Messages in this thread Patch in this message | | | Date | Sun, 4 Jan 2015 18:02:27 +0200 | From | "Michael S. Tsirkin" <> | Subject | [PATCH 3/3] virtio_pci: document why we defer kfree |
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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.
Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- drivers/virtio/virtio_pci_legacy.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c index 4beaee3..a5486e6 100644 --- a/drivers/virtio/virtio_pci_legacy.c +++ b/drivers/virtio/virtio_pci_legacy.c @@ -216,6 +216,9 @@ 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); } -- MST
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