diff --git a/sys/cddl/dev/fbt/fbt.c b/sys/cddl/dev/fbt/fbt.c
--- a/sys/cddl/dev/fbt/fbt.c
+++ b/sys/cddl/dev/fbt/fbt.c
@@ -172,7 +172,7 @@
 }
 
 static void
-fbt_provide_module(void *arg, modctl_t *lf)
+fbt_provide_module(void *arg __unused, modctl_t *lf)
 {
 	char modname[MAXPATHLEN];
 	int i;
@@ -250,7 +250,7 @@
 }
 
 static void
-fbt_destroy(void *arg, dtrace_id_t id, void *parg)
+fbt_destroy(void *arg __unused, dtrace_id_t id __unused, void *parg)
 {
 	fbt_probe_t *fbt = parg, *next;
 	modctl_t *ctl;
@@ -266,7 +266,7 @@
 }
 
 static void
-fbt_enable(void *arg, dtrace_id_t id, void *parg)
+fbt_enable(void *arg __unused, dtrace_id_t id __unused, void *parg)
 {
 	fbt_probe_t *fbt = parg;
 	modctl_t *ctl = fbt->fbtp_ctl;
@@ -295,7 +295,7 @@
 }
 
 static void
-fbt_disable(void *arg, dtrace_id_t id, void *parg)
+fbt_disable(void *arg __unused, dtrace_id_t id __unused, void *parg)
 {
 	fbt_probe_t *fbt = parg, *hash;
 	modctl_t *ctl = fbt->fbtp_ctl;
@@ -324,7 +324,7 @@
 }
 
 static void
-fbt_suspend(void *arg, dtrace_id_t id, void *parg)
+fbt_suspend(void *arg __unused, dtrace_id_t id __unused, void *parg)
 {
 	fbt_probe_t *fbt = parg;
 	modctl_t *ctl = fbt->fbtp_ctl;
@@ -339,7 +339,7 @@
 }
 
 static void
-fbt_resume(void *arg, dtrace_id_t id, void *parg)
+fbt_resume(void *arg __unused, dtrace_id_t id __unused, void *parg)
 {
 	fbt_probe_t *fbt = parg;
 	modctl_t *ctl = fbt->fbtp_ctl;
@@ -439,13 +439,13 @@
 }
 
 static void
-fbt_get_ctt_index(uint8_t version, const void *v, uint_t *indexp,
+fbt_get_ctt_index(uint8_t vers, const void *v, uint_t *indexp,
     uint_t *typep, int *ischildp)
 {
 	uint_t index, type;
 	int ischild;
 
-	if (version == CTF_VERSION_2) {
+	if (vers == CTF_VERSION_2) {
 		const struct ctf_type_v2 *ctt = v;
 
 		type = ctt->ctt_type;
@@ -468,12 +468,12 @@
 }
 
 static ssize_t
-fbt_get_ctt_size(uint8_t version, const void *tp, ssize_t *sizep,
+fbt_get_ctt_size(uint8_t vers, const void *tp, ssize_t *sizep,
     ssize_t *incrementp)
 {
 	ssize_t size, increment;
 
-	if (version == CTF_VERSION_2) {
+	if (vers == CTF_VERSION_2) {
 		const struct ctf_type_v2 *ctt = tp;
 
 		if (ctt->ctt_size == CTF_V2_LSIZE_SENT) {
@@ -504,13 +504,13 @@
 }
 
 static void
-fbt_get_ctt_info(uint8_t version, const void *tp, uint_t *kindp, uint_t *vlenp,
+fbt_get_ctt_info(uint8_t vers, const void *tp, uint_t *kindp, uint_t *vlenp,
     int *isrootp)
 {
 	uint_t kind, vlen;
 	int isroot;
 
