diff -rup binutils.orig/bfd/elfnn-aarch64.c binutils-2.30/bfd/elfnn-aarch64.c

--- binutils.orig/bfd/elfnn-aarch64.c	2020-11-04 14:53:52.144476367 +0000

+++ binutils-2.30/bfd/elfnn-aarch64.c	2020-11-04 14:56:42.275422499 +0000

@@ -2191,6 +2191,9 @@ struct elf_aarch64_obj_tdata

   /* Zero to warn when linking objects with incompatible wchar_t sizes.  */

   int no_wchar_size_warning;

+

+  /* All GNU_PROPERTY_AARCH64_FEATURE_1_AND properties.  */

+  uint32_t gnu_and_prop;

 };

 #define elf_aarch64_tdata(bfd)				\

@@ -9311,6 +9314,32 @@ elfNN_aarch64_backend_symbol_processing

     sym->flags |= BSF_KEEP;

 }

+/* Implement elf_backend_setup_gnu_properties for AArch64.  It serves as a

+   wrapper function for _bfd_aarch64_elf_link_setup_gnu_properties to account

+   for the effect of GNU properties of the output_bfd.  */

+static bfd *

+elfNN_aarch64_link_setup_gnu_properties (struct bfd_link_info *info)

+{

+  uint32_t prop = elf_aarch64_tdata (info->output_bfd)->gnu_and_prop;

+  bfd *pbfd = _bfd_aarch64_elf_link_setup_gnu_properties (info, &prop);

+  elf_aarch64_tdata (info->output_bfd)->gnu_and_prop = prop;

+  return pbfd;

+}

+

+/* Implement elf_backend_merge_gnu_properties for AArch64.  It serves as a

+   wrapper function for _bfd_aarch64_elf_merge_gnu_properties to account

+   for the effect of GNU properties of the output_bfd.  */

+static bfd_boolean

+elfNN_aarch64_merge_gnu_properties (struct bfd_link_info *info,

+				       bfd *abfd,

+				       elf_property *aprop,

+				       elf_property *bprop)

+{

+  uint32_t prop

+    = elf_aarch64_tdata (info->output_bfd)->gnu_and_prop;

+  return  _bfd_aarch64_elf_merge_gnu_properties (info, abfd, aprop,

+						 bprop, prop);

+}

 /* We use this so we can override certain functions

    (though currently we don't).  */

@@ -9453,6 +9482,12 @@ const struct elf_size_info elfNN_aarch64

 #define elf_backend_symbol_processing		\

   elfNN_aarch64_backend_symbol_processing

+#define elf_backend_setup_gnu_properties	\

+  elfNN_aarch64_link_setup_gnu_properties

+

+#define elf_backend_merge_gnu_properties	\

+  elfNN_aarch64_merge_gnu_properties

+

 #define elf_backend_can_refcount       1

 #define elf_backend_can_gc_sections    1

 #define elf_backend_plt_readonly       1

diff -rup binutils.orig/bfd/elfxx-aarch64.c binutils-2.30/bfd/elfxx-aarch64.c

--- binutils.orig/bfd/elfxx-aarch64.c	2020-11-04 14:53:52.138476401 +0000

+++ binutils-2.30/bfd/elfxx-aarch64.c	2020-11-04 14:56:42.276422492 +0000

@@ -660,3 +660,183 @@ _bfd_aarch64_elf_write_core_note (bfd *a

       }

     }

 }

+

+/* Find the first input bfd with GNU property and merge it with GPROP.  If no

+   such input is found, add it to a new section at the last input.  Update

+   GPROP accordingly.  */

+bfd *

+_bfd_aarch64_elf_link_setup_gnu_properties (struct bfd_link_info *info,

+					    uint32_t *gprop)

+{

+  asection *sec;

+  bfd *pbfd;

+  bfd *ebfd = NULL;

+  elf_property *prop;

+

+  uint32_t gnu_prop = *gprop;

