[PATCH] wl3501_cs: Add spinlock to wl3501_reset

From: Pavel Andrianov
Date: Tue Aug 02 2016 - 06:20:12 EST


Likely wl3501_reset should acquire spinlock as wl3501_{open, close}.
One of calls of wl3501_reset has been already protected.
The others were unprotected and might lead to a race condition.
The patch adds spinlock into the wl3501_reset and removes it from
wl3501_tx_timeout.

Found by Linux Driver Verification project (linuxtesting.org)

Signed-off-by: Pavel Andrianov <andrianov@xxxxxxxxx>
---
drivers/net/wireless/wl3501_cs.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/wl3501_cs.c b/drivers/net/wireless/wl3501_cs.c
index 13fd734..196f13c 100644
--- a/drivers/net/wireless/wl3501_cs.c
+++ b/drivers/net/wireless/wl3501_cs.c
@@ -1247,7 +1247,9 @@ static int wl3501_reset(struct net_device *dev)
{
struct wl3501_card *this = netdev_priv(dev);
int rc = -ENODEV;
+ unsigned long flags;

+ spin_lock_irqsave(&this->lock, flags);
wl3501_block_interrupt(this);

if (wl3501_init_firmware(this)) {
@@ -1269,20 +1271,17 @@ static int wl3501_reset(struct net_device *dev)
pr_debug("%s: device reset", dev->name);
rc = 0;
out:
+ spin_unlock_irqrestore(&this->lock, flags);
return rc;
}

static void wl3501_tx_timeout(struct net_device *dev)
{
- struct wl3501_card *this = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
- unsigned long flags;
int rc;

stats->tx_errors++;
- spin_lock_irqsave(&this->lock, flags);
rc = wl3501_reset(dev);
- spin_unlock_irqrestore(&this->lock, flags);
if (rc)
printk(KERN_ERR "%s: Error %d resetting card on Tx timeout!\n",
dev->name, rc);
--
2.7.4