* [PATCH v2] iio: light: cm32181: Unregister second I2C client if present
@ 2023-02-08 7:21 Kai-Heng Feng
2023-02-13 11:17 ` Hans de Goede
0 siblings, 1 reply; 3+ messages in thread
From: Kai-Heng Feng @ 2023-02-08 7:21 UTC (permalink / raw)
To: ktsai, jic23, lars; +Cc: hdegoede, Kai-Heng Feng, linux-iio, linux-kernel
If a second client that talks to the actual I2C address was created in
probe(), there should be a corresponding cleanup in remove() to avoid
leakage.
So if the "client" is not the same one used by I2C core, unregister it
accordingly.
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2152281
Fixes: c1e62062ff54 ("iio: light: cm32181: Handle CM3218 ACPI devices with 2 I2C resources")
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
v2:
- Use devm_add_action_or_reset() instead of remove() callback to avoid
race.
drivers/iio/light/cm32181.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
index b1674a5bfa368..a3e5f56101c9f 100644
--- a/drivers/iio/light/cm32181.c
+++ b/drivers/iio/light/cm32181.c
@@ -429,6 +429,16 @@ static const struct iio_info cm32181_info = {
.attrs = &cm32181_attribute_group,
};
+static void cm32181_disable(void *data)
+{
+ struct i2c_client *client = data;
+ struct cm32181_chip *cm32181 = iio_priv(i2c_get_clientdata(client));
+
+ /* Unregister the dummy client */
+ if (cm32181->client != client)
+ i2c_unregister_device(cm32181->client);
+}
+
static int cm32181_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
@@ -479,6 +489,12 @@ static int cm32181_probe(struct i2c_client *client)
return ret;
}
+ ret = devm_add_action_or_reset(dev, cm32181_disable, client);
+ if (ret) {
+ dev_err(dev, "%s: add devres action failed\n", __func__);
+ return ret;
+ }
+
ret = devm_iio_device_register(dev, indio_dev);
if (ret) {
dev_err(dev, "%s: regist device failed\n", __func__);
--
2.34.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] iio: light: cm32181: Unregister second I2C client if present
2023-02-08 7:21 [PATCH v2] iio: light: cm32181: Unregister second I2C client if present Kai-Heng Feng
@ 2023-02-13 11:17 ` Hans de Goede
2023-02-22 13:50 ` Kai-Heng Feng
0 siblings, 1 reply; 3+ messages in thread
From: Hans de Goede @ 2023-02-13 11:17 UTC (permalink / raw)
To: Kai-Heng Feng, ktsai, jic23, lars; +Cc: linux-iio, linux-kernel
Hi,
Thank you for working on this, some remarks inline.
On 2/8/23 08:21, Kai-Heng Feng wrote:
> If a second client that talks to the actual I2C address was created in
> probe(), there should be a corresponding cleanup in remove() to avoid
> leakage.
>
> So if the "client" is not the same one used by I2C core, unregister it
> accordingly.
>
> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2152281
> Fixes: c1e62062ff54 ("iio: light: cm32181: Handle CM3218 ACPI devices with 2 I2C resources")
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> ---
> v2:
> - Use devm_add_action_or_reset() instead of remove() callback to avoid
> race.
>
> drivers/iio/light/cm32181.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
> index b1674a5bfa368..a3e5f56101c9f 100644
> --- a/drivers/iio/light/cm32181.c
> +++ b/drivers/iio/light/cm32181.c
> @@ -429,6 +429,16 @@ static const struct iio_info cm32181_info = {
> .attrs = &cm32181_attribute_group,
> };
>
> +static void cm32181_disable(void *data)
> +{
> + struct i2c_client *client = data;
> + struct cm32181_chip *cm32181 = iio_priv(i2c_get_clientdata(client));
> +
> + /* Unregister the dummy client */
> + if (cm32181->client != client)
> + i2c_unregister_device(cm32181->client);
> +}
> +
> static int cm32181_probe(struct i2c_client *client)
> {
> struct device *dev = &client->dev;
> @@ -479,6 +489,12 @@ static int cm32181_probe(struct i2c_client *client)
> return ret;
> }
>
> + ret = devm_add_action_or_reset(dev, cm32181_disable, client);
> + if (ret) {
> + dev_err(dev, "%s: add devres action failed\n", __func__);
> + return ret;
> + }
> +
This is too late, we will still exit without unregistering the client if
the cm32181_reg_init() call fails.
