diff --git a/cddl/lib/libdtrace/Makefile b/cddl/lib/libdtrace/Makefile
index 468603633658..5232293e0be5 100644
--- a/cddl/lib/libdtrace/Makefile
+++ b/cddl/lib/libdtrace/Makefile
@@ -1,146 +1,150 @@
 # $FreeBSD$
 
 .PATH: ${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/common
 .PATH: ${SRCTOP}/cddl/contrib/opensolaris/lib/libgen/common
 
 PACKAGE=	dtrace
 LIB=		dtrace
 SRCS=		dt_aggregate.c \
 		dt_as.c \
 		dt_buf.c \
 		dt_cc.c \
 		dt_cg.c \
 		dt_consume.c \
 		dt_decl.c \
 		dt_dis.c \
 		dt_dof.c \
 		dt_error.c \
 		dt_errtags.c \
 		dt_grammar.y \
 		dt_handle.c \
 		dt_ident.c \
 		dt_isadep.c \
 		dt_inttab.c \
 		dt_lex.l \
 		dt_link.c \
 		dt_list.c \
 		dt_map.c \
 		dt_module.c \
 		dt_names.c \
 		dt_open.c \
 		dt_options.c \
 		dt_parser.c \
 		dt_pcb.c \
 		dt_pid.c \
 		dt_pq.c \
 		dt_pragma.c \
 		dt_print.c \
 		dt_printf.c \
 		dt_proc.c \
 		dt_program.c \
 		dt_provider.c \
 		dt_regset.c \
 		dt_string.c \
 		dt_strtab.c \
 		dt_subr.c \
 		dt_sugar.c \
 		dt_work.c \
 		dt_xlator.c \
 		gmatch.c
 
 DSRCS=		errno.d			\
 		io.d			\
 		ip.d			\
 		psinfo.d		\
 		sctp.d			\
 		siftr.d			\
 		signal.d		\
 		tcp.d			\
 		socket.d		\
 		udp.d			\
 		udplite.d		\
 		unistd.d
 
 FILES=		${DSRCS}
 FILESDIR=	/usr/lib/dtrace
 FILESMODE=	${NOBINMODE}
 
 INCSGROUPS=	INCS SYSINCS
 SYSINCSDIR=	${INCLUDEDIR}/sys
 INCS+=		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/common/dtrace.h
 SYSINCS+=	${SRCTOP}/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h
 SYSINCS+=	${SRCTOP}/sys/cddl/contrib/opensolaris/uts/common/sys/ctf_api.h
 
 WARNS?=		1
 
 CFLAGS+= -DIN_BASE
 CFLAGS+= -I${SRCTOP}/sys/contrib/openzfs/include
 CFLAGS+= -I${SRCTOP}/sys/contrib/openzfs/lib/libspl/include/
 CFLAGS+= -I${SRCTOP}/sys/contrib/openzfs/lib/libspl/include/os/freebsd
 CFLAGS+= -I${SRCTOP}/sys
 CFLAGS+= -include ${SRCTOP}/sys/contrib/openzfs/include/os/freebsd/spl/sys/ccompile.h
 CFLAGS+= -DHAVE_ISSETUGID
 
 
 CFLAGS+=	-I${.OBJDIR} -I${.CURDIR} \
 		-I${SRCTOP}/sys/cddl/dev/dtrace/${MACHINE_ARCH} \
 		-I${SRCTOP}/sys/cddl/dev/kinst \
 		-I${SRCTOP}/sys/cddl/compat/opensolaris \
 		-I${SRCTOP}/cddl/compat/opensolaris/include \
 		-I${OPENSOLARIS_USR_DISTDIR}/head \
 		-I${OPENSOLARIS_USR_DISTDIR}/lib/libctf/common \
 		-I${OPENSOLARIS_USR_DISTDIR}/lib/libdtrace/common \
 		-I${OPENSOLARIS_SYS_DISTDIR}/uts/common
 
 #CFLAGS+=	-DYYDEBUG
 
 .if ${MACHINE_CPUARCH} == "aarch64"
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/aarch64
 .PATH:		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/aarch64
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/aarch64
 .elif ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386"
 CFLAGS+=	-I${SRCTOP}/sys/cddl/dev/dtrace/x86
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/intel -DDIS_MEM
 .PATH:		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/i386
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/${MACHINE_ARCH}
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/x86
 .elif ${MACHINE_CPUARCH} == "arm"
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/arm
 .PATH:		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/arm
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/arm
 .elif ${MACHINE_CPUARCH} == "powerpc"
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/powerpc
 .PATH:		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/powerpc
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/powerpc
 .elif ${MACHINE_CPUARCH} == "riscv"
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/riscv
 .PATH:		${SRCTOP}/cddl/contrib/opensolaris/lib/libdtrace/riscv
 .PATH:		${SRCTOP}/sys/cddl/dev/dtrace/riscv
 .else
 # temporary hack
 CFLAGS+=	-I${OPENSOLARIS_SYS_DISTDIR}/uts/intel
 .endif
 
 .if ${MACHINE_ARCH} == "i386" || ${MACHINE_ARCH} == "amd64"
 SRCS+=		dis_tables.c instr_size.c
 DSRCS+=		regs_x86.d
 .endif
 
