From patchwork Mon Jan 24 14:51:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Meneghini X-Patchwork-Id: 12722269 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 2FCE9C433F5 for ; Mon, 24 Jan 2022 14:51:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238283AbiAXOvi (ORCPT ); Mon, 24 Jan 2022 09:51:38 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:20717 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238118AbiAXOvh (ORCPT ); Mon, 24 Jan 2022 09:51:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1643035897; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=+1jqT3LbjlOuLyo0cMqyWpnoJ+Se41HIEzTNCOpBhUk=; b=Xpx4sRVTkIbWbz1NKVHuZicIeZltX8sjvTwRkA7+Is2n5TQFFR/5mLfFG+zLUgj6OFyml4 WFrgS5JD48hon3VBIC1NhQTS6XN1+qj1N2eKlpsMNvzE9zgcJwVWc31mIoloM+LSyGRsku 8ZPDA/HQP1g06RD6nRnVKbx9lfKXvLA= 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-554-_-98kE0PMzurRtwPWJghzg-1; Mon, 24 Jan 2022 09:51:31 -0500 X-MC-Unique: _-98kE0PMzurRtwPWJghzg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B9723101F7A3; Mon, 24 Jan 2022 14:51:30 +0000 (UTC) Received: from jmeneghi.bos.com (unknown [10.22.34.217]) by smtp.corp.redhat.com (Postfix) with ESMTP id 948CF84A0E; Mon, 24 Jan 2022 14:51:21 +0000 (UTC) From: John Meneghini To: skashyap@marvell.com Cc: njavali@marvell.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, GR-QLogic-Storage-Upstream@marvell.com, mlombard@redhat.com, guazhang@redhat.com Subject: [PATCH] scsi: bnx2fc: make bnx2fc_recv_frame mp safe Date: Mon, 24 Jan 2022 09:51:10 -0500 Message-Id: <20220124145110.442335-1-jmeneghi@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org 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 Acked-by: Saurav Kashyap --- 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; }