+

+  /* Find a normal input file with GNU property note.  */

+  for (pbfd = info->input_bfds;

+       pbfd != NULL;

+       pbfd = pbfd->link.next)

+    if (bfd_get_flavour (pbfd) == bfd_target_elf_flavour

+	&& bfd_count_sections (pbfd) != 0)

+      {

+	ebfd = pbfd;

+

+	if (elf_properties (pbfd) != NULL)

+	  break;

+      }

+

+  /* If ebfd != NULL it is either an input with property note or the last

+     input.  Either way if we have gnu_prop, we should add it (by creating

+     a section if needed).  */

+  if (ebfd != NULL && gnu_prop)

+    {

+      prop = _bfd_elf_get_property (ebfd,

+				    GNU_PROPERTY_AARCH64_FEATURE_1_AND,

+				    4);

+      prop->u.number |= gnu_prop;

+      prop->pr_kind = property_number;

+

+      /* pbfd being NULL implies ebfd is the last input.  Create the GNU

+	 property note section.  */

+      if (pbfd == NULL)

+	{

+	  sec = bfd_make_section_with_flags (ebfd,

+					     NOTE_GNU_PROPERTY_SECTION_NAME,

+					     (SEC_ALLOC

+					      | SEC_LOAD

+					      | SEC_IN_MEMORY

+					      | SEC_READONLY

+					      | SEC_HAS_CONTENTS

+					      | SEC_DATA));

+	  if (sec == NULL)

+	    info->callbacks->einfo (

+	      _("%F%P: failed to create GNU property section\n"));

+

+	  elf_section_type (sec) = SHT_NOTE;

+	}

+    }

+

+  pbfd = _bfd_elf_link_setup_gnu_properties (info);

+

+  if (bfd_link_relocatable (info))

+    return pbfd;

+

+  /* If pbfd has any GNU_PROPERTY_AARCH64_FEATURE_1_AND properties, update

+     gnu_prop accordingly.  */

+  if (pbfd != NULL)

+    {

+      elf_property_list *p;

+

+      /* The property list is sorted in order of type.  */

+      for (p = elf_properties (pbfd); p; p = p->next)

+	{

+	  /* Check for all GNU_PROPERTY_AARCH64_FEATURE_1_AND.  */

+	  if (GNU_PROPERTY_AARCH64_FEATURE_1_AND == p->property.pr_type)

+	    {

+	      gnu_prop = (p->property.u.number

+			  & (GNU_PROPERTY_AARCH64_FEATURE_1_PAC

+			      | GNU_PROPERTY_AARCH64_FEATURE_1_BTI));

+	      break;

+	    }

+	  else if (GNU_PROPERTY_AARCH64_FEATURE_1_AND < p->property.pr_type)

+	    break;

+	}

+    }

+  *gprop = gnu_prop;

+  return pbfd;

+}

+

+/* Define elf_backend_parse_gnu_properties for AArch64.  */

+enum elf_property_kind

+_bfd_aarch64_elf_parse_gnu_properties (bfd *abfd, unsigned int type,

+				       bfd_byte *ptr, unsigned int datasz)

+{

+  elf_property *prop;

+

+  switch (type)

+    {

+    case GNU_PROPERTY_AARCH64_FEATURE_1_AND:

+      if (datasz != 4)

+	{

+	  _bfd_error_handler

+	    ( _("error: %pB: <corrupt AArch64 used size: 0x%x>"),

+	     abfd, datasz);

+	  return property_corrupt;

+	}

+      prop = _bfd_elf_get_property (abfd, type, datasz);

+      /* Combine properties of the same type.  */

+      prop->u.number |= bfd_h_get_32 (abfd, ptr);

+      prop->pr_kind = property_number;

+      break;

+

+    default:

+      return property_ignored;

+    }

+

+  return property_number;

+}

+

+/* Merge AArch64 GNU property BPROP with APROP also accounting for PROP.

