Add a flags argument to falloc() that lets it optionally set the

close-on-exec flag on the newly allocated fd.  Make falloc()'s
return arguments non-optional: assert that they're not NULL.

ok mpi@ millert@

10 files changed, 69 insertions, 65 deletions

diff --git a/share/man/man9/file.9 b/share/man/man9/file.9
index ad530bba0c6..b3dfe90ea95 100644
--- a/share/man/man9/file.9
+++ b/share/man/man9/file.9
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: file.9,v 1.16 2015/11/23 17:53:57 jmc Exp $
+.\"     $OpenBSD: file.9,v 1.17 2017/02/11 19:51:06 guenther Exp $
 .\"
 .\" Copyright (c) 2002 Artur Grabowski <art@openbsd.org>
 .\" All rights reserved.
@@ -22,7 +22,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: November 23 2015 $
+.Dd $Mdocdate: February 11 2017 $
 .Dt FALLOC 9
 .Os
 .Sh NAME
@@ -38,7 +38,7 @@
 .In sys/file.h
 .In sys/filedesc.h
 .Ft int
-.Fn falloc "struct proc *p" "struct file **resultfp" "int *resultfd"
+.Fn falloc "struct proc *p" "int flags" "struct file **resultfp" "int *resultfd"
 .Ft int
 .Fn fdrelease "struct proc *p" "int fd"
 .Ft void
@@ -66,17 +66,32 @@ kqueues (see
 .Xr kqueue 2 ) ,
 and various special purpose communication endpoints.
 .Pp
-A new file descriptor is allocated with the function
+A new file and a file descriptor for it are allocated with the function
+.Fn falloc .
+The
+.Fa flags
+argument can be used to set the
+.Dv UF_EXCLOSE
+flag on the new descriptor.
+The larval file and fd are returned via
+.Fa resultfp
+and
+.Fa resultfd ,
+which must not be
+.Dv NULL .
 .Fn falloc
-and freed with
+initializes the new file to have a reference count of two:
+one for the reference from the file descriptor table and one
+for the caller to release with
+.Fn FRELE
+when it done initializing it.
+.Pp
+A file descriptor is freed with
 .Fn fdrelease .
-.Fn falloc
-and
-.Fn fdrelease
-deal with allocating and freeing slots in the file descriptor table,
-expanding the table when necessary and initializing the descriptor.
-It's possible to do those things in smaller steps, but it's not
-recommended to make complicated kernel APIs that require it.
+This releases the reference that it holds to the underlying file;
+if that's the last reference then the file will be freed.
+.\" with
+.\" .Xr closef 9 .
 .Pp
 The files are extracted from the file descriptor table using the
 functions
diff --git a/sys/kern/exec_script.c b/sys/kern/exec_script.c
index 27faacfcc5f..0b9ae86e224 100644
--- a/sys/kern/exec_script.c
+++ b/sys/kern/exec_script.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: exec_script.c,v 1.39 2016/04/25 20:00:33 tedu Exp $	*/
+/*	$OpenBSD: exec_script.c,v 1.40 2017/02/11 19:51:06 guenther Exp $	*/
 /*	$NetBSD: exec_script.c,v 1.13 1996/02/04 02:15:06 christos Exp $	*/
 
 /*
@@ -169,7 +169,7 @@ check_shell:
 #endif
 
 		fdplock(p->p_fd);
-		error = falloc(p, &fp, &epp->ep_fd);
+		error = falloc(p, 0, &fp, &epp->ep_fd);
 		fdpunlock(p->p_fd);
 		if (error)
 			goto fail;
diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c
index 8e549968e98..827fc9502f6 100644
--- a/sys/kern/kern_descrip.c
+++ b/sys/kern/kern_descrip.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_descrip.c,v 1.139 2017/01/24 04:09:59 deraadt Exp $	*/
+/*	$OpenBSD: kern_descrip.c,v 1.140 2017/02/11 19:51:06 guenther Exp $	*/
 /*	$NetBSD: kern_descrip.c,v 1.42 1996/03/30 22:24:38 christos Exp $	*/
 
 /*
@@ -895,11 +895,14 @@ fdexpand(struct proc *p)
  * a file descriptor for the process that refers to it.
  */
 int
-falloc(struct proc *p, struct file **resultfp, int *resultfd)
+falloc(struct proc *p, int flags, struct file **resultfp, int *resultfd)
 {
 	struct file *fp, *fq;
 	int error, i;
 
