net: rtnetlink: use rcu to free rtnl message handlers

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rtnetlink is littered with READ_ONCE() because we can have read accesses
while another cpu can write to the structure we're reading by
(un)registering doit or dumpit handlers.

This patch changes this so that (un)registering cpu allocates a new
structure and then publishes it via rcu_assign_pointer, i.e. once
another cpu can see such pointer no modifications will occur anymore.

based on initial patch from Peter Zijlstra.

Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

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Florian Westphal 2017-12-02 21:44:05 +01:00 • committed by David S. Miller

parent 9753c21f55

commit addf9b90de

1 changed files with 101 additions and 53 deletions

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net/core/rtnetlink.c

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