diff options
| author | Frank Rowand <frank.rowand@sony.com> | 2018-10-04 20:24:17 -0700 |
|---|---|---|
| committer | Frank Rowand <frank.rowand@sony.com> | 2018-11-08 22:10:35 -0800 |
| commit | 144552c786925314c1e7cb8f91a71dae1aca8798 (patch) | |
| tree | 529691048e02c625ece39d41db6304f6f16db9a9 /drivers/of | |
| parent | 651022382c7f8da46cb4872a545ee1da6d097d2a (diff) | |
| download | lwn-144552c786925314c1e7cb8f91a71dae1aca8798.tar.gz lwn-144552c786925314c1e7cb8f91a71dae1aca8798.zip | |
of: overlay: add tests to validate kfrees from overlay removal
Add checks:
- attempted kfree due to refcount reaching zero before overlay
is removed
- properties linked to an overlay node when the node is removed
- node refcount > one during node removal in a changeset destroy,
if the node was created by the changeset
After applying this patch, several validation warnings will be
reported from the devicetree unittest during boot due to
pre-existing devicetree bugs. The warnings will be similar to:
OF: ERROR: of_node_release(), unexpected properties in /testcase-data/overlay-node/test-bus/test-unittest11
OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /testcase-data-2/substation@100/
hvac-medium-2
Tested-by: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Diffstat (limited to 'drivers/of')
| -rw-r--r-- | drivers/of/dynamic.c | 29 | ||||
| -rw-r--r-- | drivers/of/overlay.c | 1 |
2 files changed, 30 insertions, 0 deletions
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index f4f8ed9b5454..12c3f9a15e94 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -330,6 +330,25 @@ void of_node_release(struct kobject *kobj) if (!of_node_check_flag(node, OF_DYNAMIC)) return; + if (of_node_check_flag(node, OF_OVERLAY)) { + + if (!of_node_check_flag(node, OF_OVERLAY_FREE_CSET)) { + /* premature refcount of zero, do not free memory */ + pr_err("ERROR: memory leak before free overlay changeset, %pOF\n", + node); + return; + } + + /* + * If node->properties non-empty then properties were added + * to this node either by different overlay that has not + * yet been removed, or by a non-overlay mechanism. + */ + if (node->properties) + pr_err("ERROR: %s(), unexpected properties in %pOF\n", + __func__, node); + } + property_list_free(node->properties); property_list_free(node->deadprops); @@ -434,6 +453,16 @@ struct device_node *__of_node_dup(const struct device_node *np, static void __of_changeset_entry_destroy(struct of_changeset_entry *ce) { + if (ce->action == OF_RECONFIG_ATTACH_NODE && + of_node_check_flag(ce->np, OF_OVERLAY)) { + if (kref_read(&ce->np->kobj.kref) > 1) { + pr_err("ERROR: memory leak, expected refcount 1 instead of %d, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node %pOF\n", + kref_read(&ce->np->kobj.kref), ce->np); + } else { + of_node_set_flag(ce->np, OF_OVERLAY_FREE_CSET); + } + } + of_node_put(ce->np); list_del(&ce->node); kfree(ce); diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index 42b1f73ac5f6..f5fc8859a7ee 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -373,6 +373,7 @@ static int add_changeset_node(struct overlay_changeset *ovcs, return -ENOMEM; tchild->parent = target_node; + of_node_set_flag(tchild, OF_OVERLAY); ret = of_changeset_attach_node(&ovcs->cset, tchild); if (ret) |