linux-kernel - Re: [PATCH] UML: don't discard .text.exit section

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Message-ID: <e9536af2-7e69-8a53-96d0-7a7a92dbea31@nod.at>
Date:   Fri, 19 Aug 2016 13:16:53 +0200
From:   Richard Weinberger <richard@....at>
To:     Andrey Ryabinin <aryabinin@...tuozzo.com>,
        Dmitry Vyukov <dvyukov@...gle.com>
Cc:     Jeff Dike <jdike@...toit.com>,
        user-mode-linux-devel <user-mode-linux-devel@...ts.sourceforge.net>,
        LKML <linux-kernel@...r.kernel.org>,
        Stefan Traby <stefan@...lo-penguin.com>,
        stable <stable@...r.kernel.org>
Subject: Re: [PATCH] UML: don't discard .text.exit section

On 19.08.2016 12:48, Andrey Ryabinin wrote:
> On 08/19/2016 03:14 AM, Dmitry Vyukov wrote:
>> On Thu, Aug 18, 2016 at 3:08 AM, Andrey Ryabinin
>> <aryabinin@...tuozzo.com> wrote:
>>>
>>>>
>>>> Sorry for delays, I am travelling.
>>>> Do we need ".fini_array" section? It's also destructors that we don't
>>>> run. Or does UML use them? Does discarding ".fini_array" help?
>>>>
>>>
>>> libc has desctructors and use them for whatever purpose it needs.
>>
>>
>> Does UML actually gracefully exit running global destructors? That
>> would also require gracefully shutting down all threads/cpus. Doesn't
>> it just _exit (or syscall(SYS_exit_group))?
>>
> 
> Sigh, I dunno, I didn't look that far. My intention was to fix build and keep old behavior unaffected.
> If you want to wipe destructors, and think that this is ok, go ahead.

UML exits like any regular C program does.
The main() function is in arch/um/os-Linux/main.c, when the kernel terminates,
hence linux_main() returns back to main() it just returns the exit code.
At this point libc's destructors will run, right?

Thanks,
//richard