[PATCH v7 15/21] testing/radix-tree/maple: Hack around kfree_rcu not existing

[Vlastimil Babka]

From: "Liam R. Howlett" <Liam.Howlett at oracle.com>

liburcu doesn't have kfree_rcu (or anything similar). Despite that, we
can hack around it in a trivial fashion, by adding a wrapper.

The wrapper only works for maple_nodes because we cannot get the
kmem_cache pointer any other way in the test code.

Link: https://lore.kernel.org/all/20250812162124.59417-1-pfalcato@suse.de/
Suggested-by: Pedro Falcato <pfalcato at suse.de>
Signed-off-by: Liam R. Howlett <Liam.Howlett at oracle.com>
Signed-off-by: Vlastimil Babka <vbabka at suse.cz>
---
 tools/testing/shared/maple-shared.h | 11 +++++++++++
 tools/testing/shared/maple-shim.c   |  6 ++++++
 2 files changed, 17 insertions(+)

diff --git a/tools/testing/shared/maple-shared.h b/tools/testing/shared/maple-shared.h
index dc4d30f3860b9bd23b4177c7d7926ac686887815..2a1e9a8594a2834326cd9374738b2a2c7c3f9f7c 100644
--- a/tools/testing/shared/maple-shared.h
+++ b/tools/testing/shared/maple-shared.h
@@ -10,4 +10,15 @@
 #include <time.h>
 #include "linux/init.h"
 
+void maple_rcu_cb(struct rcu_head *head);
+#define rcu_cb		maple_rcu_cb
+
+#define kfree_rcu(_struct, _memb)		\
+do {                                            \
+    typeof(_struct) _p_struct = (_struct);      \
+                                                \
+    call_rcu(&((_p_struct)->_memb), rcu_cb);    \
+} while(0);
+
+
 #endif /* __MAPLE_SHARED_H__ */
diff --git a/tools/testing/shared/maple-shim.c b/tools/testing/shared/maple-shim.c
index 9d7b743415660305416e972fa75b56824211b0eb..16252ee616c0489c80490ff25b8d255427bf9fdc 100644
--- a/tools/testing/shared/maple-shim.c
+++ b/tools/testing/shared/maple-shim.c
@@ -6,3 +6,9 @@
 #include <linux/slab.h>
 
 #include "../../../lib/maple_tree.c"
+
+void maple_rcu_cb(struct rcu_head *head) {
+	struct maple_node *node = container_of(head, struct maple_node, rcu);
+
+	kmem_cache_free(maple_node_cache, node);
+}

-- 
2.51.0