From: Jakub Kicinski <jakub.kicinski@netronome.com>
To: Maxim Mikityanskiy <maximmi@mellanox.com>
Cc: "Alexei Starovoitov" <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"bpf@vger.kernel.org" <bpf@vger.kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>,
"Björn Töpel" <bjorn.topel@intel.com>,
"Saeed Mahameed" <saeedm@mellanox.com>,
"Jesper Dangaard Brouer" <hawk@kernel.org>,
"John Fastabend" <john.fastabend@gmail.com>,
"Martin KaFai Lau" <kafai@fb.com>,
"Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>
Subject: Re: [PATCH bpf-next v2] net: Don't call XDP_SETUP_PROG when nothing is changed
Date: Wed, 14 Aug 2019 15:01:23 -0700 [thread overview]
Message-ID: <20190814150123.6b5124e8@cakuba.netronome.com> (raw)
In-Reply-To: <20190814143352.3759-1-maximmi@mellanox.com>
On Wed, 14 Aug 2019 14:34:06 +0000, Maxim Mikityanskiy wrote:
> Don't uninstall an XDP program when none is installed, and don't install
> an XDP program that has the same ID as the one already installed.
>
> dev_change_xdp_fd doesn't perform any checks in case it uninstalls an
> XDP program. It means that the driver's ndo_bpf can be called with
> XDP_SETUP_PROG asking to set it to NULL even if it's already NULL. This
> case happens if the user runs `ip link set eth0 xdp off` when there is
> no XDP program attached.
>
> The symmetrical case is possible when the user tries to set the program
> that is already set.
>
> The drivers typically perform some heavy operations on XDP_SETUP_PROG,
> so they all have to handle these cases internally to return early if
> they happen. This patch puts this check into the kernel code, so that
> all drivers will benefit from it.
>
> Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
next prev parent reply other threads:[~2019-08-14 22:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 16:14 [PATCH bpf-next] net: Don't uninstall an XDP program when none is installed Maxim Mikityanskiy
2019-06-12 18:39 ` Björn Töpel
2019-06-12 21:15 ` Jakub Kicinski
2019-06-13 9:04 ` Björn Töpel
2019-06-13 17:26 ` Jakub Kicinski
2019-07-10 11:16 ` Maxim Mikityanskiy
2019-07-12 15:44 ` Daniel Borkmann
2019-08-14 14:34 ` [PATCH bpf-next v2] net: Don't call XDP_SETUP_PROG when nothing is changed Maxim Mikityanskiy
2019-08-14 17:57 ` Jonathan Lemon
2019-08-14 22:01 ` Jakub Kicinski [this message]
2019-08-17 21:29 ` Daniel Borkmann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190814150123.6b5124e8@cakuba.netronome.com \
--to=jakub.kicinski@netronome.com \
--cc=ast@kernel.org \
--cc=bjorn.topel@intel.com \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=hawk@kernel.org \
--cc=john.fastabend@gmail.com \
--cc=kafai@fb.com \
--cc=maximmi@mellanox.com \
--cc=netdev@vger.kernel.org \
--cc=saeedm@mellanox.com \
--cc=songliubraving@fb.com \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).