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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> | 2016-05-01 13:22:54 -0700 |
| commit | 0f40fbbcc34e093255a2b2d70b6b0fb48c3f39aa (patch) | |
| tree | edfa996be5ce50cd79dcfdfa96bb9d8490418660 /Documentation/serial | |
| parent | d11df61853f1d45035b7f5a6702c9b48d5f09a49 (diff) | |
| download | lwn-0f40fbbcc34e093255a2b2d70b6b0fb48c3f39aa.tar.gz lwn-0f40fbbcc34e093255a2b2d70b6b0fb48c3f39aa.zip | |
Fix OpenSSH pty regression on close
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>
Diffstat (limited to 'Documentation/serial')
| -rw-r--r-- | Documentation/serial/tty.txt | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/Documentation/serial/tty.txt b/Documentation/serial/tty.txt index 798cba82c762..b48780977a68 100644 --- a/Documentation/serial/tty.txt +++ b/Documentation/serial/tty.txt @@ -210,9 +210,6 @@ TTY_IO_ERROR If set, causes all subsequent userspace read/write TTY_OTHER_CLOSED Device is a pty and the other side has closed. -TTY_OTHER_DONE Device is a pty and the other side has closed and - all pending input processing has been completed. - TTY_NO_WRITE_SPLIT Prevent driver from splitting up writes into smaller chunks. |