selftests/bpf: Add multi_st_ops that supports multiple instances

Current struct_ops in bpf_testmod only support attaching single instance.
Add multi_st_ops that supports multiple instances. The struct_ops uses map
id as the struct_ops id and will reject attachment with an existing id.

Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20250806162540.681679-3-ameryhung@gmail.com

diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
index e9e918cdf31ff2b15bf41302ad429e8683b834d6..2beb9b2fcbd8764ec8aa1cb22dd355fa5f886b45 100644 (file)
--- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.c
@@ -1057,6 +1057,8 @@ __bpf_kfunc int bpf_kfunc_st_ops_inc10(struct st_ops_args *args)
        return args->a;
 }
 
+__bpf_kfunc int bpf_kfunc_multi_st_ops_test_1(struct st_ops_args *args, u32 id);
+
 BTF_KFUNCS_START(bpf_testmod_check_kfunc_ids)
 BTF_ID_FLAGS(func, bpf_testmod_test_mod_kfunc)
 BTF_ID_FLAGS(func, bpf_kfunc_call_test1)
@@ -1097,6 +1099,7 @@ BTF_ID_FLAGS(func, bpf_kfunc_st_ops_test_prologue, KF_TRUSTED_ARGS | KF_SLEEPABL
 BTF_ID_FLAGS(func, bpf_kfunc_st_ops_test_epilogue, KF_TRUSTED_ARGS | KF_SLEEPABLE)
 BTF_ID_FLAGS(func, bpf_kfunc_st_ops_test_pro_epilogue, KF_TRUSTED_ARGS | KF_SLEEPABLE)
 BTF_ID_FLAGS(func, bpf_kfunc_st_ops_inc10, KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_kfunc_multi_st_ops_test_1, KF_TRUSTED_ARGS)
 BTF_KFUNCS_END(bpf_testmod_check_kfunc_ids)
 
 static int bpf_testmod_ops_init(struct btf *btf)
@@ -1528,6 +1531,114 @@ static struct bpf_struct_ops testmod_st_ops = {
        .owner = THIS_MODULE,
 };
 
+struct hlist_head multi_st_ops_list;
+static DEFINE_SPINLOCK(multi_st_ops_lock);
+
+static int multi_st_ops_init(struct btf *btf)
+{
+       spin_lock_init(&multi_st_ops_lock);
+       INIT_HLIST_HEAD(&multi_st_ops_list);
+
+       return 0;
+}
+
+static int multi_st_ops_init_member(const struct btf_type *t,
+                                   const struct btf_member *member,
+                                   void *kdata, const void *udata)
+{
+       return 0;
+}
+
+static struct bpf_testmod_multi_st_ops *multi_st_ops_find_nolock(u32 id)
+{
+       struct bpf_testmod_multi_st_ops *st_ops;
+
+       hlist_for_each_entry(st_ops, &multi_st_ops_list, node) {
+               if (st_ops->id == id)
+                       return st_ops;
+       }
+
+       return NULL;
+}
+
+int bpf_kfunc_multi_st_ops_test_1(struct st_ops_args *args, u32 id)
+{
+       struct bpf_testmod_multi_st_ops *st_ops;
+       unsigned long flags;
+       int ret = -1;
+
+       spin_lock_irqsave(&multi_st_ops_lock, flags);
+       st_ops = multi_st_ops_find_nolock(id);
+       if (st_ops)
+               ret = st_ops->test_1(args);
+       spin_unlock_irqrestore(&multi_st_ops_lock, flags);
+
+       return ret;
+}
+
+static int multi_st_ops_reg(void *kdata, struct bpf_link *link)
+{
+       struct bpf_testmod_multi_st_ops *st_ops =
+               (struct bpf_testmod_multi_st_ops *)kdata;
+       unsigned long flags;
+       int err = 0;
+       u32 id;
+
+       if (!st_ops->test_1)
+               return -EINVAL;
+
+       id = bpf_struct_ops_id(kdata);
+
+       spin_lock_irqsave(&multi_st_ops_lock, flags);
+       if (multi_st_ops_find_nolock(id)) {
+               pr_err("multi_st_ops(id:%d) has already been registered\n", id);
+               err = -EEXIST;
+               goto unlock;
+       }
+
+       st_ops->id = id;
+       hlist_add_head(&st_ops->node, &multi_st_ops_list);
+unlock:
+       spin_unlock_irqrestore(&multi_st_ops_lock, flags);
+
+       return err;
+}
+
+static void multi_st_ops_unreg(void *kdata, struct bpf_link *link)
+{
+       struct bpf_testmod_multi_st_ops *st_ops;
+       unsigned long flags;
+       u32 id;
+
+       id = bpf_struct_ops_id(kdata);
+
+       spin_lock_irqsave(&multi_st_ops_lock, flags);
+       st_ops = multi_st_ops_find_nolock(id);
+       if (st_ops)
+               hlist_del(&st_ops->node);
+       spin_unlock_irqrestore(&multi_st_ops_lock, flags);
+}
+
+static int bpf_testmod_multi_st_ops__test_1(struct st_ops_args *args)
+{
+       return 0;
+}
+
+static struct bpf_testmod_multi_st_ops multi_st_ops_cfi_stubs = {
+       .test_1 = bpf_testmod_multi_st_ops__test_1,
+};
+
+struct bpf_struct_ops testmod_multi_st_ops = {
+       .verifier_ops = &bpf_testmod_verifier_ops,
+       .init = multi_st_ops_init,
+       .init_member = multi_st_ops_init_member,
+       .reg = multi_st_ops_reg,
+       .unreg = multi_st_ops_unreg,
+       .cfi_stubs = &multi_st_ops_cfi_stubs,
+       .name = "bpf_testmod_multi_st_ops",
+       .owner = THIS_MODULE,
+};
+
 extern int bpf_fentry_test1(int a);
 
