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| author | Brian Bloniarz <brian.bloniarz@gmail.com> | 2016-03-06 13:16:30 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-06-01 12:18:03 -0700 |
| commit | 0412bb0f42f6b3c31cd13d262a5143e0dc3445e2 (patch) | |
| tree | 9dbb098e3e517f043d76214b06d0a6f0064e8b61 /include | |
| parent | c106d26d41ea5b58dcd3385f3ff1f56d9a8b2aa8 (diff) | |
| download | lwn-0412bb0f42f6b3c31cd13d262a5143e0dc3445e2.tar.gz lwn-0412bb0f42f6b3c31cd13d262a5143e0dc3445e2.zip | |
Fix OpenSSH pty regression on close
commit 0f40fbbcc34e093255a2b2d70b6b0fb48c3f39aa upstream.
OpenSSH expects the (non-blocking) read() of pty master to return
EAGAIN only if it has received all of the slave-side output after
it has received SIGCHLD. This used to work on pre-3.12 kernels.
This fix effectively forces non-blocking read() and poll() to
block for parallel i/o to complete for all ttys. It also unwinds
these changes:
1) f8747d4a466ab2cafe56112c51b3379f9fdb7a12
tty: Fix pty master read() after slave closes
2) 52bce7f8d4fc633c9a9d0646eef58ba6ae9a3b73
pty, n_tty: Simplify input processing on final close
3) 1a48632ffed61352a7810ce089dc5a8bcd505a60
pty: Fix input race when closing
Inspired by analysis and patch from Marc Aurele La France <tsi@tuyoix.net>
Reported-by: Volth <openssh@volth.com>
Reported-by: Marc Aurele La France <tsi@tuyoix.net>
BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=52
BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=2492
Signed-off-by: Brian Bloniarz <brian.bloniarz@gmail.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/tty.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/tty.h b/include/linux/tty.h index 3b09f235db66..a34442031aae 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -338,7 +338,6 @@ struct tty_file_private { #define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */ #define TTY_EXCLUSIVE 3 /* Exclusive open mode */ #define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */ -#define TTY_OTHER_DONE 6 /* Closed pty has completed input processing */ #define TTY_LDISC_OPEN 11 /* Line discipline is open */ #define TTY_PTY_LOCK 16 /* pty private */ #define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */ @@ -457,6 +456,7 @@ extern void tty_buffer_init(struct tty_port *port); extern void tty_buffer_set_lock_subclass(struct tty_port *port); extern bool tty_buffer_restart_work(struct tty_port *port); extern bool tty_buffer_cancel_work(struct tty_port *port); +extern void tty_buffer_flush_work(struct tty_port *port); extern speed_t tty_termios_baud_rate(struct ktermios *termios); extern speed_t tty_termios_input_baud_rate(struct ktermios *termios); extern void tty_termios_encode_baud_rate(struct ktermios *termios, |