Hi all
Another update of my patch series to clamp down a bunch of races and gaps
around follow_pfn and other access to iomem mmaps. Previous version:
v1: https://lore.kernel.org/dri-devel/[email protected]/
v2: https://lore.kernel.org/dri-devel/[email protected]
v3: https://lore.kernel.org/dri-devel/[email protected]/
v4: https://lore.kernel.org/dri-devel/[email protected]/
v5: https://lore.kernel.org/dri-devel/[email protected]/
And the discussion that sparked this journey:
https://lore.kernel.org/dri-devel/[email protected]/
Unfortunately took way longer to update than I hoped, I got sidetracked
with a few things.
Changes in v6:
- Tested v4l userptr as Tomasz suggested. No boom observed
- Added RFC for locking down follow_pfn, per discussion with Christoph and
Jason.
- Explain why pup_fast is safe in relevant patches, there was a bit a
confusion when discussing v5.
- Fix up the resource patch, with CONFIG_IO_STRICT_DEVMEM it crashed on
boot due to an unintended change (reported by John)
Changes in v5:
- Tomasz found some issues in the media patches
- Polish suggested by Christoph for the unsafe_follow_pfn patch
Changes in v4:
- Drop the s390 patch, that was very stand-alone and now queued up to land
through s390 trees.
- Comment polish per Dan's review.
Changes in v3:
- Bunch of polish all over, no functional changes aside from one barrier
in the resource code, for consistency.
- A few more r-b tags.
Changes in v2:
- tons of small polish&fixes all over, thanks to all the reviewers who
spotted issues
- I managed to test at least the generic_access_phys and pci mmap revoke
stuff with a few gdb sessions using our i915 debug tools (hence now also
the drm/i915 patch to properly request all the pci bar regions)
- reworked approach for the pci mmap revoke: Infrastructure moved into
kernel/resource.c, address_space mapping is now set up at open time for
everyone (which required some sysfs changes). Does indeed look a lot
cleaner and a lot less invasive than I feared at first.
I feel like this is ready for some wider soaking. Since the remaining bits
are all kinda connnected probably simplest if it all goes through -mm.
Cheers, Daniel
Daniel Vetter (17):
drm/exynos: Stop using frame_vector helpers
drm/exynos: Use FOLL_LONGTERM for g2d cmdlists
misc/habana: Stop using frame_vector helpers
misc/habana: Use FOLL_LONGTERM for userptr
mm/frame-vector: Use FOLL_LONGTERM
media: videobuf2: Move frame_vector into media subsystem
mm: Close race in generic_access_phys
mm: Add unsafe_follow_pfn
media/videbuf1|2: Mark follow_pfn usage as unsafe
vfio/type1: Mark follow_pfn as unsafe
PCI: Obey iomem restrictions for procfs mmap
/dev/mem: Only set filp->f_mapping
resource: Move devmem revoke code to resource framework
sysfs: Support zapping of binary attr mmaps
PCI: Revoke mappings like devmem
RFC: kvm: pass kvm argument to follow_pfn callsites
RFC: mm: add mmu_notifier argument to follow_pfn
arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +-
arch/powerpc/kvm/book3s_64_mmu_radix.c | 2 +-
arch/powerpc/kvm/e500_mmu_host.c | 2 +-
arch/x86/kvm/mmu/mmu.c | 8 +-
drivers/char/mem.c | 86 +------------
drivers/gpu/drm/exynos/Kconfig | 1 -
drivers/gpu/drm/exynos/exynos_drm_g2d.c | 48 ++++----
drivers/media/common/videobuf2/Kconfig | 1 -
drivers/media/common/videobuf2/Makefile | 1 +
.../media/common/videobuf2}/frame_vector.c | 57 +++------
.../media/common/videobuf2/videobuf2-memops.c | 3 +-
drivers/media/platform/omap/Kconfig | 1 -
drivers/media/v4l2-core/videobuf-dma-contig.c | 2 +-
drivers/misc/habanalabs/Kconfig | 1 -
drivers/misc/habanalabs/common/habanalabs.h | 6 +-
drivers/misc/habanalabs/common/memory.c | 50 +++-----
drivers/pci/pci-sysfs.c | 4 +
drivers/pci/proc.c | 6 +
drivers/vfio/vfio_iommu_type1.c | 4 +-
fs/sysfs/file.c | 11 ++
include/linux/ioport.h | 6 +-
include/linux/kvm_host.h | 9 +-
include/linux/mm.h | 50 +-------
include/linux/sysfs.h | 2 +
include/media/frame_vector.h | 47 +++++++
include/media/videobuf2-core.h | 1 +
kernel/resource.c | 98 ++++++++++++++-
mm/Kconfig | 3 -
mm/Makefile | 1 -
mm/memory.c | 115 +++++++++++++++---
mm/nommu.c | 48 +++++++-
security/Kconfig | 13 ++
virt/kvm/kvm_main.c | 56 +++++----
33 files changed, 447 insertions(+), 298 deletions(-)
rename {mm => drivers/media/common/videobuf2}/frame_vector.c (84%)
create mode 100644 include/media/frame_vector.h
--
2.29.2
On Fri, Nov 27, 2020 at 09:12:25AM -0400, Jason Gunthorpe wrote:
> On Thu, Nov 19, 2020 at 03:41:29PM +0100, Daniel Vetter wrote:
> > I feel like this is ready for some wider soaking. Since the remaining bits
> > are all kinda connnected probably simplest if it all goes through -mm.
