Index: head/sys/compat/linux/linux_misc.c
===================================================================
--- head/sys/compat/linux/linux_misc.c
+++ head/sys/compat/linux/linux_misc.c
@@ -1207,12 +1207,8 @@
 int
 linux_nice(struct thread *td, struct linux_nice_args *args)
 {
-	struct setpriority_args bsd_args;
 
-	bsd_args.which = PRIO_PROCESS;
-	bsd_args.who = 0;		/* current process */
-	bsd_args.prio = args->inc;
-	return (sys_setpriority(td, &bsd_args));
+	return (kern_setpriority(td, PRIO_PROCESS, 0, args->inc));
 }
 #endif /* __i386__ || (__amd64__ && COMPAT_LINUX32) */
 
Index: head/sys/kern/kern_resource.c
===================================================================
--- head/sys/kern/kern_resource.c
+++ head/sys/kern/kern_resource.c
@@ -175,24 +175,31 @@
 int
 sys_setpriority(struct thread *td, struct setpriority_args *uap)
 {
+
+	return (kern_setpriority(td, uap->which, uap->who, uap->prio));
+}
+
+int
+kern_setpriority(struct thread *td, int which, int who, int prio)
+{
 	struct proc *curp, *p;
 	struct pgrp *pg;
 	int found = 0, error = 0;
 
 	curp = td->td_proc;
-	switch (uap->which) {
+	switch (which) {
 	case PRIO_PROCESS:
-		if (uap->who == 0) {
+		if (who == 0) {
 			PROC_LOCK(curp);
-			error = donice(td, curp, uap->prio);
+			error = donice(td, curp, prio);
 			PROC_UNLOCK(curp);
 		} else {
-			p = pfind(uap->who);
+			p = pfind(who);
 			if (p == NULL)
 				break;
 			error = p_cansee(td, p);
 			if (error == 0)
-				error = donice(td, p, uap->prio);
+				error = donice(td, p, prio);
 			PROC_UNLOCK(p);
 		}
 		found++;
@@ -200,11 +207,11 @@
 
 	case PRIO_PGRP:
 		sx_slock(&proctree_lock);
-		if (uap->who == 0) {
+		if (who == 0) {
 			pg = curp->p_pgrp;
 			PGRP_LOCK(pg);
 		} else {
-			pg = pgfind(uap->who);
+			pg = pgfind(who);
 			if (pg == NULL) {
 				sx_sunlock(&proctree_lock);
 				break;
@@ -215,7 +222,7 @@
 			PROC_LOCK(p);
 			if (p->p_state == PRS_NORMAL &&
 			    p_cansee(td, p) == 0) {
-				error = donice(td, p, uap->prio);
+				error = donice(td, p, prio);
 				found++;
 			}
 			PROC_UNLOCK(p);
@@ -224,15 +231,15 @@
 		break;
 
 	case PRIO_USER:
-		if (uap->who == 0)
-			uap->who = td->td_ucred->cr_uid;
+		if (who == 0)
+			who = td->td_ucred->cr_uid;
 		sx_slock(&allproc_lock);
 		FOREACH_PROC_IN_SYSTEM(p) {
 			PROC_LOCK(p);
 			if (p->p_state == PRS_NORMAL &&
-			    p->p_ucred->cr_uid == uap->who &&
+			    p->p_ucred->cr_uid == who &&
 			    p_cansee(td, p) == 0) {
-				error = donice(td, p, uap->prio);
+				error = donice(td, p, prio);
 				found++;
 			}
 			PROC_UNLOCK(p);
Index: head/sys/sys/syscallsubr.h
===================================================================
--- head/sys/sys/syscallsubr.h
+++ head/sys/sys/syscallsubr.h
@@ -251,6 +251,7 @@
 int	kern_setgroups(struct thread *td, u_int ngrp, gid_t *groups);
 int	kern_setitimer(struct thread *, u_int, struct itimerval *,
 	    struct itimerval *);
+int	kern_setpriority(struct thread *td, int which, int who, int prio);
 int	kern_setrlimit(struct thread *, u_int, struct rlimit *);
 int	kern_setsockopt(struct thread *td, int s, int level, int name,
 	    const void *optval, enum uio_seg valseg, socklen_t valsize);