[PATCH] drivers/wireless: iwlwifi/mvm: Convert timers to use timer_setup()

From: Kees Cook
Date: Tue Oct 24 2017 - 05:30:04 EST


In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

The RCU lifetime on baid_data is unclear, so this adds a direct copy of the
rcu_ptr passed to the original callback. It may be possible to improve this
to just use baid_data->mvm->baid_map[baid_data->baid] instead.

Cc: Johannes Berg <johannes.berg@xxxxxxxxx>
Cc: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Cc: Luca Coelho <luciano.coelho@xxxxxxxxx>
Cc: Intel Linux Wireless <linuxwifi@xxxxxxxxx>
Cc: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Cc: Sara Sharon <sara.sharon@xxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
drivers/net/wireless/intel/iwlwifi/mvm/mvm.h | 3 ++-
drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c | 4 ++--
drivers/net/wireless/intel/iwlwifi/mvm/sta.c | 18 +++++++++---------
3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
index bf25c3ce7c95..a22c0ecff324 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -636,6 +636,7 @@ struct iwl_mvm_baid_data {
u16 timeout;
unsigned long last_rx;
struct timer_list session_timer;
+ struct iwl_mvm_baid_data __rcu **rcu_ptr;
struct iwl_mvm *mvm;
struct iwl_mvm_reorder_buffer reorder_buf[];
};
@@ -1829,7 +1830,7 @@ void iwl_mvm_tdls_ch_switch_work(struct work_struct *work);
void iwl_mvm_sync_rx_queues_internal(struct iwl_mvm *mvm,
struct iwl_mvm_internal_rxq_notif *notif,
u32 size);
-void iwl_mvm_reorder_timer_expired(unsigned long data);
+void iwl_mvm_reorder_timer_expired(struct timer_list *t);
struct ieee80211_vif *iwl_mvm_get_bss_vif(struct iwl_mvm *mvm);
bool iwl_mvm_is_vif_assoc(struct iwl_mvm *mvm);

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
index 5e679859f948..53485dc096b3 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/rxmq.c
@@ -456,9 +456,9 @@ static void iwl_mvm_release_frames(struct iwl_mvm *mvm,
}
}

-void iwl_mvm_reorder_timer_expired(unsigned long data)
+void iwl_mvm_reorder_timer_expired(struct timer_list *t)
{
- struct iwl_mvm_reorder_buffer *buf = (void *)data;
+ struct iwl_mvm_reorder_buffer *buf = from_timer(buf, t, reorder_timer);
int i;
u16 sn = 0, index = 0;
bool expired = false;
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index 282424f40c43..b95b24a03959 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -252,9 +252,11 @@ int iwl_mvm_sta_send_to_fw(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
return ret;
}

-static void iwl_mvm_rx_agg_session_expired(unsigned long data)
+static void iwl_mvm_rx_agg_session_expired(struct timer_list *t)
{
- struct iwl_mvm_baid_data __rcu **rcu_ptr = (void *)data;
+ struct iwl_mvm_baid_data *data =
+ from_timer(data, t, session_timer);
+ struct iwl_mvm_baid_data __rcu **rcu_ptr = data->rcu_ptr;
struct iwl_mvm_baid_data *ba_data;
struct ieee80211_sta *sta;
struct iwl_mvm_sta *mvm_sta;
@@ -2150,10 +2152,8 @@ static void iwl_mvm_init_reorder_buffer(struct iwl_mvm *mvm,
reorder_buf->head_sn = ssn;
reorder_buf->buf_size = buf_size;
/* rx reorder timer */
- reorder_buf->reorder_timer.function =
- iwl_mvm_reorder_timer_expired;
- reorder_buf->reorder_timer.data = (unsigned long)reorder_buf;
- init_timer(&reorder_buf->reorder_timer);
+ timer_setup(&reorder_buf->reorder_timer,
+ iwl_mvm_reorder_timer_expired, 0);
spin_lock_init(&reorder_buf->lock);
reorder_buf->mvm = mvm;
reorder_buf->queue = i;
@@ -2250,9 +2250,9 @@ int iwl_mvm_sta_rx_agg(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
baid_data->baid = baid;
baid_data->timeout = timeout;
baid_data->last_rx = jiffies;
- setup_timer(&baid_data->session_timer,
- iwl_mvm_rx_agg_session_expired,
- (unsigned long)&mvm->baid_map[baid]);
+ baid_data->rcu_ptr = &mvm->baid_map[baid];
+ timer_setup(&baid_data->session_timer,
+ iwl_mvm_rx_agg_session_expired, 0);
baid_data->mvm = mvm;
baid_data->tid = tid;
baid_data->sta_id = mvm_sta->sta_id;
--
2.7.4


--
Kees Cook
Pixel Security