lkml.org 
[lkml]   [2010]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[043/127] TTY: ldisc, fix open flag handling
    2.6.32-stable review patch.  If anyone has any objections, please let us know.

    ------------------

    From: Jiri Slaby <jslaby@suse.cz>

    commit 7f90cfc505d613f4faf096e0d84ffe99208057d9 upstream.

    When a concrete ldisc open fails in tty_ldisc_open, we forget to clear
    TTY_LDISC_OPEN. This causes a false warning on the next ldisc open:
    WARNING: at drivers/char/tty_ldisc.c:445 tty_ldisc_open+0x26/0x38()
    Hardware name: System Product Name
    Modules linked in: ...
    Pid: 5251, comm: a.out Tainted: G W 2.6.32-5-686 #1
    Call Trace:
    [<c1030321>] ? warn_slowpath_common+0x5e/0x8a
    [<c1030357>] ? warn_slowpath_null+0xa/0xc
    [<c119311c>] ? tty_ldisc_open+0x26/0x38
    [<c11936c5>] ? tty_set_ldisc+0x218/0x304
    ...

    So clear the bit when failing...

    Introduced in c65c9bc3efa (tty: rewrite the ldisc locking) back in
    2.6.31-rc1.

    Signed-off-by: Jiri Slaby <jslaby@suse.cz>
    Cc: Alan Cox <alan@linux.intel.com>
    Reported-by: Sergey Lapin <slapin@ossfans.org>
    Tested-by: Sergey Lapin <slapin@ossfans.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    drivers/char/tty_ldisc.c | 9 +++++++--
    1 file changed, 7 insertions(+), 2 deletions(-)

    --- a/drivers/char/tty_ldisc.c
    +++ b/drivers/char/tty_ldisc.c
    @@ -444,9 +444,14 @@ static void tty_set_termios_ldisc(struct

    static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
    {
    + int ret;
    +
    WARN_ON(test_and_set_bit(TTY_LDISC_OPEN, &tty->flags));
    - if (ld->ops->open)
    - return ld->ops->open(tty);
    + if (ld->ops->open) {
    + ret = ld->ops->open(tty);
    + if (ret)
    + clear_bit(TTY_LDISC_OPEN, &tty->flags);
    + }
    return 0;
    }




    \
     
     \ /
      Last update: 2010-12-08 03:17    [W:4.087 / U:0.024 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site