From: Wilson Kok Date: Fri, 5 Jun 2015 07:52:57 +0000 (-0700) Subject: bridge: use _bh spinlock variant for br_fdb_update to avoid lockup X-Git-Tag: omap-for-v4.2/fixes-rc1^2~214^2~9 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1d7c49037b12016e7056b9f2c990380e2187e766;p=pandora-kernel.git bridge: use _bh spinlock variant for br_fdb_update to avoid lockup br_fdb_update() can be called in process context in the following way: br_fdb_add() -> __br_fdb_add() -> br_fdb_update() (if NTF_USE flag is set) so we need to use spin_lock_bh because there are softirq users of the hash_lock. One easy way to reproduce this is to modify the bridge utility to set NTF_USE, enable stp and then set maxageing to a low value so br_fdb_cleanup() is called frequently and then just add new entries in a loop. This happens because br_fdb_cleanup() is called from timer/softirq context. These locks were _bh before commit f8ae737deea1 ("[BRIDGE]: forwarding remove unneeded preempt and bh diasables") and at the time that commit was correct because br_fdb_update() couldn't be called from process context, but that changed after commit: 292d1398983f ("bridge: add NTF_USE support") Signed-off-by: Wilson Kok Signed-off-by: Nikolay Aleksandrov Fixes: 292d1398983f ("bridge: add NTF_USE support") Signed-off-by: David S. Miller --- Reading git-diff-tree failed