From: Herbert Xu Subject: Re: hanging modprobe aes_s390 Date: Thu, 26 Feb 2009 14:06:18 +0800 Message-ID: <20090226060618.GA11303@gondor.apana.org.au> References: <20090225035137.GA31538@gondor.apana.org.au> <1235583230.17311.57.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-crypto@vger.kernel.org To: Jan Glauber Return-path: Received: from rhun.apana.org.au ([64.62.148.172]:58562 "EHLO arnor.apana.org.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753249AbZBZGGY (ORCPT ); Thu, 26 Feb 2009 01:06:24 -0500 Content-Disposition: inline In-Reply-To: <1235583230.17311.57.camel@localhost.localdomain> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Wed, Feb 25, 2009 at 05:33:50PM +0000, Jan Glauber wrote: > > STACK TRACE FOR TASK: 0x3f6137c8 (modprobe) > > STACK: > 0 schedule+1136 [0x2df82c] > 1 fcntl_setlk+412 [0x107a0c] > 2 sys_fcntl+262 [0xd7076] > 3 sysc_noemu+16 [0x27a5e] I see. Please let me know if this patch fixes it. crypto: api - Fix module load deadlock with fallback algorithms With the mandatory algorithm testing at registration, we have now created a deadlock with algorithms requiring fallbacks. This can happen if the module containing the algorithm requiring fallback is loaded first, without the fallback module being loaded first. The system will then try to test the new algorithm, find that it needs to load a fallback, and then try to load that. As both algorithms share the same module alias, it can attempt to load the original algorithm again and block indefinitely. As algorithms requiring fallbacks are a special case, we can fix this by giving them a different module alias than the rest. Then it's just a matter of using the right aliases according to what algorithms we're trying to find. Signed-off-by: Herbert Xu diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c index c42cd89..6118890 100644 --- a/arch/s390/crypto/aes_s390.c +++ b/arch/s390/crypto/aes_s390.c @@ -556,7 +556,7 @@ static void __exit aes_s390_fini(void) module_init(aes_s390_init); module_exit(aes_s390_fini); -MODULE_ALIAS("aes"); +MODULE_ALIAS("aes-all"); MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); MODULE_LICENSE("GPL"); diff --git a/crypto/api.c b/crypto/api.c index efe77df..38a2bc0 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -215,8 +215,19 @@ struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask) mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD); type &= mask; - alg = try_then_request_module(crypto_alg_lookup(name, type, mask), - name); + alg = crypto_alg_lookup(name, type, mask); + if (!alg) { + char tmp[CRYPTO_MAX_ALG_NAME]; + + request_module(name); + + if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask) && + snprintf(tmp, sizeof(tmp), "%s-all", name) < sizeof(tmp)) + request_module(tmp); + + alg = crypto_alg_lookup(name, type, mask); + } + if (alg) return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg; diff --git a/drivers/crypto/padlock-aes.c b/drivers/crypto/padlock-aes.c index 856b3cc..3f0fdd1 100644 --- a/drivers/crypto/padlock-aes.c +++ b/drivers/crypto/padlock-aes.c @@ -489,4 +489,4 @@ MODULE_DESCRIPTION("VIA PadLock AES algorithm support"); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Michal Ludvig"); -MODULE_ALIAS("aes"); +MODULE_ALIAS("aes-all"); diff --git a/drivers/crypto/padlock-sha.c b/drivers/crypto/padlock-sha.c index a7fbade..a2c8e85 100644 --- a/drivers/crypto/padlock-sha.c +++ b/drivers/crypto/padlock-sha.c @@ -304,7 +304,7 @@ MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support."); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Michal Ludvig"); -MODULE_ALIAS("sha1"); -MODULE_ALIAS("sha256"); +MODULE_ALIAS("sha1-all"); +MODULE_ALIAS("sha256-all"); MODULE_ALIAS("sha1-padlock"); MODULE_ALIAS("sha256-padlock"); Thanks, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt