diff --git a/libgcc/unwind-dw2.c b/libgcc/unwind-dw2.c
index 8085a42ace15d53f4cb0c6681717012d906a6d47..35010a4065bb83f706701cb05392193f0ffa1f11 100644
--- a/libgcc/unwind-dw2.c
+++ b/libgcc/unwind-dw2.c
@@ -136,6 +136,8 @@ struct _Unwind_Context
 #define SIGNAL_FRAME_BIT ((~(_Unwind_Word) 0 >> 1) + 1)
   /* Context which has version/args_size/by_value fields.  */
 #define EXTENDED_CONTEXT_BIT ((~(_Unwind_Word) 0 >> 2) + 1)
+  /* Bit reserved on AArch64, return address has been signed with A key.  */
+#define RA_A_SIGNED_BIT ((~(_Unwind_Word) 0 >> 3) + 1)
   _Unwind_Word flags;
   /* 0 for now, can be increased when further fields are added to
      struct _Unwind_Context.  */
@@ -1185,6 +1187,11 @@ execute_cfa_program (const unsigned char *insn_ptr,
 	  break;
 
 	case DW_CFA_GNU_window_save:
+#ifdef __aarch64__
+	  /* This CFA is multiplexed with Sparc.  On AArch64 it's used to toggle
+	     return address signing status.  */
+	  fs->regs.reg[DWARF_REGNUM_AARCH64_RA_STATE].loc.offset ^= 1;
+#else
 	  /* ??? Hardcoded for SPARC register window configuration.  */
 	  if (__LIBGCC_DWARF_FRAME_REGISTERS__ >= 32)
 	    for (reg = 16; reg < 32; ++reg)
@@ -1192,6 +1199,7 @@ execute_cfa_program (const unsigned char *insn_ptr,
 		fs->regs.reg[reg].how = REG_SAVED_OFFSET;
 		fs->regs.reg[reg].loc.offset = (reg - 16) * sizeof (void *);
 	      }
+#endif
 	  break;
 
 	case DW_CFA_GNU_args_size:
@@ -1513,10 +1521,15 @@ uw_update_context (struct _Unwind_Context *context, _Unwind_FrameState *fs)
        stack frame.  */
     context->ra = 0;
   else
-    /* Compute the return address now, since the return address column
-       can change from frame to frame.  */
-    context->ra = __builtin_extract_return_addr
-      (_Unwind_GetPtr (context, fs->retaddr_column));
+    {
+      /* Compute the return address now, since the return address column
+	 can change from frame to frame.  */
+      context->ra = __builtin_extract_return_addr
+	(_Unwind_GetPtr (context, fs->retaddr_column));
+#ifdef MD_POST_EXTRACT_FRAME_ADDR
+      context->ra = MD_POST_EXTRACT_FRAME_ADDR (context, fs, context->ra);
+#endif
+    }
 }
 
 static void
@@ -1550,6 +1563,9 @@ uw_init_context_1 (struct _Unwind_Context *context,
 		   void *outer_cfa, void *outer_ra)
 {
   void *ra = __builtin_extract_return_addr (__builtin_return_address (0));
+#ifdef MD_POST_EXTRACT_ROOT_ADDR
+  ra = MD_POST_EXTRACT_ROOT_ADDR (ra);
+#endif
   _Unwind_FrameState fs;
   _Unwind_SpTmp sp_slot;
   _Unwind_Reason_Code code;
@@ -1586,6 +1602,12 @@ uw_init_context_1 (struct _Unwind_Context *context,
      initialization context, then we can't see it in the given
      call frame data.  So have the initialization context tell us.  */
   context->ra = __builtin_extract_return_addr (outer_ra);
+#ifdef MD_POST_EXTRACT_ROOT_ADDR
+  context->ra = MD_POST_EXTRACT_ROOT_ADDR (context->ra);
+#endif
+#ifdef MD_POST_INIT_CONTEXT
+  MD_POST_INIT_CONTEXT (context, &fs);
+#endif
 }
 
 static void _Unwind_DebugHook (void *, void *)
@@ -1608,6 +1630,20 @@ _Unwind_DebugHook (void *cfa __attribute__ ((__unused__)),
 #endif
 }
 
