From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751521AbeEBOHy (ORCPT ); Wed, 2 May 2018 10:07:54 -0400 Received: from smtprelay6.synopsys.com ([198.182.37.59]:33608 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750936AbeEBOHv (ORCPT ); Wed, 2 May 2018 10:07:51 -0400 Subject: Re: [PATCH] net: stmmac: Avoid VLA usage To: Kees Cook , Jose Abreu References: <20180501210130.GA47709@beast> <2587c245-1d02-22a2-d24b-90b498183fc9@synopsys.com> CC: Giuseppe Cavallaro , Alexandre Torgue , LKML , "Network Development" From: Jose Abreu Message-ID: <4c209618-8da0-ef1d-ff79-5da3f235b9bc@synopsys.com> Date: Wed, 2 May 2018 15:07:43 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.107.19.59] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02-05-2018 13:36, Kees Cook wrote: > On Wed, May 2, 2018 at 1:54 AM, Jose Abreu wrote: >> Hi Kees, >> >> On 01-05-2018 22:01, Kees Cook wrote: >>> In the quest to remove all stack VLAs from the kernel[1], this switches >>> the "status" stack buffer to use the existing small (8) upper bound on >>> how many queues can be checked for DMA, and adds a sanity-check just to >>> make sure it doesn't operate under pathological conditions. >>> >>> [1] https://urldefense.proofpoint.com/v2/url?u=http-3A__lkml.kernel.org_r_CA-2B55aFzCG-2DzNmZwX4A2FQpadafLfEzK6CC-3DqPXydAacU1RqZWA-40mail.gmail.com&d=DwIBAg&c=DPL6_X_6JkXFx7AXWqB0tg&r=WHDsc6kcWAl4i96Vm5hJ_19IJiuxx_p_Rzo2g-uHDKw&m=TBD6a7UY2VbpPmV9LOW_eHAyg8uPq1ZPDhq93VROTVE&s=4fvOST1HhWmZ4lThQe-dHCJYEXNOwey00BCXOWm8tKo&e= >>> >>> Signed-off-by: Kees Cook >>> >> I rather prefer the variables declaration in reverse-tree order, >> but thats just a minor pick. > I can explicitly reorder the other variables, if you want? No need by me, unless Giuseppe or Alexandre prefer that. Thanks! Best Regards, Jose Miguel Abreu > >> Reviewed-by: Jose Abreu > Thanks! > >> PS: Is VLA warning switch in gcc already active? Because I didn't >> see this warning in my builds. > It is not. A bunch of people have been building with KCFLAGS=-Wvla to > find the VLAs and sending patches. Once we get rid of them all, we can > add the flag to the top-level Makefile. > > -Kees >