+   If APROP isn't NULL, merge it with BPROP and/or PROP.  Vice-versa if BROP

+   isn't NULL.  Return TRUE if there is any update to APROP or if BPROP should

+   be merge with ABFD.  */

+bfd_boolean

+_bfd_aarch64_elf_merge_gnu_properties (struct bfd_link_info *info

+				       ATTRIBUTE_UNUSED,

+				       bfd *abfd ATTRIBUTE_UNUSED,

+				       elf_property *aprop,

+				       elf_property *bprop,

+				       uint32_t prop)

+{

+  unsigned int orig_number;

+  bfd_boolean updated = FALSE;

+  unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;

+

+  switch (pr_type)

+    {

+    case GNU_PROPERTY_AARCH64_FEATURE_1_AND:

+      {

+	if (aprop != NULL && bprop != NULL)

+	  {

+	    orig_number = aprop->u.number;

+	    aprop->u.number = (orig_number & bprop->u.number) | prop;

+	    updated = orig_number != aprop->u.number;

+	    /* Remove the property if all feature bits are cleared.  */

+	    if (aprop->u.number == 0)

+	      aprop->pr_kind = property_remove;

+	    break;

+	  }

+	/* If either is NULL, the AND would be 0 so, if there is

+	   any PROP, asign it to the input that is not NULL.  */

+	if (prop)

+	  {

+	    if (aprop != NULL)

+	      {

+		orig_number = aprop->u.number;

+		aprop->u.number = prop;

+		updated = orig_number != aprop->u.number;

+	      }

+	    else

+	      {

+		bprop->u.number = prop;

+		updated = TRUE;

+	      }

+	  }

+	/* No PROP and BPROP is NULL, so remove APROP.  */

+	else if (aprop != NULL)

+	  {

+	    aprop->pr_kind = property_remove;

+	    updated = TRUE;

+	  }

+      }

+      break;

+

+    default:

+      abort ();

+    }

+

+  return updated;

+}

diff -rup binutils.orig/bfd/elfxx-aarch64.h binutils-2.30/bfd/elfxx-aarch64.h

--- binutils.orig/bfd/elfxx-aarch64.h	2020-11-04 14:53:52.134476424 +0000

+++ binutils-2.30/bfd/elfxx-aarch64.h	2020-11-04 14:56:42.276422492 +0000

@@ -65,3 +65,19 @@ _bfd_aarch64_elf_write_core_note (bfd *,

 #define elf_backend_grok_prstatus	_bfd_aarch64_elf_grok_prstatus

 #define elf_backend_grok_psinfo		_bfd_aarch64_elf_grok_psinfo

 #define elf_backend_write_core_note	_bfd_aarch64_elf_write_core_note

+

+extern bfd *

+_bfd_aarch64_elf_link_setup_gnu_properties (struct bfd_link_info *,

+					    uint32_t *);

+

+extern enum elf_property_kind

+_bfd_aarch64_elf_parse_gnu_properties (bfd *, unsigned int,

+				       bfd_byte *, unsigned int);

+

+extern bfd_boolean

+_bfd_aarch64_elf_merge_gnu_properties (struct bfd_link_info *, bfd *,

+				       elf_property *, elf_property *,

+				       uint32_t);

+

+#define elf_backend_parse_gnu_properties	\

+  _bfd_aarch64_elf_parse_gnu_properties

diff -rup binutils.orig/binutils/readelf.c binutils-2.30/binutils/readelf.c

--- binutils.orig/binutils/readelf.c	2020-11-04 14:53:51.723478764 +0000

+++ binutils-2.30/binutils/readelf.c	2020-11-04 14:56:42.277422485 +0000

@@ -17103,6 +17103,33 @@ decode_x86_feature_2 (unsigned int bitma

 }

 static void

+decode_aarch64_feature_1_and (unsigned int bitmask)

+{

+  while (bitmask)

