kernel/linux.git/drivers/char/virtio_console.c, branch v5.10.252

virtio_console: fix order of fields cols and rows

2026-01-19T12:12:00+00:00

commit 5326ab737a47278dbd16ed3ee7380b26c7056ddd upstream. According to section 5.3.6.2 (Multiport Device Operation) of the virtio spec(version 1.2) a control buffer with the event VIRTIO_CONSOLE_RESIZE is followed by a virtio_console_resize struct containing cols then rows. The kernel implements this the wrong way around (rows then cols) resulting in the two values being swapped. Signed-off-by: Maximilian Immanuel Brandtner Message-Id: <20250324144300.905535-1-maxbr@linux.ibm.com> Signed-off-by: Michael S. Tsirkin Cc: Filip Hejsek Signed-off-by: Greg Kroah-Hartman

virtio_console: fix missing byte order handling for cols and rows

2025-05-02T05:41:15+00:00

commit fbd3039a64b01b769040677c4fc68badeca8e3b2 upstream. As per virtio spec the fields cols and rows are specified as little endian. Although there is no legacy interface requirement that would state that cols and rows need to be handled as native endian when legacy interface is used, unlike for the fields of the adjacent struct virtio_console_control, I decided to err on the side of caution based on some non-conclusive virtio spec repo archaeology and opt for using virtio16_to_cpu() much like for virtio_console_control.event. Strictly by the letter of the spec virtio_le_to_cpu() would have been sufficient. But when the legacy interface is not used, it boils down to the same. And when using the legacy interface, the device formatting these as little endian when the guest is big endian would surprise me more than it using guest native byte order (which would make it compatible with the current implementation). Nevertheless somebody trying to implement the spec following it to the letter could end up forcing little endian byte order when the legacy interface is in use. So IMHO this ultimately needs a judgement call by the maintainers. Fixes: 8345adbf96fc1 ("virtio: console: Accept console size along with resize control message") Signed-off-by: Halil Pasic Cc: stable@vger.kernel.org # v2.6.35+ Message-Id: <20250322002954.3129282-1-pasic@linux.ibm.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

virtio_console: fix misc probe bugs

2024-10-17T13:08:29+00:00

[ Upstream commit b9efbe2b8f0177fa97bfab290d60858900aa196b ] This fixes the following issue discovered by code review: after vqs have been created, a buggy device can send an interrupt. A control vq callback will then try to schedule control_work which has not been initialized yet. Similarly for config interrupt. Further, in and out vq callbacks invoke find_port_by_vq which attempts to take ports_lock which also has not been initialized. To fix, init all locks and work before creating vqs. Message-ID: Fixes: 17634ba25544 ("virtio: console: Add a new MULTIPORT feature, support for generic ports") Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio_console: eliminate anonymous module_init & module_exit

2022-04-13T19:01:02+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

2022-04-08T12:39:47+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

2021-07-20T14:05:49+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: fix DMA memory allocation for rproc serial

2020-11-09T17:03:33+00:00

Since commit 086d08725d34 ("remoteproc: create vdev subdevice with specific dma memory pool"), every remoteproc has a DMA subdevice ("remoteprocX#vdevYbuffer") for each virtio device, which inherits DMA capabilities from the corresponding platform device. This allowed to associate different DMA pools with each vdev, and required from virtio drivers to perform DMA operations with the parent device (vdev->dev.parent) instead of grandparent (vdev->dev.parent->parent). virtio_rpmsg_bus was already changed in the same merge cycle with commit d999b622fcfb ("rpmsg: virtio: allocate buffer from parent"), but virtio_console did not. In fact, operations using the grandparent worked fine while the grandparent was the platform device, but since commit c774ad010873 ("remoteproc: Fix and restore the parenting hierarchy for vdev") this was changed, and now the grandparent device is the remoteproc device without any DMA capabilities. So, starting v5.8-rc1 the following warning is observed: [ 2.483925] ------------[ cut here ]------------ [ 2.489148] WARNING: CPU: 3 PID: 101 at kernel/dma/mapping.c:427 0x80e7eee8 [ 2.489152] Modules linked in: virtio_console(+) [ 2.503737] virtio_rpmsg_bus rpmsg_core [ 2.508903] [ 2.528898] [ 2.913043] [ 2.914907] ---[ end trace 93ac8746beab612c ]--- [ 2.920102] virtio-ports vport1p0: Error allocating inbufs kernel/dma/mapping.c:427 is: WARN_ON_ONCE(!dev->coherent_dma_mask); obviously because the grandparent now is remoteproc dev without any DMA caps: [ 3.104943] Parent: remoteproc0#vdev1buffer, grandparent: remoteproc0 Fix this the same way as it was for virtio_rpmsg_bus, using just the parent device (vdev->dev.parent, "remoteprocX#vdevYbuffer") for DMA operations. This also allows now to reserve DMA pools/buffers for rproc serial via Device Tree. Fixes: c774ad010873 ("remoteproc: Fix and restore the parenting hierarchy for vdev") Cc: stable@vger.kernel.org # 5.1+ Reviewed-by: Mathieu Poirier Acked-by: Jason Wang Signed-off-by: Alexander Lobakin Date: Thu, 5 Nov 2020 11:10:24 +0800 Link: https://lore.kernel.org/r/AOKowLclCbOCKxyiJ71WeNyuAAj2q8EUtxrXbyky5E@cp7-web-042.plabs.ch Signed-off-by: Greg Kroah-Hartman

Merge v5.8-rc6 into char-misc-next

2020-07-20T07:43:40+00:00

We need the char/misc fixes in here as well. Signed-off-by: Greg Kroah-Hartman

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

2020-07-10T13:12:48+00:00

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: Constify some static variables

2020-07-10T12:50:51+00:00

The id_table and feature_table pointers in struct virtio_driver are pointers to const. Mark the corresponding static variables const to allow the compiler to put them in read-only memory. Before: text data bss dec hex filename 25447 713 76 26236 667c drivers/char/virtio_console.o After: text data bss dec hex filename 25488 673 76 26237 667d drivers/char/virtio_console.o Signed-off-by: Rikard Falkeborn Acked-by: Arnd Bergmann Reviewed-by: Amit Shah Link: https://lore.kernel.org/r/20200701200950.30314-6-rikard.falkeborn@gmail.com Signed-off-by: Greg Kroah-Hartman