| Message ID | 20190705110454.95302-1-sgarzare@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | vsock/virtio: several fixes in the .probe() and .remove() | expand |
From: Stefano Garzarella <sgarzare@redhat.com> Date: Fri, 5 Jul 2019 13:04:51 +0200 > During the review of "[PATCH] vsock/virtio: Initialize core virtio vsock > before registering the driver", Stefan pointed out some possible issues > in the .probe() and .remove() callbacks of the virtio-vsock driver. ... Series applied to net-next, thanks.
During the review of "[PATCH] vsock/virtio: Initialize core virtio vsock before registering the driver", Stefan pointed out some possible issues in the .probe() and .remove() callbacks of the virtio-vsock driver. This series tries to solve these issues: - Patch 1 adds RCU critical sections to avoid use-after-free of 'the_virtio_vsock' pointer. - Patch 2 stops workers before to call vdev->config->reset(vdev) to be sure that no one is accessing the device. - Patch 3 moves the works flush at the end of the .remove() to avoid use-after-free of 'vsock' object. v3: - Patch 1: use rcu_dereference_protected() to get the_virtio_vosck value in the virtio_vsock_probe() [Jason] v2: https://patchwork.kernel.org/cover/11022343/ v1: https://patchwork.kernel.org/cover/10964733/ Before this series the guest crashes in a few second. After this series the test runs (~12h) without issues. Tested on an SMP guest (-smp 4 -monitor tcp:127.0.0.1:1234,server,nowait) with these scripts to stress the .probe()/.remove() path: - guest while true; do cat /dev/urandom | nc-vsock -l 4321 > /dev/null & cat /dev/urandom | nc-vsock -l 5321 > /dev/null & cat /dev/urandom | nc-vsock -l 6321 > /dev/null & cat /dev/urandom | nc-vsock -l 7321 > /dev/null & wait done - host while true; do cat /dev/urandom | nc-vsock 3 4321 > /dev/null & cat /dev/urandom | nc-vsock 3 5321 > /dev/null & cat /dev/urandom | nc-vsock 3 6321 > /dev/null & cat /dev/urandom | nc-vsock 3 7321 > /dev/null & sleep 2 echo "device_del v1" | nc 127.0.0.1 1234 sleep 1 echo "device_add vhost-vsock-pci,id=v1,guest-cid=3" | nc 127.0.0.1 1234 sleep 1 done Stefano Garzarella (3): vsock/virtio: use RCU to avoid use-after-free on the_virtio_vsock vsock/virtio: stop workers during the .remove() vsock/virtio: fix flush of works during the .remove() net/vmw_vsock/virtio_transport.c | 134 ++++++++++++++++++++++++------- 1 file changed, 104 insertions(+), 30 deletions(-)