diff --git a/defs.h b/defs.h
index 59dc3028..f44a9fb7 100644
--- a/defs.h
+++ b/defs.h
@@ -728,7 +728,7 @@ extern unsigned int qual_flags(const unsigned int);
 
 #define DECL_IOCTL(name)						\
 extern int								\
-name ## _ioctl(struct tcb *, unsigned int request, long arg)
+name ## _ioctl(struct tcb *, unsigned int request, kernel_ureg_t arg)
 DECL_IOCTL(dm);
 DECL_IOCTL(file);
 DECL_IOCTL(fs_x);
diff --git a/dm.c b/dm.c
index 8f911e6d..c4d3c140 100644
--- a/dm.c
+++ b/dm.c
@@ -396,7 +396,8 @@ dm_ioctl_has_params(const unsigned int code)
 }
 
 static int
-dm_known_ioctl(struct tcb *tcp, const unsigned int code, long arg)
+dm_known_ioctl(struct tcb *const tcp, const unsigned int code,
+	       const kernel_ureg_t arg)
 {
 	struct dm_ioctl *ioc = NULL;
 	struct dm_ioctl *entering_ioc = NULL;
@@ -516,7 +517,7 @@ dm_known_ioctl(struct tcb *tcp, const unsigned int code, long arg)
 }
 
 int
-dm_ioctl(struct tcb *tcp, const unsigned int code, long arg)
+dm_ioctl(struct tcb *const tcp, const unsigned int code, const kernel_ureg_t arg)
 {
 	switch (code) {
 	case DM_VERSION:
@@ -544,7 +545,7 @@ dm_ioctl(struct tcb *tcp, const unsigned int code, long arg)
 # else /* !(DM_VERSION_MAJOR == 4) */
 
 int
-dm_ioctl(struct tcb *tcp, const unsigned int code, long arg)
+dm_ioctl(struct tcb *const tcp, const unsigned int code, const kernel_ureg_t arg)
 {
 	return 0;
 }
diff --git a/file_ioctl.c b/file_ioctl.c
index de810193..6f30a23d 100644
--- a/file_ioctl.c
+++ b/file_ioctl.c
@@ -123,7 +123,8 @@ print_fiemap_extent(struct tcb *tcp, void *elem_buf, size_t elem_size, void *dat
 #endif /* HAVE_LINUX_FIEMAP_H */
 
 int
-file_ioctl(struct tcb *tcp, const unsigned int code, const long arg)
+file_ioctl(struct tcb *const tcp, const unsigned int code,
+	   const kernel_ureg_t arg)
 {
 	switch (code) {
 	case FICLONE:	/* W */
diff --git a/fs_x_ioctl.c b/fs_x_ioctl.c
index 7403e6b0..619eaa91 100644
--- a/fs_x_ioctl.c
+++ b/fs_x_ioctl.c
@@ -30,7 +30,8 @@
 #include <linux/fs.h>
 
 int
-fs_x_ioctl(struct tcb *tcp, const unsigned int code, const long arg)
+fs_x_ioctl(struct tcb *const tcp, const unsigned int code,
+	   const kernel_ureg_t arg)
 {
 	switch (code) {
 #ifdef FITRIM
diff --git a/ioctl.c b/ioctl.c
index 126513fc..5f6b4595 100644
--- a/ioctl.c
+++ b/ioctl.c
@@ -227,7 +227,7 @@ static int
 ioctl_decode(struct tcb *tcp)
 {
 	const unsigned int code = tcp->u_arg[1];
-	const long arg = tcp->u_arg[2];
+	const kernel_ureg_t arg = tcp->u_arg[2];
 
 	switch (_IOC_TYPE(code)) {
 #if defined(ALPHA) || defined(POWERPC)
diff --git a/loop.c b/loop.c
index 2de33c5f..a9d7659a 100644
--- a/loop.c
+++ b/loop.c
@@ -33,7 +33,7 @@
 #include "xlat/loop_crypt_type_options.h"
 
 static void
-decode_loop_info(struct tcb *tcp, const long addr)
+decode_loop_info(struct tcb *const tcp, const kernel_ureg_t addr)
 {
 	struct loop_info info;
 
@@ -83,7 +83,7 @@ decode_loop_info(struct tcb *tcp, const long addr)
 }
 
 static void
-decode_loop_info64(struct tcb *tcp, const long addr)
+decode_loop_info64(struct tcb *const tcp, const kernel_ureg_t addr)
 {
 	struct loop_info64 info64;
 
