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 9778AC4332F for ; Tue, 7 Nov 2023 16:10:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344184AbjKGQKO (ORCPT ); Tue, 7 Nov 2023 11:10:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344521AbjKGQEE (ORCPT ); Tue, 7 Nov 2023 11:04:04 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC3959027; Tue, 7 Nov 2023 07:55:12 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 37E22C4339A; Tue, 7 Nov 2023 15:55:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699372512; bh=rN34HJccc0MgnxiL7U+b7CMTWpNgY13wMW9CktmJ3bI=; h=From:To:Cc:Subject:Date:From; b=DFlkUy2RX3kAUtDXc76yeVcvkDWX1yimD8IhcWFctJ92Coin61EnYdf+bFm5CKmut X1Yahvd5630OLxovMoTu33Toa0sdviSelQQ+1a7AnQeTYBUSP1r+zfrpa68lCJKFhm CwtwTyX4D5mP/7WHdJPuUN84y+AFapnJ/d9EhzNIOtKnqyw14HWY+TAt7sXv5kVzTr 0upRfMXGJ0hqs5w8GmPGwQjqQ9lRJXrQyHJMLCMSD+hRqnwmOj+rPzu9RxbM3Lz/kq c7+74Yc0sHHUV6oQ9URfH10zFcUstGTVaflhxBdabSsPu7gUPfzuTc18PN8EmnT1Em S2ck/52HDnK0Q== 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 4.14 1/9] crypto: pcrypt - Fix hungtask for PADATA_RESET Date: Tue, 7 Nov 2023 10:54:51 -0500 Message-ID: <20231107155509.3769038-1-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 4.14.328 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 f56ec63f60ba8..82f6d5bf5cb45 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -120,7 +120,7 @@ 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