From patchwork Tue Nov 3 08:54:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jack Pham X-Patchwork-Id: 11877475 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 253C26A2 for ; Tue, 3 Nov 2020 13:29:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED4F820786 for ; Tue, 3 Nov 2020 13:29:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="gIZ8JM5H" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729320AbgKCN3a (ORCPT ); Tue, 3 Nov 2020 08:29:30 -0500 Received: from z5.mailgun.us ([104.130.96.5]:62151 "EHLO z5.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729213AbgKCN30 (ORCPT ); Tue, 3 Nov 2020 08:29:26 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1604410166; h=Content-Transfer-Encoding: MIME-Version: Message-Id: Date: Subject: Cc: To: From: Sender; bh=X2YErXafDdkcu6A7UUnXanHOuRGPvsDZ6TouPm+F+5Q=; b=gIZ8JM5Htb+pyUdz08FEG63WOMlPmQnyD/173/ybEh8hCrNr4UiQQ/qEsa2aq0k1otoUUmmn YW3RsVyKzwkGHpKpGvUyL09ceaoSeyTbBAEw907fHo0DJgriobo/B5IJgRUOIHpZ2lNYMrQd bLaCnJGw9T1lN4ZkK6fDhMSr38k= X-Mailgun-Sending-Ip: 104.130.96.5 X-Mailgun-Sid: WyIxZTE2YSIsICJsaW51eC11c2JAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n01.prod.us-west-2.postgun.com with SMTP id 5fa15af7d8a9d167f3dc4c08 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Tue, 03 Nov 2020 13:28:23 GMT Sender: jackp=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 1ECAEC384FB; Tue, 3 Nov 2020 08:55:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=ALL_TRUSTED,BAYES_00,SPF_FAIL, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from jackp-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: jackp) by smtp.codeaurora.org (Postfix) with ESMTPSA id D2F5DC384FB; Tue, 3 Nov 2020 08:55:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D2F5DC384FB Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=jackp@codeaurora.org From: Jack Pham To: Felipe Balbi , Sebastian Andrzej Siewior Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, Chandana Kishori Chiluveru , Jack Pham Subject: [PATCH] usb: gadget: configfs: Preserve function ordering after bind failure Date: Tue, 3 Nov 2020 00:54:56 -0800 Message-Id: <20201103085456.15591-1-jackp@codeaurora.org> X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org From: Chandana Kishori Chiluveru When binding the ConfigFS gadget to a UDC, the functions in each configuration are added in list order. However, if usb_add_function() fails, the failed function is put back on its configuration's func_list and purge_configs_funcs() is called to further clean up. purge_configs_funcs() iterates over the configurations and functions in forward order, calling unbind() on each of the previously added functions. But after doing so, each function gets moved to the tail of the configuration's func_list. This results in reshuffling the original order of the functions within a configuration such that the failed function now appears first even though it may have originally appeared in the middle or even end of the list. At this point if the ConfigFS gadget is attempted to re-bind to the UDC, the functions will be added in a different order than intended, with the only recourse being to remove and relink the functions all over again. An example of this as follows: ln -s functions/mass_storage.0 configs/c.1 ln -s functions/ncm.0 configs/c.1 ln -s functions/ffs.adb configs/c.1 # oops, forgot to start adbd echo "" > UDC # fails start adbd echo "" > UDC # now succeeds, but... # bind order is # "ADB", mass_storage, ncm [30133.118289] configfs-gadget gadget: adding 'Mass Storage Function'/ffffff810af87200 to config 'c'/ffffff817d6a2520 [30133.119875] configfs-gadget gadget: adding 'cdc_network'/ffffff80f48d1a00 to config 'c'/ffffff817d6a2520 [30133.119974] using random self ethernet address [30133.120002] using random host ethernet address [30133.139604] usb0: HOST MAC 3e:27:46:ba:3e:26 [30133.140015] usb0: MAC 6e:28:7e:42:66:6a [30133.140062] configfs-gadget gadget: adding 'Function FS Gadget'/ffffff80f3868438 to config 'c'/ffffff817d6a2520 [30133.140081] configfs-gadget gadget: adding 'Function FS Gadget'/ffffff80f3868438 --> -19 [30133.140098] configfs-gadget gadget: unbind function 'Mass Storage Function'/ffffff810af87200 [30133.140119] configfs-gadget gadget: unbind function 'cdc_network'/ffffff80f48d1a00 [30133.173201] configfs-gadget a600000.dwc3: failed to start g1: -19 [30136.661933] init: starting service 'adbd'... [30136.700126] read descriptors [30136.700413] read strings [30138.574484] configfs-gadget gadget: adding 'Function FS Gadget'/ffffff80f3868438 to config 'c'/ffffff817d6a2520 [30138.575497] configfs-gadget gadget: adding 'Mass Storage Function'/ffffff810af87200 to config 'c'/ffffff817d6a2520 [30138.575554] configfs-gadget gadget: adding 'cdc_network'/ffffff80f48d1a00 to config 'c'/ffffff817d6a2520 [30138.575631] using random self ethernet address [30138.575660] using random host ethernet address [30138.595338] usb0: HOST MAC 2e:cf:43:cd:ca:c8 [30138.597160] usb0: MAC 6a:f0:9f:ee:82:a0 [30138.791490] configfs-gadget gadget: super-speed config #1: c Fix this by reversing the iteration order of the functions in purge_config_funcs() when unbinding them, and adding them back to the config's func_list at the head instead of the tail. This ensures that we unbind and unwind back to the original list order. Fixes: 88af8bbe4ef7 ("usb: gadget: the start of the configfs interface") Signed-off-by: Chandana Kishori Chiluveru Signed-off-by: Jack Pham --- drivers/usb/gadget/configfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c index 56051bb97349..3dda1d63f231 100644 --- a/drivers/usb/gadget/configfs.c +++ b/drivers/usb/gadget/configfs.c @@ -1248,9 +1248,9 @@ static void purge_configs_funcs(struct gadget_info *gi) cfg = container_of(c, struct config_usb_cfg, c); - list_for_each_entry_safe(f, tmp, &c->functions, list) { + list_for_each_entry_safe_reverse(f, tmp, &c->functions, list) { - list_move_tail(&f->list, &cfg->func_list); + list_move(&f->list, &cfg->func_list); if (f->unbind) { dev_dbg(&gi->cdev.gadget->dev, "unbind function '%s'/%p\n",