| Message ID | 1463527868-12226-1-git-send-email-xypron.glpk@gmx.de |
|---|---|
| State | Awaiting Upstream, archived |
| Delegated to: | David Miller |
| Headers | show |
On Wed, 2016-05-18 at 01:31 +0200, Heinrich Schuchardt wrote: > If we dereference a variable anyway in other parts of the code, > there is no need to check against NULL in a single place. NACK. This is not true. If lq_sta is NULL, it means that mvm_sta is also NULL. Then we call the rate_control_send with mvm_sta == NULL: if (rate_control_send_low(sta, mvm_sta, txrc)) return; The rate_control_send_low() function looks like this: bool rate_control_send_low(struct ieee80211_sta *pubsta, void *priv_sta, struct ieee80211_tx_rate_control *txrc) { [...] if (!pubsta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) { [...] return true; } [...] } Which means that if priv_sta (aka mvm_sta) is NULL, we will return without running the rest of rs_get_rate() where lq_sta is accessed without checks. I admit that the rs_get_rate() function is a bit hard to read, but removing the lq_sta check as you did doesn't help, but makes things worse. -- Cheers, Luca.
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c index 81dd2f6..bab01ea 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c @@ -2867,7 +2867,7 @@ static void rs_get_rate(void *mvm_r, struct ieee80211_sta *sta, void *mvm_sta, /* TODO: handle rate_idx_mask and rate_idx_mcs_mask */ /* Treat uninitialized rate scaling data same as non-existing. */ - if (lq_sta && !lq_sta->pers.drv) { + if (!lq_sta->pers.drv) { IWL_DEBUG_RATE(mvm, "Rate scaling not initialized yet.\n"); mvm_sta = NULL; }
If we dereference a variable anyway in other parts of the code, there is no need to check against NULL in a single place. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> --- drivers/net/wireless/intel/iwlwifi/mvm/rs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)