[Bug libgomp/67141] New: wrong libgomp mutex initialisation order

[Bug libgomp/67141] New: wrong libgomp mutex initialisation order

[mattiase at acm dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67141

            Bug ID: 67141
           Summary: wrong libgomp mutex initialisation order
           Product: gcc
           Version: 5.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgomp
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mattiase at acm dot org
                CC: jakub at gcc dot gnu.org
  Target Milestone: ---

Libgomp may use a mutex, acc_device_lock, prior to initialising it depending on
the constructor calling order: it is initialised in initialize_env and used in
goacc_host_init, both declared __attribute__ ((constructor)) but in different
files.

This was discovered on Windows after a change to the pthread library in
mingw-w64, making all-zero an invalid mutex value. Apparently the constructors
were called in the "wrong" order, and pthread_mutex_lock called before
pthread_mutex_init.

[Bug libgomp/67141] wrong libgomp mutex initialisation order

[xantares09 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67141

xantares09 at hotmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |xantares09 at hotmail dot com

--- Comment #1 from xantares09 at hotmail dot com ---
Created attachment 36169
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36169&action=edit
call initialize_env before goacc_host_init

I can reproduce here:
err:module:attach_process_dlls "libgomp-1.dll" failed to initialize, aborting

Mattias is totally right:
if i assign a higher initialization priority to env.c:initialize_env than
oacc-host.c:goacc_host_init the dll is correctly initialized

the patch may not be ok, but you get the idea

[Bug libgomp/67141] wrong libgomp mutex initialisation order

[xantares09 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67141

--- Comment #2 from xantares09 at hotmail dot com ---
Note that you'll need mingw-w64 4.0.4, not 4.0.2 to reproduce, I used gcc
5.2.0.

[Bug libgomp/67141] wrong libgomp mutex initialisation order

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67141

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |nathan at gcc dot gnu.org

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
CCing OpenACC folks.

[Bug libgomp/67141] wrong libgomp mutex initialisation order

[ktietz at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67141

Kai Tietz <ktietz at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-09-11
                 CC|                            |ktietz at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #4 from Kai Tietz <ktietz at gcc dot gnu.org> ---
I added to mingw-w64's libwinpthread a work-a-round for this sloppy code. 
Nevertheless the issue should be fixed IMO in libgomp, too

[Bug libgomp/67141] wrong libgomp mutex initialisation order

[tschwinge at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67141

Thomas Schwinge <tschwinge at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|tschwinge at gcc dot gnu.org       |cltang at gcc dot gnu.org

--- Comment #5 from Thomas Schwinge <tschwinge at gcc dot gnu.org> ---
<http://news.gmane.org/find-root.php?message_id=%3C55FBC02A.5080306%40codesourcery.com%3E>.

[Bug libgomp/67141] wrong libgomp mutex initialisation order

[cltang at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67141

--- Comment #6 from Chung-Lin Tang <cltang at gcc dot gnu.org> ---
Author: cltang
Date: Tue Sep 22 06:45:22 2015
New Revision: 227994

URL: https://gcc.gnu.org/viewcvs?rev=227994&root=gcc&view=rev
Log:
2015-09-22  Chung-Lin Tang  <cltang@codesourcery.com>

        PR libgomp/67141
        * oacc-int.h (goacc_host_init): Add declaration.
        * oacc-host.c (goacc_host_init): Remove static and constructor
attribute.
        * oacc-init.c (goacc_runtime_initialize): Call goacc_host_init() at
end.


Modified:
    trunk/libgomp/ChangeLog
    trunk/libgomp/oacc-host.c
    trunk/libgomp/oacc-init.c
    trunk/libgomp/oacc-int.h

[Bug libgomp/67141] wrong libgomp mutex initialisation order

[cltang at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67141

--- Comment #7 from Chung-Lin Tang <cltang at gcc dot gnu.org> ---
Author: cltang
Date: Tue Sep 22 11:18:23 2015
New Revision: 228011

URL: https://gcc.gnu.org/viewcvs?rev=228011&root=gcc&view=rev
Log:
2015-09-22  Chung-Lin Tang  <cltang@codesourcery.com>

        Backport from mainline:

        2015-09-22  Chung-Lin Tang  <cltang@codesourcery.com>

        PR libgomp/67141
        * oacc-int.h (goacc_host_init): Add declaration.
        * oacc-host.c (goacc_host_init): Remove static and constructor
attribute.
        * oacc-init.c (goacc_runtime_initialize): Call goacc_host_init() at
end.


Modified:
    branches/gcc-5-branch/libgomp/ChangeLog
    branches/gcc-5-branch/libgomp/oacc-host.c
    branches/gcc-5-branch/libgomp/oacc-init.c
    branches/gcc-5-branch/libgomp/oacc-int.h

[Bug libgomp/67141] wrong libgomp mutex initialisation order

[cltang at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67141

--- Comment #8 from Chung-Lin Tang <cltang at gcc dot gnu.org> ---
Can the MinGW folks confirm if the reported problem was fixed?
Thanks.

[Bug libgomp/67141] wrong libgomp mutex initialisation order

[xantares09 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67141

--- Comment #9 from xantares09 at hotmail dot com ---
I can confirm the patch from gcc-5 branch applied on top of 5.2.0 fixes the
mingw problem.
Thanks a lot.
xan.