4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Or Gerlitz <ogerlitz@xxxxxxxxxxxx>
[ Upstream commit fed06ee89b78d3af32e235e0e89ad0d946fcb95d ]
When called by HW offloading drivers, the TC action (e.g
net/sched/act_mirred.c) code uses this_cpu logic, e.g
_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets)
per the kernel documention, preemption should be disabled, add that.
Before the fix, when running with CONFIG_PREEMPT set, we get a
BUG: using smp_processor_id() in preemptible [00000000] code: tc/3793
asserion from the TC action (mirred) stats_update callback.
Fixes: aad7e08d39bd ('net/mlx5e: Hardware offloaded flower filter statistics support')
Signed-off-by: Or Gerlitz <ogerlitz@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -567,10 +567,14 @@ int mlx5e_stats_flower(struct mlx5e_priv
mlx5_fc_query_cached(counter, &bytes, &packets, &lastuse);
+ preempt_disable();
+
tcf_exts_to_list(f->exts, &actions);
list_for_each_entry(a, &actions, list)
tcf_action_stats_update(a, bytes, packets, lastuse);
+ preempt_enable();
+
return 0;
}