Re: [PATCH] tcp: check socket state before calling WARN_ON

[Eric Dumazet]

On Fri, Dec 6, 2024 at 6:50 AM Youngmin Nam <youngmin.nam@xxxxxxxxxxx> wrote:
>
> On Wed, Dec 04, 2024 at 08:13:33AM +0100, Eric Dumazet wrote:
> > On Wed, Dec 4, 2024 at 4:35 AM Youngmin Nam <youngmin.nam@xxxxxxxxxxx> wrote:
> > >
> > > On Tue, Dec 03, 2024 at 06:18:39PM -0800, Jakub Kicinski wrote:
> > > > On Tue, 3 Dec 2024 10:34:46 -0500 Neal Cardwell wrote:
> > > > > > I have not seen these warnings firing. Neal, have you seen this in the past ?
> > > > >
> > > > > I can't recall seeing these warnings over the past 5 years or so, and
> > > > > (from checking our monitoring) they don't seem to be firing in our
> > > > > fleet recently.
> > > >
> > > > FWIW I see this at Meta on 5.12 kernels, but nothing since.
> > > > Could be that one of our workloads is pinned to 5.12.
> > > > Youngmin, what's the newest kernel you can repro this on?
> > > >
> > > Hi Jakub.
> > > Thank you for taking an interest in this issue.
> > >
> > > We've seen this issue since 5.15 kernel.
> > > Now, we can see this on 6.6 kernel which is the newest kernel we are running.
> >
> > The fact that we are processing ACK packets after the write queue has
> > been purged would be a serious bug.
> >
> > Thus the WARN() makes sense to us.
> >
> > It would be easy to build a packetdrill test. Please do so, then we
> > can fix the root cause.
> >
> > Thank you !
> >
>
> Hi Eric.
>
> Unfortunately, we are not familiar with the Packetdrill test.
> Refering to the official website on Github, I tried to install it on my device.
>
> Here is what I did on my local machine.
>
> $ mkdir packetdrill
> $ cd packetdrill
> $ git clone https://github.com/google/packetdrill.git .
> $ cd gtests/net/packetdrill/
> $./configure
> $ make CC=/home/youngmin/Downloads/arm-gnu-toolchain-13.3.rel1-x86_64-aarch64-none-linux-gnu/bin/aarch64-none-linux-gnu-gcc
>
> $ adb root
> $ adb push packetdrill /data/
> $ adb shell
>
> And here is what I did on my device
>
> erd9955:/data/packetdrill/gtests/net # ./packetdrill/run_all.py -S -v -L -l tcp/
> /system/bin/sh: ./packetdrill/run_all.py: No such file or directory
>
> I'm not sure if this procedure is correct.
> Could you help us run the Packetdrill on an Android device ?

packetdrill can run anywhere, for instance on your laptop, no need to
compile / install it on Android

Then you can run single test like

# packetdrill gtests/net/tcp/sack/sack-route-refresh-ip-tos.pkt