+    {

+      unsigned int bit = bitmask & (- bitmask);

+

+      bitmask &= ~ bit;

+      switch (bit)

+	{

+	case GNU_PROPERTY_AARCH64_FEATURE_1_BTI:

+	  printf ("BTI");

+	  break;

+

+	case GNU_PROPERTY_AARCH64_FEATURE_1_PAC:

+	  printf ("PAC");

+	  break;

+

+	default:

+	  printf (_("<unknown: %x>"), bit);

+	  break;

+	}

+      if (bitmask)

+	printf (", ");

+    }

+}

+

+static void

 print_gnu_property_note (Filedata * filedata, Elf_Internal_Note * pnote)

 {

   unsigned char * ptr = (unsigned char *) pnote->descdata;

@@ -17236,6 +17263,18 @@ print_gnu_property_note (Filedata * file

 		  break;

 		}

 	    }

+	  else if (filedata->file_header.e_machine == EM_AARCH64)

+	    {

+	      if (type == GNU_PROPERTY_AARCH64_FEATURE_1_AND)

+		{

+		  printf ("AArch64 feature: ");

+		  if (datasz != 4)

+		    printf (_("<corrupt length: %#x> "), datasz);

+		  else

+		    decode_aarch64_feature_1_and (byte_get (ptr, 4));

+		  goto next;

+		}

+	    }

 	}

       else

 	{

diff -rup binutils.orig/include/elf/common.h binutils-2.30/include/elf/common.h

--- binutils.orig/include/elf/common.h	2020-11-04 14:53:52.155476304 +0000

+++ binutils-2.30/include/elf/common.h	2020-11-04 14:56:42.277422485 +0000

@@ -832,6 +832,12 @@

 #define GNU_PROPERTY_X86_FEATURE_2_XSAVEOPT	(1U << 8)

 #define GNU_PROPERTY_X86_FEATURE_2_XSAVEC	(1U << 9)

+/* AArch64 specific GNU PROPERTY.  */

+#define GNU_PROPERTY_AARCH64_FEATURE_1_AND	0xc0000000

+

+#define GNU_PROPERTY_AARCH64_FEATURE_1_BTI	(1U << 0)

+#define GNU_PROPERTY_AARCH64_FEATURE_1_PAC	(1U << 1)

+

 /* Values used in GNU .note.ABI-tag notes (NT_GNU_ABI_TAG).  */

 #define GNU_ABI_TAG_LINUX	0

 #define GNU_ABI_TAG_HURD	1

diff -rup binutils.orig/ld/testsuite/ld-aarch64/aarch64-elf.exp binutils-2.30/ld/testsuite/ld-aarch64/aarch64-elf.exp

--- binutils.orig/ld/testsuite/ld-aarch64/aarch64-elf.exp	2020-11-04 14:53:51.843478081 +0000

+++ binutils-2.30/ld/testsuite/ld-aarch64/aarch64-elf.exp	2020-11-04 14:56:42.278422479 +0000

@@ -337,6 +337,10 @@ run_dump_test_lp64 "variant_pcs-r"

 run_dump_test_lp64 "variant_pcs-shared"

 run_dump_test_lp64 "variant_pcs-now"

+run_dump_test "property-bti-pac1"

+run_dump_test "property-bti-pac2"

+run_dump_test "property-bti-pac3"

+

 set aarch64elflinktests {

   {"ld-aarch64/so with global symbol" "-shared" "" "" {copy-reloc-so.s}

     {} "copy-reloc-so.so"}

--- /dev/null	2020-11-04 08:04:13.849482156 +0000

+++ binutils-2.30/ld/testsuite/ld-aarch64/property-bti-pac1.d	2020-11-04 14:56:42.278422479 +0000

@@ -0,0 +1,11 @@

+#name: GNU Property (single input, combine section)

