On Sat, Aug 07, 2021 at 12:46:39PM +0900, Byungchul Park wrote: > > > > THREAD C > > > -------- > > > C1 cryptomgr_test() > > > C2 crypto_alg_tested() > > > C3 complete_all(c) > > > > > > For example, in this situation, I think C3 could wake up both A6 and B9 > > > before THREAD B reaches B10 which is not desired by A6. Say, is it okay > > > to wake up A6 with B7 ~ B9 having yet to complete? > > > > AFAICS thread C only wakes up test larvals, not instantiation larvals. > > Please let me know if you have any further issues. > > The both cases looks like to get the larvals from the same list, > crypto_alg_list, one from crypto_larval_lookup() and the other from > __crypto_register_alg(). So I thought a single larval can be used at the > same time both at crypto_wait_for_test() and crypto_alg_mod_lookup() by > any chance. It would be great if the code ensures it never happens :-) Perhaps it's not obvious but the distinguishing feature between test larvals and the other kind of larvals is that test larvals have a non-null cra_driver_name field. In crypto_alg_tested we specifically exclude non-test larvals when doing the lookup. > The problematic scenario I wanted to ask you looks like - I was > wondering if it's okay to nest requesting CRYPTO_MSG_ALG_REQUEST and > CRYPTO_MSG_ALG_REGISTER in a single stack, in other words, if it's okay > to try CRYPTO_MSG_ALG_REGISTER before completing CRYPTO_MSG_ALG_REQUEST. > > A1 crypto_alg_mod_lookup() > A2 crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST) > A3 cryptomgr_schedule_probe() > A4 kthread_run(cyptomgr_probe) ---> Start THREAD B > > B1 cryptomgr_probe() > B2 pkcslpad_create() > B3 crypto_wait_for_test() > B4 crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER) > B5 cryptomgr_schedule_test() > B6 kthread_run(cyptomgr_test) ---> Start THREAD C > > C1 cryptomgr_test() > C2 crypto_alg_tested() > C3 complete_all(c) <- *the point* that I'd like to ask you. Well c in this case can only be a test larval so it cannot wake up thread A which is waiting on a non-test larval. > A5 crypto_larval_wait() > A6 wait_for_completion_killable_timeout(c) /* waiting for B10 */ > (wake up and go) > > Bx wait_for_completion_killable(c) /* waiting for C3 */ > (wake up and go) > Bx tmpl->alloc() > Bx crupto_register_instance() > B10 complete_all(c) Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
