From patchwork Tue Nov 22 12:35:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Keeping X-Patchwork-Id: 13052306 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 AD267C433FE for ; Tue, 22 Nov 2022 12:35:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233770AbiKVMfh (ORCPT ); Tue, 22 Nov 2022 07:35:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233204AbiKVMff (ORCPT ); Tue, 22 Nov 2022 07:35:35 -0500 Received: from metanate.com (unknown [IPv6:2001:8b0:1628:5005::111]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0FFA55B849; Tue, 22 Nov 2022 04:35:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=metanate.com; s=stronger; h=Content-Transfer-Encoding:References: In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Content-Type:Reply-To: Content-ID:Content-Description; bh=VjcwKuzaca86AHSHKpSyWjgTPVgpR5kpdMTz8JABTVY=; b=hM6I+fMJWa/70IFhgoLB+YtUW5 vWSJ5OfUrdfleSHIx64eNSpwDZU5bQQ2HobN9HAA7JodXGy9Sz4QleDt88qP79bjgAx3ngTOlLWbg JjTvUCiQPXMe5MBu9Fr8b62VETGbZeEhMv/1VLO9u1ctsonIVRA65EnQ7Ls6sQzaZGQevjf8FVz4c qJsqxwmG4JdQQUOpnEHjZitUXKZXe3j04a+HC0HnTEYxL/halirDjAaqNmB+A48FdzcaStvW8z+z7 FHu5EvI3Ny02TkfNUKF3FSwF3OYZuBWc9NxJWuTHM+S4E9CvqM90xoqCS0C5ApkmYGcG7WOtUmmL9 nJc/A1Fg==; Received: from [81.174.171.191] (helo=donbot.metanate.com) by email.metanate.com with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1oxSUt-0003da-Qx; Tue, 22 Nov 2022 12:35:32 +0000 From: John Keeping To: linux-usb@vger.kernel.org Cc: Fabien Chouteau , Peter Korsgaard , Felipe Balbi , Andrzej Pietrasiewicz , linux-kernel@vger.kernel.org, Greg Kroah-Hartman , John Keeping , Lee Jones , Alan Stern Subject: [PATCH 3/3] usb: gadget: f_hid: tidy error handling in hidg_alloc Date: Tue, 22 Nov 2022 12:35:23 +0000 Message-Id: <20221122123523.3068034-4-john@metanate.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221122123523.3068034-1-john@metanate.com> References: <20221122123523.3068034-1-john@metanate.com> MIME-Version: 1.0 X-Authenticated: YES Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Unify error handling at the end of the function, reducing the risk of missing something on one of the error paths. Moving the increment of opts->refcnt later means there is no need to decrement it on the error path and is safe as this is guarded by opts->lock which is held for this entire section. Signed-off-by: John Keeping Reviewed-by: Andrzej Pietrasiewicz --- drivers/usb/gadget/function/f_hid.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c index 6be6009f911e..a8da3b4a2855 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -1269,18 +1269,14 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi) opts = container_of(fi, struct f_hid_opts, func_inst); mutex_lock(&opts->lock); - ++opts->refcnt; device_initialize(&hidg->dev); hidg->dev.release = hidg_release; hidg->dev.class = hidg_class; hidg->dev.devt = MKDEV(major, opts->minor); ret = dev_set_name(&hidg->dev, "hidg%d", opts->minor); - if (ret) { - --opts->refcnt; - mutex_unlock(&opts->lock); - return ERR_PTR(ret); - } + if (ret) + goto err_unlock; hidg->bInterfaceSubClass = opts->subclass; hidg->bInterfaceProtocol = opts->protocol; @@ -1291,14 +1287,13 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi) opts->report_desc_length, GFP_KERNEL); if (!hidg->report_desc) { - put_device(&hidg->dev); - --opts->refcnt; - mutex_unlock(&opts->lock); - return ERR_PTR(-ENOMEM); + ret = -ENOMEM; + goto err_put_device; } } hidg->use_out_ep = !opts->no_out_endpoint; + ++opts->refcnt; mutex_unlock(&opts->lock); hidg->func.name = "hid"; @@ -1313,6 +1308,12 @@ static struct usb_function *hidg_alloc(struct usb_function_instance *fi) hidg->qlen = 4; return &hidg->func; + +err_put_device: + put_device(&hidg->dev); +err_unlock: + mutex_unlock(&opts->lock); + return ERR_PTR(ret); } DECLARE_USB_FUNCTION_INIT(hid, hidg_alloc_inst, hidg_alloc);