matthieu@ observes % pax (without any arguments) hits pledge violation,

because it tries MTIOCTOP against stdin, the tty.  It is very inconvenient
to use isatty to distinguish this difference in userland, so return ENOTTY
for tty devices.
ok natano

diff --git a/sys/kern/kern_pledge.c b/sys/kern/kern_pledge.c
index 406fbfe..b1c5bbc 100644 (file)
--- a/sys/kern/kern_pledge.c
+++ b/sys/kern/kern_pledge.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_pledge.c,v 1.203 2017/04/13 04:06:46 guenther Exp $      */
+/*     $OpenBSD: kern_pledge.c,v 1.204 2017/04/17 20:22:14 deraadt Exp $       */
 
 /*
  * Copyright (c) 2015 Nicholas Marriott <nicm@openbsd.org>
@@ -1155,9 +1155,12 @@ pledge_ioctl(struct proc *p, long com, struct file *fp)
                case MTIOCTOP:
                        /* for pax(1) and such, checking tapes... */
                        if (fp->f_type == DTYPE_VNODE &&
-                           vp->v_type == VCHR &&
-                           (vp->v_flag & VISTTY) == 0)
-                               return (0);
+                           vp->v_type == VCHR) {
+                               if (vp->v_flag & VISTTY)
+                                       return (ENOTTY);
+                               else
+                                       return (0);
+                       }
                        break;
                }
        }