+#source: property-bti-pac1.s

+#as: -march=armv8.5-a -defsym __mult__=0

+#ld: -shared

+#readelf: -n

+#target: *linux*

+

+Displaying notes found in: .note.gnu.property

+  Owner                 Data size	Description

+  GNU                  0x00000010	NT_GNU_PROPERTY_TYPE_0

+      Properties: AArch64 feature: BTI, PAC

--- /dev/null	2020-11-04 08:04:13.849482156 +0000

+++ binutils-2.30/ld/testsuite/ld-aarch64/property-bti-pac1.s	2020-11-04 14:56:42.278422479 +0000

@@ -0,0 +1,37 @@

+	.text

+	.globl _start

+	.type _start,@function

+_start:

+	mov x1, #2

+.ifndef __mult__

+	bl foo

+.endif

+	.section ".note.gnu.property", "a"

+	.p2align 3

+	.long 1f - 0f		/* name length */

+	.long 5f - 2f		/* data length */

+	.long 5			/* note type */

+0:	.asciz "GNU"		/* vendor name */

+1:

+	.p2align 3

+2:	.long 0xc0000000	/* pr_type.  */

+	.long 4f - 3f		/* pr_datasz.  */

+3:

+	.long 0x2		/* PAC.  */

+4:

+	.p2align 3

+5:

+	.p2align 3

+	.long 1f - 0f		/* name length */

+	.long 5f - 2f		/* data length */

+	.long 5			/* note type */

+0:	.asciz "GNU"		/* vendor name */

+1:

+	.p2align 3

+2:	.long 0xc0000000	/* pr_type.  */

+	.long 4f - 3f		/* pr_datasz.  */

+3:

+	.long 0x1		/* BTI.  */

+4:

+	.p2align 3

+5:

--- /dev/null	2020-11-04 08:04:13.849482156 +0000

+++ binutils-2.30/ld/testsuite/ld-aarch64/property-bti-pac2.s	2020-11-04 14:56:42.278422479 +0000

@@ -0,0 +1,50 @@

+	.text

+	.global	foo

+	.type	foo, %function

+foo:

+	sub	sp, sp, #16

+	mov	w0, 9

+	str	w0, [sp, 12]

+	ldr	w0, [sp, 12]

+	add	w0, w0, 4

+	str	w0, [sp, 12]

+	nop

+	add	sp, sp, 16

+	ret

+	.size	foo, .-foo

+	.global	bar

+	.type	bar, %function

+.ifdef __property_bti__

+	.section ".note.gnu.property", "a"

+	.p2align 3

+	.long 1f - 0f		/* name length */

+	.long 5f - 2f		/* data length */

+	.long 5			/* note type */

+0:	.asciz "GNU"		/* vendor name */

+1:

+	.p2align 3

+2:	.long 0xc0000000	/* pr_type.  */

+	.long 4f - 3f		/* pr_datasz.  */

+3:

+	.long 0x1		/* BTI.  */

+4:

+	.p2align 3

+5:

+.endif

+.ifdef __property_pac__

+	.section ".note.gnu.property", "a"

+	.p2align 3

+	.long 1f - 0f		/* name length */

+	.long 5f - 2f		/* data length */

+	.long 5			/* note type */

+0:	.asciz "GNU"		/* vendor name */

+1:

+	.p2align 3

+2:	.long 0xc0000000	/* pr_type.  */

+	.long 4f - 3f		/* pr_datasz.  */

+3:

+	.long 0x2		/* PAC.  */

+4:

+	.p2align 3

+5:

+.endif

--- /dev/null	2020-11-04 08:04:13.849482156 +0000

+++ binutils-2.30/ld/testsuite/ld-aarch64/property-bti-pac2.d	2020-11-04 14:56:42.278422479 +0000

@@ -0,0 +1,12 @@

+#name: GNU Property (combine multiple with BTI)

