[Buildroot] [PATCH] package/mono: fix undefined reference to tls

[Buildroot] [PATCH] package/mono: fix undefined reference to tls

[Angelo Compagnucci]

This commit fixes the nasty undefined reference to tls bug experienced with musl.

Fixes:
http://autobuild.buildroot.net/results/048f04488cb8c7f4c32b828aa5214ebc22ba0153
Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
---
 package/mono/mono.mk | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/package/mono/mono.mk b/package/mono/mono.mk
index 3d0b9bc..de4f16b 100644
--- a/package/mono/mono.mk
+++ b/package/mono/mono.mk
@@ -26,6 +26,10 @@ MONO_CONF_OPTS = --disable-gtk-doc \
 	--disable-mcs-build \
 	--enable-static
 
+ifeq ($(BR2_TOOLCHAIN_USES_MUSL),y)
+MONO_CONF_OPTS += --with-tls=pthread
+endif
+
 # The libraries have been built by the host-mono build. Since they are
 # architecture-independent, we simply copy them to the target.
 define MONO_INSTALL_LIBS
-- 
1.9.1

[Buildroot] [PATCH] package/mono: fix undefined reference to tls

[Thomas Petazzoni]

Hello,

Thanks for investigating this issue!

On Thu,  8 Sep 2016 10:51:07 +0200, Angelo Compagnucci wrote:
> This commit fixes the nasty undefined reference to tls bug experienced with musl.
> 
> Fixes:
> http://autobuild.buildroot.net/results/048f04488cb8c7f4c32b828aa5214ebc22ba0153
> Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
> ---
>  package/mono/mono.mk | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/package/mono/mono.mk b/package/mono/mono.mk
> index 3d0b9bc..de4f16b 100644
> --- a/package/mono/mono.mk
> +++ b/package/mono/mono.mk
> @@ -26,6 +26,10 @@ MONO_CONF_OPTS = --disable-gtk-doc \
>  	--disable-mcs-build \
>  	--enable-static
>  
> +ifeq ($(BR2_TOOLCHAIN_USES_MUSL),y)
> +MONO_CONF_OPTS += --with-tls=pthread
> +endif

Hum, that's interesting. Do you have more details about what this
--with-tls option is doing?

Is --with-tls related to Thread Local Storage provided by the compiler ?

Indeed, TLS support in gcc was disabled for musl toolchains until
recently (i.e until commit
https://git.buildroot.org/buildroot/commit/package/gcc?id=1bd02bc230e1b3b22ca3eb23fb3dcb91b878283a).

Since the toolchain that was causing the build failure was built
*prior* to this commit, maybe this commit fixes the issue, as it would
make musl toolchains have TLS support enabled in gcc.

Could you test this using the internal toolchain backend, and see if
without your fix the problem isn't already fixed? If that's the case,
I'll simply rebuild the pre-built toolchains.

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[Buildroot] [PATCH] package/mono: fix undefined reference to tls

[Angelo Compagnucci]

Hello Thomas,

2016-09-08 13:42 GMT+02:00 Thomas Petazzoni <
thomas.petazzoni@free-electrons.com>:

> Hello,
>
> Thanks for investigating this issue!
>
> On Thu,  8 Sep 2016 10:51:07 +0200, Angelo Compagnucci wrote:
> > This commit fixes the nasty undefined reference to tls bug experienced
> with musl.
> >
> > Fixes:
> > http://autobuild.buildroot.net/results/048f04488cb8c7f4c32b828aa5214e
> bc22ba0153
> > Signed-off-by: Angelo Compagnucci <angelo.compagnucci@gmail.com>
> > ---
> >  package/mono/mono.mk | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/package/mono/mono.mk b/package/mono/mono.mk
> > index 3d0b9bc..de4f16b 100644
> > --- a/package/mono/mono.mk
> > +++ b/package/mono/mono.mk
> > @@ -26,6 +26,10 @@ MONO_CONF_OPTS = --disable-gtk-doc \
> >       --disable-mcs-build \
> >       --enable-static
> >
> > +ifeq ($(BR2_TOOLCHAIN_USES_MUSL),y)
> > +MONO_CONF_OPTS += --with-tls=pthread
> > +endif
>
> Hum, that's interesting. Do you have more details about what this
> --with-tls option is doing?
>

Actually, it sets another variable (HAVE_KW_THREAD) that it's used around
the code to accommodate the use of __thread or phtread as local storage.


> Is --with-tls related to Thread Local Storage provided by the compiler ?
>

Yes, absolutely!


>
> Indeed, TLS support in gcc was disabled for musl toolchains until
> recently (i.e until commit
> https://git.buildroot.org/buildroot/commit/package/gcc?id=
> 1bd02bc230e1b3b22ca3eb23fb3dcb91b878283a).
>
> Since the toolchain that was causing the build failure was built
> *prior* to this commit, maybe this commit fixes the issue, as it would
> make musl toolchains have TLS support enabled in gcc.
>
> Could you test this using the internal toolchain backend, and see if
> without your fix the problem isn't already fixed? If that's the case,
> I'll simply rebuild the pre-built toolchains.
>

I tested both the pre-compiled musl external toolchain and a musl internal
toolchain I compiled and I can confirm that it's working without this patch.
So, probably simply rebuilding the autobuild toolchain should solve the
problem.

Sincerely, Angelo


>
> Thanks,
>
> Thomas
> --
> Thomas Petazzoni, CTO, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com
>



-- 
Profile: http://it.linkedin.com/in/compagnucciangelo
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[Buildroot] [PATCH] package/mono: fix undefined reference to tls

[Thomas Petazzoni]

Hello,

On Fri, 9 Sep 2016 07:29:11 +0200, Angelo Compagnucci wrote:

> I tested both the pre-compiled musl external toolchain and a musl internal
> toolchain I compiled and I can confirm that it's working without this patch.
> So, probably simply rebuilding the autobuild toolchain should solve the
> problem.

Excellent, thanks! I'll kick a rebuild of the different Buildroot
toolchains soon, especially since we have move to a newer binutils
version, and have more recent version of gcc available as well.

Thanks,

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com