From f981fc3d515a588c389242b7e3a71487b40571a5 Mon Sep 17 00:00:00 2001 From: Eelco Chaudron Date: Sat, 17 Oct 2020 20:24:51 +0200 Subject: net: openvswitch: fix to make sure flow_lookup() is not preempted The flow_lookup() function uses per CPU variables, which must be called with BH disabled. However, this is fine in the general NAPI use case where the local BH is disabled. But, it's also called from the netlink context. The below patch makes sure that even in the netlink path, the BH is disabled. In addition, u64_stats_update_begin() requires a lock to ensure one writer which is not ensured here. Making it per-CPU and disabling NAPI (softirq) ensures that there is always only one writer. Fixes: eac87c413bf9 ("net: openvswitch: reorder masks array based on usage") Reported-by: Juri Lelli Signed-off-by: Eelco Chaudron Link: https://lore.kernel.org/r/160295903253.7789.826736662555102345.stgit@ebuild Signed-off-by: Jakub Kicinski --- net/openvswitch/flow_table.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/openvswitch/flow_table.h') diff --git a/net/openvswitch/flow_table.h b/net/openvswitch/flow_table.h index d8fb7a3a3dfd..9e659db78c05 100644 --- a/net/openvswitch/flow_table.h +++ b/net/openvswitch/flow_table.h @@ -38,12 +38,16 @@ struct mask_count { u64 counter; }; +struct mask_array_stats { + struct u64_stats_sync syncp; + u64 usage_cntrs[]; +}; + struct mask_array { struct rcu_head rcu; int count, max; - u64 __percpu *masks_usage_cntr; + struct mask_array_stats __percpu *masks_usage_stats; u64 *masks_usage_zero_cntr; - struct u64_stats_sync syncp; struct sw_flow_mask __rcu *masks[]; }; -- cgit v1.2.1