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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CFC5C00454 for ; Wed, 11 Dec 2019 16:08:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6349C208C3 for ; Wed, 11 Dec 2019 16:08:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576080519; bh=O/W07dSdGlWbNDMUsUSBXfWXUFhILzgxa65l8f5AhjE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fTDbsyyDLm3mEwBRz846dlZ9i9RsOeRWN3vK6IDs+yv4X/EMajQAzS92f/fnkcEOH HSF3DUPqbIdX4B9YE9CSivO8lQApGEA1nh7QoP/w3Jwd3T2Wi3FQ06WO+uhLPCm8qy MLKsgg/s9NC7y2ZlTLgwyfUpnPTg5nG/KXXu1s3w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388927AbfLKQIi (ORCPT ); Wed, 11 Dec 2019 11:08:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:33460 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731071AbfLKPMO (ORCPT ); Wed, 11 Dec 2019 10:12:14 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3B048208C3; Wed, 11 Dec 2019 15:12:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576077134; bh=O/W07dSdGlWbNDMUsUSBXfWXUFhILzgxa65l8f5AhjE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Cf//cW48+l1aSKwTZOFOjoK8qE8LEFp4E9cmHVgmfChpEDwMRxc5bYWY++0apO3lE eRW5lL+SxnFBO967YxgtPjJBVg3PLVZRwR8+tSrdsi6VF5iSeu7QdgXUAujZ6EBkaw jD4BnM8mDRPaIRJxJBqeaN5siI1O215Y41/527EA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xiang Chen , John Garry , "Martin K . Petersen" , Sasha Levin , linux-scsi@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 021/134] scsi: hisi_sas: Replace in_softirq() check in hisi_sas_task_exec() Date: Wed, 11 Dec 2019 10:09:57 -0500 Message-Id: <20191211151150.19073-21-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191211151150.19073-1-sashal@kernel.org> References: <20191211151150.19073-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiang Chen [ Upstream commit 550c0d89d52d3bec5c299f69b4ed5d2ee6b8a9a6 ] For IOs from upper layer, preemption may be disabled as it may be called by function __blk_mq_delay_run_hw_queue which will call get_cpu() (it disables preemption). So if flags HISI_SAS_REJECT_CMD_BIT is set in function hisi_sas_task_exec(), it may disable preempt twice after down() and up() which will cause following call trace: BUG: scheduling while atomic: fio/60373/0x00000002 Call trace: dump_backtrace+0x0/0x150 show_stack+0x24/0x30 dump_stack+0xa0/0xc4 __schedule_bug+0x68/0x88 __schedule+0x4b8/0x548 schedule+0x40/0xd0 schedule_timeout+0x200/0x378 __down+0x78/0xc8 down+0x54/0x70 hisi_sas_task_exec.isra.10+0x598/0x8d8 [hisi_sas_main] hisi_sas_queue_command+0x28/0x38 [hisi_sas_main] sas_queuecommand+0x168/0x1b0 [libsas] scsi_queue_rq+0x2ac/0x980 blk_mq_dispatch_rq_list+0xb0/0x550 blk_mq_do_dispatch_sched+0x6c/0x110 blk_mq_sched_dispatch_requests+0x114/0x1d8 __blk_mq_run_hw_queue+0xb8/0x130 __blk_mq_delay_run_hw_queue+0x1c0/0x220 blk_mq_run_hw_queue+0xb0/0x128 blk_mq_sched_insert_requests+0xdc/0x208 blk_mq_flush_plug_list+0x1b4/0x3a0 blk_flush_plug_list+0xdc/0x110 blk_finish_plug+0x3c/0x50 blkdev_direct_IO+0x404/0x550 generic_file_read_iter+0x9c/0x848 blkdev_read_iter+0x50/0x78 aio_read+0xc8/0x170 io_submit_one+0x1fc/0x8d8 __arm64_sys_io_submit+0xdc/0x280 el0_svc_common.constprop.0+0xe0/0x1e0 el0_svc_handler+0x34/0x90 el0_svc+0x10/0x14 ... To solve the issue, check preemptible() to avoid disabling preempt multiple when flag HISI_SAS_REJECT_CMD_BIT is set. Link: https://lore.kernel.org/r/1571926105-74636-5-git-send-email-john.garry@huawei.com Signed-off-by: Xiang Chen Signed-off-by: John Garry Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/hisi_sas/hisi_sas_main.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c index 0847e682797be..20f0cb4698b7f 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_main.c +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c @@ -587,7 +587,13 @@ static int hisi_sas_task_exec(struct sas_task *task, gfp_t gfp_flags, dev = hisi_hba->dev; if (unlikely(test_bit(HISI_SAS_REJECT_CMD_BIT, &hisi_hba->flags))) { - if (in_softirq()) + /* + * For IOs from upper layer, it may already disable preempt + * in the IO path, if disable preempt again in down(), + * function schedule() will report schedule_bug(), so check + * preemptible() before goto down(). + */ + if (!preemptible()) return -EINVAL; down(&hisi_hba->sem); -- 2.20.1