staging:iio: Disallow modifying buffer size when buffer is enabled

The buffer buffer storage is only update when enabling the buffer. Changing the
buffer size while the buffer is enabled will confuse the buffer in regard to
its actual buffer size and can cause potential memory corruption. Thus it is
only safe to modify the buffer size when the buffer is disabled.

Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Lars-Peter Clausen 2011-12-19 15:23:44 +01:00 committed by Greg Kroah-Hartman
parent 5fd6218ca5
commit e38c79e082
1 changed files with 12 additions and 5 deletions

View File

@ -396,13 +396,20 @@ ssize_t iio_buffer_write_length(struct device *dev,
if (val == buffer->access->get_length(buffer))
return len;
if (buffer->access->set_length) {
buffer->access->set_length(buffer, val);
if (buffer->access->mark_param_change)
buffer->access->mark_param_change(buffer);
mutex_lock(&indio_dev->mlock);
if (iio_buffer_enabled(indio_dev)) {
ret = -EBUSY;
} else {
if (buffer->access->set_length) {
buffer->access->set_length(buffer, val);
if (buffer->access->mark_param_change)
buffer->access->mark_param_change(buffer);
}
ret = 0;
}
mutex_unlock(&indio_dev->mlock);
return len;
return ret ? ret : len;
}
EXPORT_SYMBOL(iio_buffer_write_length);