[B.A.T.M.A.N.] [PATCH 12/17] batman-adv: Less function calls in batadv_is_ap_isolated() after error detection

Simon Wunderlich
2016-10-27T19:01:45Z

From: Markus Elfring <elfring@users.sourceforge.net>

The variables "tt_local_entry" and "tt_global_entry" were eventually
checked again despite of a corresponding null pointer test before.

* Avoid this double check by reordering a function call sequence
and the better selection of jump targets.

* Omit the initialisation for these variables at the beginning then.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
net/batman-adv/translation-table.c | 25 +++++++++++--------------
1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 7f66309..ad1e3bc 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -3835,8 +3835,8 @@ void batadv_tt_local_commit_changes(struct batadv_priv *bat_priv)
bool batadv_is_ap_isolated(struct batadv_priv *bat_priv, u8 *src, u8 *dst,
unsigned short vid)
{
- struct batadv_tt_local_entry *tt_local_entry = NULL;
- struct batadv_tt_global_entry *tt_global_entry = NULL;
+ struct batadv_tt_local_entry *tt_local_entry;
+ struct batadv_tt_global_entry *tt_global_entry;
struct batadv_softif_vlan *vlan;
bool ret = false;

@@ -3845,27 +3845,24 @@ bool batadv_is_ap_isolated(struct batadv_priv *bat_priv, u8 *src, u8 *dst,
return false;

if (!atomic_read(&vlan->ap_isolation))
- goto out;
+ goto vlan_put;

tt_local_entry = batadv_tt_local_hash_find(bat_priv, dst, vid);
if (!tt_local_entry)
- goto out;
+ goto vlan_put;

tt_global_entry = batadv_tt_global_hash_find(bat_priv, src, vid);
if (!tt_global_entry)
- goto out;
-
- if (!_batadv_is_ap_isolated(tt_local_entry, tt_global_entry))
- goto out;
+ goto local_entry_put;

- ret = true;
+ if (_batadv_is_ap_isolated(tt_local_entry, tt_global_entry))
+ ret = true;

-out:
+ batadv_tt_global_entry_put(tt_global_entry);
+local_entry_put:
+ batadv_tt_local_entry_put(tt_local_entry);
+vlan_put:
batadv_softif_vlan_put(vlan);
- if (tt_global_entry)
- batadv_tt_global_entry_put(tt_global_entry);
- if (tt_local_entry)
- batadv_tt_local_entry_put(tt_local_entry);
return ret;
}

--
2.10.1