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| author | Brian Bloniarz <brian.bloniarz@gmail.com> | 2016-03-06 13:16:30 -0800 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-06-03 19:15:40 -0400 |
| commit | 29a7543e33dbb168c1e044a3ad411ce96286924b (patch) | |
| tree | c6185f2a9f4f5410896ff94ae94c0e2cf9ab31f7 /include | |
| parent | d46be34398ab85c4d80ce2747eeef71497d8a01e (diff) | |
| download | lwn-29a7543e33dbb168c1e044a3ad411ce96286924b.tar.gz lwn-29a7543e33dbb168c1e044a3ad411ce96286924b.zip | |
Fix OpenSSH pty regression on close
[ Upstream commit 0f40fbbcc34e093255a2b2d70b6b0fb48c3f39aa ]
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>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
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 5e704e26f9a2..52baf4089bd2 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -339,7 +339,6 @@ struct tty_file_private { #define TTY_EXCLUSIVE 3 /* Exclusive open mode */ #define TTY_DEBUG 4 /* Debugging */ #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 */ @@ -467,6 +466,7 @@ extern void tty_buffer_free_all(struct tty_port *port); extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld); extern void tty_buffer_init(struct tty_port *port); extern void tty_buffer_set_lock_subclass(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, |