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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 A16EEC072B1 for ; Thu, 30 May 2019 04:05:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E7C12504D for ; Thu, 30 May 2019 04:05:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559189145; bh=ywf1nuG7kMfD5ctTdkXYQCTqMgoIsl1j0TPUzIGUXX4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zOyJUWQE1uwych5cIjpKgP3ITOUAPmvbNFrpYy2AKfMqBWvJbeU8FUT2is9iQgasx WSCJRg58riIVFFL2twiiG1Pq0Q7fk86BW8qLLNG30b/VRxD5aMADXxXVBBleoZRZeu AQ4j1zwgBY1ySvUtSwh8piw/FkJojOH8sISP37Tk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726721AbfE3EFo (ORCPT ); Thu, 30 May 2019 00:05:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:48276 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730850AbfE3DRm (ORCPT ); Wed, 29 May 2019 23:17:42 -0400 Received: from localhost (ip67-88-213-2.z213-88-67.customer.algx.net [67.88.213.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B93A82470B; Thu, 30 May 2019 03:17:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559186261; bh=ywf1nuG7kMfD5ctTdkXYQCTqMgoIsl1j0TPUzIGUXX4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WbDNGVIVohH5hXLGJeODdO+dNH2HCyPa4EChLVDusWgy+82vOdqNVHknsX9RLDYHq MGJSdN2kAi+Iv0yxOrX0hS2luU08ZsQAkTAGBLjgQh+PD3RggWlNN8Ff92fwpR58GV lLlRUw+Y4a+N+sscrbNyscaNJA/XVdPN9fI8AwN4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Piotr Figiel , Kalle Valo , Sasha Levin Subject: [PATCH 4.19 195/276] brcmfmac: convert dev_init_lock mutex to completion Date: Wed, 29 May 2019 20:05:53 -0700 Message-Id: <20190530030537.321732327@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190530030523.133519668@linuxfoundation.org> References: <20190530030523.133519668@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit a9fd0953fa4a62887306be28641b4b0809f3b2fd ] Leaving dev_init_lock mutex locked in probe causes BUG and a WARNING when kernel is compiled with CONFIG_PROVE_LOCKING. Convert mutex to completion which silences those warnings and improves code readability. Fix below errors when connecting the USB WiFi dongle: brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43143 for chip BCM43143/2 BUG: workqueue leaked lock or atomic: kworker/0:2/0x00000000/434 last function: hub_event 1 lock held by kworker/0:2/434: #0: 18d5dcdf (&devinfo->dev_init_lock){+.+.}, at: brcmf_usb_probe+0x78/0x550 [brcmfmac] CPU: 0 PID: 434 Comm: kworker/0:2 Not tainted 4.19.23-00084-g454a789-dirty #123 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Workqueue: usb_hub_wq hub_event [<8011237c>] (unwind_backtrace) from [<8010d74c>] (show_stack+0x10/0x14) [<8010d74c>] (show_stack) from [<809c4324>] (dump_stack+0xa8/0xd4) [<809c4324>] (dump_stack) from [<8014195c>] (process_one_work+0x710/0x808) [<8014195c>] (process_one_work) from [<80141a80>] (worker_thread+0x2c/0x564) [<80141a80>] (worker_thread) from [<80147bcc>] (kthread+0x13c/0x16c) [<80147bcc>] (kthread) from [<801010b4>] (ret_from_fork+0x14/0x20) Exception stack(0xed1d9fb0 to 0xed1d9ff8) 9fa0: 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 ====================================================== WARNING: possible circular locking dependency detected 4.19.23-00084-g454a789-dirty #123 Not tainted ------------------------------------------------------ kworker/0:2/434 is trying to acquire lock: e29cf799 ((wq_completion)"events"){+.+.}, at: process_one_work+0x174/0x808 but task is already holding lock: 18d5dcdf (&devinfo->dev_init_lock){+.+.}, at: brcmf_usb_probe+0x78/0x550 [brcmfmac] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&devinfo->dev_init_lock){+.+.}: mutex_lock_nested+0x1c/0x24 brcmf_usb_probe+0x78/0x550 [brcmfmac] usb_probe_interface+0xc0/0x1bc really_probe+0x228/0x2c0 __driver_attach+0xe4/0xe8 bus_for_each_dev+0x68/0xb4 bus_add_driver+0x19c/0x214 driver_register+0x78/0x110 usb_register_driver+0x84/0x148 process_one_work+0x228/0x808 worker_thread+0x2c/0x564 kthread+0x13c/0x16c ret_from_fork+0x14/0x20 (null) -> #1 (brcmf_driver_work){+.