From bce7698e2e6565bb765bd0522337f29f5f312624 Mon Sep 17 00:00:00 2001 From: Haojie Li Date: Tue, 25 Aug 2026 18:08:45 +0800 Subject: drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform device platform_device_register_data() can fail and return an ERR_PTR, but the return value is used without checking, leading to an invalid pointer being stored in ddp_comp[].dev and passed to component_match_add() and mtk_ddp_comp_init(), which could result in a kernel crash. Add an IS_ERR() check to jump to the error handling path on failure. Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195") Cc: stable@vger.kernel.org Signed-off-by: Haojie Li Reviewed-by: CK Hu Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/ Signed-off-by: Chun-Kuang Hu --- Documentation/crypto/crypto_engine.rst | 80 ++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 Documentation/crypto/crypto_engine.rst (limited to 'Documentation/crypto/crypto_engine.rst') diff --git a/Documentation/crypto/crypto_engine.rst b/Documentation/crypto/crypto_engine.rst new file mode 100644 index 000000000..7ef850e28 --- /dev/null +++ b/Documentation/crypto/crypto_engine.rst @@ -0,0 +1,80 @@ +.. SPDX-License-Identifier: GPL-2.0 + +Crypto Engine +============= + +Overview +-------- +The crypto engine (CE) API is a crypto queue manager. + +Requirement +----------- +You must put, at the start of your transform context your_tfm_ctx, the structure +crypto_engine: + +:: + + struct your_tfm_ctx { + struct crypto_engine engine; + ... + }; + +The crypto engine only manages asynchronous requests in the form of +crypto_async_request. It cannot know the underlying request type and thus only +has access to the transform structure. It is not possible to access the context +using container_of. In addition, the engine knows nothing about your +structure "``struct your_tfm_ctx``". The engine assumes (requires) the placement +of the known member ``struct crypto_engine`` at the beginning. + +Order of operations +------------------- +You are required to obtain a struct crypto_engine via ``crypto_engine_alloc_init()``. +Start it via ``crypto_engine_start()``. When finished with your work, shut down the +engine using ``crypto_engine_stop()`` and destroy the engine with +``crypto_engine_exit()``. + +Before transferring any request, you have to fill the context enginectx by +providing functions for the following: + +* ``prepare_cipher_request``/``prepare_hash_request``: Called before each + corresponding request is performed. If some processing or other preparatory + work is required, do it here. + +* ``unprepare_cipher_request``/``unprepare_hash_request``: Called after each + request is handled. Clean up / undo what was done in the prepare function. + +* ``cipher_one_request``/``hash_one_request``: Handle the current request by + performing the operation. + +Note that these functions access the crypto_async_request structure +associated with the received request. You are able to retrieve the original +request by using: + +:: + + container_of(areq, struct yourrequesttype_request, base); + +When your driver receives a crypto_request, you must to transfer it to +the crypto engine via one of: + +* crypto_transfer_aead_request_to_engine() + +* crypto_transfer_akcipher_request_to_engine() + +* crypto_transfer_hash_request_to_engine() + +* crypto_transfer_kpp_request_to_engine() + +* crypto_transfer_skcipher_request_to_engine() + +At the end of the request process, a call to one of the following functions is needed: + +* crypto_finalize_aead_request() + +* crypto_finalize_akcipher_request() + +* crypto_finalize_hash_request() + +* crypto_finalize_kpp_request() + +* crypto_finalize_skcipher_request() -- cgit v1.3.1