drm/i915/gem: Fix Virtual Memory mapping boundaries calculation

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commit 8bdd9ef7e9 upstream.

Calculating the size of the mapped area as the lesser value
between the requested size and the actual size does not consider
the partial mapping offset. This can cause page fault access.

Fix the calculation of the starting and ending addresses, the
total size is now deduced from the difference between the end and
start addresses.

Additionally, the calculations have been rewritten in a clearer
and more understandable form.

Fixes: c58305af18 ("drm/i915: Use remap_io_mapping() to prefault all PTE in a single pass")
Reported-by: Jann Horn <jannh@google.com>
Co-developed-by: Chris Wilson <chris.p.wilson@linux.intel.com>
Signed-off-by: Chris Wilson <chris.p.wilson@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: <stable@vger.kernel.org> # v4.9+
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Jonathan Cavitt <Jonathan.cavitt@intel.com>
[Joonas: Add Requires: tag]
Requires: 60a2066c50 ("drm/i915/gem: Adjust vma offset for framebuffer mmap offset")
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240802083850.103694-3-andi.shyti@linux.intel.com
(cherry picked from commit 97b6784753)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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This commit is contained in:

Andi Shyti 2024-08-02 10:38:50 +02:00 • committed by Greg Kroah-Hartman

parent 81ac1e8884

commit 4b09513ce9

1 changed files with 47 additions and 6 deletions

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drivers/gpu/drm/i915/gem/i915_gem_mman.c

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