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, 34 insertions, 0 deletions

diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile
new file mode 100644
index 000000000..204e02b10
--- /dev/null
+++ b/lib/kunit/Makefile
@@ -0,0 +1,34 @@
+obj-$(CONFIG_KUNIT) +=			kunit.o
+
+kunit-objs +=				test.o \
+					resource.o \
+					user_alloc.o \
+					static_stub.o \
+					string-stream.o \
+					assert.o \
+					try-catch.o \
+					executor.o \
+					attributes.o \
+					device.o \
+					platform.o \
+					fwnode.o \
+					bug.o
+
+ifeq ($(CONFIG_KUNIT_DEBUGFS),y)
+kunit-objs +=				debugfs.o
+endif
+
+# KUnit 'hooks' are built-in even when KUnit is built as a module.
+obj-$(if $(CONFIG_KUNIT),y) +=		hooks.o
+
+obj-$(CONFIG_KUNIT_TEST) +=		kunit-test.o
+obj-$(CONFIG_KUNIT_TEST) +=		platform-test.o
+obj-$(CONFIG_KUNIT_TEST) +=		backtrace-suppression-test.o
+
+# string-stream-test compiles built-in only.
+ifeq ($(CONFIG_KUNIT_TEST),y)
+obj-$(CONFIG_KUNIT_TEST) +=		string-stream-test.o
+obj-$(CONFIG_KUNIT_TEST) +=		assert_test.o
+endif
+
+obj-$(CONFIG_KUNIT_EXAMPLE_TEST) +=	kunit-example-test.o