| From | lizf@kernel ... | Subject | [PATCH 3.4 084/176] virtio_pci: document why we defer kfree | Date | Thu, 9 Apr 2015 16:45:32 +0800 |
| |
From: "Michael S. Tsirkin" <mst@redhat.com>
3.4.107-rc1 review patch. If anyone has any objections, please let me know.
------------------
commit a1eb03f546d651a8f39c7d0692b1f7f5b4e7e3cd upstream.
The reason we defer kfree until release function is because it's a general rule for kobjects: kfree of the reference counter itself is only legal in the release function.
Previous patch didn't make this clear, document this in code.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> [lizf: Backported to 3.4: adjust filename] Signed-off-by: Zefan Li <lizefan@huawei.com> --- drivers/virtio/virtio_pci.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index c9c93e0..cc56763 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -627,6 +627,9 @@ static void virtio_pci_release_dev(struct device *_d) struct virtio_device *vdev = dev_to_virtio(_d); struct virtio_pci_device *vp_dev = to_vp_device(vdev); + /* As struct device is a kobject, it's not safe to + * free the memory (including the reference counter itself) + * until it's release callback. */ kfree(vp_dev); } -- 1.9.1
|