[v5,00/15] follow_pfn and other iomap races

Message

Daniel Vetter Oct. 30, 2020, 10:08 a.m. UTC

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/[e-mail]/
v2: https://lore.kernel.org/dri-devel/[e-mail]
v3: https://lore.kernel.org/dri-devel/[e-mail]/
v4: https://lore.kernel.org/dri-devel/[e-mail]/

And the discussion that sparked this journey:

https://lore.kernel.org/dri-devel/[e-mail]/

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 (15):
  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

 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/mm.h                            |  47 +-------
 include/linux/sysfs.h                         |   2 +
 include/media/frame_vector.h                  |  47 ++++++++
 include/media/videobuf2-core.h                |   1 +
 kernel/resource.c                             | 101 +++++++++++++++++-
 mm/Kconfig                                    |   3 -
 mm/Makefile                                   |   1 -
 mm/memory.c                                   |  80 +++++++++++++-
 mm/nommu.c                                    |  27 ++++-
 security/Kconfig                              |  13 +++
 27 files changed, 360 insertions(+), 250 deletions(-)
 rename {mm => drivers/media/common/videobuf2}/frame_vector.c (84%)
 create mode 100644 include/media/frame_vector.h