The pppoatm_send() does not take any lock that will prevent concurrent
vcc_sendmsg(). This causes two problems:
- there is no locking between checking the send queue size
with atm_may_send() and incrementing sk_wmem_alloc,
and the real queue size can be a little higher than sk_sndbuf
- the vcc->sendmsg() can be called concurrently. I'm not sure
if it's allowed. Some drivers (eni, nicstar, ...) seem
to assume it will never happen.
Now pppoatm_send() takes ATM socket lock, the same that is used
in vcc_sendmsg() and other ATM socket functions. The pppoatm_send()
is called with BH disabled, so bh_lock_sock() is used instead
of lock_sock().
Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Cc: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
3ac108006f