Split out kernel side of {get,set}itimer(2) into two parts: the first that

pops data from the userland and pushes results back and the second which does
actual processing. Use the latter to eliminate stackgap in the linux wrappers
of those syscalls.

MFC after:	2 weeks

1 files changed, 33 insertions, 64 deletions

diff --git a/sys/compat/linux/linux_misc.c b/sys/compat/linux/linux_misc.c
index 0921907..cb77fe3 100644
--- a/sys/compat/linux/linux_misc.c
+++ b/sys/compat/linux/linux_misc.c
@@ -950,97 +950,66 @@ struct l_itimerval {
 	l_timeval it_value;
 };
 
+#define	B2L_ITIMERVAL(bip, lip) 					\
+	(bip)->it_interval.tv_sec = (lip)->it_interval.tv_sec;		\
+	(bip)->it_interval.tv_usec = (lip)->it_interval.tv_usec;	\
+	(bip)->it_value.tv_sec = (lip)->it_value.tv_sec;		\
+	(bip)->it_value.tv_usec = (lip)->it_value.tv_usec;
+
 int
 linux_setitimer(struct thread *td, struct linux_setitimer_args *uap)
 {
 	int error;
-	caddr_t sg;
-	struct l_itimerval *lp, *lop, ls;
-	struct itimerval *p = NULL, *op = NULL, s;
+	struct l_itimerval ls;
+	struct itimerval aitv, oitv;
 
 #ifdef DEBUG
 	if (ldebug(setitimer))
 		printf(ARGS(setitimer, "%p, %p"),
 		    (void *)uap->itv, (void *)uap->oitv);
 #endif
-	lp = uap->itv;
-	if (lp != NULL) {
-		sg = stackgap_init();
-		p = stackgap_alloc(&sg, sizeof(struct itimerval));
-		uap->itv = (struct l_itimerval *)p;
-		error = copyin(lp, &ls, sizeof(ls));
-		if (error != 0)
-			return (error);
-		s.it_interval.tv_sec = ls.it_interval.tv_sec;
-		s.it_interval.tv_usec = ls.it_interval.tv_usec;
-		s.it_value.tv_sec = ls.it_value.tv_sec;
-		s.it_value.tv_usec = ls.it_value.tv_usec;
-		error = copyout(&s, p, sizeof(s));
-		if (error != 0)
-			return (error);
-#ifdef DEBUG
-		if (ldebug(setitimer)) {
-			printf("setitimer: value: sec: %ld, usec: %ld\n",
-			    s.it_value.tv_sec, s.it_value.tv_usec);
-			printf("setitimer: interval: sec: %ld, usec: %ld\n",
-			    s.it_interval.tv_sec, s.it_interval.tv_usec);
-		}
-#endif
-	}
-	lop = uap->oitv;
-	if (lop != NULL) {
-		sg = stackgap_init();
-		op = stackgap_alloc(&sg, sizeof(struct itimerval));
-		uap->oitv = (struct l_itimerval *)op;
+
+	if (uap->itv == NULL) {
+		uap->itv = uap->oitv;
+		return (linux_getitimer(td, (struct linux_getitimer_args *)uap));
 	}
-	error = setitimer(td, (struct setitimer_args *) uap);
+
+	error = copyin(uap->itv, &ls, sizeof(ls));
 	if (error != 0)
 		return (error);
-	if (lop != NULL) {
-		error = copyin(op, &s, sizeof(s));
-		if (error != 0)
-			return (error);
-		ls.it_interval.tv_sec = s.it_interval.tv_sec;
-		ls.it_interval.tv_usec = s.it_interval.tv_usec;
-		ls.it_value.tv_sec = s.it_value.tv_sec;
-		ls.it_value.tv_usec = s.it_value.tv_usec;
-		error = copyout(&ls, lop, sizeof(ls));
+	B2L_ITIMERVAL(&aitv, &ls);
+#ifdef DEBUG
+	if (ldebug(setitimer)) {
+		printf("setitimer: value: sec: %ld, usec: %ld\n",
+		    aitv.it_value.tv_sec, aitv.it_value.tv_usec);
+		printf("setitimer: interval: sec: %ld, usec: %ld\n",
+		    aitv.it_interval.tv_sec, aitv.it_interval.tv_usec);
 	}
-	return (error);
+#endif
+	error = kern_setitimer(td, uap->which, &aitv, &oitv);
+	if (error != 0 || uap->oitv == NULL)
+		return (error);
+	B2L_ITIMERVAL(&ls, &oitv);
+
+	return (copyout(&ls, uap->oitv, sizeof(ls)));
 }
 
 int
 linux_getitimer(struct thread *td, struct linux_getitimer_args *uap)
 {
 	int error;
-	caddr_t sg;
-	struct l_itimerval *lp, ls;
-	struct itimerval *p = NULL, s;
+	struct l_itimerval ls;
+	struct itimerval aitv;
 
 #ifdef DEBUG
 	if (ldebug(getitimer))
 		printf(ARGS(getitimer, "%p"), (void *)uap->itv);
 #endif
-	lp = uap->itv;
-	if (lp != NULL) {
-		sg = stackgap_init();
-		p = stackgap_alloc(&sg, sizeof(struct itimerval));
-		uap->itv = (struct l_itimerval *)p;
-	}
-	error = getitimer(td, (struct getitimer_args *) uap);
+	error = kern_getitimer(td, uap->which, &aitv);
 	if (error != 0)
 		return (error);
-	if (lp != NULL) {
-		error = copyin(p, &s, sizeof(s));
-		if (error != 0)
-			return (error);
-		ls.it_interval.tv_sec = s.it_interval.tv_sec;
-		ls.it_interval.tv_usec = s.it_interval.tv_usec;
-		ls.it_value.tv_sec = s.it_value.tv_sec;
-		ls.it_value.tv_usec = s.it_value.tv_usec;
-		error = copyout(&ls, lp, sizeof(ls));
-	}
-	return (error);
+	B2L_ITIMERVAL(&ls, &aitv);
+	return (copyout(&ls, uap->itv, sizeof(ls)));
 }
 
 #ifndef __alpha__