linux-kernel - Re: [PATCH] ext4: fix clang build regression

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] [day] [month] [year] [list]

Message-ID: <20170814122938.caz2j2rqjcuxfqoz@thunk.org>
Date:   Mon, 14 Aug 2017 08:29:38 -0400
From:   Theodore Ts'o <tytso@....edu>
To:     Chandan Rajendra <chandan@...ux.vnet.ibm.com>
Cc:     Arnd Bergmann <arnd@...db.de>,
        Andreas Dilger <adilger.kernel@...ger.ca>,
        Stefan Agner <stefan@...er.ch>, Jan Kara <jack@...e.cz>,
        Daeho Jeong <daeho.jeong@...sung.com>,
        "Darrick J. Wong" <darrick.wong@...cle.com>,
        Konstantin Khlebnikov <khlebnikov@...dex-team.ru>,
        linux-ext4@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ext4: fix clang build regression

On Sat, Aug 12, 2017 at 02:09:29PM +0530, Chandan Rajendra wrote:
> On Monday, August 7, 2017 4:26:51 PM IST Arnd Bergmann wrote:
> > As Stefan pointed out, I misremembered what clang can do specifically,
> > and it turns out that the variable-length array at the end of the
> > structure did not work (a flexible array would have worked here
> > but not solved the problem):
> > 
> > fs/ext4/mballoc.c:2303:17: error: fields must have a constant size:
> > 'variable length array in structure' extension will never be supported
> >                 ext4_grpblk_t counters[blocksize_bits + 2];
> > 
> > This reverts part of my previous patch, using a fixed-size array
> > again, but keeping the check for the array overflow.
> > 
> > Fixes: 2df2c3402fc8 ("ext4: fix warning about stack corruption")
> > Reported-by: Stefan Agner <stefan@...er.ch>
> > Signed-off-by: Arnd Bergmann <arnd@...db.de>
> 
> I executed xfstests on a ppc64 machine with both 4k and 64k block size 
> combination.
> 
> Tested-by: Chandan Rajendra <chandan@...ux.vnet.ibm.com>

Thanks, applied.

						- Ted