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Subject[PATCH] w1: gpio: Fix problematic platform_data usage
Date
pdev->dev.platform_data should not be overwritten by a driver. This
patch fixes this issue by not using platform_get_pdata to get pdata. The
DT routine can then simply return a pdata struct with those information.

Without this patch the platform_data may be freed twice, by devres and
the driver framework.

Reported-by: Ingo Flaschberger <ingo.flaschberger@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
---

Hi,

Could you please try this patch? This essentially does not store anything to
platform_data anymore so it should hopefully fix your issue.

Best Regards,

Markus

drivers/w1/masters/w1-gpio.c | 42 ++++++++++++++++++++++--------------------
1 file changed, 22 insertions(+), 20 deletions(-)

diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
index b99a932ad901..63e7b1d2785f 100644
--- a/drivers/w1/masters/w1-gpio.c
+++ b/drivers/w1/masters/w1-gpio.c
@@ -75,15 +75,18 @@ static struct of_device_id w1_gpio_dt_ids[] = {
MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids);
#endif

-static int w1_gpio_probe_dt(struct platform_device *pdev)
+static struct w1_gpio_platform_data *w1_gpio_probe_dt(struct platform_device *pdev)
{
struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
struct device_node *np = pdev->dev.of_node;
int gpio;

+ if (pdata)
+ return pdata;
+
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);

if (of_get_property(np, "linux,open-drain", NULL))
pdata->is_open_drain = 1;
@@ -95,19 +98,17 @@ static int w1_gpio_probe_dt(struct platform_device *pdev)
"Failed to parse gpio property for data pin (%d)\n",
gpio);

- return gpio;
+ return ERR_PTR(gpio);
}
pdata->pin = gpio;

gpio = of_get_gpio(np, 1);
if (gpio == -EPROBE_DEFER)
- return gpio;
+ return ERR_PTR(gpio);
/* ignore other errors as the pullup gpio is optional */
pdata->ext_pullup_enable_pin = gpio;

- pdev->dev.platform_data = pdata;
-
- return 0;
+ return pdata;
}

static int w1_gpio_probe(struct platform_device *pdev)
@@ -116,17 +117,16 @@ static int w1_gpio_probe(struct platform_device *pdev)
struct w1_gpio_platform_data *pdata;
int err;

- if (of_have_populated_dt()) {
- err = w1_gpio_probe_dt(pdev);
- if (err < 0)
- return err;
- }
-
- pdata = dev_get_platdata(&pdev->dev);
+ if (of_have_populated_dt())
+ pdata = w1_gpio_probe_dt(pdev);
+ else
+ pdata = dev_get_platdata(&pdev->dev);

- if (!pdata) {
- dev_err(&pdev->dev, "No configuration data\n");
- return -ENXIO;
+ if (IS_ERR_OR_NULL(pdata)) {
+ dev_err(&pdev->dev, "No configuration data or configuration failed\n");
+ if (!pdata)
+ return -ENXIO;
+ return PTR_ERR(pdata);
}

master = devm_kzalloc(&pdev->dev, sizeof(struct w1_bus_master),
@@ -185,7 +185,7 @@ static int w1_gpio_probe(struct platform_device *pdev)
static int w1_gpio_remove(struct platform_device *pdev)
{
struct w1_bus_master *master = platform_get_drvdata(pdev);
- struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ struct w1_gpio_platform_data *pdata = master->data;

if (pdata->enable_external_pullup)
pdata->enable_external_pullup(0);
@@ -202,7 +202,8 @@ static int w1_gpio_remove(struct platform_device *pdev)

static int w1_gpio_suspend(struct platform_device *pdev, pm_message_t state)
{
- struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ struct w1_bus_master *master = platform_get_drvdata(pdev);
+ struct w1_gpio_platform_data *pdata = master->data;

if (pdata->enable_external_pullup)
pdata->enable_external_pullup(0);
@@ -212,7 +213,8 @@ static int w1_gpio_suspend(struct platform_device *pdev, pm_message_t state)

static int w1_gpio_resume(struct platform_device *pdev)
{
- struct w1_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ struct w1_bus_master *master = platform_get_drvdata(pdev);
+ struct w1_gpio_platform_data *pdata = master->data;

if (pdata->enable_external_pullup)
pdata->enable_external_pullup(1);
--
2.1.4


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