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Fix faulty error code handling in read(2) on TTYs.

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When performing a non-blocking read(2), on a TTY while no data is
available, we should return EAGAIN. But if there's a modem disconnect,
we should return 0. Right now we only return 0 when doing a blocking
read, which is wrong.

MFC after:	1 month
This commit is contained in:
Ed Schouten 2012-10-03 13:51:03 +00:00
parent 6b67444bac
commit 6b1b791da6
1 changed files with 12 additions and 12 deletions
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24
sys/kern/tty_ttydisc.c
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@ -149,10 +149,10 @@ ttydisc_read_canonical(struct tty *tp, struct uio *uio, int ioflag)
/* No more data. */
if (clen == 0) {
if (ioflag & IO_NDELAY)
return (EWOULDBLOCK);
else if (tp->t_flags & TF_ZOMBIE)
if (tp->t_flags & TF_ZOMBIE)
return (0);
else if (ioflag & IO_NDELAY)
return (EWOULDBLOCK);
error = tty_wait(tp, &tp->t_inwait);
if (error)
@ -200,10 +200,10 @@ ttydisc_read_raw_no_timer(struct tty *tp, struct uio *uio, int ioflag)
return (0);
/* We have to wait for more. */
if (ioflag & IO_NDELAY)
return (EWOULDBLOCK);
else if (tp->t_flags & TF_ZOMBIE)
if (tp->t_flags & TF_ZOMBIE)
return (0);
else if (ioflag & IO_NDELAY)
return (EWOULDBLOCK);
error = tty_wait(tp, &tp->t_inwait);
if (error)
@ -248,10 +248,10 @@ ttydisc_read_raw_read_timer(struct tty *tp, struct uio *uio, int ioflag,
* We have to wait for more. If the timer expires, we
* should return a 0-byte read.
*/
if (ioflag & IO_NDELAY)
return (EWOULDBLOCK);
else if (tp->t_flags & TF_ZOMBIE)
if (tp->t_flags & TF_ZOMBIE)
return (0);
else if (ioflag & IO_NDELAY)
return (EWOULDBLOCK);
error = tty_timedwait(tp, &tp->t_inwait, hz);
if (error)
@ -293,10 +293,10 @@ ttydisc_read_raw_interbyte_timer(struct tty *tp, struct uio *uio, int ioflag)
break;
/* We have to wait for more. */
if (ioflag & IO_NDELAY)
return (EWOULDBLOCK);
else if (tp->t_flags & TF_ZOMBIE)
if (tp->t_flags & TF_ZOMBIE)
return (0);
else if (ioflag & IO_NDELAY)
return (EWOULDBLOCK);
error = tty_wait(tp, &tp->t_inwait);
if (error)