[PATCH v3 0/7] Fixes integer overflow or integer truncation issues in page lookups, ttm place configuration and scatterlist creation

[Gwan-gyeong Mun]

This patch series fixes integer overflow or integer truncation issues in
page lookups, ttm place configuration and scatterlist creation, etc.
We need to check that we avoid integer overflows when looking up a page,
and so fix all the instances where we have mistakenly used a plain integer
instead of a more suitable long.
And there is an impedance mismatch between the scatterlist API using
unsigned int and our memory/page accounting in unsigned long. That is we
may try to create a scatterlist for a large object that overflows returning
a small table into which we try to fit very many pages. As the object size
is under the control of userspace, we have to be prudent and catch the
conversion errors. To catch the implicit truncation as we switch from
unsigned long into the scatterlist's unsigned int, we use our overflows_type
check and report E2BIG prior to the operation. This is already used in
our create ioctls to indicate if the uABI request is simply too large for
the backing store. 
And ttm place also has the same problem with scatterlist creation,
and we fix the integer truncation problem with the way approached by
scatterlist creation.
And It corrects the error code to return -E2BIG when creating gem objects
using ttm or shmem, if the size is too large in each case.
In order to provide a common macro, it moves and adds a few utility macros into drm util header

v3: Modify overflows_type() macro to consider signed data types and
	add is_type_unsigned() macro (Mauro)
    Make not use the same macro name on a function. (Mauro)
    For kernel-doc, macros and functions are handled in the same namespace,
    the same macro name on a function prevents ever adding documentation for it.
    Not to change execution inside a macro. (Mauro)
    Fix the problem that safe_conversion() macro always returns true (G.G)
    Add safe_conversion_gem_bug_on() macro and remove temporal SAFE_CONVERSION() macro. (G.G.)

Testcase: igt at gem_create@create-massive
Testcase: igt at gem_userptr_blits@input-checking
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/4991
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5411
Cc: Mauro Carvalho Chehab <mchehab at kernel.org>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld at intel.com>
Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
Cc: Nirmoy Das <nirmoy.das at intel.com>
Cc: Jani Nikula <jani.nikula at intel.com>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>

Chris Wilson (3):
  drm/i915/gem: Typecheck page lookups
  drm/i915: Check for integer truncation on scatterlist creation
  drm/i915: Remove truncation warning for large objects

Gwan-gyeong Mun (4):
  drm: Move and add a few utility macros into drm util header
  drm/i915: Check for integer truncation on the configuration of ttm
    place
  drm/i915: Check if the size is too big while creating shmem file
  drm/i915: Use error code as -E2BIG when the size of gem ttm object is
    too large

 drivers/gpu/drm/i915/gem/i915_gem_internal.c  |  6 +-
 drivers/gpu/drm/i915/gem/i915_gem_object.c    |  7 +-
 drivers/gpu/drm/i915/gem/i915_gem_object.h    | 87 +++++++++++--------
 drivers/gpu/drm/i915/gem/i915_gem_pages.c     | 27 +++---
 drivers/gpu/drm/i915/gem/i915_gem_phys.c      |  4 +
 drivers/gpu/drm/i915/gem/i915_gem_shmem.c     | 14 ++-
 drivers/gpu/drm/i915/gem/i915_gem_ttm.c       | 23 ++++-
 drivers/gpu/drm/i915/gem/i915_gem_userptr.c   |  5 +-
 .../drm/i915/gem/selftests/i915_gem_context.c | 12 +--
 .../drm/i915/gem/selftests/i915_gem_mman.c    |  8 +-
 .../drm/i915/gem/selftests/i915_gem_object.c  |  8 +-
 drivers/gpu/drm/i915/gvt/dmabuf.c             |  9 +-
 drivers/gpu/drm/i915/i915_gem.c               | 18 +++-
 drivers/gpu/drm/i915/i915_gem.h               |  4 +
 drivers/gpu/drm/i915/i915_scatterlist.h       |  8 ++
 drivers/gpu/drm/i915/i915_utils.h             |  5 +-
 drivers/gpu/drm/i915/i915_vma.c               |  8 +-
 drivers/gpu/drm/i915/intel_region_ttm.c       | 20 ++++-
 include/drm/drm_util.h                        | 77 ++++++++++++++++
 19 files changed, 257 insertions(+), 93 deletions(-)

-- 
2.34.1