From: Bruno Haible <bruno@clisp.org>
To: bug-gnulib@gnu.org
Cc: Florian Weimer <fweimer@redhat.com>,
libc-alpha@sourceware.org, binutils@sourceware.org
Subject: Re: Undefined use of weak symbols in gnulib
Date: Wed, 28 Apr 2021 01:47:10 +0200 [thread overview]
Message-ID: <19516512.8WduG5kV5J@omega> (raw)
In-Reply-To: <87o8e0p92r.fsf@oldenburg.str.redhat.com>
Hi Florian,
> This will become an urgent issue with glibc 2.34
Thank you for the early heads-up.
I would like to understand the scope and the severity of the issue.
You write:
> Dynamic linking with weak symbols is not very well-defined. ...
> the code will crash if pthread_mutexattr_gettype is ever defined.
In which situations will it crash?
(a) when the code is in an executable, that gets linked with '-lpthread'
and that does not use dlopen()?
(b) when the code is in an executable, that gets linked WITHOUT
'-lpthread' and that does not use dlopen()?
(c) when the code is in an executable, that gets linked WITHOUT
'-lpthread' and that does a dlopen("libpthread.so.X")?
Under which conditions will it crash?
($) when the executable was built before glibc 2.34 and is run
with glibc 2.34 ?
(%) when the executable is built against glibc 2.34 and is run
with glibc 2.34 ?
And if it crashes, will setting the environment variable LD_DYNAMIC_WEAK [1]
avoid the crash?
Bruno
[1] https://sourceware.org/legacy-ml/libc-hacker/2000-06/msg00029.html
next prev parent reply other threads:[~2021-04-27 23:47 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-27 5:53 Undefined use of weak symbols in gnulib Florian Weimer
2021-04-27 6:50 ` Paul Eggert
2021-04-27 6:58 ` Florian Weimer
2021-04-27 7:13 ` Paul Eggert
2021-04-27 7:24 ` Andreas Schwab
2021-04-27 11:06 ` Florian Weimer
2021-04-28 0:09 ` Bruno Haible
2021-04-28 2:10 ` H.J. Lu
2021-04-28 2:13 ` H.J. Lu
2021-05-05 20:31 ` Fangrui Song
2021-04-28 8:35 ` Florian Weimer
2021-04-28 13:15 ` Michael Matz
2021-04-28 7:44 ` Florian Weimer
2021-04-28 14:48 ` Bruno Haible
2021-04-28 17:44 ` Florian Weimer
2021-07-17 14:38 ` Bruno Haible
2021-07-17 14:55 ` Florian Weimer
2021-07-17 16:39 ` Bruno Haible
2021-07-27 20:02 ` Joseph Myers
2021-07-27 20:19 ` Florian Weimer
2021-07-27 23:38 ` Paul Eggert
2021-07-17 16:21 ` Bruno Haible
2021-04-27 23:22 ` Bruno Haible
2021-04-27 23:47 ` Bruno Haible [this message]
2021-04-28 7:57 ` Florian Weimer
2021-04-28 14:40 ` Bruno Haible
2021-04-28 17:43 ` Florian Weimer
2021-04-29 15:15 ` Bruno Haible
2021-04-30 9:55 ` Florian Weimer
2021-04-29 6:33 ` Ben Pfaff
2021-05-03 1:44 ` Alan Modra
2021-07-12 10:04 ` Michael Hudson-Doyle
2021-07-12 15:03 ` Florian Weimer
2021-07-12 15:30 ` Matthias Klose
2021-07-12 15:37 ` Florian Weimer
2021-07-13 0:22 ` Michael Hudson-Doyle
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