netdev - Re: ethtool build failure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Sat, 6 Jun 2020 15:47:52 +0200
From:   Heiko Thiery <heiko.thiery@...il.com>
To:     Michal Kubecek <mkubecek@...e.cz>
Cc:     netdev@...r.kernel.org
Subject: Re: ethtool build failure

Hi Michal,

Am Sa., 6. Juni 2020 um 15:43 Uhr schrieb Michal Kubecek <mkubecek@...e.cz>:
>
> On Sat, Jun 06, 2020 at 03:24:22PM +0200, Heiko Thiery wrote:
> > Hi Michael et all,
> >
> > I'm digging in the reason for a failure when building ethtool with
> > buildroot [1].
> >
> > I see the following error:
> > ---
> > data/buildroot/buildroot-test/instance-0/output/host/bin/i686-linux-gcc
> > -DHAVE_CONFIG_H -I.  -I./uapi  -D_LARGEFILE_SOURCE
> > -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Wall -D_LARGEFILE_SOURCE
> > -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -Os   -static -c -o
> > netlink/desc-rtnl.o netlink/desc-rtnl.c
> > In file included from ./uapi/linux/ethtool_netlink.h:12,
> >                  from netlink/desc-ethtool.c:7:
> > ./uapi/linux/ethtool.h:1294:19: warning: implicit declaration of
> > function '__KERNEL_DIV_ROUND_UP' [-Wimplicit-function-declaration]
> >   __u32 queue_mask[__KERNEL_DIV_ROUND_UP(MAX_NUM_QUEUE, 32)];
> >                    ^~~~~~~~~~~~~~~~~~~~~
> > ./uapi/linux/ethtool.h:1294:8: error: variably modified 'queue_mask'
> > at file scope
> >   __u32 queue_mask[__KERNEL_DIV_ROUND_UP(MAX_NUM_QUEUE, 32)];
> >         ^~~~~~~~~~
> > ---
>
> Thank you for the report. This is fixed by first part of this patch:
>
>   https://patchwork.ozlabs.org/project/netdev/patch/bb60cbfe99071fca4b0ea9e62d67a2341d8dd652.1590707335.git.mkubecek@suse.cz/
>
> I'm going to apply it (with the rest of the series) this weekend.

I will try to apply this patch and check if the failure is gone.

>
> > The problems seems to be injected by the "warning: implicit
> > declaration of function".
> >
> > When I move the __KERNEL_DIV_ROUND_UP macro right beside usage in
> > "uapi/linux/ethtool.h" the failure is gone.
> >
> > ---
> > diff --git a/uapi/linux/ethtool.h b/uapi/linux/ethtool.h
> > index d3dcb45..6710fa0 100644
> > --- a/uapi/linux/ethtool.h
> > +++ b/uapi/linux/ethtool.h
> > @@ -1288,6 +1288,11 @@ enum ethtool_sfeatures_retval_bits {
> >   * @queue_mask: Bitmap of the queues which sub command apply to
> >   * @data: A complete command structure following for each of the
> > queues addressed
> >   */
> > +/* ethtool.h epxects __KERNEL_DIV_ROUND_UP to be defined by <linux/kernel.h> */
> > +#include <linux/kernel.h>
> > +#ifndef __KERNEL_DIV_ROUND_UP
> > +#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
> > +#endif
> >  struct ethtool_per_queue_op {
> >         __u32   cmd;
> >         __u32   sub_command;
> > ---
>
> This would fix the warning and error too but uapi/linux/ethtool.h is
> a sanitized copy of a kernel header which we import and do not apply
> further changes. Moreover, there is no need to have multiple definitions
> of the same macro and there is already one in internal.h.

I saw that the definition is already done in internal.h. I just did a
quick hackaround to check if the failure is gone.

Thanks!

-- 
Heiko