Commit a90e1948 authored Mar 05, 2019 by Tvrtko Ursulin

drm/i915: Relax mmap VMA check



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: 5c4604e7 ("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

parent b218a80b

drivers/gpu/drm/i915/i915_gem.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1593,7 +1593,8 @@ __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);
		}

		/**

Admin message