+	KASSERT(resultfp != NULL);
+	KASSERT(resultfd != NULL);
+
 	fdpassertlocked(p->p_fd);
 restart:
 	if ((error = fdalloc(p, 0, &i)) != 0) {
@@ -929,13 +932,12 @@ restart:
 		LIST_INSERT_HEAD(&filehead, fp, f_list);
 	}
 	p->p_fd->fd_ofiles[i] = fp;
+	p->p_fd->fd_ofileflags[i] |= (flags & UF_EXCLOSE);
 	fp->f_count = 1;
 	fp->f_cred = p->p_ucred;
 	crhold(fp->f_cred);
-	if (resultfp)
-		*resultfp = fp;
-	if (resultfd)
-		*resultfd = i;
+	*resultfp = fp;
+	*resultfd = i;
 	FREF(fp);
 	return (0);
 }
diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c
index c694521c411..561b9b256ea 100644
--- a/sys/kern/kern_event.c
+++ b/sys/kern/kern_event.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_event.c,v 1.77 2016/09/24 18:39:17 tedu Exp $	*/
+/*	$OpenBSD: kern_event.c,v 1.78 2017/02/11 19:51:06 guenther Exp $	*/
 
 /*-
  * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
@@ -440,7 +440,7 @@ sys_kqueue(struct proc *p, void *v, register_t *retval)
 	int fd, error;
 
 	fdplock(fdp);
-	error = falloc(p, &fp, &fd);
+	error = falloc(p, 0, &fp, &fd);
 	fdpunlock(fdp);
 	if (error)
 		return (error);
diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index b69df723edf..6d12ae1931c 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_exec.c,v 1.186 2017/02/08 20:58:30 guenther Exp $	*/
+/*	$OpenBSD: kern_exec.c,v 1.187 2017/02/11 19:51:06 guenther Exp $	*/
 /*	$NetBSD: kern_exec.c,v 1.75 1996/02/09 18:59:28 christos Exp $	*/
 
 /*-
@@ -576,7 +576,7 @@ sys_execve(struct proc *p, void *v, register_t *retval)
 				struct vnode *vp;
 				int indx;
 
-				if ((error = falloc(p, &fp, &indx)) != 0)
+				if ((error = falloc(p, 0, &fp, &indx)) != 0)
 					break;
 #ifdef DIAGNOSTIC
 				if (indx != i)
diff --git a/sys/kern/sys_pipe.c b/sys/kern/sys_pipe.c
index e869b61cd8b..57c45d74335 100644
--- a/sys/kern/sys_pipe.c
+++ b/sys/kern/sys_pipe.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sys_pipe.c,v 1.75 2016/10/08 02:16:43 guenther Exp $	*/
+/*	$OpenBSD: sys_pipe.c,v 1.76 2017/02/11 19:51:06 guenther Exp $	*/
 
 /*
  * Copyright (c) 1996 John S. Dyson
@@ -133,7 +133,9 @@ dopipe(struct proc *p, int *ufds, int flags)
 	struct filedesc *fdp = p->p_fd;
 	struct file *rf, *wf;
 	struct pipe *rpipe, *wpipe = NULL;
-	int fds[2], error;
+	int fds[2], cloexec, error;
+
+	cloexec = (flags & O_CLOEXEC) ? UF_EXCLOSE : 0;
 
 	rpipe = pool_get(&pipe_pool, PR_WAITOK);
 	error = pipe_create(rpipe);
@@ -146,7 +148,7 @@ dopipe(struct proc *p, int *ufds, int flags)
 
 	fdplock(fdp);
 
-	error = falloc(p, &rf, &fds[0]);
+	error = falloc(p, cloexec, &rf, &fds[0]);
 	if (error != 0)
 		goto free2;
 	rf->f_flag = FREAD | FWRITE | (flags & FNONBLOCK);
@@ -154,7 +156,7 @@ dopipe(struct proc *p, int *ufds, int flags)
 	rf->f_data = rpipe;
 	rf->f_ops = &pipeops;
 
-	error = falloc(p, &wf, &fds[1]);
+	error = falloc(p, cloexec, &wf, &fds[1]);
 	if (error != 0)
 		goto free3;
 	wf->f_flag = FREAD | FWRITE | (flags & FNONBLOCK);
@@ -162,11 +164,6 @@ dopipe(struct proc *p, int *ufds, int flags)
 	wf->f_data = wpipe;
 	wf->f_ops = &pipeops;
 
