netdev - Re: [PATCH net-next v3 1/4] net: stmmac: Switch to zero-copy in non-XDP RX path

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: <20250124003501.5fff00bc@orangepi5-plus>
Date: Fri, 24 Jan 2025 00:35:01 +0800
From: Furong Xu <0x1207@...il.com>
To: Jon Hunter <jonathanh@...dia.com>
Cc: netdev@...r.kernel.org, linux-stm32@...md-mailman.stormreply.com,
 linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
 Alexander Lobakin <aleksander.lobakin@...el.com>, Joe Damato
 <jdamato@...tly.com>, Andrew Lunn <andrew+netdev@...n.ch>, "David S.
 Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub
 Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Maxime
 Coquelin <mcoquelin.stm32@...il.com>, xfr@...look.com, Brad Griffis
 <bgriffis@...dia.com>, "linux-tegra@...r.kernel.org"
 <linux-tegra@...r.kernel.org>
Subject: Re: [PATCH net-next v3 1/4] net: stmmac: Switch to zero-copy in
 non-XDP RX path

Hi Jon,

On Thu, 23 Jan 2025 14:06:42 +0000, Jon Hunter wrote: 
> We have noticed a boot regression on -next when booting with NFS.
> Bisect is pointing to this commit and reverting this on top of -next
> does fix the problem.
> 
> I only see this on Tegra234 which uses the 
> drivers/net/ethernet/stmicro/stmmac/dwmac-tegra.c driver. Tegra194
> which uses the
> drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c driver
> appears to be fine.

What is the MTU of Tegra234 and NFS server? Are they both 1500?

Could you please try attached patch to confirm if this regression is
fixed?

If the attached patch fixes this regression, and so it seems to be a
cache coherence issue specific to Tegra234, since this patch avoid
memcpy and the page buffers may be modified by upper network stack of
course, then cache lines of page buffers may become dirty. But by
reverting this patch, cache lines of page buffers never become dirty,
this is the core difference.

View attachment "force-disable-rx-checksum.diff" of type "text/x-patch" (745 bytes)