lkml.org 
[lkml]   [2021]   [Sep]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC 06/20] iommu: Add iommu_device_init[exit]_user_dma interfaces
    On Wed, Sep 29, 2021 at 12:38:35AM +0000, Tian, Kevin wrote:

    > /* If set the driver must call iommu_XX as the first action in probe() or
    > * before it attempts to do DMA
    > */
    > bool suppress_dma_owner:1;

    It is not "attempts to do DMA" but more "operates the physical device
    in any away"

    Not having ownership means another entity could be using user space
    DMA to manipulate the device state and attack the integrity of the
    kernel's programming of the device.

    Jason

    \
     
     \ /
      Last update: 2021-09-29 14:59    [W:6.577 / U:0.040 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site