Re: [PATCH 1/1] um: fix error return code in winch_tramp()

From: Nathan Chancellor <nathan@kernel.org>
To: Richard Weinberger <richard@nod.at>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>,
	Zhen Lei <thunder.leizhen@huawei.com>,
	Jeff Dike <jdike@addtoit.com>,
	anton ivanov <anton.ivanov@cambridgegreys.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Eduard-Gabriel Munteanu <maxdamage@aladin.ro>,
	linux-um <linux-um@lists.infradead.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	regressions@lists.linux.dev
Subject: Re: [PATCH 1/1] um: fix error return code in winch_tramp()
Date: Mon, 11 Apr 2022 10:48:36 -0700	[thread overview]
Message-ID: <YlRp9KR1mp3/4Txo@thelio-3990X> (raw)
In-Reply-To: <1087614384.239493.1649583213699.JavaMail.zimbra@nod.at>

Hi Richard,

On Sun, Apr 10, 2022 at 11:33:33AM +0200, Richard Weinberger wrote:
> ----- Ursprüngliche Mail -----
> > Von: "Thorsten Leemhuis" <regressions@leemhuis.info>
> > Hi, this is your Linux kernel regression tracker. Top-posting for once,
> > to make this easily accessible to everyone.
> > 
> > Zhen Lei, Richard, what's up here? Below regression report is more than
> > two weeks old now and afaics didn't even get a single reply.
> 
> Sorry, but UML is leisure pursuit, so I can only work on it when my
> schedule permits it.

No worries, it is easy enough to work around for our use case.

> > Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
> > 
> > P.S.: As the Linux kernel's regression tracker I'm getting a lot of
> > reports on my table. I can only look briefly into most of them and lack
> > knowledge about most of the areas they concern. I thus unfortunately
> > will sometimes get things wrong or miss something important. I hope
> > that's not the case here; if you think it is, don't hesitate to tell me
> > in a public reply, it's in everyone's interest to set the public record
> > straight.
> > 
> > 
> > 
> > On 23.03.22 20:41, Nathan Chancellor wrote:
> 
> [...]
> 
> >> in case it helps. I am happy to provide more information or test patches
> >> as necessary.
> 
> Nathan, can you provide me the error code from os_set_fd_block()?
> My best guess is that setting the fd is optional here and UML does
> not expect failure here.

I attempted to print out the error code but it seems like there is no
output in the console after "reboot: System halted". If I add an
unconditional print right before the call to os_set_fd_block(), I see it
during start up but I do not see it during shutdown. Is there some way
to see that console output during shutdown?

Cheers,
Nathan