+/* Frob exception handler's address kept in TARGET before installing into
+   CURRENT context.  */
+
+static void *
+uw_frob_return_addr (struct _Unwind_Context *current,
+		     struct _Unwind_Context *target)
+{
+  void *ret_addr = __builtin_frob_return_addr (target->ra);
+#ifdef MD_POST_FROB_EH_HANDLER_ADDR
+  ret_addr = MD_POST_FROB_EH_HANDLER_ADDR (current, target, ret_addr);
+#endif
+  return ret_addr;
+}
+
 /* Install TARGET into CURRENT so that we can return to it.  This is a
    macro because __builtin_eh_return must be invoked in the context of
    our caller.  */
@@ -1616,7 +1652,7 @@ _Unwind_DebugHook (void *cfa __attribute__ ((__unused__)),
   do									\
     {									\
       long offset = uw_install_context_1 ((CURRENT), (TARGET));		\
-      void *handler = __builtin_frob_return_addr ((TARGET)->ra);	\
+      void *handler = uw_frob_return_addr ((CURRENT), (TARGET));	\
       _Unwind_DebugHook ((TARGET)->cfa, handler);			\
       __builtin_eh_return (offset, handler);				\
     }									\
diff --git a/libgcc/config.host b/libgcc/config.host
index 6f2e458e74e776a6b7a310919558bcca76389232..540bfa9635802adabb36a2d1b7cf3416462c59f3 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -331,11 +331,13 @@ aarch64*-*-elf | aarch64*-*-rtems*)
 	extra_parts="$extra_parts crtfastmath.o"
 	tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
 	tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm"
+	md_unwind_header=aarch64/aarch64-unwind.h
 	;;
 aarch64*-*-freebsd*)
 	extra_parts="$extra_parts crtfastmath.o"
 	tmake_file="${tmake_file} ${cpu_type}/t-aarch64"
 	tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm"
+	md_unwind_header=aarch64/aarch64-unwind.h
 	;;
 aarch64*-*-linux*)
 	extra_parts="$extra_parts crtfastmath.o"
diff --git a/libgcc/config/aarch64/aarch64-unwind.h b/libgcc/config/aarch64/aarch64-unwind.h
new file mode 100644
index 0000000000000000000000000000000000000000..fd20feb0ce061c82c9134609438c84bc161670f9
--- /dev/null
+++ b/libgcc/config/aarch64/aarch64-unwind.h
@@ -0,0 +1,87 @@
+/* Copyright (C) 2017 Free Software Foundation, Inc.
+   Contributed by ARM Ltd.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef AARCH64_UNWIND_H
+#define AARCH64_UNWIND_H
+
+#define DWARF_REGNUM_AARCH64_RA_STATE 34
+
+#define MD_POST_EXTRACT_ROOT_ADDR(addr)  __builtin_aarch64_xpaclri (addr)
+#define MD_POST_EXTRACT_FRAME_ADDR(context, fs, addr) \
+  aarch64_post_extract_frame_addr (context, fs, addr)
+#define MD_POST_FROB_EH_HANDLER_ADDR(current, target, addr) \
+  aarch64_post_frob_eh_handler_addr (current, target, addr)
+#define MD_POST_INIT_CONTEXT(context, fs) \
+  aarch64_post_init_context (context, fs)
+
+/* Do AArch64 private extraction on ADDR based on context info CONTEXT and
+   unwind frame info FS.  If ADDR is signed, we do address authentication on it
+   using CFA of current frame.  */
+
+static void *
+aarch64_post_extract_frame_addr (struct _Unwind_Context *context,
+				 _Unwind_FrameState *fs, void *addr)
+{
+  if (fs->regs.reg[DWARF_REGNUM_AARCH64_RA_STATE].loc.offset & 0x1)
+    {
+      _Unwind_Word salt = (_Unwind_Word) context->cfa;
+      return __builtin_aarch64_autia1716 (addr, salt);
+    }
+  else
+    return addr;
+}
+
+/* Do AArch64 private frob on exception handler's address HANDLER_ADDR before
+   installing it into current context CURRENT.  TARGET is currently not used.
+   We need to sign exception handler's address if CURRENT itself is signed.  */
+
+static void *
+aarch64_post_frob_eh_handler_addr (struct _Unwind_Context *current,
+				   struct _Unwind_Context *target
+				   ATTRIBUTE_UNUSED,
+				   void *handler_addr)
+{
+  if (current->flags & RA_A_SIGNED_BIT)
+    return __builtin_aarch64_pacia1716 (handler_addr,
+					(_Unwind_Word) current->cfa);
+  else
+    return handler_addr;
+}
+
+/* Do AArch64 private initialization on CONTEXT based on frame info FS.  Mark
+   CONTEXT as return address signed if bit 0 of DWARF_REGNUM_AARCH64_RA_STATE is
+   set.  */
+
+static void
+aarch64_post_init_context (struct _Unwind_Context *context,
+			   _Unwind_FrameState *fs)
+{
+  if (fs->regs.reg[DWARF_REGNUM_AARCH64_RA_STATE].loc.offset & 0x1)
+    /* The flag is used for re-authenticating EH handler's address.  */
+    context->flags |= RA_A_SIGNED_BIT;
+
+  return;
+}
+
+#endif /* defined AARCH64_UNWIND_H */
diff --git a/libgcc/config/aarch64/linux-unwind.h b/libgcc/config/aarch64/linux-unwind.h
index 1256f010007ac964de8bb895379a7d893a446bd9..75774b30c080ad2361fb37c7208bcf3d3b57d77a 100644
--- a/libgcc/config/aarch64/linux-unwind.h
+++ b/libgcc/config/aarch64/linux-unwind.h
@@ -24,6 +24,7 @@
 
 #include <signal.h>
 #include <sys/ucontext.h>
+#include "aarch64-unwind.h"
 
 
 /* Since insns are always stored LE, on a BE system the opcodes will
