From: Nat! <nat@mulle-kybernetik.com>
To: libc-help@sourceware.org
Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Subject: Re: Problem with atexit and _dl_fini
Date: Mon, 10 Jun 2019 13:08:00 -0000 [thread overview]
Message-ID: <9497a5c2-0dc8-18fe-6120-deb551f7ddd8@mulle-kybernetik.com> (raw)
In-Reply-To: <cd53d1e5-530c-b327-9e79-69b02c3b701e@linaro.org>
On 10.06.19 13:48, Adhemerval Zanella wrote:
>
> On 09/06/2019 17:59, Nat! wrote:
>> Another datapoint to support my claim that _dl-fini breaks atexit. This time its very easy to reproduce ;)
>>
>> Here 's the README.md from the Github Repo https://github.com/mulle-nat/atexit-breakage-linux
>>
>>
>> ```
>>
>> # Shows another breakage involving `atexit` on linux
>>
>> Here the `atexit` callback is invoked mistakenly multiple times.
> This 'example' does not really show the issue because ldd script issues
> the loader multiple times, see below. You can check exactly what ldd is
> doing by calling with sh -x.
I agree it doesn't show the same issue, but it shows that something else
is going very wrong. :) Or are you happy, that atexit is called multiple
times ? Who's calling exit here anyway ? Check out the debugger output
too (see updated README.md)
>
> I will try to use your instruction to run on docker to see what exactly
> is happening in your environment.
That's not necessary anymore. I managed to make it reproducible in a
much simpler form just now.
The ld-so-breakage project is basically a recreation of the original
"docker" scenario written from scratch. I try to explain in the README ,
what is going on. But if there are questions hit me up (maybe as an
issue ?) :
   https://github.com/mulle-nat/ld-so-breakage
The "another datapoint" project shows how constructor/destructor don't
pair up:
   https://github.com/mulle-nat/atexit-breakage-linux
And as a random bonus this project indicates to me that LD_PRELOAD
doesn't do what its supposed to either:
   https://github.com/mulle-nat/LD_PRELOAD-breakage-linux
In total I think the state of affairs is pretty dismal. I didn't expect
that much basic stuff not working on linux. With hindsight, I probably
have wasted _weeks_ on these problems.
I still maintain that the concept to let `atexit` callbacks not run by
`exit` is broken. An `atexit` callback is not the same as an
`__attribute__((destructor))__`.
Ciao
  Nat!
next prev parent reply other threads:[~2019-06-10 13:08 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-18 21:23 Nat!
2019-05-19 16:23 ` Florian Weimer
2019-05-19 19:37 ` Nat!
2019-05-21 20:43 ` Adhemerval Zanella
2019-05-22 10:22 ` Nat!
2019-05-22 15:01 ` Adhemerval Zanella
2019-05-22 15:29 ` Nat!
2019-05-22 19:35 ` Adhemerval Zanella
2019-05-29 21:16 ` Nat!
2019-06-09 20:59 ` Nat!
2019-06-10 11:48 ` Adhemerval Zanella
2019-06-10 13:08 ` Nat! [this message]
2019-06-10 20:27 ` Adhemerval Zanella
2019-06-11 18:39 ` Adhemerval Zanella
2019-06-11 20:20 ` Nat!
2019-06-11 22:40 ` Nat!
2019-06-12 3:41 ` Carlos O'Donell
2019-06-13 22:53 ` Nat!
2019-06-14 12:29 ` Manfred
2019-06-14 15:14 ` Adhemerval Zanella
2019-06-11 18:53 ` Nat!
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