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=-16.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 96713C433DB for ; Wed, 10 Feb 2021 14:56:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C56664E79 for ; Wed, 10 Feb 2021 14:56:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231326AbhBJO4a (ORCPT ); Wed, 10 Feb 2021 09:56:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:42384 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230263AbhBJO41 (ORCPT ); Wed, 10 Feb 2021 09:56:27 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3C4A564EB4; Wed, 10 Feb 2021 14:55:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612968945; bh=D+I1p8kFl9V98gx/oh6Plr3WzbCSyGVrh7RCkNdJOSg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XN7u1YG3A+jYzRa8amvNC76Jaip3/lWern/bfYTAxCtfTL8zrgyCGD+ZjZ2qqUSsK VtME7XUg6AyN+2+7wNyyBmNhz04JgD2RNoFprlfLWch3e9K69TdbmMjzb9cxdTyRnK L6VnEb5VgOyEjwqTBRb4h3x4soE2UCRT7ac3IphU= Date: Wed, 10 Feb 2021 15:55:42 +0100 From: Greg KH To: Amey Narkhede Cc: dan.carpenter@oracle.com, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] staging: gdm724x: Fix DMA from stack Message-ID: References: <20210210142512.23152-1-ameynarkhede03@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210210142512.23152-1-ameynarkhede03@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 10, 2021 at 07:55:12PM +0530, Amey Narkhede wrote: > Stack allocated buffers cannot be used for DMA > on all architectures so allocate hci_packet buffer > using kmalloc. > > Signed-off-by: Amey Narkhede > --- > Changes in v3: > - Remove superfluous buf pointer > - Reduce size of allocation of hci_packet to match number of > bytes used for DMA > > drivers/staging/gdm724x/gdm_usb.c | 10 +++++++--- > 1 file changed, 7 insertions(+), 3 deletions(-) > > diff --git a/drivers/staging/gdm724x/gdm_usb.c b/drivers/staging/gdm724x/gdm_usb.c > index dc4da66c3..80c58a3ef 100644 > --- a/drivers/staging/gdm724x/gdm_usb.c > +++ b/drivers/staging/gdm724x/gdm_usb.c > @@ -56,20 +56,24 @@ static int gdm_usb_recv(void *priv_dev, > > static int request_mac_address(struct lte_udev *udev) > { > - u8 buf[16] = {0,}; > - struct hci_packet *hci = (struct hci_packet *)buf; > + struct hci_packet *hci; > struct usb_device *usbdev = udev->usbdev; > int actual; > int ret = -1; > > + hci = kmalloc(5, GFP_KERNEL); Why "5" and not: hci = kmalloc(sizeof(*hci), GFP_KERNEL); ? thanks, greg k-h