[Bug libmudflap/20339] New: mudflap abort

["eyal at eyal dot emu dot id dot au" <gcc-bugzilla at gcc dot gnu dot org>]

gcc cvs head on Linux 2.6.11 on P4.

I am chasing a problem with mudflap. Running off uptodate cvs head.
To this end I created a simple test program (attached) which does
many memory malloc/free in a heavily multithreaded environment.

The sample program aborts regularly, while the problem I am after
is different - I get register violations where another object claims
to overlap the same new address. I am rather sure that this is not
the case with my program. I suspect that the two problems may be
related.

I observed the failure for a long while now, but did not have the
time to address it earlier.

It works OK without MF. The failure has different errors logged
each time before it aborts. Here is the output of one run:

eyal@e7:~/zz$ sh zz37.sh
/data2/usr/local/gcc-4.0.0-20050303-103350/bin/../lib/gcc/i686-pc-linux-gnu/4.1.0/../../../libmudflapth.so:
warning: the use of `pthread_attr_setstackaddr' is deprecated, use
`pthread_attr_setstack'
/data2/usr/local/gcc-4.0.0-20050303-103350/bin/../lib/gcc/i686-pc-linux-gnu/4.1.0/../../../libmudflapth.so:
warning: the use of `pthread_attr_getstackaddr' is deprecated, use
`pthread_attr_getstack'
zz37.sh: line 144: 25027 Segmentation fault      $prog 2>$prog.out

eyal@e7:~/zz$ cat zz37.out
/home/eyal/zz/zz37.c(104) testing in main
/home/eyal/zz/zz37.c(109) testing in thread
/home/eyal/zz/zz37.c(79) created
free(): invalid pointer 0x80fc390!
free(): invalid pointer 0x80b2768!
free(): invalid pointer 0x810f6a8!
free(): invalid pointer 0x808ec70!
free(): invalid pointer 0x808a350!
free(): invalid pointer 0x8094430!
free(): invalid pointer 0x810bc28!
free(): invalid pointer 0x8110c98!
free(): invalid pointer 0x808d410!

And another run:

/home/eyal/zz/zz37.c(104) testing in main
/home/eyal/zz/zz37.c(109) testing in thread
/home/eyal/zz/zz37.c(79) created
mf: erroneous reentrancy detected in `__mf_register'

-- 
           Summary: mudflap abort
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: libmudflap
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: eyal at eyal dot emu dot id dot au
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: gcc version 4.1.0 20050302 (experimental)
  GCC host triplet: Linux 2.6.11 SMP  i686 GNU/Linux


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20339