 .if ${MACHINE_CPUARCH} == "riscv"
 SRCS+=		instr_size.c
 DSRCS+=		regs_riscv.d
 .endif
 
+.if ${MACHINE_CPUARCH} == "aarch64"
+SRCS+=		instr_size.c
+.endif
+
 YFLAGS+=-d
 
 LIBADD=	ctf elf proc pthread rtld_db
 
 CLEANFILES=	dt_errtags.c dt_names.c
 
 .include <bsd.lib.mk>
 
 dt_errtags.c: ${OPENSOLARIS_USR_DISTDIR}/lib/libdtrace/common/dt_errtags.h
 	sh ${OPENSOLARIS_USR_DISTDIR}/lib/libdtrace/common/mkerrtags.sh < ${.ALLSRC} > ${.TARGET}
 
 dt_names.c: ${OPENSOLARIS_SYS_DISTDIR}/uts/common/sys/dtrace.h
 	sh ${OPENSOLARIS_USR_DISTDIR}/lib/libdtrace/common/mknames.sh < ${.ALLSRC} > ${.TARGET}
diff --git a/sys/cddl/dev/dtrace/aarch64/instr_size.c b/sys/cddl/dev/dtrace/aarch64/instr_size.c
new file mode 100644
index 000000000000..35964c0f0f78
--- /dev/null
+++ b/sys/cddl/dev/dtrace/aarch64/instr_size.c
@@ -0,0 +1,14 @@
+/*
+ * SPDX-License-Identifier: CDDL 1.0
+ *
+ * Copyright 2023 Christos Margiolis <christos@FreeBSD.org>
+ */
+
+#include <sys/types.h>
+#include <sys/dtrace.h>
+
+int
+dtrace_instr_size(uint8_t *instr __unused)
+{
+	return (INSN_SIZE);
+}
diff --git a/sys/modules/dtrace/dtrace/Makefile b/sys/modules/dtrace/dtrace/Makefile
index 1513418281ad..04829bd1d2c4 100644
--- a/sys/modules/dtrace/dtrace/Makefile
+++ b/sys/modules/dtrace/dtrace/Makefile
@@ -1,66 +1,66 @@
 # $FreeBSD$
 
 SYSDIR?=	${SRCTOP}/sys
 
 ARCHDIR=	${MACHINE_CPUARCH}
 
 .PATH: ${SYSDIR}/cddl/contrib/opensolaris/uts/common/dtrace
 .PATH: ${SYSDIR}/cddl/compat/opensolaris/kern
 .PATH: ${SYSDIR}/cddl/kern
 .PATH: ${SYSDIR}/cddl/dev/dtrace
 .PATH: ${SYSDIR}/cddl/dev/dtrace/${ARCHDIR}
 
 KMOD=		dtrace
 SRCS=		dtrace.c \
 		dtrace_xoroshiro128_plus.c \
 		dtrace_asm.S \
 		dtrace_subr.c
 
 .if ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386"
 .PATH: ${SYSDIR}/cddl/dev/dtrace/x86
 SRCS+=		dis_tables.c \
 		instr_size.c
 CFLAGS+=       -I${SYSDIR}/cddl/contrib/opensolaris/uts/intel \
                -I${SYSDIR}/cddl/dev/dtrace/x86
 .endif
 
-.if ${MACHINE_CPUARCH} == "riscv"
+.if ${MACHINE_CPUARCH} == "riscv" || ${MACHINE_CPUARCH} == "aarch64"
 SRCS+=		instr_size.c
 .endif
 
 CFLAGS+= ${OPENZFS_CFLAGS}
 
 SRCS+=		bus_if.h device_if.h vnode_if.h
 
 # Needed for dtrace_asm.S
 DPSRCS+=	assym.inc
 
 # These are needed for assym.inc
 SRCS+=		opt_kstack_pages.h opt_nfs.h opt_hwpmc_hooks.h
 
 #This is needed for dtrace.c
 SRCS += 	opensolaris_taskq.c
 
 .if ${MACHINE_CPUARCH} == "i386"
 SRCS+=		opt_apic.h
 .endif
 
 CFLAGS+=	-I${SYSDIR}/cddl/compat/opensolaris \
 		-I${SYSDIR}/cddl/dev/dtrace \
 		-I${SYSDIR}/cddl/dev/dtrace/${ARCHDIR} \
 		-I${SYSDIR}/cddl/contrib/opensolaris/uts/common \
 		-I${SYSDIR}/cddl/contrib/opensolaris/uts/common/dtrace \
 		-I${SYSDIR}/cddl/contrib/opensolaris/common/util \
 		-I${SYSDIR} -DDIS_MEM
 
 EXPORT_SYMS=	YES
 
 dtrace_asm.o:  assym.inc
 
 .include <bsd.kmod.mk>
 
 CFLAGS+=	-include ${SYSDIR}/cddl/compat/opensolaris/sys/debug_compat.h
 CFLAGS.dtrace_asm.S+= -D_SYS_ERRNO_H_ -D_SYS_PARAM_H_ -DLOCORE
 CWARNFLAGS+=	-Wno-parentheses
 CWARNFLAGS+=	-Wno-cast-qual
 CWARNFLAGS+=	-Wno-unused