY_X86_FEATURE_2_X86;
@@ -9072,15 +9080,23 @@ x86_cleanup (void)
   bfd_set_section_alignment (sec, alignment);
   elf_section_type (sec) = SHT_NOTE;
 
-  /* GNU_PROPERTY_X86_ISA_1_USED: 4-byte type + 4-byte data size
+  if (x86_used_note)
-				  + 4-byte data  */
+    {
-  isa_1_descsz_raw = 4 + 4 + 4;
+      /* GNU_PROPERTY_X86_ISA_1_USED: 4-byte type + 4-byte data size
-  /* Align GNU_PROPERTY_X86_ISA_1_USED.  */
+	 + 4-byte data  */
-  isa_1_descsz = (isa_1_descsz_raw + align_size_1) & ~align_size_1;
+      isa_1_descsz_raw = 4 + 4 + 4;
+      /* Align GNU_PROPERTY_X86_ISA_1_USED.  */
+      isa_1_descsz = (isa_1_descsz_raw + align_size_1) & ~align_size_1;
+    }
+  else
+    {
+      isa_1_descsz_raw = 0;
+      isa_1_descsz = 0;
+    }
 
   feature_2_descsz_raw = isa_1_descsz;
   /* GNU_PROPERTY_X86_FEATURE_2_USED: 4-byte type + 4-byte data size
-				      + 4-byte data  */
+     + 4-byte data  */
   feature_2_descsz_raw += 4 + 4 + 4;
   /* Align GNU_PROPERTY_X86_FEATURE_2_USED.  */
   feature_2_descsz = ((feature_2_descsz_raw + align_size_1)
@@ -9102,20 +9118,23 @@ x86_cleanup (void)
   /* Write n_name.  */
   memcpy (p + 4 * 3, "GNU", 4);
 
-  /* Write 4-byte type.  */
+  if (isa_1_descsz != 0)
-  md_number_to_chars (p + 4 * 4,
+    {
-		      (valueT) GNU_PROPERTY_X86_ISA_1_USED, 4);
+      /* Write 4-byte type.  */
+      md_number_to_chars (p + 4 * 4,
+			  (valueT) GNU_PROPERTY_X86_ISA_1_USED, 4);
 
-  /* Write 4-byte data size.  */
+      /* Write 4-byte data size.  */
-  md_number_to_chars (p + 4 * 5, (valueT) 4, 4);
+      md_number_to_chars (p + 4 * 5, (valueT) 4, 4);
 
-  /* Write 4-byte data.  */
+      /* Write 4-byte data.  */
-  md_number_to_chars (p + 4 * 6, (valueT) x86_isa_1_used, 4);
+      md_number_to_chars (p + 4 * 6, (valueT) x86_isa_1_used, 4);
 
-  /* Zero out paddings.  */
+      /* Zero out paddings.  */
-  padding = isa_1_descsz - isa_1_descsz_raw;
+      padding = isa_1_descsz - isa_1_descsz_raw;
-  if (padding)
+      if (padding)
-    memset (p + 4 * 7, 0, padding);
+	memset (p + 4 * 7, 0, padding);
+    }
 
   /* Write 4-byte type.  */
   md_number_to_chars (p + isa_1_descsz + 4 * 4,

gas/testsuite/gas/i386/code16-2.d

@@ -0,0 +1,8 @@
+#name: i386 code16 2
+#as: -mx86-used-note=no --generate-missing-build-notes=no
+#readelf: -n
+
+Displaying notes found in: .note.gnu.property
+[ 	]+Owner[ 	]+Data size[ 	]+Description
+  GNU                  0x[0-9a-f]+	NT_GNU_PROPERTY_TYPE_0
+      Properties: x86 feature used: x86, CODE16

gas/testsuite/gas/i386/code16-2.s

@@ -0,0 +1,10 @@
+	.code16gcc
+	.text
+	.section	.text.default_process_op.isra.0,"ax",@progbits
+	.type	default_process_op.isra.0, @function
+default_process_op.isra.0:
+	ret
+	.section	.text.mpt_scsi_process_op,"ax",@progbits
+	.type	mpt_scsi_process_op, @function
+mpt_scsi_process_op:
+	jmp	default_process_op.isra.0

gas/testsuite/gas/i386/i386.exp

@@ -734,6 +734,7 @@ if {[is_elf_format] || [istarget "*-*-vxworks*"]} then {
     run_dump_test "property-ldmxcsr"
     run_dump_test "property-vldmxcsr"
     run_dump_test "property-vzeroall"
+    run_dump_test "code16-2"
 
     if {![istarget "*-*-dragonfly*"]
 	&& ![istarget "*-*-gnu*"]
@@ -1298,6 +1299,7 @@ if [gas_64_check] then {
 	run_dump_test "x86-64-property-8"
 	run_dump_test "x86-64-property-9"
 	run_dump_test "x86-64-property-14"
+	run_dump_test "x86-64-code16-2"
 
 	if {[istarget "*-*-linux*"]} then {
 	    run_dump_test "x86-64-align-branch-3"

gas/testsuite/gas/i386/x86-64-code16-2.d

@@ -0,0 +1,9 @@
+#source: code16-2.s
+#name: x86-64 code16 2
+#as: -mx86-used-note=no --generate-missing-build-notes=no
+#readelf: -n
+
+Displaying notes found in: .note.gnu.property
+[ 	]+Owner[ 	]+Data size[ 	]+Description
+  GNU                  0x[0-9a-f]+	NT_GNU_PROPERTY_TYPE_0
+      Properties: x86 feature used: x86, CODE16

include/ChangeLog

@@ -1,3 +1,8 @@
+2021-05-26  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/27905
+	* elf/common.h (GNU_PROPERTY_X86_FEATURE_2_CODE16): New.
+
 2021-05-23  Tiezhu Yang  <yangtiezhu@loongson.cn>
 
