Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
virtio_input: fix DMA alignment for evts
On non-cache-coherent platforms, when a structure contains a buffer
used for DMA alongside fields that the CPU writes to, cacheline sharing
can cause data corruption.
The evts array is used for DMA_FROM_DEVICE operations via
virtqueue_add_inbuf(). The adjacent lock and ready fields are written
by the CPU during normal operation. If these share cachelines with evts,
CPU writes can corrupt DMA data.
Add __dma_from_device_group_begin()/end() annotations to ensure evts is
isolated in its own cachelines.
Message-ID: <cd328233198a76618809bb5cd9a6ddcaa603a8a1.1767601130.git.mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
+3
+3
drivers/virtio/virtio_input.c
+3
drivers/virtio/virtio_input.c
···
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#include <linux/virtio_config.h>
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#include <linux/input.h>
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#include <linux/slab.h>
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+
#include <linux/dma-mapping.h>
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#include <uapi/linux/virtio_ids.h>
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#include <uapi/linux/virtio_input.h>
···
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char serial[64];
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char phys[64];
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struct virtqueue *evt, *sts;
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+
__dma_from_device_group_begin();
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struct virtio_input_event evts[64];
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__dma_from_device_group_end();
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spinlock_t lock;
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bool ready;
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};