Ar Maw, 2006-06-27 am 23:29 -0400, ysgrifennodd Jon Smirl:
> Why does this need to be protected? exit.c
> mutex_lock(&tty_mutex);
> current->signal->tty = NULL;
> mutex_unlock(&tty_mutex);
It races against things like a third party haungup of the controlling
tty session if the lock is not held.
> After looking at all of this for a couple of hours it looks to me like
> tty_mutex could be removed if ref counts were used to control when the
> tty_struct gets destroyed.
You would still want memory barriers and to audit the time things took
effect as there is a fairly defined ordering involved here. Fully
refcounting ttys would not be a bad thing but would require some driver
work because the driver level objects hung off a tty are often not
dynamically allocated and are not themselves refcounted so would get
corrupted if the tty object was freed and a new one allocated and opened
in the meantime.
Alan
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]