selftests/bpf: Test rhtab kptr cancellation semanticsgrafted

Resizable hash-map updates and deletions must not perform full special-field
destruction in their caller context. In particular, a referenced kptr must
remain attached to the allocation until the memory allocator destructor can
release it safely.

Add separate coverage for both affected paths. The update test stores a task
kptr, replaces the ordinary value bytes with BPF_EXIST, and verifies that the
kptr survived. The delete test removes an element and exchanges its kptr
through the still-valid map-value pointer before the allocation is reclaimed.

Both cases observe a NULL kptr when rhtab uses bpf_obj_free_fields(). They
recover and release the reference after rhtab switches to cancellation
semantics.

Signed-off-by: Nuoqi Gui <gnq25@mails.tsinghua.edu.cn>
[ kkd: Split update and delete coverage and rewrote the commit log ]
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904104203.345917-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 106 insertions, 0 deletions

diff --git a/include/crypto/engine.h b/include/crypto/engine.h
new file mode 100644
index 000000000..2e6034443
--- /dev/null
+++ b/include/crypto/engine.h
@@ -0,0 +1,106 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Crypto engine API
+ *
+ * Copyright (c) 2016 Baolin Wang <baolin.wang@linaro.org>
+ */
+#ifndef _CRYPTO_ENGINE_H
+#define _CRYPTO_ENGINE_H
+
+#include <crypto/aead.h>
+#include <crypto/akcipher.h>
+#include <crypto/hash.h>
+#include <crypto/kpp.h>
+#include <crypto/skcipher.h>
+#include <linux/types.h>
+
+struct crypto_engine;
+struct device;
+
+/*
+ * struct crypto_engine_op - crypto hardware engine operations
+ * @do_one_request: do encryption for current request
+ */
+struct crypto_engine_op {
+	int (*do_one_request)(struct crypto_engine *engine,
+			      void *areq);
+};
+
+struct aead_engine_alg {
+	struct aead_alg base;
+	struct crypto_engine_op op;
+};
+
+struct ahash_engine_alg {
+	struct ahash_alg base;
+	struct crypto_engine_op op;
+};
+
+struct akcipher_engine_alg {
+	struct akcipher_alg base;
+	struct crypto_engine_op op;
+};
+
+struct kpp_engine_alg {
+	struct kpp_alg base;
+	struct crypto_engine_op op;
+};
+
+struct skcipher_engine_alg {
+	struct skcipher_alg base;
+	struct crypto_engine_op op;
+};
+
+int crypto_transfer_aead_request_to_engine(struct crypto_engine *engine,
+					   struct aead_request *req);
+int crypto_transfer_akcipher_request_to_engine(struct crypto_engine *engine,
+					       struct akcipher_request *req);
+int crypto_transfer_hash_request_to_engine(struct crypto_engine *engine,
+					       struct ahash_request *req);
+int crypto_transfer_kpp_request_to_engine(struct crypto_engine *engine,
+					  struct kpp_request *req);
+int crypto_transfer_skcipher_request_to_engine(struct crypto_engine *engine,
+					       struct skcipher_request *req);
+void crypto_finalize_aead_request(struct crypto_engine *engine,
+				  struct aead_request *req, int err);
+void crypto_finalize_akcipher_request(struct crypto_engine *engine,
+				      struct akcipher_request *req, int err);
+void crypto_finalize_hash_request(struct crypto_engine *engine,
+				  struct ahash_request *req, int err);
+void crypto_finalize_kpp_request(struct crypto_engine *engine,
+				 struct kpp_request *req, int err);
+void crypto_finalize_skcipher_request(struct crypto_engine *engine,
+				      struct skcipher_request *req, int err);
+int crypto_engine_start(struct crypto_engine *engine);
+int crypto_engine_stop(struct crypto_engine *engine);
+struct crypto_engine *crypto_engine_alloc_init(struct device *dev, bool rt);
+struct crypto_engine *crypto_engine_alloc_init_and_set(struct device *dev,
+						       bool retry_support,
+						       bool rt, int qlen);
+void crypto_engine_exit(struct crypto_engine *engine);
+
+int crypto_engine_register_aead(struct aead_engine_alg *alg);
+void crypto_engine_unregister_aead(struct aead_engine_alg *alg);
+int crypto_engine_register_aeads(struct aead_engine_alg *algs, int count);
+void crypto_engine_unregister_aeads(struct aead_engine_alg *algs, int count);
+
+int crypto_engine_register_ahash(struct ahash_engine_alg *alg);
+void crypto_engine_unregister_ahash(struct ahash_engine_alg *alg);
+int crypto_engine_register_ahashes(struct ahash_engine_alg *algs, int count);
+void crypto_engine_unregister_ahashes(struct ahash_engine_alg *algs,
+				      int count);
+
+int crypto_engine_register_akcipher(struct akcipher_engine_alg *alg);
+void crypto_engine_unregister_akcipher(struct akcipher_engine_alg *alg);
+
+int crypto_engine_register_kpp(struct kpp_engine_alg *alg);
+void crypto_engine_unregister_kpp(struct kpp_engine_alg *alg);
+
+int crypto_engine_register_skcipher(struct skcipher_engine_alg *alg);
+void crypto_engine_unregister_skcipher(struct skcipher_engine_alg *alg);
+int crypto_engine_register_skciphers(struct skcipher_engine_alg *algs,
+				     int count);
+void crypto_engine_unregister_skciphers(struct skcipher_engine_alg *algs,
+					int count);
+
+#endif /* _CRYPTO_ENGINE_H */