From a6d4491c71877016dd4d4dd04846121224fcd47c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dag-Erling=20Sm=C3=B8rgrav?= <des@FreeBSD.org>
Date: Sat, 17 Jan 2004 00:59:04 +0000
Subject: [PATCH] Restore correct semantics for F_DUPFD fcntl.  This should fix
 the errors people have been getting with configure scripts.

---
 sys/kern/kern_descrip.c | 8 ++++----
 sys/kern/uipc_usrreq.c  | 2 +-
 sys/sys/filedesc.h      | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index a391fed95135..b6eaee271a6c 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -602,7 +602,7 @@ do_dup(td, type, old, new, retval)
 		if (fdp->fd_ofiles[new] == NULL)
 			fdused(fdp, new);
 	} else {
-		if ((error = fdalloc(td, &new)) != 0) {
+		if ((error = fdalloc(td, new, &new)) != 0) {
 			FILEDESC_UNLOCK(fdp);
 			fdrop(fp, td);
 			return (error);
@@ -1205,7 +1205,7 @@ fdgrowtable(struct filedesc *fdp, int nfd)
  * Allocate a file descriptor for the process.
  */
 int
-fdalloc(struct thread *td, int *result)
+fdalloc(struct thread *td, int minfd, int *result)
 {
 	struct proc *p = td->td_proc;
 	struct filedesc *fdp = p->p_fd;
@@ -1222,7 +1222,7 @@ fdalloc(struct thread *td, int *result)
 	 * may drop the filedesc lock, so we're in a race.
 	 */
 	for (;;) {
-		fd = fd_first_free(fdp, fdp->fd_freefile, fdp->fd_nfiles);
+		fd = fd_first_free(fdp, minfd, fdp->fd_nfiles);
 		if (fd >= maxfd)
 			return (EMFILE);
 		if (fd < fdp->fd_nfiles)
@@ -1326,7 +1326,7 @@ falloc(td, resultfp, resultfd)
 		LIST_INSERT_HEAD(&filehead, fp, f_list);
 	}
 	sx_xunlock(&filelist_lock);
-	if ((error = fdalloc(td, &i))) {
+	if ((error = fdalloc(td, 0, &i))) {
 		FILEDESC_UNLOCK(p->p_fd);
 		fdrop(fp, td);
 		if (resultfp)
diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c
index 8dd9b7e4595d..1f9ca3d2007b 100644
--- a/sys/kern/uipc_usrreq.c
+++ b/sys/kern/uipc_usrreq.c
@@ -1047,7 +1047,7 @@ unp_externalize(control, controlp)
 			fdp = (int *)
 			    CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 			for (i = 0; i < newfds; i++) {
-				if (fdalloc(td, &f))
+				if (fdalloc(td, 0, &f))
 					panic("unp_externalize fdalloc failed");
 				fp = *rp++;
 				td->td_proc->p_fd->fd_ofiles[f] = fp;
diff --git a/sys/sys/filedesc.h b/sys/sys/filedesc.h
index ff8cefea2fff..8904435f32e5 100644
--- a/sys/sys/filedesc.h
+++ b/sys/sys/filedesc.h
@@ -147,7 +147,7 @@ int	dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd,
 int	falloc(struct thread *p, struct file **resultfp, int *resultfd);
 void	fdused(struct filedesc *fdp, int fd);
 void	fdunused(struct filedesc *fdp, int fd);
-int	fdalloc(struct thread *p, int *result);
+int	fdalloc(struct thread *p, int minfd, int *result);
 int	fdavail(struct thread *td, int n);
 void	fdcloseexec(struct thread *td);
 int	fdcheckstd(struct thread *td);