From e1eafe8c87612a94552e9ad5df56c489cb6f0ff2 Mon Sep 17 00:00:00 2001 From: Richard Levitte Date: Thu, 14 Apr 2022 17:52:12 +0200 Subject: "Reserve" the method store when constructing methods Introducing the concept of reserving the store where a number of provided operation methods are to be stored. This avoids racing when constructing provided methods, which is especially pertinent when multiple threads are trying to fetch the same method, or even any implementation for the same given operation type. This introduces a |biglock| in OSSL_METHOD_STORE, which is separate from the |lock| which is used for more internal and finer grained locking. Fixes #18152 Reviewed-by: Hugo Landau Reviewed-by: Tomas Mraz (Merged from https://github.com/openssl/openssl/pull/18153) --- crypto/evp/evp_fetch.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'crypto/evp') diff --git a/crypto/evp/evp_fetch.c b/crypto/evp/evp_fetch.c index 9af92bd412..4908f6cfee 100644 --- a/crypto/evp/evp_fetch.c +++ b/crypto/evp/evp_fetch.c @@ -63,6 +63,28 @@ static OSSL_METHOD_STORE *get_evp_method_store(OSSL_LIB_CTX *libctx) return ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_EVP_METHOD_STORE_INDEX); } +static int reserve_evp_method_store(void *store, void *data) +{ + struct evp_method_data_st *methdata = data; + + if (store == NULL + && (store = get_evp_method_store(methdata->libctx)) == NULL) + return 0; + + return ossl_method_lock_store(store); +} + +static int unreserve_evp_method_store(void *store, void *data) +{ + struct evp_method_data_st *methdata = data; + + if (store == NULL + && (store = get_evp_method_store(methdata->libctx)) == NULL) + return 0; + + return ossl_method_unlock_store(store); +} + /* * To identify the method in the EVP method store, we mix the name identity * with the operation identity, under the assumption that we don't have more @@ -271,6 +293,8 @@ inner_evp_generic_fetch(struct evp_method_data_st *methdata, || !ossl_method_store_cache_get(store, prov, meth_id, propq, &method)) { OSSL_METHOD_CONSTRUCT_METHOD mcm = { get_tmp_evp_method_store, + reserve_evp_method_store, + unreserve_evp_method_store, get_evp_method_from_store, put_evp_method_in_store, construct_evp_method, -- cgit v1.2.1