+.}: worker_thread+0x2c/0x564 kthread+0x13c/0x16c ret_from_fork+0x14/0x20 (null) -> #0 ((wq_completion)"events"){+.+.}: process_one_work+0x1b8/0x808 worker_thread+0x2c/0x564 kthread+0x13c/0x16c ret_from_fork+0x14/0x20 (null) other info that might help us debug this: Chain exists of: (wq_completion)"events" --> brcmf_driver_work --> &devinfo->dev_init_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&devinfo->dev_init_lock); lock(brcmf_driver_work); lock(&devinfo->dev_init_lock); lock((wq_completion)"events"); *** DEADLOCK *** 1 lock held by kworker/0:2/434: #0: 18d5dcdf (&devinfo->dev_init_lock){+.+.}, at: brcmf_usb_probe+0x78/0x550 [brcmfmac] stack backtrace: CPU: 0 PID: 434 Comm: kworker/0:2 Not tainted 4.19.23-00084-g454a789-dirty #123 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Workqueue: events request_firmware_work_func [<8011237c>] (unwind_backtrace) from [<8010d74c>] (show_stack+0x10/0x14) [<8010d74c>] (show_stack) from [<809c4324>] (dump_stack+0xa8/0xd4) [<809c4324>] (dump_stack) from [<80172838>] (print_circular_bug+0x210/0x330) [<80172838>] (print_circular_bug) from [<80175940>] (__lock_acquire+0x160c/0x1a30) [<80175940>] (__lock_acquire) from [<8017671c>] (lock_acquire+0xe0/0x268) [<8017671c>] (lock_acquire) from [<80141404>] (process_one_work+0x1b8/0x808) [<80141404>] (process_one_work) from [<80141a80>] (worker_thread+0x2c/0x564) [<80141a80>] (worker_thread) from [<80147bcc>] (kthread+0x13c/0x16c) [<80147bcc>] (kthread) from [<801010b4>] (ret_from_fork+0x14/0x20) Exception stack(0xed1d9fb0 to 0xed1d9ff8) 9fa0: 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 Signed-off-by: Piotr Figiel Signed-off-by: Kalle Valo Signed-off-by: Sasha Levin --- .../wireless/broadcom/brcm80211/brcmfmac/usb.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c index a4308c6e72d79..5aeb401d9a024 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c @@ -160,7 +160,7 @@ struct brcmf_usbdev_info { struct usb_device *usbdev; struct device *dev; - struct mutex dev_init_lock; + struct completion dev_init_done; int ctl_in_pipe, ctl_out_pipe; struct urb *ctl_urb; /* URB for control endpoint */ @@ -1195,11 +1195,11 @@ static void brcmf_usb_probe_phase2(struct device *dev, int ret, if (ret) goto error; - mutex_unlock(&devinfo->dev_init_lock); + complete(&devinfo->dev_init_done); return; error: brcmf_dbg(TRACE, "failed: dev=%s, err=%d\n", dev_name(dev), ret); - mutex_unlock(&devinfo->dev_init_lock); + complete(&devinfo->dev_init_done); device_release_driver(dev); } @@ -1267,7 +1267,7 @@ static int brcmf_usb_probe_cb(struct brcmf_usbdev_info *devinfo) if (ret) goto fail; /* we are done */ - mutex_unlock(&devinfo->dev_init_lock); + complete(&devinfo->dev_init_done); return 0; } bus->chip = bus_pub->devid; @@ -1327,11 +1327,10 @@ brcmf_usb_probe(struct usb_interface *intf, const struct usb_device_id *id) devinfo->usbdev = usb; devinfo->dev = &usb->dev; - /* Take an init lock, to protect for disconnect while still loading. + /* Init completion, to protect for disconnect while still loading. * Necessary because of the asynchronous firmware load construction */ - mutex_init(&devinfo->dev_init_lock); - mutex_lock(&devinfo->dev_init_lock); + init_completion(&devinfo->dev_init_done); usb_set_intfdata(intf, devinfo); @@ -1409,7 +1408,7 @@ brcmf_usb_probe(struct usb_interface *intf, const struct usb_device_id *id) return 0; fail: - mutex_unlock(&devinfo->dev_init_lock); + complete(&devinfo->dev_init_done); kfree(devinfo); usb_set_intfdata(intf, NULL); return ret; @@ -1424,7 +1423,7 @@ brcmf_usb_disconnect(struct usb_interface *intf) devinfo = (struct brcmf_usbdev_info *)usb_get_intfdata(intf); if (devinfo) { - mutex_lock(&devinfo->dev_init_lock); + wait_for_completion(&devinfo->dev_init_done); /* Make sure that devinfo still exists. Firmware probe routines * may have released the device and cleared the intfdata. */ -- 2.20.1