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From: "Venkataramanan, Anirudh" <anirudh.venkataramanan@intel.com>
To: "kuba@kernel.org" <kuba@kernel.org>,
	"Nguyen, Anthony L" <anthony.l.nguyen@intel.com>
Cc: "davem@davemloft.net" <davem@davemloft.net>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"Jankowski, Konrad0" <konrad0.jankowski@intel.com>
Subject: Re: [PATCH net 2/4] ice: Stop processing VF messages during teardown
Date: Tue, 10 Aug 2021 17:42:03 +0000	[thread overview]
Message-ID: <8568eb9755224d5062337ab67f8a7a709ac2f2d8.camel@intel.com> (raw)
In-Reply-To: <20210809155838.208796aa@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>

On Mon, 2021-08-09 at 15:58 -0700, Jakub Kicinski wrote:
> On Mon,  9 Aug 2021 10:14:00 -0700 Tony Nguyen wrote:
> > When VFs are setup and torn down in quick succession, it is
> > possible
> > that a VF is torn down by the PF while the VF's virtchnl requests
> > are
> > still in the PF's mailbox ring. Processing the VF's virtchnl
> > request
> > when the VF itself doesn't exist results in undefined behavior. Fix
> > this by adding a check to stop processing virtchnl requests when VF
> > teardown is in progress.
> 
> What is "undefined behavior" in this context? Please improve the
> commit
> message. It should describe misbehavior visible to the user, failing
> that what will happen from kernel/device perspective. Or state that
> it's
> just a "fix" to align with some internal driver <> firmware spec...

Three different call traces were reported, and that's the reason I
chose to say "undefined behavior" which I suppose isn't very helpful.
Will update the commit message to include more details.

Ani


  reply	other threads:[~2021-08-10 17:50 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-09 17:13 [PATCH net 0/4][pull request] Intel Wired LAN Driver Updates 2021-08-09 Tony Nguyen
2021-08-09 17:13 ` [PATCH net 1/4] ice: Prevent probing virtual functions Tony Nguyen
2021-08-09 22:56   ` Jakub Kicinski
2021-08-09 17:14 ` [PATCH net 2/4] ice: Stop processing VF messages during teardown Tony Nguyen
2021-08-09 22:58   ` Jakub Kicinski
2021-08-10 17:42     ` Venkataramanan, Anirudh [this message]
2021-08-10 14:30   ` Jonathan Toppins
2021-08-09 17:14 ` [PATCH net 3/4] ice: don't remove netdev->dev_addr from uc sync list Tony Nguyen
2021-08-10 14:29   ` Jonathan Toppins
2021-08-09 17:14 ` [PATCH net 4/4] iavf: Set RSS LUT and key in reset handle path Tony Nguyen

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