Date: Wed, 3 Oct 2012 13:51:03 +0000 (UTC) From: Ed Schouten <ed@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r241161 - head/sys/kern Message-ID: <201210031351.q93Dp35B038584@svn.freebsd.org>
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Author: ed Date: Wed Oct 3 13:51:03 2012 New Revision: 241161 URL: http://svn.freebsd.org/changeset/base/241161 Log: Fix faulty error code handling in read(2) on TTYs. 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 Modified: head/sys/kern/tty_ttydisc.c Modified: head/sys/kern/tty_ttydisc.c ============================================================================== --- head/sys/kern/tty_ttydisc.c Wed Oct 3 12:43:26 2012 (r241160) +++ head/sys/kern/tty_ttydisc.c Wed Oct 3 13:51:03 2012 (r241161) @@ -149,10 +149,10 @@ ttydisc_read_canonical(struct tty *tp, s /* 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 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 * * 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 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)
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