 	* elf/common.h (EM_LOONGARCH): Change Loongson Loongarch to

include/elf/common.h

@@ -872,6 +872,7 @@
 #define GNU_PROPERTY_X86_FEATURE_2_XSAVEC	(1U << 9)
 #define GNU_PROPERTY_X86_FEATURE_2_TMM		(1U << 10)
 #define GNU_PROPERTY_X86_FEATURE_2_MASK		(1U << 11)
+#define GNU_PROPERTY_X86_FEATURE_2_CODE16	(1U << 12)
 
 #define GNU_PROPERTY_X86_COMPAT_2_ISA_1_NEEDED \
   (GNU_PROPERTY_X86_UINT32_OR_LO + 0)

ld/ChangeLog

@@ -1,3 +1,13 @@
+2021-05-26  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/27905
+	* testsuite/ld-i386/code16.d: New file.
+	* testsuite/ld-i386/code16.t: Likewise.
+	* testsuite/ld-x86-64/code16.d: Likewise.
+	* testsuite/ld-x86-64/code16.t: Likewise.
+	* testsuite/ld-i386/i386.exp: Run code16.
+	* testsuite/ld-x86-64/x86-64.exp: Likewise.
+
 2021-05-26  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* testsuite/ld-x86-64/ilp32-12.d: New file.

ld/testsuite/ld-i386/code16.d

@@ -0,0 +1,19 @@
+#name: i386 R_386_PC16 reloc in 16-bit mode
+#as: --32 -mx86-used-note=no --generate-missing-build-notes=no
+#source: ${srcdir}/../../../gas/testsuite/gas/i386/code16-2.s
+#ld: -T code16.t
+#objdump: -dw -Mi8086
+
+.*: +file format .*
+
+
+Disassembly of section .text.default_process_op.isra.0:
+
+0+737c <default_process_op.isra.0>:
+ +[a-f0-9]+:	66 c3                	retl   
+
+Disassembly of section .text.mpt_scsi_process_op:
+
+0+f869 <mpt_scsi_process_op>:
+ +[a-f0-9]+:	e9 10 7b             	jmp    737c <default_process_op.isra.0>
+#pass

ld/testsuite/ld-i386/code16.t

@@ -0,0 +1,7 @@
+OUTPUT_FORMAT("elf32-i386")
+OUTPUT_ARCH("i386")
+SECTIONS
+{
+.text.default_process_op.isra.0 0x737c : { *(.text.default_process_op.isra.0) }
+.text.mpt_scsi_process_op 0xf869 : { *(.text.mpt_scsi_process_op) }
+}

ld/testsuite/ld-i386/i386.exp

@@ -492,6 +492,7 @@ run_dump_test "property-x86-isa2"
 run_dump_test "property-x86-isa3"
 run_dump_test "property-x86-isa4"
 run_dump_test "pr26869"
+run_dump_test "code16"
 
 if { !([istarget "i?86-*-linux*"]
        || [istarget "i?86-*-gnu*"]

ld/testsuite/ld-x86-64/code16.d

@@ -0,0 +1,19 @@
+#name: x86-64 R_X86_64_PC16 reloc in 16-bit mode
+#as: --64 -mx86-used-note=no --generate-missing-build-notes=no
+#source: ${srcdir}/../../../gas/testsuite/gas/i386/code16-2.s
+#ld: -T code16.t
+#objdump: -dw -Mi8086
+
+.*: +file format .*
+
+
+Disassembly of section .text.default_process_op.isra.0:
+
+0+737c <default_process_op.isra.0>:
+ +[a-f0-9]+:	66 c3                	retl   
+
+Disassembly of section .text.mpt_scsi_process_op:
+
+0+f869 <mpt_scsi_process_op>:
+ +[a-f0-9]+:	e9 10 7b             	jmp    737c <default_process_op.isra.0>
+#pass

ld/testsuite/ld-x86-64/code16.t

@@ -0,0 +1,7 @@
+OUTPUT_FORMAT("elf64-x86-64")
+OUTPUT_ARCH("i386:x86-64")
+SECTIONS
+{
+.text.default_process_op.isra.0 0x737c : { *(.text.default_process_op.isra.0) }
+.text.mpt_scsi_process_op 0xf869 : { *(.text.mpt_scsi_process_op) }
+}

ld/testsuite/ld-x86-64/x86-64.exp

@@ -474,6 +474,7 @@ run_dump_test "property-x86-isa3"
 run_dump_test "property-x86-isa3-x32"
 run_dump_test "property-x86-isa4"
 run_dump_test "property-x86-isa4-x32"
+run_dump_test "code16"
 
 if ![istarget "x86_64-*-linux*"] {
     return