diff --git a/lib/libc/arch/m68k/genassym.cf b/lib/libc/arch/m68k/genassym.cf
index a9cad0aa4c29..3faac9623080 100644
--- a/lib/libc/arch/m68k/genassym.cf
+++ b/lib/libc/arch/m68k/genassym.cf
@@ -1,4 +1,4 @@
-#	$NetBSD: genassym.cf,v 1.1 2013/07/17 01:41:17 matt Exp $
+#	$NetBSD: genassym.cf,v 1.2 2021/11/21 23:58:09 thorpej Exp $
 
 #
 # Copyright (c) 2013 The NetBSD Foundation, Inc.
@@ -36,11 +36,32 @@ include <signal.h>
 
 define	UC_LINK		offsetof(ucontext_t, uc_link)
 define	UC_SIGMASK	offsetof(ucontext_t, uc_sigmask)
+define	UC_GREGS	offsetof(ucontext_t, uc_mcontext.__gregs[0])
 define	UC_MCONTEXT_D0	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_D0])
 define	UC_MCONTEXT_SP	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_A7])
 define	UC_MCONTEXT_PC	offsetof(ucontext_t, uc_mcontext.__gregs[_REG_PC])
 define	UC_SIZE		sizeof(ucontext_t)
 
+define	_REG_D0		_REG_D0
+define	_REG_D1		_REG_D1
+define	_REG_D2		_REG_D2
+define	_REG_D3		_REG_D3
+define	_REG_D4		_REG_D4
+define	_REG_D5		_REG_D5
+define	_REG_D6		_REG_D6
+define	_REG_D7		_REG_D7
+define	_REG_A0		_REG_A0
+define	_REG_A1		_REG_A1
+define	_REG_A2		_REG_A2
+define	_REG_A3		_REG_A3
+define	_REG_A4		_REG_A4
+define	_REG_A5		_REG_A5
+define	_REG_A6		_REG_A6
+define	_REG_A7		_REG_A7
+define	_REG_PC		_REG_PC
+
+define	SIZEOF_SIGINFO	sizeof(siginfo_t)
+
 define	SC_ONSTACK	offsetof(struct sigcontext, sc_onstack)
 define	SC___MASK13	offsetof(struct sigcontext, __sc_mask13)
 define	SC_SP		offsetof(struct sigcontext, sc_sp)
diff --git a/lib/libc/arch/m68k/sys/__sigtramp2.S b/lib/libc/arch/m68k/sys/__sigtramp2.S
index e1c78c5a15d7..a85f206f60b5 100755
--- a/lib/libc/arch/m68k/sys/__sigtramp2.S
+++ b/lib/libc/arch/m68k/sys/__sigtramp2.S
@@ -1,4 +1,4 @@
-/*	$NetBSD: __sigtramp2.S,v 1.4 2013/07/16 22:19:16 matt Exp $ */
+/*	$NetBSD: __sigtramp2.S,v 1.5 2021/11/21 23:58:09 thorpej Exp $ */
 
 /*-
  * Copyright (c) 2003 The NetBSD Foundation, Inc.
@@ -27,6 +27,7 @@
  */
 
 #include "SYS.h"
+#include "assym.h"
 
 /*
  * The m68k signal trampoline is invoked only to return from
@@ -39,7 +40,57 @@
  *		pointer to ucontext structure		[8]
  *		pointer to siginfo structure		[4]
  *	sp->	signal number				[0]
+ *
+ * The DWARF register numbers are 0-7 (dX), 8-15 (aX), 16-23 (fpX),
+ * which maps nicely to _REG_D[0-7] and _REG_A[0-7].  For m68k, there
+ * is a DWARF pseudo-register for the return address, and additionally
+ * another DWARF pseudo-register for signal handler return addresses.
+ * We will specify both return address pseudo-registers (without
+ * explicitly specifying .cfi_return_column) to keep the compiler
+ * run-time happy with whichever one it decides to use.
  */
+
+#define	DWARF_RETURN_REG		24
+#if defined(__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__)
+#define	DWARF_SIGRETURN_REG		__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__
+#else
+#define	DWARF_SIGRETURN_REG		25
+#endif
+
+#define	CFI_OFFSET_DWARF_REG(d, r)	.cfi_offset d, r * 4
+#define	CFI_OFFSET(r)			CFI_OFFSET_DWARF_REG(r, r)
+
+	.text
+	.cfi_startproc simple
+	.cfi_signal_frame
+	.cfi_def_cfa _REG_A7, 12 + SIZEOF_SIGINFO + UC_GREGS
+	CFI_OFFSET(_REG_D0)
+	CFI_OFFSET(_REG_D1)
+	CFI_OFFSET(_REG_D2)
+	CFI_OFFSET(_REG_D3)
+	CFI_OFFSET(_REG_D4)
+	CFI_OFFSET(_REG_D5)
+	CFI_OFFSET(_REG_D6)
+	CFI_OFFSET(_REG_D7)
+	CFI_OFFSET(_REG_A0)
+	CFI_OFFSET(_REG_A1)
+	CFI_OFFSET(_REG_A2)
+	CFI_OFFSET(_REG_A3)
+	CFI_OFFSET(_REG_A4)
+	CFI_OFFSET(_REG_A5)
+	CFI_OFFSET(_REG_A6)
+	CFI_OFFSET(_REG_A7)
+	CFI_OFFSET_DWARF_REG(DWARF_RETURN_REG, _REG_PC)
+	CFI_OFFSET_DWARF_REG(DWARF_SIGRETURN_REG, _REG_PC)
+
+/*
+ * The unwind entry includes one instruction slot prior to the trampoline
+ * because the unwinder will look up to (return PC - 1 insn) while unwinding.
+ * Normally this would be the jump / branch, but since there isn't one in
+ * this case, we place an explicit nop there instead.
+ */
+	nop
+
 ENTRY_NOPROFILE(__sigtramp_siginfo_2)
 	movl	8(%sp),%a0	/* get pointer to ucontext */
 	movl	%a0,4(%sp)	/* put it in the argument slot */
@@ -47,4 +98,5 @@ ENTRY_NOPROFILE(__sigtramp_siginfo_2)
 	SYSTRAP(setcontext)
 	movl	%d0,4(%sp)	/* error code */
 	SYSTRAP(exit)		/* exit */
+	.cfi_endproc
 END(__sigtramp_siginfo_2)