1. 18 11月, 2011 3 次提交
    • J
      TTY: ldisc, wait for ldisc infinitely in hangup · 0c73c08e
      Jiri Slaby 提交于
      For /dev/console case, we do not kill all ldisc users. It's due to
      redirected_tty_write test in __tty_hangup. In that case there still
      might be a process waiting e.g. in n_tty_read for input.
      
      We wait for such processes to disappear. The problem is that we use a
      timeout. After this timeout, we continue closing the ldisc and start
      freeing tty resources. It obviously leads to crashes when the other
      process is woken.
      
      So to fix this, we wait infinitely before reiniting the ldisc. (The
      tiocsetd remains untouched -- times out after 5s.)
      
      This is nicely reproducible with this run from shell:
        exec 0<>/dev/console 1<>/dev/console 2<>/dev/console
      and stopping a getty like:
        systemctl stop serial-getty@ttyS0.service
      
      The crash proper may be produced only under load or with constified
      timing the same as for 92f6fa09.
      Signed-off-by: NJiri Slaby <jslaby@suse.cz>
      Cc: Dave Young <hidave.darkstar@gmail.com>
      Cc: Dave Jones <davej@redhat.com>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Cc: Dmitriy Matrosov <sgf.dma@gmail.com>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      0c73c08e
    • J
      TTY: ldisc, move wait idle to caller · 30042072
      Jiri Slaby 提交于
      It is the only place where reinit is called from. And we really need
      to wait for the old ldisc to go once. Actually this is the place where
      the waiting originally was (before removed and re-added later).
      
      This will make the fix in the following patch easier to implement.
      Signed-off-by: NJiri Slaby <jslaby@suse.cz>
      Cc: Dave Young <hidave.darkstar@gmail.com>
      Cc: Dave Jones <davej@redhat.com>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Cc: Dmitriy Matrosov <sgf.dma@gmail.com>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      30042072
    • J
      TTY: ldisc, allow waiting for ldisc arbitrarily long · df92d056
      Jiri Slaby 提交于
      To fix a nasty bug in ldisc hup vs. reinit we need to wait infinitely
      long for ldisc to be gone. So here we add a parameter to
      tty_ldisc_wait_idle to allow that.
      
      This is only a preparation for the real fix which is done in the
      following patches.
      Signed-off-by: NJiri Slaby <jslaby@suse.cz>
      Cc: Dave Young <hidave.darkstar@gmail.com>
      Cc: Dave Jones <davej@redhat.com>
      Cc: Ben Hutchings <ben@decadent.org.uk>
      Cc: Dmitriy Matrosov <sgf.dma@gmail.com>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      df92d056
  2. 16 11月, 2011 10 次提交
  3. 08 11月, 2011 27 次提交