Date: Fri, 22 Jan 2016 20:38:47 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r294598 - head/sys/kern Message-ID: <201601222038.u0MKclDo014575@repo.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: kib Date: Fri Jan 22 20:38:46 2016 New Revision: 294598 URL: https://svnweb.freebsd.org/changeset/base/294598 Log: In tty_dealloc(), clear the queues. See the comment for a scenario which explains why ttydev_leave() cleanup might not happen. Submitted by: bde MFC after: 3 weeks Modified: head/sys/kern/tty.c Modified: head/sys/kern/tty.c ============================================================================== --- head/sys/kern/tty.c Fri Jan 22 20:36:03 2016 (r294597) +++ head/sys/kern/tty.c Fri Jan 22 20:38:46 2016 (r294598) @@ -213,7 +213,7 @@ ttydev_leave(struct tty *tp) ttydisc_close(tp); - /* Destroy associated buffers already. */ + /* Free i/o queues now since they might be large. */ ttyinq_free(&tp->t_inq); tp->t_inlow = 0; ttyoutq_free(&tp->t_outq); @@ -1031,10 +1031,15 @@ tty_dealloc(void *arg) { struct tty *tp = arg; - /* Make sure we haven't leaked buffers. */ - MPASS(ttyinq_getsize(&tp->t_inq) == 0); - MPASS(ttyoutq_getsize(&tp->t_outq) == 0); - + /* + * ttyydev_leave() usually frees the i/o queues earlier, but it is + * not always called between queue allocation and here. The queues + * may be allocated by ioctls on a pty control device without the + * corresponding pty slave device ever being open, or after it is + * closed. + */ + ttyinq_free(&tp->t_inq); + ttyoutq_free(&tp->t_outq); seldrain(&tp->t_inpoll); seldrain(&tp->t_outpoll); knlist_destroy(&tp->t_inpoll.si_note);
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201601222038.u0MKclDo014575>