[PATCH v7 00/17] follow_pfn and other iomap races
Daniel Vetter
daniel at ffwll.ch
Tue Jan 12 08:24:27 EST 2021
On Fri, Nov 27, 2020 at 05:41:14PM +0100, Daniel Vetter wrote:
> 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/20201007164426.1812530-1-daniel.vetter@ffwll.ch/
> v2: https://lore.kernel.org/dri-devel/20201009075934.3509076-1-daniel.vetter@ffwll.ch
> v3: https://lore.kernel.org/dri-devel/20201021085655.1192025-1-daniel.vetter@ffwll.ch/
> v4: https://lore.kernel.org/dri-devel/20201026105818.2585306-1-daniel.vetter@ffwll.ch/
> v5: https://lore.kernel.org/dri-devel/20201030100815.2269-1-daniel.vetter@ffwll.ch/
> v6: https://lore.kernel.org/dri-devel/20201119144146.1045202-1-daniel.vetter@ffwll.ch/
>
> And the discussion that sparked this journey:
>
> https://lore.kernel.org/dri-devel/20201007164426.1812530-1-daniel.vetter@ffwll.ch/
>
> I think the first 12 patches are ready for landing. The parts starting
> with "mm: Add unsafe_follow_pfn" probably need more baking time.
>
> Andrew, can you please pick these up, or do you prefer I do a topic branch
> and send them to Linus directly in the next merge window?
>
> Changes in v7:
> - more acks/reviews
> - reordered with the ready pieces at the front
> - simplified the new follow_pfn function as Jason suggested
>
> 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.
>
> Coments and review on the remaining bits very much welcome, especially
> from the kvm and vfio side.
>
> 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
> 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
As Jason suggested, I've pulled the first 1 patches into a topic branch.
Stephen, can you please add the below to linux-next for the 5.12 merge
window?
git://anongit.freedesktop.org/drm/drm topic/iomem-mmap-vs-gup
Once this part has landed I'll see what to do with the below part.
Thanks, Daniel
> mm: Add unsafe_follow_pfn
> media/videobuf1|2: Mark follow_pfn usage as unsafe
> vfio/type1: Mark follow_pfn as unsafe
> kvm: pass kvm argument to follow_pfn callsites
> 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 | 52 +++-----
> 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 | 112 +++++++++++++++---
> mm/nommu.c | 16 ++-
> security/Kconfig | 13 ++
> virt/kvm/kvm_main.c | 56 +++++----
> 33 files changed, 413 insertions(+), 299 deletions(-)
> rename {mm => drivers/media/common/videobuf2}/frame_vector.c (84%)
> create mode 100644 include/media/frame_vector.h
>
> --
> 2.29.2
>
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--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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