[Intel-gfx] [CI] drm/i915/selftests: Make evict tolerant of foreign objects

[Matthew Auld]

On Fri, 18 Jan 2019 at 11:53, Chris Wilson <chris at chris-wilson.co.uk> wrote:
>
> The evict selftests presumed that all objects in use had been allocated
> by itself. This is a dubious claim and so instead of asserting complete
> control over the object lists, take (temporary) ownership of them
> instead.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>  .../gpu/drm/i915/selftests/i915_gem_evict.c   | 64 +++++++++++++++----
>  1 file changed, 53 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_evict.c b/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
> index 067e5dfa0a24..543d618c152b 100644
> --- a/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
> +++ b/drivers/gpu/drm/i915/selftests/i915_gem_evict.c
> @@ -31,30 +31,63 @@
>
>  static int populate_ggtt(struct drm_i915_private *i915)
>  {
> -       struct drm_i915_gem_object *obj;
> +       struct drm_i915_gem_object *obj, *on;
> +       unsigned long expected_unbound, expected_bound;
> +       unsigned long unbound, bound, count;
>         u64 size;
> +       int err;
> +
> +       expected_unbound = 0;
> +       list_for_each_entry(obj, &i915->mm.unbound_list, mm.link) {
> +               i915_gem_object_get(obj);
> +               expected_unbound++;
> +       }
> +
> +       expected_bound = 0;
> +       list_for_each_entry(obj, &i915->mm.bound_list, mm.link) {
> +               i915_gem_object_get(obj);
> +               expected_bound++;
> +       }
>
> +       count = 0;
>         for (size = 0;
>              size + I915_GTT_PAGE_SIZE <= i915->ggtt.vm.total;
>              size += I915_GTT_PAGE_SIZE) {
>                 struct i915_vma *vma;
>
>                 obj = i915_gem_object_create_internal(i915, I915_GTT_PAGE_SIZE);
> -               if (IS_ERR(obj))
> -                       return PTR_ERR(obj);
> +               if (IS_ERR(obj)) {
> +                       err = PTR_ERR(obj);
> +                       goto cleanup;
> +               }
>
>                 vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
> -               if (IS_ERR(vma))
> -                       return PTR_ERR(vma);
> +               if (IS_ERR(vma)) {
> +                       err = PTR_ERR(vma);
> +                       goto cleanup;
> +               }
> +
> +               count++;
>         }
>
> -       if (!list_empty(&i915->mm.unbound_list)) {
> -               size = 0;
> -               list_for_each_entry(obj, &i915->mm.unbound_list, mm.link)
> -                       size++;
> +       unbound = 0;
> +       list_for_each_entry(obj, &i915->mm.unbound_list, mm.link)
> +               unbound++;
> +       if (unbound != expected_unbound) {
> +               pr_err("%s: Found %lu objects unbound, expected %lu!\n",
> +                      __func__, unbound, expected_unbound);
> +               err = -EINVAL;
> +               goto cleanup;
> +       }
>
> -               pr_err("Found %lld objects unbound!\n", size);
> -               return -EINVAL;
> +       bound = 0;
> +       list_for_each_entry(obj, &i915->mm.bound_list, mm.link)
> +               bound++;
> +       if (bound != expected_bound + count) {
> +               pr_err("%s: Found %lu objects bound, expected %lu!\n",
> +                      __func__, bound, expected_bound + count);
> +               err = -EINVAL;
> +               goto cleanup;
>         }
>
>         if (list_empty(&i915->ggtt.vm.inactive_list)) {
> @@ -63,6 +96,15 @@ static int populate_ggtt(struct drm_i915_private *i915)
>         }
>
>         return 0;
> +
> +cleanup:
> +       list_for_each_entry_safe(obj, on, &i915->mm.unbound_list, mm.link)
> +               i915_gem_object_put(obj);
> +
> +       list_for_each_entry_safe(obj, on, &i915->mm.bound_list, mm.link)
> +               i915_gem_object_put(obj);
> +

Drive-by-question: we don't need a drop-lock-drain here to prevent
potential double free for when we land in cleanup_objects ?