From: Jakub Kicinski <kuba@kernel.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: "Ömer Mete Kaya" <omermetekaya0@gmail.com>,
oneukum@suse.com,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
netdev@vger.kernel.org, andrew+netdev@lunn.ch,
davem@davemloft.net, edumazet@google.com, pabeni@redhat.com,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
david.laight.linux@gmail.com,
syzbot+04cd90bb99c6ef81a65d@syzkaller.appspotmail.com
Subject: Re: [PATCH net v6] usbnet: fix smp_processor_id() use in preemptible context
Date: Thu, 8 Oct 2026 09:43:38 -0700 [thread overview]
Message-ID: <20261008094338.301a75fa@kernel.org> (raw)
In-Reply-To: <7c4a2f1c-f16d-479b-a11f-cef962d5e2c7@rowland.harvard.edu>
On Thu, 8 Oct 2026 10:16:02 -0400 Alan Stern wrote:
> > This looks odd, how did we miss this for 8 years.
> >
> > Greg is probably busy, but would be good to get a confirmation
> > from either him or some other USB expert that the callbacks
> > can indeed be called in process context.
>
> They can be called in BH context with interrupts enabled. Is that close
> enough?
BH should be fine on !RT. The patch, AFAIU, is because vhci calls
the completion callbacks in pure, unadulterated process context.
I'm trying to figure out how urgent the fix is, basically.
If it's a vhci bug then the usbnet fix is at most an RT problem.
Also if vhci is doing something wrong we don't want a truckload
of slop patches sent our way to fix 300 drivers :S
next prev parent reply other threads:[~2026-10-08 16:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-04 21:59 Ömer Mete Kaya
2026-10-08 3:00 ` Jakub Kicinski
2026-10-08 14:16 ` Alan Stern
2026-10-08 16:43 ` Jakub Kicinski [this message]
2026-10-08 18:03 ` Alan Stern
2026-10-09 11:31 ` Greg Kroah-Hartman
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