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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 2BF08C433E1 for ; Thu, 16 Jul 2020 15:45:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0826620787 for ; Thu, 16 Jul 2020 15:45:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728374AbgGPPpP (ORCPT ); Thu, 16 Jul 2020 11:45:15 -0400 Received: from netrider.rowland.org ([192.131.102.5]:34359 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1728126AbgGPPpP (ORCPT ); Thu, 16 Jul 2020 11:45:15 -0400 Received: (qmail 1114215 invoked by uid 1000); 16 Jul 2020 11:45:10 -0400 Date: Thu, 16 Jul 2020 11:45:10 -0400 From: Alan Stern To: Bixuan Cui Cc: linux-next@vger.kernel.org, gustavoars@kernel.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, qiang.zhang@windriver.com, "Wanghui \(John\)" Subject: Re: [PATCH -next v2] usb: usbtest: reduce stack usage in test_queue Message-ID: <20200716154510.GE1112537@rowland.harvard.edu> References: <20200716082735.66342-1-cuibixuan@huawei.com> <42fe1a83-38a5-816b-9258-8a344008f398@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <42fe1a83-38a5-816b-9258-8a344008f398@huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-next-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-next@vger.kernel.org On Thu, Jul 16, 2020 at 09:47:10PM +0800, Bixuan Cui wrote: > Fix the warning: [-Werror=-Wframe-larger-than=] > > drivers/usb/misc/usbtest.c: In function 'test_queue': > drivers/usb/misc/usbtest.c:2148:1: > warning: the frame size of 1232 bytes is larger than 1024 bytes > > Reported-by: kbuild test robot > Signed-off-by: Bixuan Cui > --- > drivers/usb/misc/usbtest.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c > index 8b220d56647b..a9b40953d6bc 100644 > --- a/drivers/usb/misc/usbtest.c > +++ b/drivers/usb/misc/usbtest.c > @@ -2043,7 +2043,7 @@ test_queue(struct usbtest_dev *dev, struct usbtest_param_32 *param, > unsigned i; > unsigned long packets = 0; > int status = 0; > - struct urb *urbs[MAX_SGLEN]; > + struct urb **urbs; > > if (!param->sglen || param->iterations > UINT_MAX / param->sglen) > return -EINVAL; > @@ -2051,6 +2051,10 @@ test_queue(struct usbtest_dev *dev, struct usbtest_param_32 *param, > if (param->sglen > MAX_SGLEN) > return -EINVAL; > > + urbs = kcalloc(MAX_SGLEN, sizeof(*urbs), GFP_KERNEL); Since you know at runtime how many URBs will be needed, why not use that information? Change MAX_SGLEN to param->sglen. Aside from that, Acked-by: Alan Stern Alan Stern