On 12/08/2010 04:50 PM, Greg KH wrote: > On Wed, Dec 08, 2010 at 04:09:26PM +0100, Jiri Slaby wrote: >> On 12/08/2010 04:02 PM, Greg KH wrote: >>> On Wed, Dec 08, 2010 at 07:24:46AM +0100, Jiri Slaby wrote: >>>> On 12/08/2010 01:43 AM, Greg KH wrote: >>>>> 2.6.32-stable review patch. If anyone has any objections, please let us >>>>> know. >>>>> >>>>> ------------------ >>>>> >>>>> From: Jiri Slaby <[email protected]> >>>>> >>>>> 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 <[email protected]> >>>>> Cc: Alan Cox <[email protected]> >>>>> Reported-by: Sergey Lapin <[email protected]> >>>>> Tested-by: Sergey Lapin <[email protected]> >>>>> Signed-off-by: Greg Kroah-Hartman <[email protected]> >>>>> >>>>> --- >>>>> 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; >>>> >>>> Whoops, this should write return ret; (with int ret = 0;) >>>> >>>> Do you want me to send the patch against rebased on .32? >>> >>> No, send it based on Linus's tree as it's wrong there, right? Then it >>> will move through to the stable kernels. >> >> Nope, in 2.6.36 and newer it looks differently, only the .32 backport is >> broken. > > Ick, ok, sorry about that. Yes, can you just send me a tiny patch that > I can merge with the .32 patch to resolve this?
JFYI, Ben did last night in: [PATCH] TTY: Fix error return from tty_ldisc_open() thanks, -- js suse labs _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
