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Date:   Mon, 8 Feb 2021 13:55:35 -0500
From:   Sasha Levin <sashal@kernel.org>
To:     Johannes Berg <johannes@sipsolutions.net>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>,
        Peter Oberparleiter <oberpar@linux.ibm.com>,
        Arnd Bergmann <arnd@arndb.de>, Jessica Yu <jeyu@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH AUTOSEL 4.9 4/4] init/gcov: allow CONFIG_CONSTRUCTORS on
 UML to fix module gcov
Message-ID: <20210208185535.GB4035784@sasha-vm>
References: <20210208180000.2092497-1-sashal@kernel.org>
 <20210208180000.2092497-4-sashal@kernel.org>
 <69e7fbb93740c0116c358a2f40aadb2dbde702fe.camel@sipsolutions.net>
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On Mon, Feb 08, 2021 at 07:25:21PM +0100, Johannes Berg wrote:
>On Mon, 2021-02-08 at 18:00 +0000, Sasha Levin wrote:
>> From: Johannes Berg <johannes.berg@intel.com>
>>
>> [ Upstream commit 55b6f763d8bcb5546997933105d66d3e6b080e6a ]
>>
>> On ARCH=um, loading a module doesn't result in its constructors getting
>> called, which breaks module gcov since the debugfs files are never
>> registered.  On the other hand, in-kernel constructors have already been
>> called by the dynamic linker, so we can't call them again.
>>
>> Get out of this conundrum by allowing CONFIG_CONSTRUCTORS to be
>> selected, but avoiding the in-kernel constructor calls.
>>
>> Also remove the "if !UML" from GCOV selecting CONSTRUCTORS now, since we
>> really do want CONSTRUCTORS, just not kernel binary ones.
>>
>> Link: https://lkml.kernel.org/r/20210120172041.c246a2cac2fb.I1358f584b76f1898373adfed77f4462c8705b736@changeid
>>
>
>
>While I don't really *object* to this getting backported, it's also a
>(development) corner case that somebody wants gcov and modules in
>ARCH=um ... I'd probably not backport this.

I'll drop it then, thanks!

-- 
Thanks,
Sasha