From: Matthew Auld Date: Mon, 7 Nov 2022 16:54:14 +0000 (+0000) Subject: drm/i915/ttm: add some sanity checks for lmem_userfault_list X-Git-Tag: v6.6.17~3937^2~16^2~441 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ccb0e02787d0f80d0081c446aec3756dd8f7bfe0;p=platform%2Fkernel%2Flinux-rpi.git drm/i915/ttm: add some sanity checks for lmem_userfault_list Rather than getting some hard to debug uaf, add some warns to hopefully catch issues with userfault_count being non-zero when destroying the object. Also if we somehow add an object to lmem_userfault_list that somehow doesn't map lmem. References: https://gitlab.freedesktop.org/drm/intel/-/issues/7469 Signed-off-by: Matthew Auld Cc: Anshuman Gupta Cc: Rodrigo Vivi Cc: Andrzej Hajda Cc: Nirmoy Das Reviewed-by: Andrzej Hajda Link: https://patchwork.freedesktop.org/patch/msgid/20221107165414.56970-2-matthew.auld@intel.com --- diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c index 9421dc4..2c8b2d5 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c @@ -1098,6 +1098,8 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf) spin_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); list_add(&obj->userfault_link, &to_i915(obj->base.dev)->runtime_pm.lmem_userfault_list); spin_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock); + + GEM_WARN_ON(!i915_ttm_cpu_maps_iomem(bo->resource)); } if (wakeref & CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND) @@ -1180,6 +1182,8 @@ static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj) } } + GEM_WARN_ON(obj->userfault_count); + ttm_bo_unmap_virtual(i915_gem_to_ttm(obj)); if (wakeref)