[PATCH 1/2] HID: logitech-dj: prevent false errors to be shown

[PATCH 1/2] HID: logitech-dj: prevent false errors to be shown

[Benjamin Tissoires]

Commit "HID: logitech: perform bounds checking on device_id early
enough" unfortunately leaks some errors to dmesg which are not real
ones:
- if the report is not a DJ one, then there is not point in checking
  the device_id
- the receiver (index 0) can also receive some notifications which
  can be safely ignored given the current implementation

Move out the test regarding the report_id and also discards
printing errors when the receiver got notified.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---
 drivers/hid/hid-logitech-dj.c | 43 +++++++++++++++++++++++++------------------
 drivers/hid/hid-logitech-dj.h |  1 +
 2 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
index b7ba829..9bf8637 100644
--- a/drivers/hid/hid-logitech-dj.c
+++ b/drivers/hid/hid-logitech-dj.c
@@ -656,7 +656,6 @@ static int logi_dj_raw_event(struct hid_device *hdev,
 	struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);
 	struct dj_report *dj_report = (struct dj_report *) data;
 	unsigned long flags;
-	bool report_processed = false;
 
 	dbg_hid("%s, size:%d\n", __func__, size);
 
@@ -683,34 +682,42 @@ static int logi_dj_raw_event(struct hid_device *hdev,
 	 * device (via hid_input_report() ) and return 1 so hid-core does not do
 	 * anything else with it.
 	 */
+
+	/* case 1) */
+	if (data[0] != REPORT_ID_DJ_SHORT)
+		return false;
+
 	if ((dj_report->device_index < DJ_DEVICE_INDEX_MIN) ||
 	    (dj_report->device_index > DJ_DEVICE_INDEX_MAX)) {
-		dev_err(&hdev->dev, "%s: invalid device index:%d\n",
+		/*
+		 * Device index is wrong, bail out.
+		 * This driver can ignore safely the receiver notifications,
+		 * so ignore those reports too.
+		 */
+		if (dj_report->device_index != DJ_RECEIVER_INDEX)
+			dev_err(&hdev->dev, "%s: invalid device index:%d\n",
 				__func__, dj_report->device_index);
 		return false;
 	}
 
 	spin_lock_irqsave(&djrcv_dev->lock, flags);
-	if (dj_report->report_id == REPORT_ID_DJ_SHORT) {
-		switch (dj_report->report_type) {
-		case REPORT_TYPE_NOTIF_DEVICE_PAIRED:
-		case REPORT_TYPE_NOTIF_DEVICE_UNPAIRED:
-			logi_dj_recv_queue_notification(djrcv_dev, dj_report);
-			break;
-		case REPORT_TYPE_NOTIF_CONNECTION_STATUS:
-			if (dj_report->report_params[CONNECTION_STATUS_PARAM_STATUS] ==
-			    STATUS_LINKLOSS) {
-				logi_dj_recv_forward_null_report(djrcv_dev, dj_report);
-			}
-			break;
-		default:
-			logi_dj_recv_forward_report(djrcv_dev, dj_report);
+	switch (dj_report->report_type) {
+	case REPORT_TYPE_NOTIF_DEVICE_PAIRED:
+	case REPORT_TYPE_NOTIF_DEVICE_UNPAIRED:
+		logi_dj_recv_queue_notification(djrcv_dev, dj_report);
+		break;
+	case REPORT_TYPE_NOTIF_CONNECTION_STATUS:
+		if (dj_report->report_params[CONNECTION_STATUS_PARAM_STATUS] ==
+		    STATUS_LINKLOSS) {
+			logi_dj_recv_forward_null_report(djrcv_dev, dj_report);
 		}
-		report_processed = true;
+		break;
+	default:
+		logi_dj_recv_forward_report(djrcv_dev, dj_report);
 	}
 	spin_unlock_irqrestore(&djrcv_dev->lock, flags);
 
