wifi: mac80211: fix link manipulation

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@intel.com>
This commit is contained in:
Johannes Berg 2022-07-06 14:03:07 +02:00
parent 939c4c7e82
commit d3e2439b0f

View File

@ -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 */