 static int bpf_testmod_init(void)
@@ -1550,6 +1661,7 @@ static int bpf_testmod_init(void)
        ret = ret ?: register_bpf_struct_ops(&bpf_testmod_ops2, bpf_testmod_ops2);
        ret = ret ?: register_bpf_struct_ops(&bpf_testmod_ops3, bpf_testmod_ops3);
        ret = ret ?: register_bpf_struct_ops(&testmod_st_ops, bpf_testmod_st_ops);
+       ret = ret ?: register_bpf_struct_ops(&testmod_multi_st_ops, bpf_testmod_multi_st_ops);
        ret = ret ?: register_btf_id_dtor_kfuncs(bpf_testmod_dtors,
                                                 ARRAY_SIZE(bpf_testmod_dtors),
                                                 THIS_MODULE);

diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.h b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.h
index c9fab51f16e2b7d850f329de3ea569e4a87fdbce..f6e492f9d04268de05d65e745edc998cb6f4ec56 100644 (file)
--- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod.h
+++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod.h
@@ -116,4 +116,10 @@ struct bpf_testmod_st_ops {
        struct module *owner;
 };
 
+struct bpf_testmod_multi_st_ops {
+       int (*test_1)(struct st_ops_args *args);
+       struct hlist_node node;
+       int id;
+};
+
 #endif /* _BPF_TESTMOD_H */

diff --git a/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h b/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h
index b58817938debd84fdad6050aa6f7efb31064a869..286e7faa47544ede97db329daa7d5214750527f3 100644 (file)
--- a/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h
+++ b/tools/testing/selftests/bpf/test_kmods/bpf_testmod_kfunc.h
@@ -159,4 +159,6 @@ void bpf_kfunc_trusted_task_test(struct task_struct *ptr) __ksym;
 void bpf_kfunc_trusted_num_test(int *ptr) __ksym;
 void bpf_kfunc_rcu_task_test(struct task_struct *ptr) __ksym;
 
+int bpf_kfunc_multi_st_ops_test_1(struct st_ops_args *args, u32 id) __ksym;
+
 #endif /* _BPF_TESTMOD_KFUNC_H */