netdev - Re: [PATCH net-next v19 03/13] netdev: support binding dma-buf to netdevice

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]

Message-ID: <CAHS8izN0Wb7isGbhO+cvYNfG+v2bsvvfy7P0cSsMD7USfd+4bQ@mail.gmail.com>
Date: Fri, 16 Aug 2024 09:56:36 -0400
From: Mina Almasry <almasrymina@...gle.com>
To: Jakub Kicinski <kuba@...nel.org>
Cc: netdev@...r.kernel.org, linux-kernel@...r.kernel.org, 
	linux-doc@...r.kernel.org, linux-alpha@...r.kernel.org, 
	linux-mips@...r.kernel.org, linux-parisc@...r.kernel.org, 
	sparclinux@...r.kernel.org, linux-trace-kernel@...r.kernel.org, 
	linux-arch@...r.kernel.org, linux-kselftest@...r.kernel.org, 
	bpf@...r.kernel.org, linux-media@...r.kernel.org, 
	dri-devel@...ts.freedesktop.org, "David S. Miller" <davem@...emloft.net>, 
	Eric Dumazet <edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com>, 
	Donald Hunter <donald.hunter@...il.com>, Jonathan Corbet <corbet@....net>, 
	Richard Henderson <richard.henderson@...aro.org>, Ivan Kokshaysky <ink@...assic.park.msu.ru>, 
	Matt Turner <mattst88@...il.com>, Thomas Bogendoerfer <tsbogend@...ha.franken.de>, 
	"James E.J. Bottomley" <James.Bottomley@...senpartnership.com>, Helge Deller <deller@....de>, 
	Andreas Larsson <andreas@...sler.com>, Jesper Dangaard Brouer <hawk@...nel.org>, 
	Ilias Apalodimas <ilias.apalodimas@...aro.org>, Steven Rostedt <rostedt@...dmis.org>, 
	Masami Hiramatsu <mhiramat@...nel.org>, Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, 
	Arnd Bergmann <arnd@...db.de>, Steffen Klassert <steffen.klassert@...unet.com>, 
	Herbert Xu <herbert@...dor.apana.org.au>, David Ahern <dsahern@...nel.org>, 
	Willem de Bruijn <willemdebruijn.kernel@...il.com>, Shuah Khan <shuah@...nel.org>, 
	Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann <daniel@...earbox.net>, 
	John Fastabend <john.fastabend@...il.com>, Sumit Semwal <sumit.semwal@...aro.org>, 
	Christian König <christian.koenig@....com>, 
	Bagas Sanjaya <bagasdotme@...il.com>, Christoph Hellwig <hch@...radead.org>, 
	Nikolay Aleksandrov <razor@...ckwall.org>, Taehee Yoo <ap420073@...il.com>, 
	Pavel Begunkov <asml.silence@...il.com>, David Wei <dw@...idwei.uk>, Jason Gunthorpe <jgg@...pe.ca>, 
	Yunsheng Lin <linyunsheng@...wei.com>, Shailend Chand <shailend@...gle.com>, 
	Harshitha Ramamurthy <hramamurthy@...gle.com>, Shakeel Butt <shakeel.butt@...ux.dev>, 
	Jeroen de Borst <jeroendb@...gle.com>, Praveen Kaligineedi <pkaligineedi@...gle.com>, 
	Willem de Bruijn <willemb@...gle.com>, Kaiyuan Zhang <kaiyuanz@...gle.com>, 
	Daniel Vetter <daniel.vetter@...ll.ch>
Subject: Re: [PATCH net-next v19 03/13] netdev: support binding dma-buf to netdevice

On Thu, Aug 15, 2024 at 8:48 PM Jakub Kicinski <kuba@...nel.org> wrote:
>
> On Tue, 13 Aug 2024 21:13:05 +0000 Mina Almasry wrote:
> > +int dev_get_max_mp_channel(const struct net_device *dev)
> > +{
> > +     int i, max = -1;
>
> I presume the bug from yesterday is self evident once reported? :)
>

Yes, my apologies. The int return value from this function was being
implicitly cast to unsigned in the check I think, and that failed the
check.

My test didn't catch that due to a test environment issue. I had 2
ethtools installed by accident on the machine, and the test was
invoking the wrong one. I think I have that ironed out now.

> > +     ASSERT_RTNL();
> > +
> > +     for (i = 0; i < dev->real_num_rx_queues; i++)
> > +             if (dev->_rx[i].mp_params.mp_priv)
> > +                     /* The number of queues is the idx plus 1. */
> > +                     max = i + 1;
>
> The +1 is odd. The function as it stands reports min channel count.
> Not max_mp_channel, if you ask me. And if you renamed it, you don't
> have to use -1 as "not installed".
>

Will do.

--
Thanks,
Mina