[bug report] drm: kselftest for drm_mm and eviction

[Chris Wilson]

On Tue, Jan 10, 2017 at 05:17:46PM +0300, Dan Carpenter wrote:
> Hello Chris Wilson,
> 
> The patch 560b32842912: "drm: kselftest for drm_mm and eviction" from
> Dec 22, 2016, leads to the following static checker warning:
> 
> 	drivers/gpu/drm/selftests/test-drm_mm.c:1277 evict_everything()
> 	warn: calling list_del() inside list_for_each
> 
> drivers/gpu/drm/selftests/test-drm_mm.c
>   1260  static bool evict_everything(struct drm_mm *mm,
>   1261                               unsigned int total_size,
>   1262                               struct evict_node *nodes)
>   1263  {
>   1264          struct drm_mm_scan scan;
>   1265          LIST_HEAD(evict_list);
>   1266          struct evict_node *e;
>   1267          unsigned int n;
>   1268          int err;
>   1269  
>   1270          drm_mm_scan_init(&scan, mm, total_size, 0, 0, 0);
>   1271          for (n = 0; n < total_size; n++) {
>   1272                  e = &nodes[n];
>   1273                  list_add(&e->link, &evict_list);
>   1274                  if (drm_mm_scan_add_block(&scan, &e->node))
>   1275                          break;
>   1276          }
>   1277          list_for_each_entry(e, &evict_list, link) {
>   1278                  if (!drm_mm_scan_remove_block(&scan, &e->node)) {
>   1279                          pr_err("Node %lld not marked for eviction!\n",
>   1280                                 e->node.start);
>   1281                          list_del(&e->link);
> 
> Probably this should be using list_for_each_entry_safe(), I guess?

It can be a return false; (or something along those lines) since after
finding the first error, there are likely plenty more.

Thanks for catching this.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre