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From:   Florian Weimer <fw@deneb.enyo.de>
To:     Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc:     Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Michael Kerrisk <mtk.manpages@gmail.com>,
        libc-alpha <libc-alpha@sourceware.org>,
        carlos <carlos@redhat.com>, Rich Felker <dalias@libc.org>,
        linux-api <linux-api@vger.kernel.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        Will Deacon <will.deacon@arm.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Ben Maurer <bmaurer@fb.com>, Dave Watson <davejwatson@fb.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Paul <paulmck@linux.vnet.ibm.com>, Paul Turner <pjt@google.com>,
        Joseph Myers <joseph@codesourcery.com>
Subject: Re: [PATCH glibc 5/9] glibc: Perform rseq(2) registration at C startup and thread creation (v17)
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Date:   Wed, 29 Apr 2020 10:18:08 +0200
In-Reply-To: <20200429081606.GP29015@arm.com> (Szabolcs Nagy's message of
        "Wed, 29 Apr 2020 09:16:09 +0100")
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* Szabolcs Nagy:

> The 04/28/2020 10:58, Mathieu Desnoyers wrote:
>> ----- On Apr 28, 2020, at 8:54 AM, Florian Weimer fw@deneb.enyo.de wrote:
>> > That one definitely should work.
>> > 
>> > I expect you might see this if libgcc_s.so.1 is installed into a
>> > multiarch subdirectory that upstream glibc does not search.  (The
>> > Debian patches are unfortunately not upstream.)
>> 
>> My test environment is a Ubuntu 18.04.1 LTS.
>> 
>> > 
>> > I think on my system, the built glibc can find the system libgcc_s via
>> > /etc/ld.so.cache, so I haven't seen this issue yet.
>> 
>> On my system, libgcc_s is provided here:
>> 
>> /lib/x86_64-linux-gnu/libgcc_s.so.1
>> 
>> by this package:
>> 
>> Package: libgcc1
>> Architecture: amd64
>> Version: 1:8.4.0-1ubuntu1~18.04
>
> before running the tests
>
> cp `$CC --print-file-name libgcc_s.so.1` glibc/build/dir
> cp `$CC --print-file-name libstdc++.so.6` glibc/build/dir
>
> so those toolchain libs are in the search path
> of the newly built libc when running tests.

Do you actually see the need for these steps yourself?

I guess the correct fix would be to upstream the Debian multiarch
changes and activate them automatically with a configure check on
systems that use multiarch paths.