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| author | Sven Eckelmann <sven@narfation.org> | 2020-02-16 18:30:12 +0100 |
|---|---|---|
| committer | Simon Wunderlich <sw@simonwunderlich.de> | 2020-02-17 16:07:50 +0100 |
| commit | 3b2582c7affde5f30bcc8321385507e66f4299e1 (patch) | |
| tree | 45bb6894c030f2799980ad83a2c22bb88cc054e7 | |
| parent | edddb36644d56efc5833405bdf1c46f85677fc5c (diff) | |
| download | linux-3b2582c7affde5f30bcc8321385507e66f4299e1.tar.gz linux-3b2582c7affde5f30bcc8321385507e66f4299e1.tar.bz2 linux-3b2582c7affde5f30bcc8321385507e66f4299e1.zip | |
batman-adv: Avoid RCU list-traversal in spinlock
The new CONFIG_PROVE_RCU_LIST requires a condition statement in
(h)list_for_each_entry_rcu when the code might be executed in a non RCU
non-reader section with the writer lock. Otherwise lockdep might cause a
false positive warning like
=============================
WARNING: suspicious RCU usage
-----------------------------
translation-table.c:940 RCU-list traversed in non-reader section!!
batman-adv is (mostly) following the examples from the RCU documentation
and is using the normal list-traversal primitives instead of the RCU
list-traversal primitives when the writer (spin)lock is held.
The remaining users of RCU list-traversal primitives with writer spinlock
have to be converted to the same style as the rest of the code.
Reported-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
| -rw-r--r-- | net/batman-adv/translation-table.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 852932838ddc..a9635c882fe0 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -862,7 +862,7 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, u8 *tt_change_ptr; spin_lock_bh(&orig_node->vlan_list_lock); - hlist_for_each_entry_rcu(vlan, &orig_node->vlan_list, list) { + hlist_for_each_entry(vlan, &orig_node->vlan_list, list) { num_vlan++; num_entries += atomic_read(&vlan->tt.num_entries); } @@ -888,7 +888,7 @@ batadv_tt_prepare_tvlv_global_data(struct batadv_orig_node *orig_node, (*tt_data)->num_vlan = htons(num_vlan); tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(*tt_data + 1); - hlist_for_each_entry_rcu(vlan, &orig_node->vlan_list, list) { + hlist_for_each_entry(vlan, &orig_node->vlan_list, list) { tt_vlan->vid = htons(vlan->vid); tt_vlan->crc = htonl(vlan->tt.crc); @@ -937,7 +937,7 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, int change_offset; spin_lock_bh(&bat_priv->softif_vlan_list_lock); - hlist_for_each_entry_rcu(vlan, &bat_priv->softif_vlan_list, list) { + hlist_for_each_entry(vlan, &bat_priv->softif_vlan_list, list) { vlan_entries = atomic_read(&vlan->tt.num_entries); if (vlan_entries < 1) continue; @@ -967,7 +967,7 @@ batadv_tt_prepare_tvlv_local_data(struct batadv_priv *bat_priv, (*tt_data)->num_vlan = htons(num_vlan); tt_vlan = (struct batadv_tvlv_tt_vlan_data *)(*tt_data + 1); - hlist_for_each_entry_rcu(vlan, &bat_priv->softif_vlan_list, list) { + hlist_for_each_entry(vlan, &bat_priv->softif_vlan_list, list) { vlan_entries = atomic_read(&vlan->tt.num_entries); if (vlan_entries < 1) continue; |