From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Lars-Peter Clausen To: Jonathan Cameron CC: Michael Hennerich , , , , Lars-Peter Clausen Subject: [PATCH 3/8] staging:iio: Disallow modifying buffer size when buffer is enabled Date: Fri, 16 Dec 2011 11:19:46 +0100 Message-ID: <1324030791-17983-3-git-send-email-lars@metafoo.de> In-Reply-To: <1324030791-17983-1-git-send-email-lars@metafoo.de> References: <1324030791-17983-1-git-send-email-lars@metafoo.de> MIME-Version: 1.0 Content-Type: text/plain List-ID: 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. Signed-off-by: Lars-Peter Clausen --- drivers/staging/iio/industrialio-buffer.c | 17 ++++++++++++----- 1 files changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/staging/iio/industrialio-buffer.c b/drivers/staging/iio/industrialio-buffer.c index 91cb37a..9528026 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); -- 1.7.7.3