-	return report_processed;
+	return true;
 }
 
 static int logi_dj_probe(struct hid_device *hdev,
diff --git a/drivers/hid/hid-logitech-dj.h b/drivers/hid/hid-logitech-dj.h
index 4a40003..daeb0aa 100644
--- a/drivers/hid/hid-logitech-dj.h
+++ b/drivers/hid/hid-logitech-dj.h
@@ -27,6 +27,7 @@
 
 #define DJ_MAX_PAIRED_DEVICES			6
 #define DJ_MAX_NUMBER_NOTIFICATIONS		8
+#define DJ_RECEIVER_INDEX			0
 #define DJ_DEVICE_INDEX_MIN 			1
 #define DJ_DEVICE_INDEX_MAX 			6
 
-- 
2.1.0

[PATCH 2/2] HID: logitech-dj: break out testing of validity of dj_device

[Benjamin Tissoires]

We can do once the test of the validity of the dj_device, which removes
some duplicated code in various functions.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---
 drivers/hid/hid-logitech-dj.c | 35 +++++++++++------------------------
 1 file changed, 11 insertions(+), 24 deletions(-)

diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
index 9bf8637..71f5692 100644
--- a/drivers/hid/hid-logitech-dj.c
+++ b/drivers/hid/hid-logitech-dj.c
@@ -385,18 +385,6 @@ static void logi_dj_recv_forward_null_report(struct dj_receiver_dev *djrcv_dev,
 
 	djdev = djrcv_dev->paired_dj_devices[dj_report->device_index];
 
-	if (!djdev) {
-		dbg_hid("djrcv_dev->paired_dj_devices[dj_report->device_index]"
-			" is NULL, index %d\n", dj_report->device_index);
-		kfifo_in(&djrcv_dev->notif_fifo, dj_report, sizeof(struct dj_report));
-
-		if (schedule_work(&djrcv_dev->work) == 0) {
-			dbg_hid("%s: did not schedule the work item, was already "
-			"queued\n", __func__);
-		}
-		return;
-	}
-
 	memset(reportbuffer, 0, sizeof(reportbuffer));
 
 	for (i = 0; i < NUMBER_OF_HID_REPORTS; i++) {
@@ -421,18 +409,6 @@ static void logi_dj_recv_forward_report(struct dj_receiver_dev *djrcv_dev,
 
 	dj_device = djrcv_dev->paired_dj_devices[dj_report->device_index];
 
-	if (dj_device == NULL) {
-		dbg_hid("djrcv_dev->paired_dj_devices[dj_report->device_index]"
-			" is NULL, index %d\n", dj_report->device_index);
-		kfifo_in(&djrcv_dev->notif_fifo, dj_report, sizeof(struct dj_report));
-
-		if (schedule_work(&djrcv_dev->work) == 0) {
-			dbg_hid("%s: did not schedule the work item, was already "
-			"queued\n", __func__);
-		}
-		return;
-	}
-
 	if ((dj_report->report_type > ARRAY_SIZE(hid_reportid_size_map) - 1) ||
 	    (hid_reportid_size_map[dj_report->report_type] == 0)) {
 		dbg_hid("invalid report type:%x\n", dj_report->report_type);
@@ -701,8 +677,17 @@ static int logi_dj_raw_event(struct hid_device *hdev,
 	}
 
 	spin_lock_irqsave(&djrcv_dev->lock, flags);
+
+	if (!djrcv_dev->paired_dj_devices[dj_report->device_index]) {
+		/* received an event for an unknown device, bail out */
+		logi_dj_recv_queue_notification(djrcv_dev, dj_report);
+		goto out;
+	}
+
 	switch (dj_report->report_type) {
 	case REPORT_TYPE_NOTIF_DEVICE_PAIRED:
+		/* pairing notifications are handled above the switch */
+		break;
 	case REPORT_TYPE_NOTIF_DEVICE_UNPAIRED:
 		logi_dj_recv_queue_notification(djrcv_dev, dj_report);
 		break;
@@ -715,6 +700,8 @@ static int logi_dj_raw_event(struct hid_device *hdev,
 	default:
 		logi_dj_recv_forward_report(djrcv_dev, dj_report);
 	}
+
+out:
 	spin_unlock_irqrestore(&djrcv_dev->lock, flags);
 
 	return true;
-- 
2.1.0

Re: [PATCH 1/2] HID: logitech-dj: prevent false errors to be shown

[Jiri Kosina]