>
> Did you figure out a sumbission plan for this stuff?
I was kinda hoping Andrew would pick it all up.
> > Daniel Vetter (17):
> > drm/exynos: Stop using frame_vector helpers
> > drm/exynos: Use FOLL_LONGTERM for g2d cmdlists
> > misc/habana: Stop using frame_vector helpers
> > misc/habana: Use FOLL_LONGTERM for userptr
> > mm/frame-vector: Use FOLL_LONGTERM
> > media: videobuf2: Move frame_vector into media subsystem
>
> At the very least it would be good to get those in right away.
>
> > mm: Add unsafe_follow_pfn
> > media/videbuf1|2: Mark follow_pfn usage as unsafe
> > vfio/type1: Mark follow_pfn as unsafe
>
> I'm surprised nobody from VFIO has remarked on this, I think thety
> won't like it
Same here tbh :-)
> > mm: Close race in generic_access_phys
> > PCI: Obey iomem restrictions for procfs mmap
> > /dev/mem: Only set filp->f_mapping
> > resource: Move devmem revoke code to resource framework
> > sysfs: Support zapping of binary attr mmaps
> > PCI: Revoke mappings like devmem
>
> This sequence seems fairly stand alone, and in good shape as well
Yeah your split makes sense. I'll reorder them for the next round (which
I'm prepping right now).
>
> My advice is to put the done things on a branch and get Stephen to put
> them in linux-next. You can send a PR to Lins. There is very little mm
> stuff in here, and cross subsystem stuff works better in git land,
> IMHO.
Yeah could do. Andrew, any preferences?
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
On Thu, Nov 19, 2020 at 03:41:29PM +0100, Daniel Vetter wrote:
> I feel like this is ready for some wider soaking. Since the remaining bits
> are all kinda connnected probably simplest if it all goes through -mm.
Did you figure out a sumbission plan for this stuff?
> Daniel Vetter (17):
> drm/exynos: Stop using frame_vector helpers
> drm/exynos: Use FOLL_LONGTERM for g2d cmdlists
> misc/habana: Stop using frame_vector helpers
> misc/habana: Use FOLL_LONGTERM for userptr
> mm/frame-vector: Use FOLL_LONGTERM
> media: videobuf2: Move frame_vector into media subsystem
At the very least it would be good to get those in right away.
> mm: Add unsafe_follow_pfn
> media/videbuf1|2: Mark follow_pfn usage as unsafe
> vfio/type1: Mark follow_pfn as unsafe
I'm surprised nobody from VFIO has remarked on this, I think thety
won't like it
> mm: Close race in generic_access_phys
> PCI: Obey iomem restrictions for procfs mmap
> /dev/mem: Only set filp->f_mapping
> resource: Move devmem revoke code to resource framework
> sysfs: Support zapping of binary attr mmaps
> PCI: Revoke mappings like devmem
This sequence seems fairly stand alone, and in good shape as well
My advice is to put the done things on a branch and get Stephen to put
them in linux-next. You can send a PR to Lins. There is very little mm
stuff in here, and cross subsystem stuff works better in git land,
IMHO.
Jason