@@ -140,7 +140,8 @@ decode_loop_info64(struct tcb *tcp, const long addr)
 }
 
 int
-loop_ioctl(struct tcb *tcp, const unsigned int code, long arg)
+loop_ioctl(struct tcb *const tcp, const unsigned int code,
+	   const kernel_ureg_t arg)
 {
 	if (!verbose(tcp))
 		return RVAL_DECODED;
diff --git a/ptp.c b/ptp.c
index 69880e14..83e0b17b 100644
--- a/ptp.c
+++ b/ptp.c
@@ -33,7 +33,8 @@
 #include "xlat/ptp_flags_options.h"
 
 int
-ptp_ioctl(struct tcb *tcp, const unsigned int code, const long arg)
+ptp_ioctl(struct tcb *const tcp, const unsigned int code,
+	  const kernel_ureg_t arg)
 {
 	if (!verbose(tcp))
 		return RVAL_DECODED;
diff --git a/scsi.c b/scsi.c
index 482c5b8f..db59323d 100644
--- a/scsi.c
+++ b/scsi.c
@@ -61,7 +61,7 @@ print_sg_io_buffer(struct tcb *const tcp, const kernel_ureg_t addr,
 }
 
 static int
-print_sg_io_v3_req(struct tcb *tcp, const long arg)
+print_sg_io_v3_req(struct tcb *const tcp, const kernel_ureg_t arg)
 {
 	struct sg_io_hdr sg_io;
 
@@ -96,7 +96,7 @@ print_sg_io_v3_req(struct tcb *tcp, const long arg)
 }
 
 static void
-print_sg_io_v3_res(struct tcb *tcp, const long arg)
+print_sg_io_v3_res(struct tcb *const tcp, const kernel_ureg_t arg)
 {
 	struct sg_io_hdr sg_io;
 
@@ -135,7 +135,7 @@ print_sg_io_v3_res(struct tcb *tcp, const long arg)
 #ifdef HAVE_LINUX_BSG_H
 
 static int
-print_sg_io_v4_req(struct tcb *tcp, const long arg)
+print_sg_io_v4_req(struct tcb *const tcp, const kernel_ureg_t arg)
 {
 	struct sg_io_v4 sg_io;
 
@@ -173,7 +173,7 @@ print_sg_io_v4_req(struct tcb *tcp, const long arg)
 }
 
 static void
-print_sg_io_v4_res(struct tcb *tcp, const long arg)
+print_sg_io_v4_res(struct tcb *const tcp, const kernel_ureg_t arg)
 {
 	struct sg_io_v4 sg_io;
 	uint32_t din_len;
@@ -211,21 +211,22 @@ print_sg_io_v4_res(struct tcb *tcp, const long arg)
 #else /* !HAVE_LINUX_BSG_H */
 
 static int
-print_sg_io_v4_req(struct tcb *tcp, const long arg)
+print_sg_io_v4_req(struct tcb *const tcp, const kernel_ureg_t arg)
 {
 	tprints("...}");
 	return RVAL_DECODED | 1;
 }
 
 static void
-print_sg_io_v4_res(struct tcb *tcp, const long arg)
+print_sg_io_v4_res(struct tcb *const tcp, const kernel_ureg_t arg)
 {
 }
 
 #endif
 
 static int
-print_sg_io_req(struct tcb *tcp, uint32_t iid, const long arg)
+print_sg_io_req(struct tcb *const tcp, const uint32_t iid,
+		const kernel_ureg_t arg)
 {
 	tprintf("{'%c', ", iid);
 
@@ -242,7 +243,8 @@ print_sg_io_req(struct tcb *tcp, uint32_t iid, const long arg)
 }
 
 static void
-print_sg_io_res(struct tcb *tcp, uint32_t iid, const long arg)
+print_sg_io_res(struct tcb *const tcp, const uint32_t iid,
+		const kernel_ureg_t arg)
 {
 	switch (iid) {
 	case 'S':
@@ -255,7 +257,8 @@ print_sg_io_res(struct tcb *tcp, uint32_t iid, const long arg)
 }
 
 int
-scsi_ioctl(struct tcb *tcp, const unsigned int code, const long arg)
+scsi_ioctl(struct tcb *const tcp, const unsigned int code,
+	   const kernel_ureg_t arg)
 {
 	uint32_t iid;
 