It would be best to do this directly after the i2c_acpi_new_device()
call, so inside the "if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) {"
block.
This way you can also remove the "if (cm32181->client != client)"
check from cm32181_disable() since it now only runs when the client
was registered in the first place.
Also please rename cm32181_disable() to cm32181_unregister_dummy_client()
so that the name actually matches what it does.
Regards,
Hans
> ret = devm_iio_device_register(dev, indio_dev);
> if (ret) {
> dev_err(dev, "%s: regist device failed\n", __func__);
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] iio: light: cm32181: Unregister second I2C client if present
2023-02-13 11:17 ` Hans de Goede
@ 2023-02-22 13:50 ` Kai-Heng Feng
0 siblings, 0 replies; 3+ messages in thread
From: Kai-Heng Feng @ 2023-02-22 13:50 UTC (permalink / raw)
To: Hans de Goede; +Cc: ktsai, jic23, lars, linux-iio, linux-kernel
Hi Hans,
On Mon, Feb 13, 2023 at 7:17 PM Hans de Goede <hdegoede@redhat.com> wrote:
>
> Hi,
>
> Thank you for working on this, some remarks inline.
>
> On 2/8/23 08:21, Kai-Heng Feng wrote:
> > If a second client that talks to the actual I2C address was created in
> > probe(), there should be a corresponding cleanup in remove() to avoid
> > leakage.
> >
> > So if the "client" is not the same one used by I2C core, unregister it
> > accordingly.
> >
> > Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2152281
> > Fixes: c1e62062ff54 ("iio: light: cm32181: Handle CM3218 ACPI devices with 2 I2C resources")
> > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > ---
> > v2:
> > - Use devm_add_action_or_reset() instead of remove() callback to avoid
> > race.
> >
> > drivers/iio/light/cm32181.c | 16 ++++++++++++++++
> > 1 file changed, 16 insertions(+)
> >
> > diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c
> > index b1674a5bfa368..a3e5f56101c9f 100644
> > --- a/drivers/iio/light/cm32181.c
> > +++ b/drivers/iio/light/cm32181.c
> > @@ -429,6 +429,16 @@ static const struct iio_info cm32181_info = {
> > .attrs = &cm32181_attribute_group,
> > };
> >
> > +static void cm32181_disable(void *data)
> > +{
> > + struct i2c_client *client = data;
> > + struct cm32181_chip *cm32181 = iio_priv(i2c_get_clientdata(client));
> > +
> > + /* Unregister the dummy client */
> > + if (cm32181->client != client)
> > + i2c_unregister_device(cm32181->client);
> > +}
> > +
> > static int cm32181_probe(struct i2c_client *client)
> > {
> > struct device *dev = &client->dev;
> > @@ -479,6 +489,12 @@ static int cm32181_probe(struct i2c_client *client)
> > return ret;
> > }
> >
> > + ret = devm_add_action_or_reset(dev, cm32181_disable, client);
> > + if (ret) {
> > + dev_err(dev, "%s: add devres action failed\n", __func__);
> > + return ret;
> > + }
> > +
>
> This is too late, we will still exit without unregistering the client if
> the cm32181_reg_init() call fails.
>
> It would be best to do this directly after the i2c_acpi_new_device()
> call, so inside the "if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) {"
> block.
You are right, not sure what I was thinking but this is much better.
>
> This way you can also remove the "if (cm32181->client != client)"
> check from cm32181_disable() since it now only runs when the client
> was registered in the first place.
>
> Also please rename cm32181_disable() to cm32181_unregister_dummy_client()
> so that the name actually matches what it does.
Sure, will change that in next version.
>
> Regards,
>
> Hans
>
>
>
>
>
> > ret = devm_iio_device_register(dev, indio_dev);
> > if (ret) {
> > dev_err(dev, "%s: regist device failed\n", __func__);
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2023-02-22 13:50 ` Kai-Heng Feng
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