From 3e977ac6179b39faa3c0eda5fce4f00663ae298d Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 12 Jul 2018 19:53:13 +0100 Subject: drm/i915: Prevent writing into a read-only object via a GGTT mmap If the user has created a read-only object, they should not be allowed to circumvent the write protection by using a GGTT mmapping. Deny it. Also most machines do not support read-only GGTT PTEs, so again we have to reject attempted writes. Fortunately, this is known a priori, so we can at least reject in the call to create the mmap (with a sanity check in the fault handler). v2: Check the vma->vm_flags during mmap() to allow readonly access. v3: Remove VM_MAYWRITE to curtail mprotect() Testcase: igt/gem_userptr_blits/readonly_mmap* Signed-off-by: Chris Wilson Cc: Jon Bloomfield Cc: Joonas Lahtinen Cc: Matthew Auld Cc: David Herrmann Reviewed-by: Matthew Auld #v1 Reviewed-by: Jon Bloomfield Reviewed-by: Joonas Lahtinen Link: https://patchwork.freedesktop.org/patch/msgid/20180712185315.3288-4-chris@chris-wilson.co.uk --- include/drm/drm_vma_manager.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/drm') diff --git a/include/drm/drm_vma_manager.h b/include/drm/drm_vma_manager.h index 8758df94e9a0..c7987daeaed0 100644 --- a/include/drm/drm_vma_manager.h +++ b/include/drm/drm_vma_manager.h @@ -41,6 +41,7 @@ struct drm_vma_offset_node { rwlock_t vm_lock; struct drm_mm_node vm_node; struct rb_root vm_files; + bool readonly:1; }; struct drm_vma_offset_manager { -- cgit v1.2.3