On Fri, 22 Aug 2014, Benjamin Tissoires wrote:

> Commit "HID: logitech: perform bounds checking on device_id early
> enough" unfortunately leaks some errors to dmesg which are not real
> ones:
> - if the report is not a DJ one, then there is not point in checking
>   the device_id
> - the receiver (index 0) can also receive some notifications which
>   can be safely ignored given the current implementation
> 
> Move out the test regarding the report_id and also discards
> printing errors when the receiver got notified.
> 
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

I have now queued this one for 3.17. Adding Markus to CC -- Markus, this 
should make the spurious error messages you have reported go away.

Thanks.

> ---
>  drivers/hid/hid-logitech-dj.c | 43 +++++++++++++++++++++++++------------------
>  drivers/hid/hid-logitech-dj.h |  1 +
>  2 files changed, 26 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
> index b7ba829..9bf8637 100644
> --- a/drivers/hid/hid-logitech-dj.c
> +++ b/drivers/hid/hid-logitech-dj.c
> @@ -656,7 +656,6 @@ static int logi_dj_raw_event(struct hid_device *hdev,
>  	struct dj_receiver_dev *djrcv_dev = hid_get_drvdata(hdev);
>  	struct dj_report *dj_report = (struct dj_report *) data;
>  	unsigned long flags;
> -	bool report_processed = false;
>  
>  	dbg_hid("%s, size:%d\n", __func__, size);
>  
> @@ -683,34 +682,42 @@ static int logi_dj_raw_event(struct hid_device *hdev,
>  	 * device (via hid_input_report() ) and return 1 so hid-core does not do
>  	 * anything else with it.
>  	 */
> +
> +	/* case 1) */
> +	if (data[0] != REPORT_ID_DJ_SHORT)
> +		return false;
> +
>  	if ((dj_report->device_index < DJ_DEVICE_INDEX_MIN) ||
>  	    (dj_report->device_index > DJ_DEVICE_INDEX_MAX)) {
> -		dev_err(&hdev->dev, "%s: invalid device index:%d\n",
> +		/*
> +		 * Device index is wrong, bail out.
> +		 * This driver can ignore safely the receiver notifications,
> +		 * so ignore those reports too.
> +		 */
> +		if (dj_report->device_index != DJ_RECEIVER_INDEX)
> +			dev_err(&hdev->dev, "%s: invalid device index:%d\n",
>  				__func__, dj_report->device_index);
>  		return false;
>  	}
>  
>  	spin_lock_irqsave(&djrcv_dev->lock, flags);
> -	if (dj_report->report_id == REPORT_ID_DJ_SHORT) {
> -		switch (dj_report->report_type) {
> -		case REPORT_TYPE_NOTIF_DEVICE_PAIRED:
> -		case REPORT_TYPE_NOTIF_DEVICE_UNPAIRED:
> -			logi_dj_recv_queue_notification(djrcv_dev, dj_report);
> -			break;
> -		case REPORT_TYPE_NOTIF_CONNECTION_STATUS:
> -			if (dj_report->report_params[CONNECTION_STATUS_PARAM_STATUS] ==
> -			    STATUS_LINKLOSS) {
> -				logi_dj_recv_forward_null_report(djrcv_dev, dj_report);
> -			}
> -			break;
> -		default:
> -			logi_dj_recv_forward_report(djrcv_dev, dj_report);
> +	switch (dj_report->report_type) {
> +	case REPORT_TYPE_NOTIF_DEVICE_PAIRED:
> +	case REPORT_TYPE_NOTIF_DEVICE_UNPAIRED:
> +		logi_dj_recv_queue_notification(djrcv_dev, dj_report);
> +		break;
> +	case REPORT_TYPE_NOTIF_CONNECTION_STATUS:
> +		if (dj_report->report_params[CONNECTION_STATUS_PARAM_STATUS] ==
> +		    STATUS_LINKLOSS) {
> +			logi_dj_recv_forward_null_report(djrcv_dev, dj_report);
>  		}
> -		report_processed = true;
> +		break;
> +	default:
> +		logi_dj_recv_forward_report(djrcv_dev, dj_report);
>  	}
>  	spin_unlock_irqrestore(&djrcv_dev->lock, flags);
>  
> -	return report_processed;
> +	return true;
>  }
>  
>  static int logi_dj_probe(struct hid_device *hdev,
> diff --git a/drivers/hid/hid-logitech-dj.h b/drivers/hid/hid-logitech-dj.h
> index 4a40003..daeb0aa 100644
> --- a/drivers/hid/hid-logitech-dj.h
> +++ b/drivers/hid/hid-logitech-dj.h
> @@ -27,6 +27,7 @@
>  
>  #define DJ_MAX_PAIRED_DEVICES			6
>  #define DJ_MAX_NUMBER_NOTIFICATIONS		8
> +#define DJ_RECEIVER_INDEX			0
>  #define DJ_DEVICE_INDEX_MIN 			1
>  #define DJ_DEVICE_INDEX_MAX 			6
>  
> -- 
> 2.1.0
> 

