RE: 2.6.9 chrdev_open: serial_core: uart_open

karl malbrain
2005-07-15T22:03:52Z

> -----Original Message-----
> From: Russell King
> Sent: Friday, July 15, 2005 2:54 PM
> To: karl malbrain
> Cc: Linux-Kernel@Vger. Kernel. Org
> Subject: Re: 2.6.9 chrdev_open: serial_core: uart_open
>
>
> On Fri, Jul 15, 2005 at 02:17:01PM -0700, karl malbrain wrote:
> > > -----Original Message-----
> > > From: Russell King
> > > Sent: Friday, July 15, 2005 1:59 PM
> > > To: karl malbrain
> > > Cc: Linux-Kernel@Vger. Kernel. Org
> > > Subject: Re: 2.6.9 chrdev_open: serial_core: uart_open
> > >
> > >
> > > On Fri, Jul 15, 2005 at 01:52:15PM -0700, karl malbrain wrote:
> > > > On my 2.6.9-11EL source it clearly shows the up(&tty_sem) after
> > > the call to
> > > > uart_open. Init_dev never touches tty_sem.
> > >
> > > In which case, I have to say...
> > >
> > > Congratulations! You've found a bug with Red Hat's Enterprise Linux
> > > kernel! Go straight to Red Hat's bugzilla! Do not collect 200$. Do
> > > not pass go.
> > >
> > > Seriously though, this bug is not present in mainline kernels, so I
> > > can't resolve this issue for you. Mainline kernels appear to work
> > > properly.
> >
> > Could tty_io.c be all that changed by a small set of red-hat patches to
> > 2.6.9? Why would they need to go in there to make so many
> changes in the
> > first place? Which 2.6 release changed tty_io.c's use of tty_sem so
> > heavily?
>
> These are questions to ask of Red Hat, and can only be answered by
> their representatives.

I've since answered part of my question. Red Hat pulled some code-changes
from 2.6.10 tty_io.c with the somewhat cryptic comment "fix the trivial
exploits caused by Rolands controlling tty changes (part 1)" and moved the
tty_sem ops.

Do you know if this would be Roland at Red Hat, or a Roland at lkml?

Thanks, karl m