On Tue, Jan 12, 2021 at 2:24 PM Daniel Vetter daniel@ffwll.ch wrote:
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@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
As Jason suggested, I've pulled the first 1 patches into a topic branch.
Uh this was meant to read "first _12_ patches" ofc. -Daniel
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