lkml.org 
[lkml]   [2022]   [Mar]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    Subject[PATCH v2 26/48] kmsan: virtio: check/unpoison scatterlist in vring_map_one_sg()
    From
    If vring doesn't use the DMA API, KMSAN is unable to tell whether the
    memory is initialized by hardware. Explicitly call kmsan_handle_dma()
    from vring_map_one_sg() in this case to prevent false positives.

    Signed-off-by: Alexander Potapenko <glider@google.com>
    Acked-by: Michael S. Tsirkin <mst@redhat.com>

    ---
    Link: https://linux-review.googlesource.com/id/I211533ecb86a66624e151551f83ddd749536b3af
    ---
    drivers/virtio/virtio_ring.c | 10 +++++++++-
    1 file changed, 9 insertions(+), 1 deletion(-)

    diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
    index 962f1477b1fab..461e08f7f0a0f 100644
    --- a/drivers/virtio/virtio_ring.c
    +++ b/drivers/virtio/virtio_ring.c
    @@ -11,6 +11,7 @@
    #include <linux/module.h>
    #include <linux/hrtimer.h>
    #include <linux/dma-mapping.h>
    +#include <linux/kmsan-checks.h>
    #include <linux/spinlock.h>
    #include <xen/xen.h>

    @@ -331,8 +332,15 @@ static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq,
    struct scatterlist *sg,
    enum dma_data_direction direction)
    {
    - if (!vq->use_dma_api)
    + if (!vq->use_dma_api) {
    + /*
    + * If DMA is not used, KMSAN doesn't know that the scatterlist
    + * is initialized by the hardware. Explicitly check/unpoison it
    + * depending on the direction.
    + */
    + kmsan_handle_dma(sg_page(sg), sg->offset, sg->length, direction);
    return (dma_addr_t)sg_phys(sg);
    + }

    /*
    * We can't use dma_map_sg, because we don't use scatterlists in
    --
    2.35.1.1021.g381101b075-goog
    \
     
     \ /
      Last update: 2022-03-29 14:43    [W:2.553 / U:0.044 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site