--- /dev/null
+From e6e06b3feafff4a9eed796d85e744233a08058d6 Mon Sep 17 00:00:00 2001
+From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
+Date: Tue, 5 Mar 2019 11:04:08 +0000
+Subject: drm/i915: Relax mmap VMA check
+
+[ Upstream commit ca22f32a6296cbfa29de56328c8505560a18cfa8 ]
+
+Legacy behaviour was to allow non-page-aligned mmap requests, as does the
+linux mmap(2) implementation by virtue of automatically rounding up for
+the caller.
+
+To avoid breaking legacy userspace relax the newly introduced fix.
+
+Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
+Fixes: 5c4604e757ba ("drm/i915: Prevent a race during I915_GEM_MMAP ioctl with WC set")
+Reported-by: Guenter Roeck <linux@roeck-us.net>
+Cc: Adam Zabrocki <adamza@microsoft.com>
+Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
+Cc: <stable@vger.kernel.org> # v4.0+
+Cc: Akash Goel <akash.goel@intel.com>
+Cc: Chris Wilson <chris@chris-wilson.co.uk>
+Cc: Jani Nikula <jani.nikula@linux.intel.com>
+Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
+Cc: intel-gfx@lists.freedesktop.org
+Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
+Link: https://patchwork.freedesktop.org/patch/msgid/20190305110409.28633-1-tvrtko.ursulin@linux.intel.com
+(cherry picked from commit a90e1948efb648f567444f87f3c19b2a0787affd)
+Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/gpu/drm/i915/i915_gem.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
+index 5d8a67c65141..727018a16cca 100644
+--- a/drivers/gpu/drm/i915/i915_gem.c
++++ b/drivers/gpu/drm/i915/i915_gem.c
+@@ -1640,7 +1640,8 @@ __vma_matches(struct vm_area_struct *vma, struct file *filp,
+ if (vma->vm_file != filp)
+ return false;
+
+- return vma->vm_start == addr && (vma->vm_end - vma->vm_start) == size;
++ return vma->vm_start == addr &&
++ (vma->vm_end - vma->vm_start) == PAGE_ALIGN(size);
+ }
+
+ /**
+--
+2.19.1
+