selftests/bpf: Add a test for objects stuck in free_by_rcu_ttracegrafted

Delete all elements of BPF_F_NO_PREALLOC hash map in one batch. The first
free_bulk() starts RCU tasks trace GP and the rest of the elements are
freed while it's in flight. Wait for call_rcu_ttrace_in_progress to clear
in bpf_mem_cache of every cpu and check that free_by_rcu_ttrace and
waiting_for_gp_ttrace lists are empty.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-4-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/rust/helpers/slab.c b/rust/helpers/slab.c
new file mode 100644
index 000000000..9279f0824
--- /dev/null
+++ b/rust/helpers/slab.c
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/slab.h>
+
+__rust_helper void *__must_check __realloc_size(2)
+rust_helper_krealloc_node_align(const void *objp, size_t new_size, unsigned long align,
+				gfp_t flags, int node)
+{
+	return krealloc_node_align(objp, new_size, align, flags, node);
+}
+
+__rust_helper void *__must_check __realloc_size(2)
+rust_helper_kvrealloc_node_align(const void *p, size_t size, unsigned long align,
+				 gfp_t flags, int node)
+{
+	return kvrealloc_node_align(p, size, align, flags, node);
+}