kernel/linux.git/drivers/char/virtio_console.c, branch v4.11.5

virtio_console: fix uninitialized variable use

2017-04-07T13:39:00+00:00

We try to disable callbacks on c_ivq even without multiport even though that vq is not initialized in this configuration. Fixes: c743d09dbd01 ("virtio: console: Disable callbacks for virtqueues at start of S4 freeze") Suggested-by: Mike Galbraith Signed-off-by: Michael S. Tsirkin

virtio-console: avoid DMA from stack

2017-03-01T23:35:06+00:00

put_chars() stuffs the buffer it gets into an sg, but that buffer may be on the stack. This breaks with CONFIG_VMAP_STACK=y (for me, it manifested as printks getting turned into NUL bytes). Signed-off-by: Omar Sandoval Signed-off-by: Michael S. Tsirkin Reviewed-by: Amit Shah

virtio: allow drivers to request IRQ affinity when creating VQs

2017-02-27T18:54:04+00:00

Add a struct irq_affinity pointer to the find_vqs methods, which if set is used to tell the PCI layer to create the MSI-X vectors for our I/O virtqueues with the proper affinity from the start. Compared to after the fact affinity hints this gives us an instantly working setup and allows to allocate the irq descritors node-local and avoid interconnect traffic. Last but not least this will allow blk-mq queues are created based on the interrupt affinity for storage drivers. Signed-off-by: Christoph Hellwig Reviewed-by: Jason Wang Signed-off-by: Michael S. Tsirkin

virtio_console: fix a crash in config_work_handler

2017-01-19T21:46:31+00:00

Using control_work instead of config_work as the 3rd argument to container_of results in an invalid portdev pointer. Indeed, the work structure is initialized as below: INIT_WORK(&portdev->config_work, &config_work_handler); It leads to a crash when portdev->vdev is dereferenced later. This bug is triggered when the guest uses a virtio-console without multiport feature and receives a config_changed virtio interrupt. Signed-off-by: G. Campana Reviewed-by: Amit Shah Signed-off-by: Michael S. Tsirkin

virtio_console: drop unused config fields

2016-12-15T04:59:15+00:00

struct ports_device includes a config field including the whole virtio_console_config, but only max_nr_ports in there is ever updated or used. The rest is unused and in fact does not even mirror the device config. Drop everything except max_nr_ports, saving some memory. Signed-off-by: Michael S. Tsirkin Reviewed-by: Jason Wang

virtio: console: Unlock vqs while freeing buffers

2016-10-30T22:21:44+00:00

Commit c6017e793b93 ("virtio: console: add locks around buffer removal in port unplug path") added locking around the freeing of buffers in the vq. However, when free_buf() is called with can_sleep = true and rproc is enabled, it calls dma_free_coherent() directly, requiring interrupts to be enabled. Currently a WARNING is triggered due to the spin locking around free_buf, with a call stack like this: WARNING: CPU: 3 PID: 121 at ./include/linux/dma-mapping.h:433 free_buf+0x1a8/0x288 Call Trace: [<8040c538>] show_stack+0x74/0xc0 [<80757240>] dump_stack+0xd0/0x110 [<80430d98>] __warn+0xfc/0x130 [<80430ee0>] warn_slowpath_null+0x2c/0x3c [<807e7c6c>] free_buf+0x1a8/0x288 [<807ea590>] remove_port_data+0x50/0xac [<807ea6a0>] unplug_port+0xb4/0x1bc [<807ea858>] virtcons_remove+0xb0/0xfc [<807b6734>] virtio_dev_remove+0x58/0xc0 [<807f918c>] __device_release_driver+0xac/0x134 [<807f924c>] device_release_driver+0x38/0x50 [<807f7edc>] bus_remove_device+0xfc/0x130 [<807f4b74>] device_del+0x17c/0x21c [<807f4c38>] device_unregister+0x24/0x38 [<807b6b50>] unregister_virtio_device+0x28/0x44 Fix this by restructuring the loops to allow the locks to only be taken where it is necessary to protect the vqs, and release it while the buffer is being freed. Fixes: c6017e793b93 ("virtio: console: add locks around buffer removal in port unplug path") Cc: stable@vger.kernel.org Signed-off-by: Matt Redfearn Signed-off-by: Michael S. Tsirkin

treewide: remove redundant #include

2016-10-11T22:06:33+00:00

Kernel source files need not include explicitly because the top Makefile forces to include it with: -include $(srctree)/include/linux/kconfig.h This commit removes explicit includes except the following: * arch/s390/include/asm/facilities_src.h * tools/testing/radix-tree/linux/kernel.h These two are used for host programs. Link: http://lkml.kernel.org/r/1473656164-11929-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pipe: add pipe_buf_steal() helper

2016-10-05T22:23:59+00:00

Signed-off-by: Miklos Szeredi Signed-off-by: Al Viro

virtio_console: Stop doing DMA on the stack

2016-09-09T18:12:45+00:00

virtio_console uses a small DMA buffer for control requests. Move that buffer into heap memory. Doing virtio DMA on the stack is normally okay on non-DMA-API virtio systems (which is currently most of them), but it breaks completely if the stack is virtually mapped. Tested by typing both directions using picocom aimed at /dev/hvc0. Signed-off-by: Andy Lutomirski Signed-off-by: Michael S. Tsirkin Reviewed-by: Amit Shah

virtio_console: silence a static checker warning

2015-05-24T19:24:35+00:00

My static checker complains that this sprintf() can overflow but really it can't. Just silence the warning by using snprintf(). Signed-off-by: Dan Carpenter Reviewed-by: Amit Shah Signed-off-by: Greg Kroah-Hartman