Do not hold onto the fdplock longer then needed. Release the lock after

the initial falloc() calls and then regrab it for the fdinsert() or
fdremove() calls respectiviely. Also move closef() outside of the lock.
This replaces the previously reverted lock order change that was reverted.
OK mvs@ visa@

diff --git a/sys/kern/tty_pty.c b/sys/kern/tty_pty.c
index 4c97ba8..660a2e8 100644 (file)
--- a/sys/kern/tty_pty.c
+++ b/sys/kern/tty_pty.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: tty_pty.c,v 1.107 2021/02/04 13:32:33 claudio Exp $   */
+/*     $OpenBSD: tty_pty.c,v 1.108 2021/02/08 09:18:30 claudio Exp $   */
 /*     $NetBSD: tty_pty.c,v 1.33.4.1 1996/06/02 09:08:11 mrg Exp $     */
 
 /*
@@ -1088,12 +1088,12 @@ ptmclose(dev_t dev, int flag, int mode, struct proc *p)
 int
 ptmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
 {
-       dev_t newdev, error;
+       dev_t newdev;
        struct pt_softc * pti;
        struct nameidata cnd, snd;
        struct filedesc *fdp = p->p_fd;
        struct file *cfp = NULL, *sfp = NULL;
-       int cindx, sindx;
+       int cindx, sindx, error;
        uid_t uid;
        gid_t gid;
        struct vattr vattr;
@@ -1110,10 +1110,11 @@ ptmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
                }
                if ((error = falloc(p, &sfp, &sindx)) != 0) {
                        fdremove(fdp, cindx);
-                       closef(cfp, p);
                        fdpunlock(fdp);
+                       closef(cfp, p);
                        break;
                }
+               fdpunlock(fdp);
 
 retry:
                /* Find and open a free master pty. */
@@ -1203,6 +1204,7 @@ retry:
                memcpy(ptm->sn, pti->pty_sn, sizeof(pti->pty_sn));
 
                /* insert files now that we've passed all errors */
+               fdplock(fdp);
                fdinsert(fdp, cindx, 0, cfp);
                fdinsert(fdp, sindx, 0, sfp);
                fdpunlock(fdp);
@@ -1215,10 +1217,11 @@ retry:
        }
        return (error);
 bad:
+       fdplock(fdp);
        fdremove(fdp, cindx);
-       closef(cfp, p);
        fdremove(fdp, sindx);
-       closef(sfp, p);
        fdpunlock(fdp);
+       closef(cfp, p);
+       closef(sfp, p);
        return (error);
 }