| Message ID | 20121114081547.GA573@bloggs.ozlabs.ibm.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
On 11/14/2012 09:15 AM, Paul Mackerras wrote: > Commit bdb498c20040 "TTY: hvc_console, add tty install" took the port > refcounting out of hvc_open()/hvc_close(), but failed to remove the > kref_put() and tty_kref_put() calls in hvc_hangup() that were there to > remove the extra references that hvc_open() had taken. > > The result was that doing a vhangup() when the current terminal was > a hvc_console, then closing the current terminal, would end up calling > destroy_hvc_struct() and making the port disappear entirely. This > meant that Fedora 17 systems would boot up but then not display the > login prompt on the console, and attempts to open /dev/hvc0 would > give a "No such device" error. > > This fixes it by removing the extra kref_put() and tty_kref_put() calls. Oh yeah. Thanks. Acked-by: Jiri Slaby <jslaby@suse.cz> > Signed-off-by: Paul Mackerras <paulus@samba.org> > Cc: stable@vger.kernel.org > --- > drivers/tty/hvc/hvc_console.c | 7 ------- > 1 file changed, 7 deletions(-) > > diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c > index a5dec1c..13ee53b 100644 > --- a/drivers/tty/hvc/hvc_console.c > +++ b/drivers/tty/hvc/hvc_console.c > @@ -424,7 +424,6 @@ static void hvc_hangup(struct tty_struct *tty) > { > struct hvc_struct *hp = tty->driver_data; > unsigned long flags; > - int temp_open_count; > > if (!hp) > return; > @@ -444,7 +443,6 @@ static void hvc_hangup(struct tty_struct *tty) > return; > } > > - temp_open_count = hp->port.count; > hp->port.count = 0; > spin_unlock_irqrestore(&hp->port.lock, flags); > tty_port_tty_set(&hp->port, NULL); > @@ -453,11 +451,6 @@ static void hvc_hangup(struct tty_struct *tty) > > if (hp->ops->notifier_hangup) > hp->ops->notifier_hangup(hp, hp->data); > - > - while(temp_open_count) { > - --temp_open_count; > - tty_port_put(&hp->port); > - } > } > > /* >
On Wed, 2012-11-14 at 10:45 +0100, Jiri Slaby wrote: > > This fixes it by removing the extra kref_put() and tty_kref_put() calls. > > Oh yeah. Thanks. > > Acked-by: Jiri Slaby <jslaby@suse.cz> So who's merging it ? Cheers, Ben. > > Signed-off-by: Paul Mackerras <paulus@samba.org> > > Cc: stable@vger.kernel.org > > --- > > drivers/tty/hvc/hvc_console.c | 7 ------- > > 1 file changed, 7 deletions(-) > > > > diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c > > index a5dec1c..13ee53b 100644 > > --- a/drivers/tty/hvc/hvc_console.c > > +++ b/drivers/tty/hvc/hvc_console.c > > @@ -424,7 +424,6 @@ static void hvc_hangup(struct tty_struct *tty) > > { > > struct hvc_struct *hp = tty->driver_data; > > unsigned long flags; > > - int temp_open_count; > > > > if (!hp) > > return; > > @@ -444,7 +443,6 @@ static void hvc_hangup(struct tty_struct *tty) > > return; > > } > > > > - temp_open_count = hp->port.count; > > hp->port.count = 0; > > spin_unlock_irqrestore(&hp->port.lock, flags); > > tty_port_tty_set(&hp->port, NULL); > > @@ -453,11 +451,6 @@ static void hvc_hangup(struct tty_struct *tty) > > > > if (hp->ops->notifier_hangup) > > hp->ops->notifier_hangup(hp, hp->data); > > - > > - while(temp_open_count) { > > - --temp_open_count; > > - tty_port_put(&hp->port); > > - } > > } > > > > /* > > > >
On Wed, Nov 14, 2012 at 11:47:59PM +1100, Benjamin Herrenschmidt wrote: > On Wed, 2012-11-14 at 10:45 +0100, Jiri Slaby wrote: > > > > This fixes it by removing the extra kref_put() and tty_kref_put() calls. > > > > Oh yeah. Thanks. > > > > Acked-by: Jiri Slaby <jslaby@suse.cz> > > So who's merging it ? Give me a chance to at least wake up please :) I will. greg k-h
On Wed, 2012-11-14 at 07:09 -0800, Greg KH wrote: > > So who's merging it ? > > Give me a chance to at least wake up please :) Sure ;-) Just asking since I'm about to cook up a powerpc batch :-) > I will. Thanks ! It should go into stable 3.6 as well. Cheers, Ben.
