From patchwork Mon Oct 17 16:43:20 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin Tee X-Patchwork-Id: 13009027 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 83551C433FE for ; Mon, 17 Oct 2022 16:35:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229960AbiJQQfk (ORCPT ); Mon, 17 Oct 2022 12:35:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229898AbiJQQfj (ORCPT ); Mon, 17 Oct 2022 12:35:39 -0400 Received: from mail-qt1-x82b.google.com (mail-qt1-x82b.google.com [IPv6:2607:f8b0:4864:20::82b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BAAC3B975 for ; Mon, 17 Oct 2022 09:35:38 -0700 (PDT) Received: by mail-qt1-x82b.google.com with SMTP id h24so7703597qta.7 for ; Mon, 17 Oct 2022 09:35:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=ptDyamYofHoy/erqE6WWoA4EsxdHTu9VdtG5MEtr8E0=; b=ax5+RwyHDFR4h3iMfan47kvNEaq+hM1pnpz3PHuA3uYp+IJS24sv81TY27aQ9ufJ4Q OFJiNp166HsgqGtflrXat2UldH3DEeeEjiriZrqcO4+UpDRSoL6ankXsmvG5lyS57fjV qbtqKzMf1ejqqh6xRY3y3ngC6bREQZZKnX6Rv38p2r+szJkG9XHPcqZYzbN/D/78/HGu 6qhUQZhWtCtK0UWN8HY5jIrB5A6QRLUx6MLUuPovHyLXUHCG5z0iEDcrcQpnlzoec4yp ooTJ8C0lTICeOial3QGdSy6aWMNfG5yuR8fnDvWnYWsovr3QIkNWM7Go+5WaZTq2Wz0q Unpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ptDyamYofHoy/erqE6WWoA4EsxdHTu9VdtG5MEtr8E0=; b=V+8Tel1/pzCDjmaIOknnlsz3w3g5b98k5cm1NdfiUWDbwTT/gymKxCnnx17gUF9b6F 35JukVWVra0cAuT6oaMn6hkxlygcBo1nEtr1dwNkSFCdx0AUGxq99DZSv1JhQJ4wG0B7 KpofvovDZBoumEuQfzRZMcSm6ucUJQRYYwHbHtBirsZ8o4sv5RerwW/RQEtBdS+Mkr6z NogodQ8QDEj1mnXCZ0IhWRI8WecKkkSObSfIdGuPeWU6qknFGrDHB2PaAglLugHLUkdo +KYBzlZdRYQlZlViiyHdaeDkryO0jOwMYu6J9Fnzru4hQ59IVjAO3Kd0qi21fsgn1Jcp v1ZQ== X-Gm-Message-State: ACrzQf2d3hQrg6qdquVOWh/jXkSGyti8l4a8PRNW4KHNXcr2DnbaDvC5 BIgJRc1txx6WrjjpInXtUiabFoYoKHI= X-Google-Smtp-Source: AMsMyM6sqNFdjO14ZYHUIY5Ai2b2WBaj/ojZBa0rS5fJHaWKK2mSn0o/zqTv9v1gfVllwbvl4bBf+w== X-Received: by 2002:ac8:7d49:0:b0:399:d201:840b with SMTP id h9-20020ac87d49000000b00399d201840bmr9623921qtb.309.1666024537642; Mon, 17 Oct 2022 09:35:37 -0700 (PDT) Received: from dhcp-10-231-55-133.dhcp.broadcom.net ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id r2-20020ae9d602000000b006ceb933a9fesm152235qkk.81.2022.10.17.09.35.36 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 17 Oct 2022 09:35:37 -0700 (PDT) From: Justin Tee To: linux-scsi@vger.kernel.org Cc: jsmart2021@gmail.com, Justin Tee , Justin Tee Subject: [PATCH 2/5] lpfc: Fix hard lockup when reading the rx_monitor from debugfs Date: Mon, 17 Oct 2022 09:43:20 -0700 Message-Id: <20221017164323.14536-2-justintee8345@gmail.com> X-Mailer: git-send-email 2.38.0.83.gd420dda057 In-Reply-To: <20221017164323.14536-1-justintee8345@gmail.com> References: <20221017164323.14536-1-justintee8345@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org During I/O and simultaneous cat of /sys/kernel/debug/lpfc/fnX/rx_monitor, a hard lockup similar to the call trace below may occur. The spin_lock_bh in lpfc_rx_monitor_report is not protecting from timer interrupts as expected, so change the strength of the spin lock to _irq. Kernel panic - not syncing: Hard LOCKUP CPU: 3 PID: 110402 Comm: cat Kdump: loaded exception RIP: native_queued_spin_lock_slowpath+91 [IRQ stack] native_queued_spin_lock_slowpath at ffffffffb814e30b _raw_spin_lock at ffffffffb89a667a lpfc_rx_monitor_record at ffffffffc0a73a36 [lpfc] lpfc_cmf_timer at ffffffffc0abbc67 [lpfc] __hrtimer_run_queues at ffffffffb8184250 hrtimer_interrupt at ffffffffb8184ab0 smp_apic_timer_interrupt at ffffffffb8a026ba apic_timer_interrupt at ffffffffb8a01c4f [End of IRQ stack] apic_timer_interrupt at ffffffffb8a01c4f lpfc_rx_monitor_report at ffffffffc0a73c80 [lpfc] lpfc_rx_monitor_read at ffffffffc0addde1 [lpfc] full_proxy_read at ffffffffb83e7fc3 vfs_read at ffffffffb833fe71 ksys_read at ffffffffb83402af do_syscall_64 at ffffffffb800430b entry_SYSCALL_64_after_hwframe at ffffffffb8a000ad Signed-off-by: Justin Tee --- drivers/scsi/lpfc/lpfc_sli.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index 768294b9bc0b..86ba45ac91c8 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -8150,10 +8150,10 @@ u32 lpfc_rx_monitor_report(struct lpfc_hba *phba, "IO_cnt", "Info", "BWutil(ms)"); } - /* Needs to be _bh because record is called from timer interrupt + /* Needs to be _irq because record is called from timer interrupt * context */ - spin_lock_bh(ring_lock); + spin_lock_irq(ring_lock); while (*head_idx != *tail_idx) { entry = &ring[*head_idx]; @@ -8197,7 +8197,7 @@ u32 lpfc_rx_monitor_report(struct lpfc_hba *phba, if (cnt >= max_read_entries) break; } - spin_unlock_bh(ring_lock); + spin_unlock_irq(ring_lock); return cnt; }