From patchwork Fri Apr 7 08:29:33 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chunfeng Yun X-Patchwork-Id: 13204581 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 705BAC6FD1D for ; Fri, 7 Apr 2023 08:30:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240107AbjDGIaD (ORCPT ); Fri, 7 Apr 2023 04:30:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239780AbjDGI3y (ORCPT ); Fri, 7 Apr 2023 04:29:54 -0400 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A6532AF25; Fri, 7 Apr 2023 01:29:49 -0700 (PDT) X-UUID: 576754fad51e11edb6b9f13eb10bd0fe-20230407 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=N09cAwcaHlqM3x5RvXqAyDDVVPSor4fraHJ/xFed9PM=; b=lHQvkWD0XDTZ49xx+7kgxHidQ+IE8LMRU6f9YRcVdTHm/fUAKUCvjQKlM7uVWaXScRtWRTXNSg9UXVYhtK3qNB8bYCyP1+Rai+A1CjmmCVLgk9qQtdbECtKxnBU39R3jAhjcDqaMQIQwsrYzNvmd1voxTn+0MaE984+0bZB7S9k=; X-CID-CACHE: Type:Local,Time:202304071629+08,HitQuantity:1 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.22,REQID:50995b94-cc9d-4da8-9986-d5bd4a7bd53d,IP:0,U RL:0,TC:0,Content:-5,EDM:0,RT:1,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTION :release,TS:-4 X-CID-META: VersionHash:120426c,CLOUDID:4734a02a-564d-42d9-9875-7c868ee415ec,B ulkID:nil,BulkQuantity:0,Recheck:0,SF:102,TC:nil,Content:0,EDM:-3,IP:nil,U RL:11|1,File:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0 X-CID-BVR: 0,NGT X-CID-BAS: 0,NGT,0,_ X-UUID: 576754fad51e11edb6b9f13eb10bd0fe-20230407 Received: from mtkmbs10n2.mediatek.inc [(172.21.101.183)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 440793704; Fri, 07 Apr 2023 16:29:41 +0800 Received: from mtkmbs13n1.mediatek.inc (172.21.101.193) by mtkmbs10n2.mediatek.inc (172.21.101.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.25; Fri, 7 Apr 2023 16:29:40 +0800 Received: from mhfsdcap04.gcn.mediatek.inc (10.17.3.154) by mtkmbs13n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1118.25 via Frontend Transport; Fri, 7 Apr 2023 16:29:40 +0800 From: Chunfeng Yun To: Greg Kroah-Hartman , Rob Herring CC: Chunfeng Yun , Krzysztof Kozlowski , Matthias Brugger , AngeloGioacchino Del Regno , , , , , , Tianping Fang Subject: [PATCH v2 3/7] usb: mtu3: fix kernel panic at qmu transfer done irq handler Date: Fri, 7 Apr 2023 16:29:33 +0800 Message-ID: <20230407082937.14558-3-chunfeng.yun@mediatek.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230407082937.14558-1-chunfeng.yun@mediatek.com> References: <20230407082937.14558-1-chunfeng.yun@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org When handle qmu transfer irq, it will unlock @mtu->lock before give back request, if another thread handle disconnect event at the same time, and try to disable ep, it may lock @mtu->lock and free qmu ring, then qmu irq hanlder may get a NULL gpd, avoid the KE by checking gpd's value before handling it. e.g. qmu done irq on cpu0 thread running on cpu1 qmu_done_tx() handle gpd [0] mtu3_requ_complete() mtu3_gadget_ep_disable() unlock @mtu->lock give back request lock @mtu->lock mtu3_ep_disable() mtu3_gpd_ring_free() unlock @mtu->lock lock @mtu->lock get next gpd [1] [1]: goto [0] to handle next gpd, and next gpd may be NULL. Signed-off-by: Chunfeng Yun --- v2: fix typo suggested by AngeloGioacchino --- drivers/usb/mtu3/mtu3_qmu.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/mtu3/mtu3_qmu.c b/drivers/usb/mtu3/mtu3_qmu.c index 6be4977a5db5..3d77408e3133 100644 --- a/drivers/usb/mtu3/mtu3_qmu.c +++ b/drivers/usb/mtu3/mtu3_qmu.c @@ -210,6 +210,7 @@ static struct qmu_gpd *advance_enq_gpd(struct mtu3_gpd_ring *ring) return ring->enqueue; } +/* @dequeue may be NULL if ring is unallocated or freed */ static struct qmu_gpd *advance_deq_gpd(struct mtu3_gpd_ring *ring) { if (ring->dequeue < ring->end) @@ -522,7 +523,7 @@ static void qmu_done_tx(struct mtu3 *mtu, u8 epnum) dev_dbg(mtu->dev, "%s EP%d, last=%p, current=%p, enq=%p\n", __func__, epnum, gpd, gpd_current, ring->enqueue); - while (gpd != gpd_current && !GET_GPD_HWO(gpd)) { + while (gpd && gpd != gpd_current && !GET_GPD_HWO(gpd)) { mreq = next_request(mep); @@ -561,7 +562,7 @@ static void qmu_done_rx(struct mtu3 *mtu, u8 epnum) dev_dbg(mtu->dev, "%s EP%d, last=%p, current=%p, enq=%p\n", __func__, epnum, gpd, gpd_current, ring->enqueue); - while (gpd != gpd_current && !GET_GPD_HWO(gpd)) { + while (gpd && gpd != gpd_current && !GET_GPD_HWO(gpd)) { mreq = next_request(mep);