-	if (version == CTF_VERSION_2) {
+	if (vers == CTF_VERSION_2) {
 		const struct ctf_type_v2 *ctt = tp;
 
 		kind = CTF_V2_INFO_KIND(ctt->ctt_info);
@@ -542,14 +542,14 @@
 	int ctf_typemax = 0;
 	uint32_t *xp;
 	ulong_t pop[CTF_K_MAX + 1] = { 0 };
-	uint8_t version;
+	uint8_t vers;
 
 	/* Sanity check. */
 	if (hp->cth_magic != CTF_MAGIC)
 		return (EINVAL);
 
-	version = hp->cth_version;
-	idwidth = version == CTF_VERSION_2 ? 2 : 4;
+	vers = hp->cth_version;
+	idwidth = vers == CTF_VERSION_2 ? 2 : 4;
 
 	tbuf = (const void *) (ctfdata + hp->cth_typeoff);
 	tend = (const void *) (ctfdata + hp->cth_stroff);
@@ -563,9 +563,9 @@
 		ssize_t size, increment;
 		size_t vbytes;
 
-		(void) fbt_get_ctt_size(version, tp, &size, &increment);
-		fbt_get_ctt_info(version, tp, &kind, &vlen, NULL);
-		fbt_get_ctt_index(version, tp, NULL, &type, NULL);
+		(void) fbt_get_ctt_size(vers, tp, &size, &increment);
+		fbt_get_ctt_info(vers, tp, &kind, &vlen, NULL);
+		fbt_get_ctt_index(vers, tp, NULL, &type, NULL);
 
 		switch (kind) {
 		case CTF_K_INTEGER:
@@ -573,7 +573,7 @@
 			vbytes = sizeof (uint_t);
 			break;
 		case CTF_K_ARRAY:
-			if (version == CTF_VERSION_2)
+			if (vers == CTF_VERSION_2)
 				vbytes = sizeof (struct ctf_array_v2);
 			else
 				vbytes = sizeof (struct ctf_array_v3);
@@ -583,7 +583,7 @@
 			break;
 		case CTF_K_STRUCT:
 		case CTF_K_UNION:
-			if (version == CTF_VERSION_2) {
+			if (vers == CTF_VERSION_2) {
 				if (size < CTF_V2_LSTRUCT_THRESH)
 					vbytes =
 					    sizeof (struct ctf_member_v2) * vlen;
@@ -652,8 +652,8 @@
 
 		size_t vbytes;
 
-		(void) fbt_get_ctt_size(version, tp, &size, &increment);
-		fbt_get_ctt_info(version, tp, &kind, &vlen, NULL);
+		(void) fbt_get_ctt_size(vers, tp, &size, &increment);
+		fbt_get_ctt_info(vers, tp, &kind, &vlen, NULL);
 
 		switch (kind) {
 		case CTF_K_INTEGER:
@@ -661,7 +661,7 @@
 			vbytes = sizeof (uint_t);
 			break;
 		case CTF_K_ARRAY:
-			if (version == CTF_VERSION_2)
+			if (vers == CTF_VERSION_2)
 				vbytes = sizeof (struct ctf_array_v2);
 			else
 				vbytes = sizeof (struct ctf_array_v3);
@@ -671,7 +671,7 @@
 			break;
 		case CTF_K_STRUCT:
 		case CTF_K_UNION:
-			if (version == CTF_VERSION_2) {
+			if (vers== CTF_VERSION_2) {
 				if (size < CTF_V2_LSTRUCT_THRESH)
 					vbytes =
 					    sizeof (struct ctf_member_v2) * vlen;
@@ -909,7 +909,7 @@
 	const ctf_header_t *hp = (const ctf_header_t *) lc->ctftab;
 	const char *strp = "";
 
-	if (name < 0 || name >= hp->cth_strlen)
+	if (name < 0 || (uint32_t)name >= hp->cth_strlen)
 		return(strp);
 
 	strp = (const char *)(lc->ctftab + hp->cth_stroff + name + sizeof(ctf_header_t));