kernel/linux.git/drivers/char/virtio_console.c, branch v4.14.286

virtio_console: eliminate anonymous module_init & module_exit

2022-04-20T07:08:28+00:00

[ Upstream commit fefb8a2a941338d871e2d83fbd65fbfa068857bd ] Eliminate anonymous module_init() and module_exit(), which can lead to confusion or ambiguity when reading System.map, crashes/oops/bugs, or an initcall_debug log. Give each of these init and exit functions unique driver-specific names to eliminate the anonymous names. Example 1: (System.map) ffffffff832fc78c t init ffffffff832fc79e t init ffffffff832fc8f8 t init Example 2: (initcall_debug log) calling init+0x0/0x12 @ 1 initcall init+0x0/0x12 returned 0 after 15 usecs calling init+0x0/0x60 @ 1 initcall init+0x0/0x60 returned 0 after 2 usecs calling init+0x0/0x9a @ 1 initcall init+0x0/0x9a returned 0 after 74 usecs Signed-off-by: Randy Dunlap Reviewed-by: Amit Shah Cc: virtualization@lists.linux-foundation.org Cc: Arnd Bergmann Link: https://lore.kernel.org/r/20220316192010.19001-3-rdunlap@infradead.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

virtio_console: break out of buf poll on remove

2022-04-20T07:08:08+00:00

[ Upstream commit 0e7174b9d5877130fec41fb4a16e0c2ee4958d44 ] A common pattern for device reset is currently: vdev->config->reset(vdev); .. cleanup .. reset prevents new interrupts from arriving and waits for interrupt handlers to finish. However if - as is common - the handler queues a work request which is flushed during the cleanup stage, we have code adding buffers / trying to get buffers while device is reset. Not good. This was reproduced by running modprobe virtio_console modprobe -r virtio_console in a loop. Fix this up by calling virtio_break_device + flush before reset. Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1786239 Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio_console: Assure used length from device is limited

2021-07-20T14:17:53+00:00

[ Upstream commit d00d8da5869a2608e97cfede094dfc5e11462a46 ] The buf->len might come from an untrusted device. This ensures the value would not exceed the size of the buffer to avoid data corruption or loss. Signed-off-by: Xie Yongji Acked-by: Jason Wang Link: https://lore.kernel.org/r/20210525125622.1203-1-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio: virtio_console: add missing MODULE_DEVICE_TABLE() for rproc serial

2020-07-22T07:22:27+00:00

commit 897c44f0bae574c5fb318c759b060bebf9dd6013 upstream. rproc_serial_id_table lacks an exposure to module devicetable, so when remoteproc firmware requests VIRTIO_ID_RPROC_SERIAL, no uevent is generated and no module autoloading occurs. Add missing MODULE_DEVICE_TABLE() annotation and move the existing one for VIRTIO_ID_CONSOLE right to the table itself. Fixes: 1b6370463e88 ("virtio_console: Add support for remoteproc serial") Cc: # v3.8+ Signed-off-by: Alexander Lobakin Reviewed-by: Amit Shah Link: https://lore.kernel.org/r/x7C_CbeJtoGMy258nwAXASYz3xgFMFpyzmUvOyZzRnQrgWCREBjaqBOpAUS7ol4NnZYvSVwmTsCG0Ohyfvta-ygw6HMHcoeKK0C3QFiAO_Q=@pm.me Signed-off-by: Greg Kroah-Hartman

virtio_console: allocate inbufs in add_port() only if it is needed

2019-12-01T08:13:14+00:00

commit d791cfcbf98191122af70b053a21075cb450d119 upstream. When we hot unplug a virtserialport and then try to hot plug again, it fails: (qemu) chardev-add socket,id=serial0,path=/tmp/serial0,server,nowait (qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\ chardev=serial0,id=serial0,name=serial0 (qemu) device_del serial0 (qemu) device_add virtserialport,bus=virtio-serial0.0,nr=2,\ chardev=serial0,id=serial0,name=serial0 kernel error: virtio-ports vport2p2: Error allocating inbufs qemu error: virtio-serial-bus: Guest failure in adding port 2 for device \ virtio-serial0.0 This happens because buffers for the in_vq are allocated when the port is added but are not released when the port is unplugged. They are only released when virtconsole is removed (see a7a69ec0d8e4) To avoid the problem and to be symmetric, we could allocate all the buffers in init_vqs() as they are released in remove_vqs(), but it sounds like a waste of memory. Rather than that, this patch changes add_port() logic to ignore ENOSPC error in fill_queue(), which means queue has already been filled. Fixes: a7a69ec0d8e4 ("virtio_console: free buffers after reset") Cc: mst@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Laurent Vivier Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

virtio_console: initialize vtermno value for ports

2019-05-31T13:47:32+00:00

[ Upstream commit 4b0a2c5ff7215206ea6135a405f17c5f6fca7d00 ] For regular serial ports we do not initialize value of vtermno variable. A garbage value is assigned for non console ports. The value can be observed as a random integer with [1]. [1] vim /sys/kernel/debug/virtio-ports/vport*p* This patch initialize the value of vtermno for console serial ports to '1' and regular serial ports are initiaized to '0'. Reported-by: siliu@redhat.com Signed-off-by: Pankaj Gupta Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

virtio_console: reset on out of memory

2018-05-01T19:58:12+00:00

commit 5c60300d68da32ca77f7f978039dc72bfc78b06b upstream. When out of memory and we can't add ctrl vq buffers, probe fails. Unfortunately the error handling is out of spec: it calls del_vqs without bothering to reset the device first. To fix, call the full cleanup function in this case. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

virtio_console: move removal code

2018-05-01T19:58:12+00:00

commit aa44ec867030a72e8aa127977e37dec551d8df19 upstream. Will make it reusable for error handling. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

virtio_console: drop custom control queue cleanup

2018-05-01T19:58:12+00:00

commit 61a8950c5c5708cf2068b29ffde94e454e528208 upstream. We now cleanup all VQs on device removal - no need to handle the control VQ specially. Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

virtio_console: free buffers after reset

2018-05-01T19:58:12+00:00

commit a7a69ec0d8e4a58be7db88d33cbfa2912807bb2b upstream. Console driver is out of spec. The spec says: A driver MUST NOT decrement the available idx on a live virtqueue (ie. there is no way to “unexpose” buffers). and it does exactly that by trying to detach unused buffers without doing a device reset first. Defer detaching the buffers until device unplug. Of course this means we might get an interrupt for a vq without an attached port now. Handle that by discarding the consumed buffer. Reported-by: Tiwei Bie Fixes: b3258ff1d6 ("virtio: Decrement avail idx on buffer detach") Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman