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 44A88C4332F for ; Fri, 28 Jan 2022 20:48:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235142AbiA1Usy (ORCPT ); Fri, 28 Jan 2022 15:48:54 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:35840 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234741AbiA1Usv (ORCPT ); Fri, 28 Jan 2022 15:48:51 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643402930; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ac/R7Nle50JhmzIM8hFqFYPCurgpW7MZIFOk9+B/A4U=; b=WgGjzAzFggm4BdosLQc/7xFrIUiyszUB64ambWf3//Y9WJfgEt1dyIY6awHthiNfivchMK VgimbvUUigy1Ab8TM6UqSTTLCB0XkvburdlMLZuqsnRp3YdkkkZ63KklyOdAzDmiq9KL0h riB24LKHsJTo9M4p6bEamLBE0B8DLHA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-22-OcHjuN9jOs6Ac0nRWWonxg-1; Fri, 28 Jan 2022 15:48:49 -0500 X-MC-Unique: OcHjuN9jOs6Ac0nRWWonxg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CCCF61006AA7; Fri, 28 Jan 2022 20:48:47 +0000 (UTC) Received: from [10.22.34.217] (unknown [10.22.34.217]) by smtp.corp.redhat.com (Postfix) with ESMTP id E96CD6AB86; Fri, 28 Jan 2022 20:48:46 +0000 (UTC) Message-ID: Date: Fri, 28 Jan 2022 15:48:46 -0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [EXT] [PATCH] scsi: bnx2fc: make bnx2fc_recv_frame mp safe Content-Language: en-US To: "Martin K. Petersen" Cc: Nilesh Javali , "linux-scsi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , GR-QLogic-Storage-Upstream , Saurav Kashyap , "mlombard@redhat.com" , "guazhang@redhat.com" References: <20220124145110.442335-1-jmeneghi@redhat.com> From: John Meneghini Organization: RHEL Core Storge Team In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks. Martin, is it too late to get this into staging for v5.17-rc2? Please merge this patch. /John On 1/27/22 00:13, Saurav Kashyap wrote: > Hi John, > >> -----Original Message----- >> From: John Meneghini >> Sent: Monday, January 24, 2022 8:21 PM >> To: Saurav Kashyap >> Cc: Nilesh Javali ; linux-scsi@vger.kernel.org; linux- >> kernel@vger.kernel.org; GR-QLogic-Storage-Upstream > Upstream@marvell.com>; mlombard@redhat.com; guazhang@redhat.com >> Subject: [EXT] [PATCH] scsi: bnx2fc: make bnx2fc_recv_frame mp safe >> >> External Email >> >> ---------------------------------------------------------------------- >> Running tests with a debug kernel shows that bnx2fc_recv_frame is >> modifying the per_cpu lport stats counters in a non-mpsafe way. >> Just boot a debug kernel and run the bnx2fc driver with the hardware >> enabled. >> >> [ 1391.699147] BUG: using smp_processor_id() in preemptible [00000000] >> code: bnx2fc_ >> [ 1391.699160] caller is bnx2fc_recv_frame+0xbf9/0x1760 [bnx2fc] >> [ 1391.699174] CPU: 2 PID: 4355 Comm: bnx2fc_l2_threa Kdump: loaded >> Tainted: G B >> [ 1391.699180] Hardware name: HP ProLiant DL120 G7, BIOS J01 >> 07/01/2013 >> [ 1391.699183] Call Trace: >> [ 1391.699188] dump_stack_lvl+0x57/0x7d >> [ 1391.699198] check_preemption_disabled+0xc8/0xd0 >> [ 1391.699205] bnx2fc_recv_frame+0xbf9/0x1760 [bnx2fc] >> [ 1391.699215] ? do_raw_spin_trylock+0xb5/0x180 >> [ 1391.699221] ? bnx2fc_npiv_create_vports.isra.0+0x4e0/0x4e0 [bnx2fc] >> [ 1391.699229] ? bnx2fc_l2_rcv_thread+0xb7/0x3a0 [bnx2fc] >> [ 1391.699240] bnx2fc_l2_rcv_thread+0x1af/0x3a0 [bnx2fc] >> [ 1391.699250] ? bnx2fc_ulp_init+0xc0/0xc0 [bnx2fc] >> [ 1391.699258] kthread+0x364/0x420 >> [ 1391.699263] ? _raw_spin_unlock_irq+0x24/0x50 >> [ 1391.699268] ? set_kthread_struct+0x100/0x100 >> [ 1391.699273] ret_from_fork+0x22/0x30 >> >> To fix the problem: restore the old get_cpu/put_cpu code with some >> modifications to reduce the size of the critical section. >> >> Fixes: d576a5e80cd0 ("bnx2fc: Improve stats update mechanism") >> Tested-by: Guangwu Zhang >> Signed-off-by: John Meneghini >> --- >> drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 21 +++++++++++++-------- >> 1 file changed, 13 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c >> b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c >> index 71fa62bd3083..e41a94dc2d1f 100644 >> --- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c >> +++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c >> @@ -508,7 +508,8 @@ static int bnx2fc_l2_rcv_thread(void *arg) >> >> static void bnx2fc_recv_frame(struct sk_buff *skb) >> { >> - u32 fr_len; >> + u64 crc_err; >> + u32 fr_len, fr_crc; >> struct fc_lport *lport; >> struct fcoe_rcv_info *fr; >> struct fc_stats *stats; >> @@ -542,6 +543,11 @@ static void bnx2fc_recv_frame(struct sk_buff *skb) >> skb_pull(skb, sizeof(struct fcoe_hdr)); >> fr_len = skb->len - sizeof(struct fcoe_crc_eof); >> >> + stats = per_cpu_ptr(lport->stats, get_cpu()); >> + stats->RxFrames++; >> + stats->RxWords += fr_len / FCOE_WORD_TO_BYTE; >> + put_cpu(); >> + >> fp = (struct fc_frame *)skb; >> fc_frame_init(fp); >> fr_dev(fp) = lport; >> @@ -624,16 +630,15 @@ static void bnx2fc_recv_frame(struct sk_buff *skb) >> return; >> } >> >> - stats = per_cpu_ptr(lport->stats, smp_processor_id()); >> - stats->RxFrames++; >> - stats->RxWords += fr_len / FCOE_WORD_TO_BYTE; >> + fr_crc = le32_to_cpu(fr_crc(fp)); >> >> - if (le32_to_cpu(fr_crc(fp)) != >> - ~crc32(~0, skb->data, fr_len)) { >> - if (stats->InvalidCRCCount < 5) >> + if (unlikely(fr_crc != ~crc32(~0, skb->data, fr_len))) { >> + stats = per_cpu_ptr(lport->stats, get_cpu()); >> + crc_err = (stats->InvalidCRCCount++); >> + put_cpu(); >> + if (crc_err < 5) >> printk(KERN_WARNING PFX "dropping frame with " >> "CRC error\n"); >> - stats->InvalidCRCCount++; >> kfree_skb(skb); >> return; >> } >> -- > > Thanks for the patch. > > Acked-by: Saurav Kashyap > >> 2.27.0 >