-	if (flags & O_CLOEXEC) {
-		fdp->fd_ofileflags[fds[0]] |= UF_EXCLOSE;
-		fdp->fd_ofileflags[fds[1]] |= UF_EXCLOSE;
-	}
-
 	rpipe->pipe_peer = wpipe;
 	wpipe->pipe_peer = rpipe;
 
diff --git a/sys/kern/tty_pty.c b/sys/kern/tty_pty.c
index 1f1f43880ee..4d79348e7a3 100644
--- a/sys/kern/tty_pty.c
+++ b/sys/kern/tty_pty.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tty_pty.c,v 1.78 2016/05/24 16:09:07 deraadt Exp $	*/
+/*	$OpenBSD: tty_pty.c,v 1.79 2017/02/11 19:51:06 guenther Exp $	*/
 /*	$NetBSD: tty_pty.c,v 1.33.4.1 1996/06/02 09:08:11 mrg Exp $	*/
 
 /*
@@ -1055,11 +1055,11 @@ ptmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
 	case PTMGET:
 		fdplock(fdp);
 		/* Grab two filedescriptors. */
-		if ((error = falloc(p, &cfp, &cindx)) != 0) {
+		if ((error = falloc(p, 0, &cfp, &cindx)) != 0) {
 			fdpunlock(fdp);
 			break;
 		}
-		if ((error = falloc(p, &sfp, &sindx)) != 0) {
+		if ((error = falloc(p, 0, &sfp, &sindx)) != 0) {
 			fdremove(fdp, cindx);
 			closef(cfp, p);
 			fdpunlock(fdp);
diff --git a/sys/kern/uipc_syscalls.c b/sys/kern/uipc_syscalls.c
index 7a8841c4988..40433a86527 100644
--- a/sys/kern/uipc_syscalls.c
+++ b/sys/kern/uipc_syscalls.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uipc_syscalls.c,v 1.148 2017/01/26 01:58:00 dhill Exp $	*/
+/*	$OpenBSD: uipc_syscalls.c,v 1.149 2017/02/11 19:51:06 guenther Exp $	*/
 /*	$NetBSD: uipc_syscalls.c,v 1.19 1996/02/09 19:00:48 christos Exp $	*/
 
 /*
@@ -94,9 +94,7 @@ sys_socket(struct proc *p, void *v, register_t *retval)
 		return (error);
 
 	fdplock(fdp);
-	error = falloc(p, &fp, &fd);
-	if (error == 0 && (type & SOCK_CLOEXEC))
-		fdp->fd_ofileflags[fd] |= UF_EXCLOSE;
+	error = falloc(p, (type & SOCK_CLOEXEC) ? UF_EXCLOSE : 0, &fp, &fd);
 	fdpunlock(fdp);
 	if (error != 0)
 		goto out;
@@ -279,9 +277,7 @@ doaccept(struct proc *p, int sock, struct sockaddr *name, socklen_t *anamelen,
 	headfp = fp;
 
 	fdplock(fdp);
-	error = falloc(p, &fp, &tmpfd);
-	if (!error && (flags & SOCK_CLOEXEC))
-		fdp->fd_ofileflags[tmpfd] |= UF_EXCLOSE;
+	error = falloc(p, (flags & SOCK_CLOEXEC) ? UF_EXCLOSE : 0, &fp, &tmpfd);
 	fdpunlock(fdp);
 	if (error) {
 		FRELE(headfp, p);
@@ -447,11 +443,12 @@ sys_socketpair(struct proc *p, void *v, register_t *retval)
 	struct filedesc *fdp = p->p_fd;
 	struct file *fp1, *fp2;
 	struct socket *so1, *so2;
-	int type, flags, fflag, error, sv[2];
+	int type, cloexec, nonblock, fflag, error, sv[2];
 
 	type  = SCARG(uap, type) & ~(SOCK_CLOEXEC | SOCK_NONBLOCK);
-	flags = SCARG(uap, type) &  (SOCK_CLOEXEC | SOCK_NONBLOCK);
-	fflag = FREAD | FWRITE | (flags & SOCK_NONBLOCK ? FNONBLOCK : 0);
+	cloexec = (SCARG(uap, type) & SOCK_CLOEXEC) ? UF_EXCLOSE : 0;
+	nonblock = SCARG(uap, type) &  SOCK_NONBLOCK;
+	fflag = FREAD | FWRITE | (nonblock ? FNONBLOCK : 0);
 
