From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B9730315AB for ; Tue, 7 Nov 2023 15:52:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OssHrQqm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7460AC433C9; Tue, 7 Nov 2023 15:52:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699372374; bh=PsjWDKrvCnrYkyQWoxTiJemIijmjf0M5UJ0Pzvb3jBg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OssHrQqmgyI6F0q7ncw3ivdswPlnhRVCx9OG3i7W4/uKSjI9Igftf3OFpbeOKJBOn /LbKaObMCs3IDAxMednkOw8OWVCe45VU+/ju5olqKPTyGzVHQhLlkJjIh9iXCcaiSP YG4lQtdIcXXaEBX+tRF5qe+o0+n4hPLEhAZIx3IRIEb0tnEnmzWLzXNI2HXK5UZx7d GSm5mnsR4vTn9HEN4aA+rc+x3pTgffTO1YwPB2u6b6nr0SZrZCxjFxD5orlHcA6p/n qqRsRCmQbkuX8UU/zmPAFygC9ZLBBZ3BRez39MhyjelDz1hxnh8BKe4jPcuj+UkrQL WNul4jN1BNUXg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Lu Jialin , Guo Zihua , Herbert Xu , Sasha Levin , steffen.klassert@secunet.com, davem@davemloft.net, daniel.m.jordan@oracle.com, linux-crypto@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 02/16] crypto: pcrypt - Fix hungtask for PADATA_RESET Date: Tue, 7 Nov 2023 10:52:21 -0500 Message-ID: <20231107155249.3768098-2-sashal@kernel.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231107155249.3768098-1-sashal@kernel.org> References: <20231107155249.3768098-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.10.199 Content-Transfer-Encoding: 8bit From: Lu Jialin [ Upstream commit 8f4f68e788c3a7a696546291258bfa5fdb215523 ] We found a hungtask bug in test_aead_vec_cfg as follows: INFO: task cryptomgr_test:391009 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Call trace: __switch_to+0x98/0xe0 __schedule+0x6c4/0xf40 schedule+0xd8/0x1b4 schedule_timeout+0x474/0x560 wait_for_common+0x368/0x4e0 wait_for_completion+0x20/0x30 wait_for_completion+0x20/0x30 test_aead_vec_cfg+0xab4/0xd50 test_aead+0x144/0x1f0 alg_test_aead+0xd8/0x1e0 alg_test+0x634/0x890 cryptomgr_test+0x40/0x70 kthread+0x1e0/0x220 ret_from_fork+0x10/0x18 Kernel panic - not syncing: hung_task: blocked tasks For padata_do_parallel, when the return err is 0 or -EBUSY, it will call wait_for_completion(&wait->completion) in test_aead_vec_cfg. In normal case, aead_request_complete() will be called in pcrypt_aead_serial and the return err is 0 for padata_do_parallel. But, when pinst->flags is PADATA_RESET, the return err is -EBUSY for padata_do_parallel, and it won't call aead_request_complete(). Therefore, test_aead_vec_cfg will hung at wait_for_completion(&wait->completion), which will cause hungtask. The problem comes as following: (padata_do_parallel) | rcu_read_lock_bh(); | err = -EINVAL; | (padata_replace) | pinst->flags |= PADATA_RESET; err = -EBUSY | if (pinst->flags & PADATA_RESET) | rcu_read_unlock_bh() | return err In order to resolve the problem, we replace the return err -EBUSY with -EAGAIN, which means parallel_data is changing, and the caller should call it again. v3: remove retry and just change the return err. v2: introduce padata_try_do_parallel() in pcrypt_aead_encrypt and pcrypt_aead_decrypt to solve the hungtask. Signed-off-by: Lu Jialin Signed-off-by: Guo Zihua Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin --- crypto/pcrypt.c | 4 ++++ kernel/padata.c | 2 +- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c index 9d10b846ccf73..005a36cb21bc4 100644 --- a/crypto/pcrypt.c +++ b/crypto/pcrypt.c @@ -117,6 +117,8 @@ static int pcrypt_aead_encrypt(struct aead_request *req) err = padata_do_parallel(ictx->psenc, padata, &ctx->cb_cpu); if (!err) return -EINPROGRESS; + if (err == -EBUSY) + return -EAGAIN; return err; } @@ -164,6 +166,8 @@ static int pcrypt_aead_decrypt(struct aead_request *req) err = padata_do_parallel(ictx->psdec, padata, &ctx->cb_cpu); if (!err) return -EINPROGRESS; + if (err == -EBUSY) + return -EAGAIN; return err; } diff --git a/kernel/padata.c b/kernel/padata.c index 11ca3ebd8b123..ece4a2b77d32b 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -207,7 +207,7 @@ int padata_do_parallel(struct padata_shell *ps, *cb_cpu = cpu; } - err = -EBUSY; + err = -EBUSY; if ((pinst->flags & PADATA_RESET)) goto out; -- 2.42.0