On Thu, May 07, 2015 at 06:58:44PM +0530, Sumit Semwal wrote: > Add reference counting on a kernel module that exports dma-buf and > implements its operations. This prevents the module from being unloaded > while DMABUF file is in use. > > The original patch [1] was submitted by Tomasz Stanislawski, but this > is a simpler way to do it. > > v2: move owner to struct dma_buf, and use DEFINE_DMA_BUF_EXPORT_INFO > macro to simplify the change. > > Signed-off-by: Sumit Semwal <sumit.semwal@xxxxxxxxxx> > > [1]: https://lkml.org/lkml/2012/8/8/163 > --- > drivers/dma-buf/dma-buf.c | 10 +++++++++- > include/linux/dma-buf.h | 10 ++++++++-- > 2 files changed, 17 insertions(+), 3 deletions(-) > > diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > index c5a9138a6a8d..0eff4bf56ef6 100644 > --- a/drivers/dma-buf/dma-buf.c > +++ b/drivers/dma-buf/dma-buf.c > @@ -29,6 +29,7 @@ > #include <linux/anon_inodes.h> > #include <linux/export.h> > #include <linux/debugfs.h> > +#include <linux/module.h> > #include <linux/seq_file.h> > #include <linux/poll.h> > #include <linux/reservation.h> > @@ -64,6 +65,7 @@ static int dma_buf_release(struct inode *inode, struct file *file) > BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active); > > dmabuf->ops->release(dmabuf); > + module_put(dmabuf->owner); The module can now go away. > > mutex_lock(&db_list.lock); > list_del(&dmabuf->list_node); But you reference it here :( Please drop the reference at the last possible moment. thanks, greg k-h _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
