[PATCH v4 1/6] drm/xe/xe_gt_pagefault: Disallow writes to read-only VMAs

[Jonathan Cavitt <jonathan.cavitt@intel.com>]

The page fault handler should reject write/atomic access to read only
VMAs.  Add code to handle this in handle_pagefault after the VMA lookup.

Fixes: 3d420e9fa848 ("drm/xe: Rework GPU page fault handling")
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Suggested-by: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/xe/xe_gt_pagefault.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c b/drivers/gpu/drm/xe/xe_gt_pagefault.c
index 17d69039b866..f608a765fa7c 100644
--- a/drivers/gpu/drm/xe/xe_gt_pagefault.c
+++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c
@@ -235,6 +235,11 @@ static int handle_pagefault(struct xe_gt *gt, struct pagefault *pf)
 		goto unlock_vm;
 	}
 
+	if (xe_vma_read_only(vma) && pf->access_type != ACCESS_TYPE_READ) {
+		err = -EPERM;
+		goto unlock_vm;
+	}
+
 	err = handle_vma_pagefault(gt, pf, vma);
 
 unlock_vm:
-- 
2.43.0