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH 2/2] HID: logitech-dj: break out testing of validity of dj_device

[Jiri Kosina]

On Fri, 22 Aug 2014, Benjamin Tissoires wrote:

> We can do once the test of the validity of the dj_device, which removes
> some duplicated code in various functions.
> 
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

I will queue this cleanup for next merge window. Thanks.

> ---
>  drivers/hid/hid-logitech-dj.c | 35 +++++++++++------------------------
>  1 file changed, 11 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
> index 9bf8637..71f5692 100644
> --- a/drivers/hid/hid-logitech-dj.c
> +++ b/drivers/hid/hid-logitech-dj.c
> @@ -385,18 +385,6 @@ static void logi_dj_recv_forward_null_report(struct dj_receiver_dev *djrcv_dev,
>  
>  	djdev = djrcv_dev->paired_dj_devices[dj_report->device_index];
>  
> -	if (!djdev) {
> -		dbg_hid("djrcv_dev->paired_dj_devices[dj_report->device_index]"
> -			" is NULL, index %d\n", dj_report->device_index);
> -		kfifo_in(&djrcv_dev->notif_fifo, dj_report, sizeof(struct dj_report));
> -
> -		if (schedule_work(&djrcv_dev->work) == 0) {
> -			dbg_hid("%s: did not schedule the work item, was already "
> -			"queued\n", __func__);
> -		}
> -		return;
> -	}
> -
>  	memset(reportbuffer, 0, sizeof(reportbuffer));
>  
>  	for (i = 0; i < NUMBER_OF_HID_REPORTS; i++) {
> @@ -421,18 +409,6 @@ static void logi_dj_recv_forward_report(struct dj_receiver_dev *djrcv_dev,
>  
>  	dj_device = djrcv_dev->paired_dj_devices[dj_report->device_index];
>  
> -	if (dj_device == NULL) {
> -		dbg_hid("djrcv_dev->paired_dj_devices[dj_report->device_index]"
> -			" is NULL, index %d\n", dj_report->device_index);
> -		kfifo_in(&djrcv_dev->notif_fifo, dj_report, sizeof(struct dj_report));
> -
> -		if (schedule_work(&djrcv_dev->work) == 0) {
> -			dbg_hid("%s: did not schedule the work item, was already "
> -			"queued\n", __func__);
> -		}
> -		return;
> -	}
> -
>  	if ((dj_report->report_type > ARRAY_SIZE(hid_reportid_size_map) - 1) ||
>  	    (hid_reportid_size_map[dj_report->report_type] == 0)) {
>  		dbg_hid("invalid report type:%x\n", dj_report->report_type);
> @@ -701,8 +677,17 @@ static int logi_dj_raw_event(struct hid_device *hdev,
>  	}
>  
>  	spin_lock_irqsave(&djrcv_dev->lock, flags);
> +
> +	if (!djrcv_dev->paired_dj_devices[dj_report->device_index]) {
> +		/* received an event for an unknown device, bail out */
> +		logi_dj_recv_queue_notification(djrcv_dev, dj_report);
> +		goto out;
> +	}
> +
>  	switch (dj_report->report_type) {
>  	case REPORT_TYPE_NOTIF_DEVICE_PAIRED:
> +		/* pairing notifications are handled above the switch */
> +		break;
>  	case REPORT_TYPE_NOTIF_DEVICE_UNPAIRED:
>  		logi_dj_recv_queue_notification(djrcv_dev, dj_report);
>  		break;
> @@ -715,6 +700,8 @@ static int logi_dj_raw_event(struct hid_device *hdev,
>  	default:
>  		logi_dj_recv_forward_report(djrcv_dev, dj_report);
>  	}
> +
> +out:
>  	spin_unlock_irqrestore(&djrcv_dev->lock, flags);
>  
>  	return true;
> -- 
> 2.1.0
> 

