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=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 009DEC432BE for ; Tue, 10 Aug 2021 17:56:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D4EA460E52 for ; Tue, 10 Aug 2021 17:56:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234579AbhHJR4t (ORCPT ); Tue, 10 Aug 2021 13:56:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:44064 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237602AbhHJRyr (ORCPT ); Tue, 10 Aug 2021 13:54:47 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C4BAB60F94; Tue, 10 Aug 2021 17:44:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1628617469; bh=pmt69219FsgsD6lek03tImuuC77ApbiGhpNJ8iFTEsg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V8xqXrN78oDXaDNYu9crpjj3+/Eul0ybCPlyLuLONc+p/30ey5QTc1tspXE4kjmDR At3W+lTbxyh+TVGOY5YV8lz9h74oEBt7S6QFYFD0E2Uju651d7W2D+qALd5M+Smf82 ZAIEU3MFOD4OUBWjcttk5DxEKv/yGdWo19p+gkr8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+e2eae5639e7203360018@syzkaller.appspotmail.com, "Qiang.zhang" , Guido Kiener Subject: [PATCH 5.13 073/175] USB: usbtmc: Fix RCU stall warning Date: Tue, 10 Aug 2021 19:29:41 +0200 Message-Id: <20210810173003.339868453@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210810173000.928681411@linuxfoundation.org> References: <20210810173000.928681411@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: Qiang.zhang commit 30fad76ce4e98263edfa8f885c81d5426c1bf169 upstream. rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (2 ticks this GP) idle=d92/1/0x4000000000000000 softirq=25390/25392 fqs=3 (t=12164 jiffies g=31645 q=43226) rcu: rcu_preempt kthread starved for 12162 jiffies! g31645 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task ........... usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: unknown status received: -71 usbtmc 3-1:0.0: usb_submit_urb failed: -19 The function usbtmc_interrupt() resubmits urbs when the error status of an urb is -EPROTO. In systems using the dummy_hcd usb controller this can result in endless interrupt loops when the usbtmc device is disconnected from the host system. Since host controller drivers already try to recover from transmission errors, there is no need to resubmit the urb or try other solutions to repair the error situation. In case of errors the INT pipe just stops to wait for further packets. Fixes: dbf3e7f654c0 ("Implement an ioctl to support the USMTMC-USB488 READ_STATUS_BYTE operation") Cc: stable@vger.kernel.org Reported-by: syzbot+e2eae5639e7203360018@syzkaller.appspotmail.com Signed-off-by: Qiang.zhang Acked-by: Guido Kiener Link: https://lore.kernel.org/r/20210723004334.458930-1-qiang.zhang@windriver.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/usbtmc.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -2324,17 +2324,10 @@ static void usbtmc_interrupt(struct urb dev_err(dev, "overflow with length %d, actual length is %d\n", data->iin_wMaxPacketSize, urb->actual_length); fallthrough; - case -ECONNRESET: - case -ENOENT: - case -ESHUTDOWN: - case -EILSEQ: - case -ETIME: - case -EPIPE: + default: /* urb terminated, clean up */ dev_dbg(dev, "urb terminated, status: %d\n", status); return; - default: - dev_err(dev, "unknown status received: %d\n", status); } exit: rv = usb_submit_urb(urb, GFP_ATOMIC);