In case a channel that is going to be destroyed has been tagged as not
"healthy" by the function hdm_poison_channel() while the functions
hdm_write_completion() or hdm_read_completion() are being executed, they
race for destruction of buf_anchor.
This patch fixes the problem.
Signed-off-by: Andrey Shvetsov <andrey.shvetsov@xxxxxx>
Signed-off-by: Christian Gromm <christian.gromm@xxxxxxxxxxxxx>
---
drivers/staging/most/hdm-usb/hdm_usb.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/most/hdm-usb/hdm_usb.c b/drivers/staging/most/hdm-usb/hdm_usb.c
index 5fea5f4..ed49640 100644
--- a/drivers/staging/most/hdm-usb/hdm_usb.c
+++ b/drivers/staging/most/hdm-usb/hdm_usb.c
@@ -285,6 +285,8 @@ static unsigned int get_stream_frame_size(struct most_channel_config *cfg)
static int hdm_poison_channel(struct most_interface *iface, int channel)
{
struct most_dev *mdev;
+ unsigned long flags;
+ spinlock_t *lock; /* temp. lock */
mdev = to_mdev(iface);
if (unlikely(!iface)) {
@@ -296,7 +298,10 @@ static int hdm_poison_channel(struct most_interface *iface, int channel)
return -ECHRNG;
}
+ lock = mdev->anchor_list_lock + channel;
+ spin_lock_irqsave(lock, flags);
mdev->is_channel_healthy[channel] = false;
+ spin_unlock_irqrestore(lock, flags);
cancel_work_sync(&mdev->clear_work[channel].ws);
@@ -407,8 +412,10 @@ static void hdm_write_completion(struct urb *urb)
dev = &mdev->usb_device->dev;
lock = mdev->anchor_list_lock + channel;
+ spin_lock_irqsave(lock, flags);
if ((urb->status == -ENOENT) || (urb->status == -ECONNRESET) ||
(!mdev->is_channel_healthy[channel])) {
+ spin_unlock_irqrestore(lock, flags);
complete(&anchor->urb_compl);
return;
}
@@ -419,6 +426,7 @@ static void hdm_write_completion(struct urb *urb)
case -EPIPE:
dev_warn(dev, "Broken OUT pipe detected\n");
mdev->is_channel_healthy[channel] = false;
+ spin_unlock_irqrestore(lock, flags);
mbo->status = MBO_E_INVAL;
mdev->clear_work[channel].pipe = urb->pipe;
schedule_work(&mdev->clear_work[channel].ws);
@@ -436,7 +444,6 @@ static void hdm_write_completion(struct urb *urb)
mbo->processed_length = urb->actual_length;
}
- spin_lock_irqsave(lock, flags);
list_del(&anchor->list);
spin_unlock_irqrestore(lock, flags);
kfree(anchor);
@@ -571,8 +578,10 @@ static void hdm_read_completion(struct urb *urb)
dev = &mdev->usb_device->dev;
lock = mdev->anchor_list_lock + channel;
+ spin_lock_irqsave(lock, flags);
if ((urb->status == -ENOENT) || (urb->status == -ECONNRESET) ||
(!mdev->is_channel_healthy[channel])) {
+ spin_unlock_irqrestore(lock, flags);
complete(&anchor->urb_compl);
return;
}
@@ -583,6 +592,7 @@ static void hdm_read_completion(struct urb *urb)
case -EPIPE:
dev_warn(dev, "Broken IN pipe detected\n");
mdev->is_channel_healthy[channel] = false;
+ spin_unlock_irqrestore(lock, flags);
mbo->status = MBO_E_INVAL;
mdev->clear_work[channel].pipe = urb->pipe;
schedule_work(&mdev->clear_work[channel].ws);
@@ -606,7 +616,7 @@ static void hdm_read_completion(struct urb *urb)
mbo->status = MBO_E_INVAL;
}
}
- spin_lock_irqsave(lock, flags);
+
list_del(&anchor->list);
spin_unlock_irqrestore(lock, flags);
kfree(anchor);
--
1.9.1
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