On Fri, 16 Dec 2022 11:16:59 -0500
Steven Sistare <steven.sistare@xxxxxxxxxx> wrote:
> On 12/16/2022 11:10 AM, Alex Williamson wrote:
> > On Fri, 16 Dec 2022 10:42:13 -0500
> > Steven Sistare <steven.sistare@xxxxxxxxxx> wrote:
> >
> >> On 12/16/2022 9:09 AM, Jason Gunthorpe wrote:
> >>> On Thu, Dec 15, 2022 at 01:56:59PM -0800, Steve Sistare wrote:
> >>>> When a vfio container is preserved across exec, the task does not change,
> >>>> but it gets a new mm with locked_vm=0. If the user later unmaps a dma
> >>>> mapping, locked_vm underflows to a large unsigned value, and a subsequent
> >>>> dma map request fails with ENOMEM in __account_locked_vm.
> >>>>
> >>>> To avoid underflow, grab and save the mm at the time a dma is mapped.
> >>>> Use that mm when adjusting locked_vm, rather than re-acquiring the saved
> >>>> task's mm, which may have changed. If the saved mm is dead, do nothing.
> >>>>
> >>>> Signed-off-by: Steve Sistare <steven.sistare@xxxxxxxxxx>
> >>>> ---
> >>>> drivers/vfio/vfio_iommu_type1.c | 17 ++++++++++-------
> >>>> 1 file changed, 10 insertions(+), 7 deletions(-)
> >>>
> >>> Add fixes lines and a CC stable
> >>
> >> This predates the update vaddr functionality, so AFAICT:
> >>
> >> Fixes: 73fa0d10d077 ("vfio: Type1 IOMMU implementation")
> >>
> >> I'll wait on cc'ing stable until alex has chimed in.
> >
> > Technically, adding the stable Cc tag is still the correct approach per
> > the stable process docs, but the Fixes: tag alone is generally
> > sufficient to crank up the backport engines. The original
> > implementation is probably the correct commit to identify, exec was
> > certainly not considered there. Thanks,
>
> Should I cc stable on the whole series, or re-send individually? If the
> latter, which ones?
Only for the Fixes: commits, and note that Cc: stable is effectively
just a tag like Fixes:, you don't actually need to copy the stable@vger
list on the patch (and IIRC you'll get some correctional email if you
do). Thanks,
Alex
