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 2339EC4707A for ; Mon, 7 Feb 2022 11:44:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1384910AbiBGLae (ORCPT ); Mon, 7 Feb 2022 06:30:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1383978AbiBGLYS (ORCPT ); Mon, 7 Feb 2022 06:24:18 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 767CCC043181; Mon, 7 Feb 2022 03:24:17 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id BE2BEB811AF; Mon, 7 Feb 2022 11:24:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D28D2C004E1; Mon, 7 Feb 2022 11:24:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1644233054; bh=jIwfAxVEMGhpnFVreXI7ObayC/K7pZmZBtoSvlANXFU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YT4vb2Io5YHyRfG0V41G7Zt0ZNOjOdrXRV9xxwVE6+x0y6CsTrO17bwFcqVVwoUXm pyHu53ZYqi2kVCGigCf/UvW+4Xtz6my+stTkZfNoWowXo2qgwXiCT91v9vn2MoJIKb CCW1bavXjkdswmqKB9mkg0eidFH3CznaL/gRps8A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Guangwu Zhang , Saurav Kashyap , John Meneghini , "Martin K. Petersen" Subject: [PATCH 5.10 52/74] scsi: bnx2fc: Make bnx2fc_recv_frame() mp safe Date: Mon, 7 Feb 2022 12:06:50 +0100 Message-Id: <20220207103758.922363514@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220207103757.232676988@linuxfoundation.org> References: <20220207103757.232676988@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: John Meneghini commit 936bd03405fc83ba039d42bc93ffd4b88418f1d3 upstream. 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 Restore the old get_cpu/put_cpu code with some modifications to reduce the size of the critical section. Link: https://lore.kernel.org/r/20220124145110.442335-1-jmeneghi@redhat.com Fixes: d576a5e80cd0 ("bnx2fc: Improve stats update mechanism") Tested-by: Guangwu Zhang Acked-by: Saurav Kashyap Signed-off-by: John Meneghini Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) --- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c +++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c @@ -506,7 +506,8 @@ static int bnx2fc_l2_rcv_thread(void *ar 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; @@ -540,6 +541,11 @@ static void bnx2fc_recv_frame(struct sk_ 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; @@ -622,16 +628,15 @@ static void bnx2fc_recv_frame(struct sk_ 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; }