+#source: property-bti-pac1.s

+#source: property-bti-pac2.s

+#as: -mabi=lp64 -defsym __property_bti__=1

+#ld: -e _start

+#readelf: -n

+#target: *linux*

+

+Displaying notes found in: .note.gnu.property

+  Owner                 Data size	Description

+  GNU                  0x00000010	NT_GNU_PROPERTY_TYPE_0

+      Properties: AArch64 feature: BTI

--- /dev/null	2020-11-04 08:04:13.849482156 +0000

+++ binutils-2.30/ld/testsuite/ld-aarch64/property-bti-pac3.d	2020-11-04 14:56:42.278422479 +0000

@@ -0,0 +1,12 @@

+#name: GNU Property (combine multiple with PAC)

+#source: property-bti-pac1.s

+#source: property-bti-pac2.s

+#as: -mabi=lp64 -defsym __property_pac__=1

+#ld: -e _start

+#readelf: -n

+#target: *linux*

+

+Displaying notes found in: .note.gnu.property

+  Owner                 Data size	Description

+  GNU                  0x00000010	NT_GNU_PROPERTY_TYPE_0

+      Properties: AArch64 feature: PAC

diff -rup binutils.orig/bfd/elfnn-aarch64.c binutils-2.30/bfd/elfnn-aarch64.c

--- binutils.orig/bfd/elfnn-aarch64.c	2020-11-25 11:53:26.648275978 +0000

+++ binutils-2.30/bfd/elfnn-aarch64.c	2020-11-25 12:21:39.276864970 +0000

@@ -9331,12 +9331,14 @@ elfNN_aarch64_link_setup_gnu_properties

    for the effect of GNU properties of the output_bfd.  */

 static bfd_boolean

 elfNN_aarch64_merge_gnu_properties (struct bfd_link_info *info,

-				       bfd *abfd,

-				       elf_property *aprop,

-				       elf_property *bprop)

+				    bfd *abfd,

+				    bfd *bbfd ATTRIBUTE_UNUSED,

+				    elf_property *aprop,

+				    elf_property *bprop)

 {

   uint32_t prop

     = elf_aarch64_tdata (info->output_bfd)->gnu_and_prop;

+

   return  _bfd_aarch64_elf_merge_gnu_properties (info, abfd, aprop,

 						 bprop, prop);

 }

diff -rup binutils.orig/bfd/elfxx-aarch64.c binutils-2.30/bfd/elfxx-aarch64.c

--- binutils.orig/bfd/elfxx-aarch64.c	2020-11-25 11:53:26.655275930 +0000

+++ binutils-2.30/bfd/elfxx-aarch64.c	2020-11-25 12:21:34.689895875 +0000

@@ -22,6 +22,7 @@

 #include "elfxx-aarch64.h"

 #include <stdarg.h>

 #include <string.h>

+#include "libbfd.h"

 #define MASK(n) ((1u << (n)) - 1)

@@ -835,7 +836,10 @@ _bfd_aarch64_elf_merge_gnu_properties (s

       break;

     default:

-      abort ();

+      _bfd_error_handler

+	( _("error: %pB: <corrupt AArch64 property note: 0x%x>"),

+	  abfd, pr_type);

+      return FALSE;

     }

   return updated;

diff -rup binutils.orig/ld/testsuite/ld-aarch64/property-bti-pac1.d binutils-2.30/ld/testsuite/ld-aarch64/property-bti-pac1.d

--- binutils.orig/ld/testsuite/ld-aarch64/property-bti-pac1.d	2020-11-25 11:53:26.344278044 +0000

+++ binutils-2.30/ld/testsuite/ld-aarch64/property-bti-pac1.d	2020-11-25 11:57:53.179471900 +0000

@@ -1,6 +1,6 @@

 #name: GNU Property (single input, combine section)

 #source: property-bti-pac1.s

-#as: -march=armv8.5-a -defsym __mult__=0

+#as: -defsym __mult__=0

 #ld: -shared

 #readelf: -n

 #target: *linux*