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author | Lior Cohen <lior2.cohen@intel.com> | 2019-08-30 14:24:49 +0300 |
---|---|---|
committer | Johannes Berg <johannes.berg@intel.com> | 2019-09-11 09:33:28 +0200 |
commit | 624ff4b210ecccb0a39387993302b1a6af74176e (patch) | |
tree | 4e99e2fd624d4bc1aeaae2bf6675c72c7497eb8a /net/mac80211/key.c | |
parent | 1c9559734eca3dc03a4c805fbf5103349d7a7cf3 (diff) | |
download | linux-stable-624ff4b210ecccb0a39387993302b1a6af74176e.tar.gz linux-stable-624ff4b210ecccb0a39387993302b1a6af74176e.tar.bz2 linux-stable-624ff4b210ecccb0a39387993302b1a6af74176e.zip |
mac80211: clear crypto tx tailroom counter upon keys enable
In case we got a fw restart while roaming from encrypted AP to
non-encrypted one, we might end up with hitting a warning on the pending
counter crypto_tx_tailroom_pending_dec having a non-zero value.
The following comment taken from net/mac80211/key.c explains the rational
for the delayed tailroom needed:
/*
* The reason for the delayed tailroom needed decrementing is to
* make roaming faster: during roaming, all keys are first deleted
* and then new keys are installed. The first new key causes the
* crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
* the cost of synchronize_net() (which can be slow). Avoid this
* by deferring the crypto_tx_tailroom_needed_cnt decrementing on
* key removal for a while, so if we roam the value is larger than
* zero and no 0->1 transition happens.
*
* The cost is that if the AP switching was from an AP with keys
* to one without, we still allocate tailroom while it would no
* longer be needed. However, in the typical (fast) roaming case
* within an ESS this usually won't happen.
*/
The next flow lead to the warning eventually reported as a bug:
1. Disconnect from encrypted AP
2. Set crypto_tx_tailroom_pending_dec = 1 for the key
3. Schedule work
4. Reconnect to non-encrypted AP
5. Add a new key, setting the tailroom counter = 1
6. Got FW restart while pending counter is set ---> hit the warning
While on it, the ieee80211_reset_crypto_tx_tailroom() func was merged into
its single caller ieee80211_reenable_keys (previously called
ieee80211_enable_keys). Also, we reset the crypto_tx_tailroom_pending_dec
and remove the counters warning as we just reset both.
Signed-off-by: Lior Cohen <lior2.cohen@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20190830112451.21655-7-luca@coelho.fi
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211/key.c')
-rw-r--r-- | net/mac80211/key.c | 40 |
1 files changed, 12 insertions, 28 deletions
diff --git a/net/mac80211/key.c b/net/mac80211/key.c index 1be3686562ee..93ea03b86b80 100644 --- a/net/mac80211/key.c +++ b/net/mac80211/key.c @@ -843,46 +843,30 @@ void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom) ieee80211_key_destroy(key, delay_tailroom); } -void ieee80211_enable_keys(struct ieee80211_sub_if_data *sdata) +void ieee80211_reenable_keys(struct ieee80211_sub_if_data *sdata) { struct ieee80211_key *key; struct ieee80211_sub_if_data *vlan; ASSERT_RTNL(); - if (WARN_ON(!ieee80211_sdata_running(sdata))) - return; - - mutex_lock(&sdata->local->key_mtx); - - WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt || - sdata->crypto_tx_tailroom_pending_dec); - - if (sdata->vif.type == NL80211_IFTYPE_AP) { - list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) - WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt || - vlan->crypto_tx_tailroom_pending_dec); - } - - list_for_each_entry(key, &sdata->key_list, list) { - increment_tailroom_need_count(sdata); - ieee80211_key_enable_hw_accel(key); - } - - mutex_unlock(&sdata->local->key_mtx); -} - -void ieee80211_reset_crypto_tx_tailroom(struct ieee80211_sub_if_data *sdata) -{ - struct ieee80211_sub_if_data *vlan; - mutex_lock(&sdata->local->key_mtx); sdata->crypto_tx_tailroom_needed_cnt = 0; + sdata->crypto_tx_tailroom_pending_dec = 0; if (sdata->vif.type == NL80211_IFTYPE_AP) { - list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) + list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) { vlan->crypto_tx_tailroom_needed_cnt = 0; + vlan->crypto_tx_tailroom_pending_dec = 0; + } + } + + if (ieee80211_sdata_running(sdata)) { + list_for_each_entry(key, &sdata->key_list, list) { + increment_tailroom_need_count(sdata); + ieee80211_key_enable_hw_accel(key); + } } mutex_unlock(&sdata->local->key_mtx); |