[PATCH 04/24] gpio: fix dangling pointers

From: Wolfram Sang
Date: Sat Mar 20 2010 - 10:13:54 EST


Fix I2C-drivers which missed setting clientdata to NULL before freeing the
structure it points to. Also fix drivers which do this _after_ the structure
was freed already.

Signed-off-by: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
---

Found using coccinelle, then reviewed. Full patchset is available via
kernel-janitors, linux-i2c, and LKML.
---
drivers/gpio/adp5588-gpio.c | 1 +
drivers/gpio/max732x.c | 1 +
drivers/gpio/pca953x.c | 1 +
drivers/gpio/pcf857x.c | 7 ++++---
4 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/adp5588-gpio.c b/drivers/gpio/adp5588-gpio.c
index afc097a..c0cb5c1 100644
--- a/drivers/gpio/adp5588-gpio.c
+++ b/drivers/gpio/adp5588-gpio.c
@@ -227,6 +227,7 @@ static int __devexit adp5588_gpio_remove(struct i2c_client *client)
return ret;
}

+ i2c_set_clientdata(client, NULL);
kfree(dev);
return 0;
}
diff --git a/drivers/gpio/max732x.c b/drivers/gpio/max732x.c
index f786824..85fe675 100644
--- a/drivers/gpio/max732x.c
+++ b/drivers/gpio/max732x.c
@@ -356,6 +356,7 @@ static int __devexit max732x_remove(struct i2c_client *client)
if (chip->client_dummy)
i2c_unregister_device(chip->client_dummy);

+ i2c_set_clientdata(client, NULL);
kfree(chip);
return 0;
}
diff --git a/drivers/gpio/pca953x.c b/drivers/gpio/pca953x.c
index ab5daab..05242dc 100644
--- a/drivers/gpio/pca953x.c
+++ b/drivers/gpio/pca953x.c
@@ -571,6 +571,7 @@ static int pca953x_remove(struct i2c_client *client)

pca953x_irq_teardown(chip);
kfree(chip->dyn_pdata);
+ i2c_set_clientdata(client, NULL);
kfree(chip);
return 0;
}
diff --git a/drivers/gpio/pcf857x.c b/drivers/gpio/pcf857x.c
index 29f19ce..c2aed8a 100644
--- a/drivers/gpio/pcf857x.c
+++ b/drivers/gpio/pcf857x.c
@@ -259,9 +259,7 @@ static int pcf857x_probe(struct i2c_client *client,
goto fail;

gpio->chip.label = client->name;
-
gpio->client = client;
- i2c_set_clientdata(client, gpio);

/* NOTE: these chips have strange "quasi-bidirectional" I/O pins.
* We can't actually know whether a pin is configured (a) as output
@@ -307,6 +305,7 @@ static int pcf857x_probe(struct i2c_client *client,
dev_warn(&client->dev, "setup --> %d\n", status);
}

+ i2c_set_clientdata(client, gpio);
return 0;

fail:
@@ -334,8 +333,10 @@ static int pcf857x_remove(struct i2c_client *client)
}

status = gpiochip_remove(&gpio->chip);
- if (status == 0)
+ if (status == 0) {
+ i2c_set_clientdata(client, NULL);
kfree(gpio);
+ }
else
dev_err(&client->dev, "%s --> %d\n", "remove", status);
return status;
--
1.7.0

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