 	error = socreate(SCARG(uap, domain), &so1, type, SCARG(uap, protocol));
 	if (error)
@@ -471,32 +468,28 @@ sys_socketpair(struct proc *p, void *v, register_t *retval)
 			goto free2;
 	}
 	fdplock(fdp);
-	if ((error = falloc(p, &fp1, &sv[0])) != 0)
+	if ((error = falloc(p, cloexec, &fp1, &sv[0])) != 0)
 		goto free3;
 	fp1->f_flag = fflag;
 	fp1->f_type = DTYPE_SOCKET;
 	fp1->f_ops = &socketops;
 	fp1->f_data = so1;
-	if ((error = falloc(p, &fp2, &sv[1])) != 0)
+	if ((error = falloc(p, cloexec, &fp2, &sv[1])) != 0)
 		goto free4;
 	fp2->f_flag = fflag;
 	fp2->f_type = DTYPE_SOCKET;
 	fp2->f_ops = &socketops;
 	fp2->f_data = so2;
-	if (flags & SOCK_CLOEXEC) {
-		fdp->fd_ofileflags[sv[0]] |= UF_EXCLOSE;
-		fdp->fd_ofileflags[sv[1]] |= UF_EXCLOSE;
-	}
 	error = copyout(sv, SCARG(uap, rsv), 2 * sizeof (int));
 	if (error == 0) {
 #ifdef KTRACE
 		if (KTRPOINT(p, KTR_STRUCT))
 			ktrfds(p, sv, 2);
 #endif
-		if (flags & SOCK_NONBLOCK) {
-			(*fp1->f_ops->fo_ioctl)(fp1, FIONBIO, (caddr_t)&flags,
+		if (nonblock) {
+			(*fp1->f_ops->fo_ioctl)(fp1, FIONBIO, (caddr_t)&type,
 			    p);
-			(*fp2->f_ops->fo_ioctl)(fp2, FIONBIO, (caddr_t)&flags,
+			(*fp2->f_ops->fo_ioctl)(fp2, FIONBIO, (caddr_t)&type,
 			    p);
 		}
 		FILE_SET_MATURE(fp1, p);
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index 585485281cb..f2e1604c98a 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfs_syscalls.c,v 1.269 2017/01/23 22:34:10 deraadt Exp $	*/
+/*	$OpenBSD: vfs_syscalls.c,v 1.270 2017/02/11 19:51:06 guenther Exp $	*/
 /*	$NetBSD: vfs_syscalls.c,v 1.71 1996/04/23 10:29:02 mycroft Exp $	*/
 
 /*
@@ -802,7 +802,8 @@ doopenat(struct proc *p, int fd, const char *path, int oflags, mode_t mode,
 
 	fdplock(fdp);
 
-	if ((error = falloc(p, &fp, &indx)) != 0)
+	if ((error = falloc(p, (oflags & O_CLOEXEC) ? UF_EXCLOSE : 0, &fp,
+	    &indx)) != 0)
 		goto out;
 	flags = FFLAGS(oflags);
 	if (flags & FREAD)
@@ -812,9 +813,6 @@ doopenat(struct proc *p, int fd, const char *path, int oflags, mode_t mode,
 	if (oflags & O_CREAT)
 		ni_pledge |= PLEDGE_CPATH;
 
-	if (flags & O_CLOEXEC)
-		fdp->fd_ofileflags[indx] |= UF_EXCLOSE;
-
 	cmode = ((mode &~ fdp->fd_cmask) & ALLPERMS) &~ S_ISTXT;
 	if ((p->p_p->ps_flags & PS_PLEDGE))
 		cmode &= ACCESSPERMS;
@@ -970,12 +968,11 @@ sys_fhopen(struct proc *p, void *v, register_t *retval)
 		return (EINVAL);
 
 	fdplock(fdp);
-	if ((error = falloc(p, &fp, &indx)) != 0) {
+	if ((error = falloc(p, (flags & O_CLOEXEC) ? UF_EXCLOSE : 0, &fp,
+	    &indx)) != 0) {
 		fp = NULL;
 		goto bad;
 	}
-	if (flags & O_CLOEXEC)
-		fdp->fd_ofileflags[indx] |= UF_EXCLOSE;
 
 	if ((error = copyin(SCARG(uap, fhp), &fh, sizeof(fhandle_t))) != 0)
 		goto bad;
diff --git a/sys/sys/filedesc.h b/sys/sys/filedesc.h
index 3c9b6b88aaf..8fd0dc38efc 100644
--- a/sys/sys/filedesc.h
+++ b/sys/sys/filedesc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: filedesc.h,v 1.33 2017/01/25 06:15:50 mpi Exp $	*/
+/*	$OpenBSD: filedesc.h,v 1.34 2017/02/11 19:51:06 guenther Exp $	*/
 /*	$NetBSD: filedesc.h,v 1.14 1996/04/09 20:55:28 cgd Exp $	*/
 
 /*
@@ -125,7 +125,7 @@ void	filedesc_init(void);
 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);
+int	falloc(struct proc *_p, int _flags, struct file **_rfp, int *_rfd);
 struct	filedesc *fdinit(void);
 struct	filedesc *fdshare(struct process *);
 struct	filedesc *fdcopy(struct process *);