[lxc-devel] [PATCH] remove static_lock()/static_unlock() and start to use thread local storage (v2)

[Stéphane Graber]

On Mon, Dec 23, 2013 at 09:25:55AM -0600, Serge Hallyn wrote:
> Quoting Andrey Mazo (mazo at telum.ru):
> > Hi all,
> > 
> > Sorry for coming too late to the discussion.
> > In fact, I've already acked [1] the changeset.
> > But after sleeping more on it, I'm concerned about __thread and bionic.
> > Quoting android-ndk-r9c/docs/text/system/libc/OVERVIEW.text:
> >   At the moment, thread-local storage defined through the __thread compiler
> >   keyword is not supported by the Bionic C library and dynamic linker.
> > 
> > The same OVERVIEW.TXT was present until recently in bionic sources [2].
> > Moreover, grepping (today's git HEAD) bionic sources for __thread, PT_TLS (thread-local storage segment), .tbss and .tdata section names shows nothing.
> > So, while utils.c compiles fine (due to GNU gcc/binutils support for __thread), lxc-* will likely segfault on the first access to the "values" array (because of missing memory segment due to bionic dynamic loader's lack of __thread support).
> > I suppose, we could allocate a TLS slot for "values" pointer via pthread_key_create() and set it to a per-thread malloc()'ed memory chunk via pthread_setspecific(). (this seems to be quite verbose though)
> 
> Stéphane, have you run lxc with this patch on android without
> passing -P (which should get the lxcpath from default values)?

I'm unfortunately 7000km away from my LXC on Android hardware and will
only be able to test it on the 3rd of January.

-- 
Stéphane Graber
Ubuntu developer
http://www.ubuntu.com
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