[Bug gcov-profile/43825] New: gcov is initialized wrong on x86_64

[Bug gcov-profile/43825] New: gcov is initialized wrong on x86_64

[tglek at mozilla dot com]

Building Mozilla with pgo results in a binary that can't even start to generate
profiling data. Turns out that even CXX="g++ --coverage" and CC="gcc
--coverage" resulting a binary that segfaults on start.

The crash looks like 
 #0  0x00007ffff40807c1 in strlen () from /lib/libc.so.6
#1  0x00007ffff6823a92 in __gcov_init () from /tmp/xulrunner/dist/bin/libxul.so
#2  0x00007ffff6824f56 in __do_global_ctors_aux () from
/tmp/xulrunner/dist/bin/libxul.so
#3  0x00007ffff51888ab in _init () from /tmp/xulrunner/dist/bin/libxul.so
#4  0x00007fffffffe908 in ?? ()
#5  0x00007ffff7dee429 in ?? () from /lib64/ld-linux-x86-64.so.2
#6  0x00007ffff7dee5af in ?? () from /lib64/ld-linux-x86-64.so.2
#7  0x00007ffff7de1b2a in ?? () from /lib64/ld-linux-x86-64.so.2
#8  0x0000000000000001 in ?? ()
#9  0x00007fffffffeb8c in ?? ()
#10 0x0000000000000000 in ?? ()

Looks like the info parameter passed to __gcov_init is buggered. This broken in
gcc 4.4-trunk, didn't test on prior releases.


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           Summary: gcov is initialized wrong on x86_64
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: gcov-profile
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: tglek at mozilla dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43825

[Bug gcov-profile/43825] gcov is initialized wrong on x86_64

[hjl dot tools at gmail dot com]

------- Comment #1 from hjl dot tools at gmail dot com  2010-04-21 00:04 -------
Do you have a small testcase?


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hjl dot tools at gmail dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hjl dot tools at gmail dot
                   |                            |com
             Status|UNCONFIRMED                 |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43825

[Bug gcov-profile/43825] gcov is initialized wrong on x86_64

[tglek at mozilla dot com]

------- Comment #2 from tglek at mozilla dot com  2010-04-21 00:05 -------
(In reply to comment #1)
> Do you have a small testcase?
> 

I wish. A minimal testcase works, but mozilla doesn't. Any suggestions on how
to reduce this?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43825

[Bug gcov-profile/43825] gcov is initialized wrong on x86_64

[hjl dot tools at gmail dot com]

------- Comment #3 from hjl dot tools at gmail dot com  2010-04-21 00:14 -------
I have Fedora 12 and Fedora 13. Is there a way to reproduce it with only
executable and leave libraries alone?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43825

[Bug gcov-profile/43825] gcov is initialized wrong on x86_64

[tglek at mozilla dot com]

------- Comment #4 from tglek at mozilla dot com  2010-04-21 00:15 -------
(In reply to comment #3)
> I have Fedora 12 and Fedora 13. Is there a way to reproduce it with only
> executable and leave libraries alone?
> 

I'm not sure what you mean.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43825

[Bug gcov-profile/43825] gcov is initialized wrong on x86_64

[hjl dot tools at gmail dot com]

------- Comment #5 from hjl dot tools at gmail dot com  2010-04-21 00:17 -------
(In reply to comment #4)
> (In reply to comment #3)
> > I have Fedora 12 and Fedora 13. Is there a way to reproduce it with only
> > executable and leave libraries alone?
> > 
> 
> I'm not sure what you mean.
> 

Fedora comes with Firefox. If I recompile /usr/lib64/firefox-3.5/firefox
with --coverage, will I see the problem?


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43825

[Bug gcov-profile/43825] gcov is initialized wrong on x86_64

[tglek at mozilla dot com]

------- Comment #6 from tglek at mozilla dot com  2010-04-21 00:19 -------
(In reply to comment #5)
> (In reply to comment #4)
> > (In reply to comment #3)
> > > I have Fedora 12 and Fedora 13. Is there a way to reproduce it with only
> > > executable and leave libraries alone?
> > > 
> > 
> > I'm not sure what you mean.
> > 
> 
> Fedora comes with Firefox. If I recompile /usr/lib64/firefox-3.5/firefox
> with --coverage, will I see the problem?
> 

I presume you'd recompile the whole firefox rpm. I think you should be able to
reproduce the problem there.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43825

[Bug gcov-profile/43825] gcov is initialized wrong on x86_64

[amonakov at gcc dot gnu dot org]

------- Comment #7 from amonakov at gcc dot gnu dot org  2010-04-21 16:45 -------


*** This bug has been marked as a duplicate of 43341 ***


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amonakov at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amonakov at gcc dot gnu dot
                   |                            |org
             Status|WAITING                     |RESOLVED
         Resolution|                            |DUPLICATE


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43825

[Bug gcov-profile/43825] gcov is initialized wrong on x86_64

[amonakov at gcc dot gnu dot org]

------- Comment #8 from amonakov at gcc dot gnu dot org  2010-04-21 16:48 -------
Taras, to avoid triggering the problem from firefox you can search for the file
(as I remember there is only one in xulrunner) with #pragma pack(1) and does
not reset it, and add #pragma pack() in the end of that file.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43825

[Bug gcov-profile/43825] gcov is initialized wrong on x86_64

[tglek at mozilla dot com]

------- Comment #9 from tglek at mozilla dot com  2010-04-21 17:48 -------
(In reply to comment #8)
> Taras, to avoid triggering the problem from firefox you can search for the file
> (as I remember there is only one in xulrunner) with #pragma pack(1) and does
> not reset it, and add #pragma pack() in the end of that file.
> 

This wouldn't have even crossed my mind. Works great, thanks for debugging
this.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43825