Date:   Mon, 23 Jan 2023 11:12:38 -0800
From:   "Paul E. McKenney" <paulmck@kernel.org>
To:     Ammar Faizi <ammarfaizi2@gnuweeb.org>
Cc:     Willy Tarreau <w@1wt.eu>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Shuah Khan <shuah@kernel.org>,
        Linux Kselftest Mailing List 
        <linux-kselftest@vger.kernel.org>
Subject: Re: [PATCH 0/2] selftests/nolibc: small simplification of test
 development phase
Message-ID: <20230123191238.GX2948950@paulmck-ThinkPad-P17-Gen-1>
Reply-To: paulmck@kernel.org
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On Tue, Jan 24, 2023 at 02:01:50AM +0700, Ammar Faizi wrote:
> On Mon, Jan 23, 2023 at 09:40:03AM -0800, Paul E. McKenney wrote: 
> > I looked for that, but didn't find it, so thank you!
> > 
> > (Yes, I should have used dpkg, but I was lazy.)
> > 
> > Except that when I install Ubuntu 20.04's version, I get this:
> > 
> > ------------------------------------------------------------------------
> > 
> > $ sudo make run-user
> >   MKDIR   sysroot/x86/include
> > make[1]: Entering directory '/home/git/linux-rcu/tools/include/nolibc'
> > make[2]: Entering directory '/home/git/linux-rcu'
> > make[2]: Leaving directory '/home/git/linux-rcu'
> > make[2]: Entering directory '/home/git/linux-rcu'
> >   INSTALL /home/git/linux-rcu/tools/testing/selftests/nolibc/sysroot/sysroot/include
> > make[2]: Leaving directory '/home/git/linux-rcu'
> > make[1]: Leaving directory '/home/git/linux-rcu/tools/include/nolibc'
> >   CC      nolibc-test
> > 32 gettimeofday_null = -1 EFAULT        [FAIL]
> > See all results in /home/git/linux-rcu/tools/testing/selftests/nolibc/run.out
> > 
> > ------------------------------------------------------------------------
> > 
> > I have attached run.out.
> > 
> > In contrast, with my hand-built qemu-x86_64, all tests passed.
> > 
> > This might be just a version-related bug, but figured I should let you
> > guys know.
> 
> This is an interesting bug.
> 
> I'm a bit reluctant to say that this is a qemu bug. But I can't
> reproduce it on my machine. I use qemu that comes from Ubuntu 22.04.
> 
> FWIW, my qemu version is:
> 
>    $ qemu-x86_64 -version
>    qemu-x86_64 version 6.2.0 (Debian 1:6.2+dfsg-2ubuntu6.6)
>    Copyright (c) 2003-2021 Fabrice Bellard and the QEMU Project developers
> 
> I'll take a look at that gettimeofday() code and see if we have a bug in
> it. In meantime, could you send your qemu version info?

Thank you for looking into this, and here you go:

    $ qemu-x86_64 -version
    qemu-x86_64 version 4.2.1 (Debian 1:4.2-3ubuntu6.24)
    Copyright (c) 2003-2019 Fabrice Bellard and the QEMU Project developers

The version that I built by hand (which passed all tests) is as follows:

    $ /home/git/qemu/build/qemu-x86_64 -version
    qemu-x86_64 version 7.2.0 (v7.2.0)
    Copyright (c) 2003-2022 Fabrice Bellard and the QEMU Project developers

							Thanx, Paul