From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 225B3C4332F for ; Tue, 7 Nov 2023 16:20:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235195AbjKGQUy (ORCPT ); Tue, 7 Nov 2023 11:20:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235203AbjKGQUh (ORCPT ); Tue, 7 Nov 2023 11:20:37 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26C20385B; Tue, 7 Nov 2023 07:54:34 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95B72C433C8; Tue, 7 Nov 2023 15:54:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699372473; bh=2WdsVUiAfYxrVcPeYECimo+kHKgZIJKwzaynU8H25qc=; h=From:To:Cc:Subject:Date:From; b=XczKj+XoqEJ3o8tWljioNqDxgFHV7oSjGWRKJ1r48CqWZE8IpEODRK97tYEVi/ODz i2Gudo0kaZ0y1yGp0yYonpShUPbRp6pw4Mkd8vJZOKn9TUsCV6pSnpxsv+CIVvN3i7 2L57aw3rrAqVKJyA7a33dYzrtW7uL0kx18zcW1G0NkZT3Kexoiezw8lYK+BN3WWGD6 JLfjOQiN3s+wxKUxGogkb/tJAjDTWch03SjMSPLqvev9oHa2ZKm17iGSH/bh7MvR0y BbT59QVAUQXY3XRDLFzyWZGkMyxij4bhzlcv4sYp7B9XXXXra6p8dSlpkkjtSYJ8cD 7R0pWPwd3144g== 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 4.19 01/11] crypto: pcrypt - Fix hungtask for PADATA_RESET Date: Tue, 7 Nov 2023 10:54:09 -0500 Message-ID: <20231107155430.3768779-1-sashal@kernel.org> X-Mailer: git-send-email 2.42.0 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.19.297 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 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 62e11835f220e..1e9de81ef84fa 100644 --- a/crypto/pcrypt.c +++ b/crypto/pcrypt.c @@ -174,6 +174,8 @@ static int pcrypt_aead_encrypt(struct aead_request *req) err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pencrypt); if (!err) return -EINPROGRESS; + if (err == -EBUSY) + return -EAGAIN; return err; } @@ -218,6 +220,8 @@ static int pcrypt_aead_decrypt(struct aead_request *req) err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pdecrypt); if (!err) return -EINPROGRESS; + if (err == -EBUSY) + return -EAGAIN; return err; } diff --git a/kernel/padata.c b/kernel/padata.c index 7f2b6d369fd47..a9e14183e1884 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -121,7 +121,7 @@ int padata_do_parallel(struct padata_instance *pinst, if (!cpumask_test_cpu(cb_cpu, pd->cpumask.cbcpu)) goto out; - err = -EBUSY; + err = -EBUSY; if ((pinst->flags & PADATA_RESET)) goto out; -- 2.42.0