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 15DAC2C1A2; Fri, 24 Nov 2023 19:22:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Ycoq4Vno" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99122C433C8; Fri, 24 Nov 2023 19:22:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700853760; bh=vJ/PkprCH+8/aCO8UKP64MvzfV1xXLuwG8rQu/zEV5U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ycoq4VnogywFPQTl3w3D0DLjqOZJ/GDcMQmMbxwty8SrAJ9vp6pL77joK3qCa6Lvs 8wRjaIQEcme04WK/kHoCXU0KsdREBt2QUvYiZaTZmbfPzi85qH08bRMqiG5w8aPfS1 S4n3WYLDX+mklCZiIS93p264GrKMTDxEBJc5bNlM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lu Jialin , Guo Zihua , Herbert Xu , Sasha Levin Subject: [PATCH 5.4 020/159] crypto: pcrypt - Fix hungtask for PADATA_RESET Date: Fri, 24 Nov 2023 17:53:57 +0000 Message-ID: <20231124171942.701924461@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231124171941.909624388@linuxfoundation.org> References: <20231124171941.909624388@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ 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 276d2fd9e911c..63e64164900e8 100644 --- a/crypto/pcrypt.c +++ b/crypto/pcrypt.c @@ -118,6 +118,8 @@ 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; } @@ -165,6 +167,8 @@ 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 92a4867e8adc7..a544da60014c0 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -130,7 +130,7 @@ 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