On Thu, Jul 13, 2017 at 12:29:54PM +0100, Okash Khawaja wrote: > On Wed, Jul 12, 2017 at 07:20:28PM +0100, Alan Cox wrote: > > > > > When opening from kernel, we don't use file pointer. The count mismatch > > > is between tty->count and #fd's. So opening from kernel leads to #fd's > > > being less than tty->count. I thought this difference is relevant to > > > user-space opening of tty, and not to kernel opening of tty. Can you > > > suggest how to address this mismatch? > > > > Your kernel reference is the same as having a file open reference so I > > think this actually needs addressing in the maths. In other words count > > the number of kernel references and also add that into the test for > > check_tty_count (kernel references + #fds == count). > > > > I'd really like to keep this right because that check has a long history > > of catching really nasty race conditions in the tty code. The > > open/close/hangup code is really fragile so worth the debugability. > > I see. Okay based this, check_tty_count can be easily updated to take > into account kernel references. Ok, I'll drop this series from my "to-apply" queue and wait for you to redo it. thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
