[PATCH AUTOSEL 4.9 07/12] cfg80211: check reg_rule for NULL in handle_channel_custom()

[PATCH AUTOSEL 4.9 07/12] cfg80211: check reg_rule for NULL in handle_channel_custom()

[Sasha Levin]

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit a7ee7d44b57c9ae174088e53a668852b7f4f452d ]

We may end up with a NULL reg_rule after the loop in
handle_channel_custom() if the bandwidth didn't fit,
check if this is the case and bail out if so.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20200221104449.3b558a50201c.I4ad3725c4dacaefd2d18d3cc65ba6d18acd5dbfe@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/wireless/reg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 0e66768427ba7..6d5f3f737207d 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1730,7 +1730,7 @@ static void handle_channel_custom(struct wiphy *wiphy,
 			break;
 	}
 
-	if (IS_ERR(reg_rule)) {
+	if (IS_ERR_OR_NULL(reg_rule)) {
 		pr_debug("Disabling freq %d MHz as custom regd has no rule that fits it\n",
 			 chan->center_freq);
 		if (wiphy->regulatory_flags & REGULATORY_WIPHY_SELF_MANAGED) {
-- 
2.20.1

[PATCH AUTOSEL 4.9 08/12] net: ks8851-ml: Fix IRQ handling and locking

[Sasha Levin]

From: Marek Vasut <marex@denx.de>

[ Upstream commit 44343418d0f2f623cb9da6f5000df793131cbe3b ]

The KS8851 requires that packet RX and TX are mutually exclusive.
Currently, the driver hopes to achieve this by disabling interrupt
from the card by writing the card registers and by disabling the
interrupt on the interrupt controller. This however is racy on SMP.

Replace this approach by expanding the spinlock used around the
ks_start_xmit() TX path to ks_irq() RX path to assure true mutual
exclusion and remove the interrupt enabling/disabling, which is
now not needed anymore. Furthermore, disable interrupts also in
ks_net_stop(), which was missing before.

Note that a massive improvement here would be to re-use the KS8851
driver approach, which is to move the TX path into a worker thread,
interrupt handling to threaded interrupt, and synchronize everything
with mutexes, but that would be a much bigger rework, for a separate
patch.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Petr Stetiar <ynezz@true.cz>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/micrel/ks8851_mll.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/micrel/ks8851_mll.c b/drivers/net/ethernet/micrel/ks8851_mll.c
index 8dc1f0277117d..cc44143f86a5e 100644
--- a/drivers/net/ethernet/micrel/ks8851_mll.c
+++ b/drivers/net/ethernet/micrel/ks8851_mll.c
@@ -866,14 +866,17 @@ static irqreturn_t ks_irq(int irq, void *pw)
 {
 	struct net_device *netdev = pw;
 	struct ks_net *ks = netdev_priv(netdev);
+	unsigned long flags;
 	u16 status;
 
+	spin_lock_irqsave(&ks->statelock, flags);
 	/*this should be the first in IRQ handler */
 	ks_save_cmd_reg(ks);
 
 	status = ks_rdreg16(ks, KS_ISR);
 	if (unlikely(!status)) {
 		ks_restore_cmd_reg(ks);
+		spin_unlock_irqrestore(&ks->statelock, flags);
 		return IRQ_NONE;
 	}
 
@@ -899,6 +902,7 @@ static irqreturn_t ks_irq(int irq, void *pw)
 		ks->netdev->stats.rx_over_errors++;
 	/* this should be the last in IRQ handler*/
 	ks_restore_cmd_reg(ks);
+	spin_unlock_irqrestore(&ks->statelock, flags);
 	return IRQ_HANDLED;
 }
 
@@ -968,6 +972,7 @@ static int ks_net_stop(struct net_device *netdev)
 
 	/* shutdown RX/TX QMU */
 	ks_disable_qmu(ks);
+	ks_disable_int(ks);
 
 	/* set powermode to soft power down to save power */
 	ks_set_powermode(ks, PMECR_PM_SOFTDOWN);
@@ -1024,10 +1029,9 @@ static netdev_tx_t ks_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 {
 	netdev_tx_t retv = NETDEV_TX_OK;
 	struct ks_net *ks = netdev_priv(netdev);
+	unsigned long flags;
 
-	disable_irq(netdev->irq);
-	ks_disable_int(ks);
-	spin_lock(&ks->statelock);
+	spin_lock_irqsave(&ks->statelock, flags);
 
 	/* Extra space are required:
 	*  4 byte for alignment, 4 for status/length, 4 for CRC
@@ -1041,9 +1045,7 @@ static netdev_tx_t ks_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 		dev_kfree_skb(skb);
 	} else
 		retv = NETDEV_TX_BUSY;
-	spin_unlock(&ks->statelock);
-	ks_enable_int(ks);
-	enable_irq(netdev->irq);
+	spin_unlock_irqrestore(&ks->statelock, flags);
 	return retv;
 }
 
-- 
2.20.1

[PATCH AUTOSEL 4.9 09/12] mac80211: rx: avoid RCU list traversal under mutex

[Sasha Levin]

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

[ Upstream commit 253216ffb2a002a682c6f68bd3adff5b98b71de8 ]

local->sta_mtx is held in __ieee80211_check_fast_rx_iface().
No need to use list_for_each_entry_rcu() as it also requires
a cond argument to avoid false lockdep warnings when not used in
RCU read-side section (with CONFIG_PROVE_RCU_LIST).
Therefore use list_for_each_entry();

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Link: https://lore.kernel.org/r/20200223143302.15390-1-madhuparnabhowmik10@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/mac80211/rx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 74652eb2f90fd..a6f265262f151 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -3841,7 +3841,7 @@ void __ieee80211_check_fast_rx_iface(struct ieee80211_sub_if_data *sdata)
 
 	lockdep_assert_held(&local->sta_mtx);
 
-	list_for_each_entry_rcu(sta, &local->sta_list, list) {
+	list_for_each_entry(sta, &local->sta_list, list) {
 		if (sdata != sta->sdata &&
 		    (!sta->sdata->bss || sta->sdata->bss != sdata->bss))
 			continue;
-- 
2.20.1