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@ffw... v2: https://lore.kernel.org/dri-devel/20201009075934.3509076-1-daniel.vetter@ffw... v3: https://lore.kernel.org/dri-devel/20201021085655.1192025-1-daniel.vetter@ffw... v4: https://lore.kernel.org/dri-devel/20201026105818.2585306-1-daniel.vetter@ffw... v5: https://lore.kernel.org/dri-devel/20201030100815.2269-1-daniel.vetter@ffwll.... v6: https://lore.kernel.org/dri-devel/20201119144146.1045202-1-daniel.vetter@ffw...
And the discussion that sparked this journey:
https://lore.kernel.org/dri-devel/20201007164426.1812530-1-daniel.vetter@ffw...
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 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