Avoid curproc dance in dupfdopen(), by passing a struct proc *

ok guenther mpi

3 files changed, 13 insertions, 11 deletions

diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index e3201b9f2c1..e4b44839b37 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_descrip.c,v 1.136 2016/09/24 18:39:17 tedu Exp $	*/
+/*	$OpenBSD: kern_descrip.c,v 1.137 2017/01/23 22:34:10 deraadt Exp $	*/
 /*	$NetBSD: kern_descrip.c,v 1.42 1996/03/30 22:24:38 christos Exp $	*/
 
 /*
@@ -1253,8 +1253,10 @@ filedescopen(dev_t dev, int mode, int type, struct proc *p)
  * Duplicate the specified descriptor to a free descriptor.
  */
 int
-dupfdopen(struct filedesc *fdp, int indx, int dfd, int mode)
+dupfdopen(struct proc *p, int indx, int mode)
 {
+	struct filedesc *fdp = p->p_fd;
+	int dupfd = p->p_dupfd;
 	struct file *wfp;
 
 	fdpassertlocked(fdp);
@@ -1263,10 +1265,10 @@ dupfdopen(struct filedesc *fdp, int indx, int dfd, int mode)
 	 * Assume that the filename was user-specified; applications do
 	 * not tend to open /dev/fd/# when they can just call dup()
 	 */
-	if ((curproc->p_p->ps_flags & (PS_SUGIDEXEC | PS_SUGID))) {
-		if (curproc->p_descfd == 255)
+	if ((p->p_p->ps_flags & (PS_SUGIDEXEC | PS_SUGID))) {
+		if (p->p_descfd == 255)
 			return (EPERM);
-		if (curproc->p_descfd != curproc->p_dupfd)
+		if (p->p_descfd != dupfd)
 			return (EPERM);
 	}
 
@@ -1277,7 +1279,7 @@ dupfdopen(struct filedesc *fdp, int indx, int dfd, int mode)
 	 * because fd_getfile will return NULL if the file at indx is
 	 * newly created by falloc (FIF_LARVAL).
 	 */
-	if ((wfp = fd_getfile(fdp, dfd)) == NULL)
+	if ((wfp = fd_getfile(fdp, dupfd)) == NULL)
 		return (EBADF);
 
 	/*
@@ -1291,7 +1293,7 @@ dupfdopen(struct filedesc *fdp, int indx, int dfd, int mode)
 
 	fdp->fd_ofiles[indx] = wfp;
 	fdp->fd_ofileflags[indx] = (fdp->fd_ofileflags[indx] & UF_EXCLOSE) |
-	    (fdp->fd_ofileflags[dfd] & ~UF_EXCLOSE);
+	    (fdp->fd_ofileflags[dupfd] & ~UF_EXCLOSE);
 	wfp->f_count++;
 	fd_used(fdp, indx);
 	return (0);
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index 04df68e17d4..585485281cb 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfs_syscalls.c,v 1.268 2017/01/15 23:18:05 bluhm Exp $	*/
+/*	$OpenBSD: vfs_syscalls.c,v 1.269 2017/01/23 22:34:10 deraadt Exp $	*/
 /*	$NetBSD: vfs_syscalls.c,v 1.71 1996/04/23 10:29:02 mycroft Exp $	*/
 
 /*
@@ -829,7 +829,7 @@ doopenat(struct proc *p, int fd, const char *path, int oflags, mode_t mode,
 		if (error == ENODEV &&
 		    p->p_dupfd >= 0 &&			/* XXX from fdopen */
 		    (error =
-			dupfdopen(fdp, indx, p->p_dupfd, flags)) == 0) {
+			dupfdopen(p, indx, flags)) == 0) {
 			closef(fp, p);
 			*retval = indx;
 			goto out;
diff --git a/sys/sys/filedesc.h b/sys/sys/filedesc.h
index 148c8bc0182..136133189b7 100644
--- a/sys/sys/filedesc.h
+++ b/sys/sys/filedesc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: filedesc.h,v 1.30 2015/05/06 08:52:17 mpi Exp $	*/
+/*	$OpenBSD: filedesc.h,v 1.31 2017/01/23 22:34:10 deraadt Exp $	*/
 /*	$NetBSD: filedesc.h,v 1.14 1996/04/09 20:55:28 cgd Exp $	*/
 
 /*
@@ -121,7 +121,7 @@ struct filedesc0 {
  * Kernel global variables and routines.
  */
 void	filedesc_init(void);
-int	dupfdopen(struct filedesc *, int, int, int);
+int	dupfdopen(struct proc *, int, int);
 int	fdalloc(struct proc *p, int want, int *result);
 void	fdexpand(struct proc *);
 int	falloc(struct proc *p, struct file **resultfp, int *resultfd);