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iio: accel: bmc150: Fix dereferencing the wrong pointer in bmc150_get/set_second_device

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The drvdata for iio-parent devices points to the struct iio_dev for
the iio-device. So by directly casting the return from i2c_get_clientdata()
to struct bmc150_accel_data * the code was ending up storing the second_dev
pointer in (and retrieving it from) some semi-random offset inside
struct iio_dev, rather then storing it in the second_dev member of the
bmc150_accel_data struct.

Fix the code to get the struct bmc150_accel_data * pointer to call
iio_priv() on the struct iio_dev * returned by i2c_get_clientdata(),
so that the correct pointer gets dereferenced.

This fixes the following oops on rmmod, caused by trying to
dereference the wrong return of bmc150_get_second_device():

[  238.980737] BUG: unable to handle page fault for address: 0000000000004710
[  238.980755] #PF: supervisor read access in kernel mode
[  238.980760] #PF: error_code(0x0000) - not-present page
...
[  238.980841]  i2c_unregister_device.part.0+0x19/0x60
[  238.980856]  0xffffffffc0815016
[  238.980863]  i2c_device_remove+0x25/0xb0
[  238.980869]  __device_release_driver+0x180/0x240
[  238.980876]  driver_detach+0xd4/0x120
[  238.980882]  bus_remove_driver+0x5b/0xd0
[  238.980888]  i2c_del_driver+0x44/0x70

While at it also remove the now no longer sensible checks for data
being NULL, iio_priv never returns NULL for an iio_dev with non 0
sized private-data.

Fixes: 5bfb3a4bd8 ("iio: accel: bmc150: Check for a second ACPI device for BOSC0200")
Cc: Jeremy Cline <jeremy@jcline.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Hans de Goede 2021-05-23 19:00:55 +02:00 committed by Jonathan Cameron
parent c9d52c89e7
commit f2bf22dc9e
1 changed files with 3 additions and 7 deletions
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10
drivers/iio/accel/bmc150-accel-core.c
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@ -1805,10 +1805,7 @@ EXPORT_SYMBOL_GPL(bmc150_accel_core_probe);
struct i2c_client *bmc150_get_second_device(struct i2c_client *client)
{
struct bmc150_accel_data *data = i2c_get_clientdata(client);
if (!data)
return NULL;
struct bmc150_accel_data *data = iio_priv(i2c_get_clientdata(client));
return data->second_device;
}
@ -1816,10 +1813,9 @@ EXPORT_SYMBOL_GPL(bmc150_get_second_device);
void bmc150_set_second_device(struct i2c_client *client)
{
struct bmc150_accel_data *data = i2c_get_clientdata(client);
struct bmc150_accel_data *data = iio_priv(i2c_get_clientdata(client));
if (data)
data->second_device = client;
data->second_device = client;
}
EXPORT_SYMBOL_GPL(bmc150_set_second_device);