From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Torgue Subject: Re: [PATCH] net: stmmac: Avoid VLA usage Date: Wed, 2 May 2018 16:22:18 +0200 Message-ID: <0046335b-c9a5-9da5-244c-46fe6f2e5a5b@st.com> References: <20180501210130.GA47709@beast> <2587c245-1d02-22a2-d24b-90b498183fc9@synopsys.com> <4c209618-8da0-ef1d-ff79-5da3f235b9bc@synopsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Cc: Giuseppe Cavallaro , LKML , Network Development To: Jose Abreu , Kees Cook Return-path: In-Reply-To: <4c209618-8da0-ef1d-ff79-5da3f235b9bc@synopsys.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 05/02/2018 04:07 PM, Jose Abreu wrote: > > > 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! No need. > > 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 >> >