From patchwork Thu Nov 26 12:55:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislaw Gruszka X-Patchwork-Id: 11933469 X-Patchwork-Delegate: kvalo@adurom.com 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 7BCB0C63697 for ; Thu, 26 Nov 2020 12:55:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D7EF321D1A for ; Thu, 26 Nov 2020 12:55:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=wp.pl header.i=@wp.pl header.b="NyIPWsx+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389522AbgKZMz0 (ORCPT ); Thu, 26 Nov 2020 07:55:26 -0500 Received: from mx3.wp.pl ([212.77.101.10]:45911 "EHLO mx3.wp.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388892AbgKZMz0 (ORCPT ); Thu, 26 Nov 2020 07:55:26 -0500 Received: (wp-smtpd smtp.wp.pl 29100 invoked from network); 26 Nov 2020 13:55:21 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wp.pl; s=1024a; t=1606395321; bh=Bcpqgz9nMC2b2yCKgxveFN6YnzZXtZhxC3XIUSSDvEk=; h=From:To:Cc:Subject; b=NyIPWsx+/63rBuc7QnaUYu7BqucKTBx+fYv1c9l+dPQLRX5aKiX5zgAoihSncPq9N BXIS3yl4w2FBjoBzqkWbvXXyeg7oVEXA/eQvgjsQ9fPmhWNL2j6PzV3oBGic91pcq6 OEjOgAUX8ONxXAhVHZ6M01+1P6hft5NmEDrflaQ8= Received: from ip4-46-39-164-203.cust.nbox.cz (HELO localhost) (stf_xl@wp.pl@[46.39.164.203]) (envelope-sender ) by smtp.wp.pl (WP-SMTPD) with ECDHE-RSA-AES256-GCM-SHA384 encrypted SMTP for ; 26 Nov 2020 13:55:21 +0100 From: stf_xl@wp.pl To: linux-wireless@vger.kernel.org Cc: Felix Fietkau , Lorenzo Bianconi Subject: [PATCH 5.10] mt76: usb: fix crash on device removal Date: Thu, 26 Nov 2020 13:55:20 +0100 Message-Id: <20201126125520.72912-1-stf_xl@wp.pl> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 X-WP-MailID: a93846a6806ef607c3e3a836b105f205 X-WP-AV: skaner antywirusowy Poczty Wirtualnej Polski X-WP-SPAM: NO 0000001 [AbKU] Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Stanislaw Gruszka Currently 'while (q->queued > 0)' loop was removed from mt76u_stop_tx() code. This causes crash on device removal as we try to cleanup empty queue: [ 96.495571] kernel BUG at include/linux/skbuff.h:2297! [ 96.498983] invalid opcode: 0000 [#1] SMP PTI [ 96.501162] CPU: 3 PID: 27 Comm: kworker/3:0 Not tainted 5.10.0-rc5+ #11 [ 96.502754] Hardware name: LENOVO 20DGS08H00/20DGS08H00, BIOS J5ET48WW (1.19 ) 08/27/2015 [ 96.504378] Workqueue: usb_hub_wq hub_event [ 96.505983] RIP: 0010:skb_pull+0x2d/0x30 [ 96.507576] Code: 00 00 8b 47 70 39 c6 77 1e 29 f0 89 47 70 3b 47 74 72 17 48 8b 87 c8 00 00 00 89 f6 48 01 f0 48 89 87 c8 00 00 00 c3 31 c0 c3 <0f> 0b 90 0f 1f 44 00 00 53 48 89 fb 48 8b bf c8 00 00 00 8b 43 70 [ 96.509296] RSP: 0018:ffffb11b801639b8 EFLAGS: 00010287 [ 96.511038] RAX: 000000001c6939ed RBX: ffffb11b801639f8 RCX: 0000000000000000 [ 96.512964] RDX: ffffb11b801639f8 RSI: 0000000000000018 RDI: ffff90c64e4fb800 [ 96.514710] RBP: ffff90c654551ee0 R08: ffff90c652bce7a8 R09: ffffb11b80163728 [ 96.516450] R10: 0000000000000001 R11: 0000000000000001 R12: ffff90c64e4fb800 [ 96.519749] R13: 0000000000000010 R14: 0000000000000020 R15: ffff90c64e352ce8 [ 96.523455] FS: 0000000000000000(0000) GS:ffff90c96eec0000(0000) knlGS:0000000000000000 [ 96.527171] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 96.530900] CR2: 0000242556f18288 CR3: 0000000146a10002 CR4: 00000000003706e0 [ 96.534678] Call Trace: [ 96.538418] mt76x02u_tx_complete_skb+0x1f/0x50 [mt76x02_usb] [ 96.542231] mt76_queue_tx_complete+0x23/0x50 [mt76] [ 96.546028] mt76u_stop_tx.cold+0x71/0xa2 [mt76_usb] [ 96.549797] mt76x0u_stop+0x2f/0x90 [mt76x0u] [ 96.553638] drv_stop+0x33/0xd0 [mac80211] [ 96.557449] ieee80211_do_stop+0x558/0x860 [mac80211] [ 96.561262] ? dev_deactivate_many+0x298/0x2d0 [ 96.565101] ieee80211_stop+0x16/0x20 [mac80211] Fix that by adding while loop again. We need loop, not just single check, to clean all pending entries. Additionally move mt76_worker_disable/enable after !mt76_has_tx_pending() as we want to tx_worker to run to process tx queues, while we wait for exactly that. I was a bit worried about accessing q->queued without lock, but mt76_worker_disable() -> kthread_park() should assure this value will be seen updated on other cpus. Fixes: fe5b5ab52e9d ("mt76: unify queue tx cleanup code") Signed-off-by: Stanislaw Gruszka Acked-by: Felix Fietkau --- drivers/net/wireless/mediatek/mt76/usb.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c index 7d3f0a2e5fa0..f1ae9ff835b2 100644 --- a/drivers/net/wireless/mediatek/mt76/usb.c +++ b/drivers/net/wireless/mediatek/mt76/usb.c @@ -1020,8 +1020,6 @@ void mt76u_stop_tx(struct mt76_dev *dev) { int ret; - mt76_worker_disable(&dev->tx_worker); - ret = wait_event_timeout(dev->tx_wait, !mt76_has_tx_pending(&dev->phy), HZ / 5); if (!ret) { @@ -1040,6 +1038,8 @@ void mt76u_stop_tx(struct mt76_dev *dev) usb_kill_urb(q->entry[j].urb); } + mt76_worker_disable(&dev->tx_worker); + /* On device removal we maight queue skb's, but mt76u_tx_kick() * will fail to submit urb, cleanup those skb's manually. */ @@ -1048,18 +1048,19 @@ void mt76u_stop_tx(struct mt76_dev *dev) if (!q) continue; - entry = q->entry[q->tail]; - q->entry[q->tail].done = false; - - mt76_queue_tx_complete(dev, q, &entry); + while (q->queued > 0) { + entry = q->entry[q->tail]; + q->entry[q->tail].done = false; + mt76_queue_tx_complete(dev, q, &entry); + } } + + mt76_worker_enable(&dev->tx_worker); } cancel_work_sync(&dev->usb.stat_work); clear_bit(MT76_READING_STATS, &dev->phy.state); - mt76_worker_enable(&dev->tx_worker); - mt76_tx_status_check(dev, NULL, true); } EXPORT_SYMBOL_GPL(mt76u_stop_tx);