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH 1/2] HID: logitech-dj: prevent false errors to be shown

[Markus Trippelsdorf]

On 2014.08.25 at 02:50 -0500, Jiri Kosina wrote:
> On Fri, 22 Aug 2014, Benjamin Tissoires wrote:
> 
> > Commit "HID: logitech: perform bounds checking on device_id early
> > enough" unfortunately leaks some errors to dmesg which are not real
> > ones:
> > - if the report is not a DJ one, then there is not point in checking
> >   the device_id
> > - the receiver (index 0) can also receive some notifications which
> >   can be safely ignored given the current implementation
> > 
> > Move out the test regarding the report_id and also discards
> > printing errors when the receiver got notified.
> > 
> > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> 
> I have now queued this one for 3.17. Adding Markus to CC -- Markus, this 
> should make the spurious error messages you have reported go away.

Indeed it does. Feel free to add:

Reported-and-tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>

-- 
Markus

Re: [PATCH 1/2] HID: logitech-dj: prevent false errors to be shown

[Jiri Kosina]

On Mon, 25 Aug 2014, Markus Trippelsdorf wrote:

> > > Commit "HID: logitech: perform bounds checking on device_id early
> > > enough" unfortunately leaks some errors to dmesg which are not real
> > > ones:
> > > - if the report is not a DJ one, then there is not point in checking
> > >   the device_id
> > > - the receiver (index 0) can also receive some notifications which
> > >   can be safely ignored given the current implementation
> > > 
> > > Move out the test regarding the report_id and also discards
> > > printing errors when the receiver got notified.
> > > 
> > > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> > 
> > I have now queued this one for 3.17. Adding Markus to CC -- Markus, this 
> > should make the spurious error messages you have reported go away.
> 
> Indeed it does. Feel free to add:
> 
> Reported-and-tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>

Excellent, thanks. Will be pushing it to Linus this week.

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH 2/2] HID: logitech-dj: break out testing of validity of dj_device

[Jiri Kosina]

On Fri, 22 Aug 2014, Benjamin Tissoires wrote:

> We can do once the test of the validity of the dj_device, which removes
> some duplicated code in various functions.

Queued for 3.18, thanks Benjamin.

-- 
Jiri Kosina
SUSE Labs