From: Szabolcs Nagy <szabolcs.nagy@arm.com>
To: Florian Weimer <fweimer@redhat.com>,
Carlos O'Donell <codonell@redhat.com>
Cc: nd@arm.com, GNU C Library <libc-alpha@sourceware.org>
Subject: Re: [PATCH] Reserve static TLS for dynamically loaded initial-exec TLS only [BZ #25051]
Date: Thu, 27 Feb 2020 16:21:17 +0000 [thread overview]
Message-ID: <d2d07b0f-7be4-630c-a2ac-2f3f680b79ae@arm.com> (raw)
In-Reply-To: <87d0a8hzbi.fsf@oldenburg2.str.redhat.com>
On 21/02/2020 12:58, Florian Weimer wrote:
> * Carlos O'Donell:
>
>> On 2/17/20 11:01 AM, Florian Weimer wrote:
>>> * Carlos O'Donell:
>>>
>>>> Let me take a stab at this:
>>>>
>>>> (1) File a bug to indicate all libraries must stop using
>>>> TLS IE to fix dlmopen issues with TLS IE.
>>>
>>> Do you mean glibc components, or do you view this as a distribution-wide
>>> change?
>>
>> All glibc libraries should stop using TLS IE and we should file bugs for
>> fixing these instances where TLS IE was used to work around startup ordering
>> problems.
>
> This has performance implications, in particular for malloc.
> I'll try to get some numbers.
it has correctness implications too, e.g. in case of
errno or soft-float fenv emulation (ppc only?) tls
access may happen in signal handlers and i think
currently only initial (and local) exec tls is
guaranteed to be as-safe.
libc also has struct pthread, i wonder if any of that
needs to be duplicated for dlmopen (is it valid to
dlmopen a different version of libc.so.6 ?)
next prev parent reply other threads:[~2020-02-27 16:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-07 11:54 [PATCH] Reserve static TLS for dynamically loaded initial-exec TLS only [BZ #25051] Szabolcs Nagy
2020-01-07 12:09 ` Florian Weimer
2020-01-07 12:50 ` Szabolcs Nagy
2020-02-13 16:38 ` Szabolcs Nagy
2020-02-13 18:07 ` Carlos O'Donell
2020-02-17 16:01 ` Florian Weimer
2020-02-20 15:05 ` Carlos O'Donell
2020-02-21 12:58 ` Florian Weimer
2020-02-27 16:21 ` Szabolcs Nagy [this message]
2020-02-27 16:31 ` Florian Weimer
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