Messages in this thread | | | Date | Wed, 18 May 2011 16:44:29 +0200 | From | Jiri Olsa <> | Subject | Re: BUG: NULL pointer deref in tty port / uart |
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On Wed, May 18, 2011 at 03:36:36PM +0100, Alan Cox wrote: > > have the same issue.. looks like we should not NULL the port->tty > > if there's blocked open, but not sure what's exactly the logic > > behind "port's block_open and count" .. > > A pending open is not a user of the tty as far as the rest of the stack > is concerned. I also don't see why clearing port->tty is causing this > crash because nothing on that path should ever be going via port->tty and > it isn't safe to do so. > > > attached patch fixes it for me > > But still breaks on hangup where we can't do that. > > Where is port->tty getting misused to cause the crash, that is the bit > I'm missing somewhere.
I think it's the
uart_update_termios in uart_dtr_rts (drivers/tty/serial/serial_core.c)
called path:
tty_port_block_til_ready tty_port_raise_dtr_rts uart_dtr_rts uart_update_termios
jirka
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