From e38c79e0825b673d97cecfb36bae9e859e724f1b Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Mon, 19 Dec 2011 15:23:44 +0100 Subject: [PATCH] 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 Signed-off-by: Lars-Peter Clausen Signed-off-by: Greg Kroah-Hartman --- drivers/staging/iio/industrialio-buffer.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/staging/iio/industrialio-buffer.c b/drivers/staging/iio/industrialio-buffer.c index 747b9013a666..59472890cb2a 100644 --- a/drivers/staging/iio/industrialio-buffer.c +++ b/drivers/staging/iio/industrialio-buffer.c @@ -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); -- 2.34.1