• Jonathan Cameron's avatar
    Revert "iio:humidity:si7020: fix pointer to i2c client" · 75552ee5
    Jonathan Cameron authored
    commit e765537a upstream.
    
    This reverts commit e0922e5e.
    Requested by Andrey Smirnov.
    
    It incorrectly assumes that the level of indirection is not needed
    which is not true(probably because the driver incorrectly allocates
    sizeof(*client) instead of sizeof(*data) via devm_iio_device_alloc).
    If you look at the code of the probe function(see below) it is easy to
    see that what is being stored in the private memory of the IIO device
    instance is not a copy of a 'struct i2c_client' but a pointer to an
    instance passed as an argument to the probe function.
    
    struct i2c_client **data;
    int ret;
    
    < Some code skipped >
    
    indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*client));
    if (!indio_dev)
    return -ENOMEM;
    
    data = iio_priv(indio_dev);
    *data = client;
    
    Without reverting this change any read of a raw value of this sensor
    leads to a kernel oops due to a NULL pointer de-reference on my
    hardware setup.
    Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    75552ee5
si7020.c 4.57 KB