On 1/3/2023 10:22 AM, Jason Gunthorpe wrote:
> On Tue, Dec 20, 2022 at 12:39:22PM -0800, Steve Sistare wrote:
>> When a vfio container is preserved across exec or fork-exec, the new
>> task's mm has a locked_vm count of 0. After a dma vaddr is updated using
>> VFIO_DMA_MAP_FLAG_VADDR, locked_vm remains 0, and the pinned memory does
>> not count against the task's RLIMIT_MEMLOCK.
>>
>> To restore the correct locked_vm count, when VFIO_DMA_MAP_FLAG_VADDR is
>> used and the dma's mm has changed, add the dma's locked_vm count to
>> the new mm->locked_vm, subject to the rlimit.
>>
>> Fixes: c3cbab24db38 ("vfio/type1: implement interfaces to update vaddr")
>> Cc: stable@xxxxxxxxxxxxxxx
>> Signed-off-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
>> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
>> ---
>> drivers/vfio/vfio_iommu_type1.c | 32 ++++++++++++++++++++++++++++++++
>> 1 file changed, 32 insertions(+)
>
> But you should subtract it from the old one as well?
Yes, as implemented. I'll add that to the commit message.
- Steve
