From: Jakub Kicinski <kuba@kernel.org>
To: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Cc: Alexander Lobakin <aleksander.lobakin@intel.com>,
Jesper Dangaard Brouer <hawk@kernel.org>, <bpf@vger.kernel.org>,
<ast@kernel.org>, <daniel@iogearbox.net>,
<ilias.apalodimas@linaro.org>, <toke@redhat.com>,
<lorenzo@kernel.org>, <netdev@vger.kernel.org>,
<magnus.karlsson@intel.com>, <andrii@kernel.org>,
<stfomichev@gmail.com>,
<syzbot+ff145014d6b0ce64a173@syzkaller.appspotmail.com>,
Ihor Solodrai <ihor.solodrai@linux.dev>,
Octavian Purdila <tavip@google.com>
Subject: Re: [PATCH v2 bpf 1/2] xdp: update xdp_rxq_info's mem type in XDP generic hook
Date: Tue, 21 Oct 2025 18:01:36 -0700 [thread overview]
Message-ID: <20251021180136.39431ed3@kernel.org> (raw)
In-Reply-To: <aPZ3FvcIVOPVxQum@boxer>
On Mon, 20 Oct 2025 19:53:26 +0200 Maciej Fijalkowski wrote:
> > > The SKB should be marked via skb->pp_recycle, but I guess you are trying
> > > to catch code that doesn't set this correctly?
> > > (Slightly worried this will "paper-over" some other buggy code?)
> > >
> > >> + xdp->rxq->mem.type = page_pool_page_is_pp(virt_to_page(xdp->data)) ?
> >
> > BTW this may return incorrect results if the page is not order-0.
> > IIRC system PPs always return order-0 pages, what about veth code etc?
>
> veth's pp works on order-0 pages well, however I agree it would be better
> to use virt_to_head_page() here.
In this case the mem.type update is for consuming frags only, right?
We can't free the head itself since the skb is attached to it.
So running the predicates on xdp->data is probably wrong.
Is it possible to get to bpf_prog_run_generic_xdp() (with frags)
and without going thru netif_skb_check_for_xdp() ? If no then
frags must have come from skb_pp_cow().
And the type is always MEM_TYPE_PAGE_POOL ?
next prev parent reply other threads:[~2025-10-22 1:01 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-17 14:31 [PATCH v2 bpf 0/2] xdp: fix page_pool leaks Maciej Fijalkowski
2025-10-17 14:31 ` [PATCH v2 bpf 1/2] xdp: update xdp_rxq_info's mem type in XDP generic hook Maciej Fijalkowski
2025-10-17 16:45 ` Toke Høiland-Jørgensen
2025-10-20 11:20 ` Jesper Dangaard Brouer
2025-10-20 15:36 ` Alexander Lobakin
2025-10-20 17:53 ` Maciej Fijalkowski
2025-10-22 1:01 ` Jakub Kicinski [this message]
2025-10-22 11:22 ` Maciej Fijalkowski
2025-10-22 14:04 ` Jakub Kicinski
2025-10-17 14:31 ` [PATCH v2 bpf 2/2] veth: update mem type in xdp_buff Maciej Fijalkowski
2025-10-17 16:33 ` Toke Høiland-Jørgensen
2025-10-17 16:52 ` Maciej Fijalkowski
2025-10-17 17:51 ` Toke Høiland-Jørgensen
2025-10-17 18:12 ` Toke Høiland-Jørgensen
2025-10-17 20:08 ` Maciej Fijalkowski
2025-10-20 10:25 ` Toke Høiland-Jørgensen
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