On Thu, Nov 15, 2012 at 07:48:17AM +1100, Benjamin Herrenschmidt wrote: > On Wed, 2012-11-14 at 07:09 -0800, Greg KH wrote: > > > So who's merging it ? > > > > Give me a chance to at least wake up please :) > > Sure ;-) Just asking since I'm about to cook up a powerpc batch :-) It's now in my tree, and will get to Linus in time for 3.7. > > I will. > > Thanks ! It should go into stable 3.6 as well. Why? The offending patch didn't show up until 3.7-rc1. thanks, greg k-h
On Wed, 2012-11-14 at 12:54 -0800, Greg KH wrote: > > Thanks ! It should go into stable 3.6 as well. > > Why? The offending patch didn't show up until 3.7-rc1. Ah, my bad, I though Paulus had observed the problem with 3.6 as well but it looks like you are right. So 3.7 then. Thanks. Cheers, Ben.
On Wed, Nov 14, 2012 at 12:54:07PM -0800, Greg KH wrote: > On Thu, Nov 15, 2012 at 07:48:17AM +1100, Benjamin Herrenschmidt wrote: > > On Wed, 2012-11-14 at 07:09 -0800, Greg KH wrote: > > > > So who's merging it ? > > > > > > Give me a chance to at least wake up please :) > > > > Sure ;-) Just asking since I'm about to cook up a powerpc batch :-) > > It's now in my tree, and will get to Linus in time for 3.7. Turns out I stuffed up the commit message a bit, I talk about kref_put and tty_kref_put when I should be talking about tty_port_put. If there is still a chance to update the commit message, that would be good. The patch itself is correct. > > > I will. > > > > Thanks ! It should go into stable 3.6 as well. > > Why? The offending patch didn't show up until 3.7-rc1. Yes. I had thought it was in 3.6 but it isn't. Paul.
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index a5dec1c..13ee53b 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -424,7 +424,6 @@ static void hvc_hangup(struct tty_struct *tty) { struct hvc_struct *hp = tty->driver_data; unsigned long flags; - int temp_open_count; if (!hp) return; @@ -444,7 +443,6 @@ static void hvc_hangup(struct tty_struct *tty) return; } - temp_open_count = hp->port.count; hp->port.count = 0; spin_unlock_irqrestore(&hp->port.lock, flags); tty_port_tty_set(&hp->port, NULL); @@ -453,11 +451,6 @@ static void hvc_hangup(struct tty_struct *tty) if (hp->ops->notifier_hangup) hp->ops->notifier_hangup(hp, hp->data); - - while(temp_open_count) { - --temp_open_count; - tty_port_put(&hp->port); - } } /*
Commit bdb498c20040 "TTY: hvc_console, add tty install" took the port refcounting out of hvc_open()/hvc_close(), but failed to remove the kref_put() and tty_kref_put() calls in hvc_hangup() that were there to remove the extra references that hvc_open() had taken. The result was that doing a vhangup() when the current terminal was a hvc_console, then closing the current terminal, would end up calling destroy_hvc_struct() and making the port disappear entirely. This meant that Fedora 17 systems would boot up but then not display the login prompt on the console, and attempts to open /dev/hvc0 would give a "No such device" error. This fixes it by removing the extra kref_put() and tty_kref_put() calls. Signed-off-by: Paul Mackerras <paulus@samba.org> Cc: stable@vger.kernel.org --- drivers/tty/hvc/hvc_console.c | 7 ------- 1 file changed, 7 deletions(-)