tree 6dcd64ef200dbae047a4c26bd84a4c904650f105
parent 0a7ca3681116ca39ac3cd20200c213c93ad4e1e8
author Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1378421490 -0700
committer Paul E. McKenney <paulmck@linux.vnet.ibm.com> 1379953300 -0700

bonding/bond_main: Apply rcu_access_pointer() to avoid sparse false positive

The sparse checking for rcu_assign_pointer() was recently upgraded
to reject non-__kernel address spaces.  This also rejects __rcu,
which is almost always the right thing to do.  However, the uses in
bond_change_active_slave(), bond_enslave(), and __bond_release_one()
are legitimate: They are assigning a pointer to an element from an
RCU-protected list (or a NULL pointer), and all elements of this list
are already visible to caller.

This commit therefore silences these false positives either by laundering
the pointers using rcu_access_pointer() as suggested by Josh Triplett,
or by using RCU_INIT_POINTER() for NULL pointer assignments.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: bridge@lists.linux-foundation.org
Cc: netdev@vger.kernel.org