diff options
| -rw-r--r-- | drivers/dma-buf/dma-buf.c | 10 | ||||
| -rw-r--r-- | 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..63a9914e42b8 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> @@ -72,6 +73,7 @@ static int dma_buf_release(struct inode *inode, struct file *file) if (dmabuf->resv == (struct reservation_object *)&dmabuf[1]) reservation_object_fini(dmabuf->resv); + module_put(dmabuf->owner); kfree(dmabuf); return 0; } @@ -302,14 +304,20 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info) return ERR_PTR(-EINVAL); } + if (!try_module_get(exp_info->owner)) + return ERR_PTR(-ENOENT); + dmabuf = kzalloc(alloc_size, GFP_KERNEL); - if (dmabuf == NULL) + if (!dmabuf) { + module_put(exp_info->owner); return ERR_PTR(-ENOMEM); + } dmabuf->priv = exp_info->priv; dmabuf->ops = exp_info->ops; dmabuf->size = exp_info->size; dmabuf->exp_name = exp_info->exp_name; + dmabuf->owner = exp_info->owner; init_waitqueue_head(&dmabuf->poll); dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0; diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 2f0b431b73e0..f98bd7068d55 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -115,6 +115,8 @@ struct dma_buf_ops { * @attachments: list of dma_buf_attachment that denotes all devices attached. * @ops: dma_buf_ops associated with this buffer object. * @exp_name: name of the exporter; useful for debugging. + * @owner: pointer to exporter module; used for refcounting when exporter is a + * kernel module. * @list_node: node for dma_buf accounting and debugging. * @priv: exporter specific private data for this buffer object. * @resv: reservation object linked to this dma-buf @@ -129,6 +131,7 @@ struct dma_buf { unsigned vmapping_counter; void *vmap_ptr; const char *exp_name; + struct module *owner; struct list_head list_node; void *priv; struct reservation_object *resv; @@ -164,7 +167,8 @@ struct dma_buf_attachment { /** * struct dma_buf_export_info - holds information needed to export a dma_buf - * @exp_name: name of the exporting module - useful for debugging. + * @exp_name: name of the exporter - useful for debugging. + * @owner: pointer to exporter module - used for refcounting kernel module * @ops: Attach allocator-defined dma buf ops to the new buffer * @size: Size of the buffer * @flags: mode flags for the file @@ -176,6 +180,7 @@ struct dma_buf_attachment { */ struct dma_buf_export_info { const char *exp_name; + struct module *owner; const struct dma_buf_ops *ops; size_t size; int flags; @@ -187,7 +192,8 @@ struct dma_buf_export_info { * helper macro for exporters; zeros and fills in most common values */ #define DEFINE_DMA_BUF_EXPORT_INFO(a) \ - struct dma_buf_export_info a = { .exp_name = KBUILD_MODNAME } + struct dma_buf_export_info a = { .exp_name = KBUILD_MODNAME, \ + .owner = THIS_MODULE } /** * get_dma_buf - convenience wrapper for get_file. |