Date: Thu, 3 Dec 2009 22:42:06 GMT From: john hood <jh@sandstorm.net>, sandstorm-ni@sandstorm.net To: freebsd-gnats-submit@FreeBSD.org Subject: kern/141150: TIOCDRAIN ioctl on pts/pty master hangs Message-ID: <200912032242.nB3Mg6RN013891@www.freebsd.org> Resent-Message-ID: <200912032250.nB3Mo15u065202@freefall.freebsd.org>
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>Number: 141150 >Category: kern >Synopsis: TIOCDRAIN ioctl on pts/pty master hangs >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Thu Dec 03 22:50:01 UTC 2009 >Closed-Date: >Last-Modified: >Originator: john hood >Release: 8.0-RELEASE >Organization: Sandstorm Enterprises >Environment: FreeBSD lister.sandstorm.net 8.0-RELEASE FreeBSD 8.0-RELEASE #0: Tue Dec 1 20:49:34 EST 2009 jh@lister.sandstorm.net:/usr/src/sys/amd64/compile/NOCD amd64 >Description: our ancient 'gksu' port is broken-- it hangs after running the su/sudo command, and so output from the command never appears and gksu never exits. the problem is twofold-- a bug in libgksu, which calls tcdrain() on the master side of a pty; and a bug in kernel, which hangs rather than returning an error on the tty ioctl. see ports/141149 for a report + patch on libgksu. I observe this on both 7.1 and 8.0. 8.0 kernel sleeps on ttyout when this happens. In 8.0, ptsdev_ioctl() already seems to have some code to handle just this case, but it's only applied to the TIOCSETA[FW] ioctls used by tcsetattr(). So maybe it just needs to do this for TIOCFLUSH/TIOCDRAIN too. In 7.1, something different happens, of course-- it looks like all these cases go through to the slave pty, and just TIOCSETA[FW] get a flush beforehand. >How-To-Repeat: sudo pkg_add -r gksu gdb gksu id ^C >Fix: >Release-Note: >Audit-Trail: >Unformatted:
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