diff --git a/sock.c b/sock.c
index 3e197ed0..dcc3e41e 100644
--- a/sock.c
+++ b/sock.c
@@ -50,8 +50,8 @@ print_ifname(const char *ifname)
 }
 
 static void
-print_ifreq(struct tcb *tcp, const unsigned int code, const long arg,
-	    const struct ifreq *ifr)
+print_ifreq(struct tcb *const tcp, const unsigned int code,
+	    const kernel_ureg_t arg, const struct ifreq *const ifr)
 {
 	switch (code) {
 	case SIOCSIFADDR:
@@ -132,7 +132,7 @@ print_ifc_len(int len)
 }
 
 static int
-decode_ifconf(struct tcb *tcp, const long addr)
+decode_ifconf(struct tcb *const tcp, const kernel_ureg_t addr)
 {
 	struct ifconf ifc;
 
@@ -195,7 +195,7 @@ decode_ifconf(struct tcb *tcp, const long addr)
 }
 
 int
-sock_ioctl(struct tcb *tcp, const unsigned int code, const long arg)
+sock_ioctl(struct tcb *const tcp, const unsigned int code, const kernel_ureg_t arg)
 {
 	struct ifreq ifr;
 
diff --git a/term.c b/term.c
index 2b0be68e..62a2efeb 100644
--- a/term.c
+++ b/term.c
@@ -38,7 +38,7 @@
 #include "xlat/modem_flags.h"
 
 static void
-decode_termios(struct tcb *tcp, const long addr)
+decode_termios(struct tcb *const tcp, const kernel_ureg_t addr)
 {
 	struct termios tios;
 	int i;
@@ -74,7 +74,7 @@ decode_termios(struct tcb *tcp, const long addr)
 }
 
 static void
-decode_termio(struct tcb *tcp, const long addr)
+decode_termio(struct tcb *const tcp, const kernel_ureg_t addr)
 {
 	struct termio tio;
 	int i;
@@ -116,7 +116,7 @@ decode_termio(struct tcb *tcp, const long addr)
 }
 
 static void
-decode_winsize(struct tcb *tcp, const long addr)
+decode_winsize(struct tcb *const tcp, const kernel_ureg_t addr)
 {
 	struct winsize ws;
 
@@ -132,7 +132,7 @@ decode_winsize(struct tcb *tcp, const long addr)
 
 #ifdef TIOCGSIZE
 static void
-decode_ttysize(struct tcb *tcp, const long addr)
+decode_ttysize(struct tcb *const tcp, const kernel_ureg_t addr)
 {
 	struct ttysize ts;
 
@@ -148,7 +148,7 @@ decode_ttysize(struct tcb *tcp, const long addr)
 #endif
 
 static void
-decode_modem_flags(struct tcb *tcp, const long addr)
+decode_modem_flags(struct tcb *const tcp, const kernel_ureg_t addr)
 {
 	int i;
 
@@ -164,7 +164,8 @@ decode_modem_flags(struct tcb *tcp, const long addr)
 }
 
 int
-term_ioctl(struct tcb *tcp, const unsigned int code, const long arg)
+term_ioctl(struct tcb *const tcp, const unsigned int code,
+	   const kernel_ureg_t arg)
 {
 	switch (code) {
 	/* struct termios */
diff --git a/ubi.c b/ubi.c
index dfac0be0..4d46a3cd 100644
--- a/ubi.c
+++ b/ubi.c
@@ -40,7 +40,8 @@
 #include "xlat/ubi_volume_props.h"
 
 int
-ubi_ioctl(struct tcb *tcp, const unsigned int code, const long arg)
+ubi_ioctl(struct tcb *const tcp, const unsigned int code,
+	  const kernel_ureg_t arg)
 {
 	if (!verbose(tcp))
 		return RVAL_DECODED;
diff --git a/userfaultfd.c b/userfaultfd.c
index 07094a10..4be01d14 100644
--- a/userfaultfd.c
+++ b/userfaultfd.c
@@ -55,7 +55,8 @@ tprintf_uffdio_range(const struct uffdio_range *range)
 }
 
 int
-uffdio_ioctl(struct tcb *tcp, const unsigned int code, const long arg)
+uffdio_ioctl(struct tcb *const tcp, const unsigned int code,
+	     const kernel_ureg_t arg)
 {
 	switch (code) {
 	case UFFDIO_API: {