From: Krzysztof Mazur <krzysiek@podlesie.net>
Date: Tue, 6 Nov 2012 22:17:00 +0000 (+0100)
Subject: pppoatm: take ATM socket lock in pppoatm_send()
X-Git-Tag: omap-for-v3.8/fixes-for-merge-window-v4-signed~45^2~138^2~13
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3ac108006fd7f20cb8fc8ea2287f1497bcda00a1;p=pandora-kernel.git

pppoatm: take ATM socket lock in pppoatm_send()

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>
---

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