[lvc-project] [PATCH 6.12 v2 4/5] selftests/bpf: Use the correct destructor kfunc type

[Dmitry Antipov]

From: Sami Tolvanen <samitolvanen at google.com>

commit ba7f1024a1024f219a18c40b4ab2d7d900fd2d15 upstream.

With CONFIG_CFI enabled, the kernel strictly enforces that indirect
function calls use a function pointer type that matches the target
function. As bpf_testmod_ctx_release() signature differs from the
btf_dtor_kfunc_t pointer type used for the destructor calls in
bpf_obj_free_fields(), add a stub function with the correct type to
fix the type mismatch.

Signed-off-by: Sami Tolvanen <samitolvanen at google.com>
Acked-by: Yonghong Song <yonghong.song at linux.dev>
Link: https://lore.kernel.org/r/20260110082548.113748-9-samitolvanen@google.com
Signed-off-by: Alexei Starovoitov <ast at kernel.org>
Signed-off-by: Dmitry Antipov <dmantipov at yandex.ru>
---
 tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index 4e6a9e9c0368..321b867e8630 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -245,6 +245,12 @@ __bpf_kfunc void bpf_testmod_ctx_release(struct bpf_testmod_ctx *ctx)
 		call_rcu(&ctx->rcu, testmod_free_cb);
 }
 
+__bpf_kfunc void bpf_testmod_ctx_release_dtor(void *ctx)
+{
+	bpf_testmod_ctx_release(ctx);
+}
+CFI_NOSEAL(bpf_testmod_ctx_release_dtor);
+
 struct bpf_testmod_btf_type_tag_1 {
 	int a;
 };
@@ -590,7 +596,7 @@ BTF_KFUNCS_END(bpf_testmod_common_kfunc_ids)
 
 BTF_ID_LIST(bpf_testmod_dtor_ids)
 BTF_ID(struct, bpf_testmod_ctx)
-BTF_ID(func, bpf_testmod_ctx_release)
+BTF_ID(func, bpf_testmod_ctx_release_dtor)
 
 static const struct btf_kfunc_id_set bpf_testmod_common_kfunc_set = {
 	.owner = THIS_MODULE,
-- 
2.56.0