xnu-6153.41.3.tar.gz

[apple/xnu.git] / bsd / kern / tty_dev.c

diff --git a/bsd/kern/tty_dev.c b/bsd/kern/tty_dev.c
index ccfd752fb142254bb2df75c0dd272ed887dd8d09..302b76aa53521f2879a69601126a16d7274c0ca6 100644 (file)
--- a/bsd/kern/tty_dev.c
+++ b/bsd/kern/tty_dev.c
@@ -506,6 +506,16 @@ out:
        return;
 }
 
+static void
+ptcwakeup_knote(struct selinfo *sip, long hint)
+{
+       if ((sip->si_flags & SI_KNPOSTING) == 0) {
+               sip->si_flags |= SI_KNPOSTING;
+               KNOTE(&sip->si_note, hint);
+               sip->si_flags &= ~SI_KNPOSTING;
+       }
+}
+
 /*
  * Locks:      Assumes tty_lock() is held over this call.
  */
@@ -520,12 +530,12 @@ ptcwakeup(struct tty *tp, int flag)
        if (flag & FREAD) {
                selwakeup(&pti->pt_selr);
                wakeup(TSA_PTC_READ(tp));
-               KNOTE(&pti->pt_selr.si_note, 1);
+               ptcwakeup_knote(&pti->pt_selr, 1);
        }
        if (flag & FWRITE) {
                selwakeup(&pti->pt_selw);
                wakeup(TSA_PTC_WRITE(tp));
-               KNOTE(&pti->pt_selw.si_note, 1);
+               ptcwakeup_knote(&pti->pt_selw, 1);
        }
 }
 
@@ -1011,6 +1021,9 @@ block:
        goto again;
 }
 
+/*
+ * ptyioctl: Assumes dev was opened and lock was initilized
+ */
 __private_extern__ int
 ptyioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
 {
@@ -1020,9 +1033,10 @@ ptyioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
        int stop, error = 0;
        int allow_ext_ioctl = 1;
 
-       if (pti == NULL) {
+       if (pti == NULL || pti->pt_tty == NULL) {
                return ENXIO;
        }
+
        tp = pti->pt_tty;
        tty_lock(tp);