diff mbox

input: gpio_keys: Fix check for disabling unsupported key

Message ID 1451856076-29045-1-git-send-email-ivo.g.dimitrov.75@gmail.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Ivaylo Dimitrov Jan. 3, 2016, 9:21 p.m. UTC
Commit 4ea14a53d8f881034fa9e186653821c4e3d9a8fb ("Input: gpio-keys -
report error when disabling unsupported key") tried to prevent an
unsupported key to disabled. Unfortunately it effectively broke the driver
in a way so no key is possible to be disabled. Fix that by providing the
correct verify logic.

Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
---
 drivers/input/keyboard/gpio_keys.c | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

Comments

Dmitry Torokhov Jan. 5, 2016, 1:19 a.m. UTC | #1
On Sun, Jan 03, 2016 at 11:21:16PM +0200, Ivaylo Dimitrov wrote:
> Commit 4ea14a53d8f881034fa9e186653821c4e3d9a8fb ("Input: gpio-keys -
> report error when disabling unsupported key") tried to prevent an
> unsupported key to disabled. Unfortunately it effectively broke the driver
> in a way so no key is possible to be disabled. Fix that by providing the
> correct verify logic.

Hmm, indeed...

> 
> Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
> ---
>  drivers/input/keyboard/gpio_keys.c | 28 +++++++++++++++++++---------
>  1 file changed, 19 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
> index bef317f..a371805 100644
> --- a/drivers/input/keyboard/gpio_keys.c
> +++ b/drivers/input/keyboard/gpio_keys.c
> @@ -226,22 +226,32 @@ static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
>  		goto out;
>  
>  	/* First validate */
> -	for (i = 0; i < ddata->pdata->nbuttons; i++) {
> -		struct gpio_button_data *bdata = &ddata->data[i];
> +	for (i = 0; i < n_events; i++) {

for_each_set_bit()?

OTOH maybe we should do

	bitmap = get_bitmap_events_by_type(type); // new, return keybit or swbit
	if (!bitmap_subset(bits, bitmap, n_events)) {
		error = -EINVAL;
		goto out;
	}

... and leave the rest of the loop as is?

Thanks.
Ivaylo Dimitrov Jan. 5, 2016, 7:24 a.m. UTC | #2
Hi,

On  5.01.2016 03:19, Dmitry Torokhov wrote:
>>   	/* First validate */
>> -	for (i = 0; i < ddata->pdata->nbuttons; i++) {
>> -		struct gpio_button_data *bdata = &ddata->data[i];
>> +	for (i = 0; i < n_events; i++) {
>
> for_each_set_bit()?

Yeah, seems I must have overslept that helper, will send an updated version.

>
> OTOH maybe we should do
>
> 	bitmap = get_bitmap_events_by_type(type); // new, return keybit or swbit

new helper function? or static function in gpio-keys? who 
allocates/frees the bitmap memory? or this is static data? Maybe I don't 
get the idea :) .

> 	if (!bitmap_subset(bits, bitmap, n_events)) {
> 		error = -EINVAL;
> 		goto out;
> 	}
>
> ... and leave the rest of the loop as is?
>

Not sure about that. Unless I miss something, what we want is:

1. make sure that what user has written is within the range of the event 
type. I hope bitmap_parselist already does it for us.

2. Make sure that for every bit in bits set based on what user has 
provided, there is a matching gpio in this particular gpio-keys device.

3. Make sure that every gpio user wants disabled is actually allowed to 
be disabled.

I don't see how 2 is achieved with ^^^ code.

So, shall I send a new version of the patch with for_each_set_bit() 
used, or you'll fix the $subject problem with whatever magic you think 
is needed?

Thanks,
Ivo
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diff mbox

Patch

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index bef317f..a371805 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -226,22 +226,32 @@  static ssize_t gpio_keys_attr_store_helper(struct gpio_keys_drvdata *ddata,
 		goto out;
 
 	/* First validate */
-	for (i = 0; i < ddata->pdata->nbuttons; i++) {
-		struct gpio_button_data *bdata = &ddata->data[i];
+	for (i = 0; i < n_events; i++) {
+		int j;
 
-		if (bdata->button->type != type)
+		if (!test_bit(i, bits))
 			continue;
 
-		if (test_bit(bdata->button->code, bits) &&
-		    !bdata->button->can_disable) {
+		for (j = 0; j < ddata->pdata->nbuttons; j++) {
+			struct gpio_button_data *bdata = &ddata->data[j];
+
+			if (bdata->button->type != type)
+				continue;
+
+			if (bdata->button->code == i) {
+				if (!bdata->button->can_disable) {
+					error = -EINVAL;
+					goto out;
+				}
+				break;
+			}
+		}
+
+		if (j == ddata->pdata->nbuttons) {
 			error = -EINVAL;
 			goto out;
 		}
-	}
 
-	if (i == ddata->pdata->nbuttons) {
-		error = -EINVAL;
-		goto out;
 	}
 
 	mutex_lock(&ddata->disable_lock);