From: Johannes Berg <johannes.berg@xxxxxxxxx>
When we add non-deflink pointers, we need to remove the
link[0] pointer to deflink in case link[0] is not valid
afterwards. Also, we need to add that back when there
are no more valid links. Reorg the code to fix that.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
net/mac80211/iface.c | 44 ++++++++++++++++++++++++++------------------
1 file changed, 26 insertions(+), 18 deletions(-)
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index fc5869f40279..271fc81a5ea4 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -463,6 +463,10 @@ static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
if (old_links == new_links)
return 0;
+ /* if there were no old links, need to clear the pointers to deflink */
+ if (!old_links)
+ rem |= BIT(0);
+
/* allocate new link structures first */
for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
link = kzalloc(sizeof(*link), GFP_KERNEL);
@@ -480,6 +484,22 @@ static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
BUILD_BUG_ON(sizeof(old_data) != sizeof(sdata->link));
memcpy(old_data, sdata->link, sizeof(old_data));
+ /* grab old links to free later */
+ for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
+ RCU_INIT_POINTER(sdata->link[link_id], NULL);
+ RCU_INIT_POINTER(sdata->vif.link_conf[link_id], NULL);
+
+ if (rcu_access_pointer(sdata->link[link_id]) == &sdata->deflink)
+ continue;
+ /*
+ * we must have allocated the data through this path so
+ * we know we can free both at the same time
+ */
+ to_free[link_id] = container_of(rcu_access_pointer(sdata->link[link_id]),
+ typeof(*links[link_id]),
+ data);
+ }
+
/* link them into data structures */
for_each_set_bit(link_id, &add, IEEE80211_MLD_MAX_NUM_LINKS) {
WARN_ON(!use_deflink &&
@@ -490,10 +510,9 @@ static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
ieee80211_link_setup(&link->data);
}
- for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
- RCU_INIT_POINTER(sdata->link[link_id], NULL);
- RCU_INIT_POINTER(sdata->vif.link_conf[link_id], NULL);
- }
+ if (new_links == 0)
+ ieee80211_link_init(sdata, -1, &sdata->deflink,
+ &sdata->vif.bss_conf);
sdata->vif.valid_links = new_links;
@@ -506,25 +525,14 @@ static int ieee80211_vif_update_links(struct ieee80211_sub_if_data *sdata,
memcpy(sdata->link, old_data, sizeof(old_data));
memcpy(sdata->vif.link_conf, old, sizeof(old));
sdata->vif.valid_links = old_links;
- /* and free the newly allocated links */
- goto deinit;
+ /* and free (only) the newly allocated links */
+ memset(to_free, 0, sizeof(links));
+ goto free;
}
/* use deflink/bss_conf again if and only if there are no more links */
use_deflink = new_links == 0;
- for_each_set_bit(link_id, &rem, IEEE80211_MLD_MAX_NUM_LINKS) {
- if (rcu_access_pointer(sdata->link[link_id]) == &sdata->deflink)
- continue;
- /*
- * we must have allocated the data through this path so
- * we know we can free both at the same time
- */
- to_free[link_id] = container_of(rcu_access_pointer(sdata->link[link_id]),
- typeof(*links[link_id]),
- data);
- }
-
goto deinit;
free:
/* if we failed during allocation, only free all */
--
2.36.1
