[Bug libmudflap/44661] New: Link order (?) might cause threaded libmudflap to assert

[Bug libmudflap/44661] New: Link order (?) might cause threaded libmudflap to assert

[davi dot arnaut at sun dot com]

Tweaking the order of library names might cause the mudflap runtime to assert.

$ cat foo.c 
#include <stdio.h>
#include <unistd.h>
#include <pthread.h>

static void *routine(void* arg)
{
  pthread_t thr = pthread_self();
  printf("foo %d\n", 1);
  return NULL;
}

int main()
{
  pthread_t thr;
  pthread_create(&thr, NULL, routine, NULL);
  pthread_join(thr, NULL);
  return 0;
}

$ gcc -o foo foo.c  -fmudflapth -lpthread -lmudflapth 
$ ./foo 
mf: erroneous reentrancy detected in `__mf_check'
Aborted (core dumped)
$ gcc -o foo foo.c  -fmudflapth -lmudflapth -lpthread
$ ./foo 
foo 1

g++ (Ubuntu 20100621-0ubuntu1) 4.6.0 20100621 (experimental) [trunk revision
161065]
GNU gold (GNU Binutils for Ubuntu 2.20.51-system.20100617) 1.9


-- 
           Summary: Link order (?) might cause threaded libmudflap to assert
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libmudflap
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: davi dot arnaut at sun dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44661

[Bug libmudflap/44661] Link order (?) might cause threaded libmudflap to assert

[pinskia at gcc dot gnu dot org]

------- Comment #1 from pinskia at gcc dot gnu dot org  2010-06-28 00:48 -------
>-lpthread

I think it is better to use -pthread instead.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44661

[Bug libmudflap/44661] Link order (?) might cause threaded libmudflap to assert

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2010-07-21 23:53 -------
I think libmudflapth does have a dependency on libpthread which is causing this
issue.  I think libmudflapth have a weak check in it too.

                 w pthread_join


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2010-07-21 23:53:05
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44661

[Bug libmudflap/44661] Link order (?) might cause threaded libmudflap to assert

[jakub at gcc dot gnu dot org]

------- Comment #3 from jakub at gcc dot gnu dot org  2010-07-22 07:53 -------
Of course libmudflapth needs to come first, otherwise it doesn't override
libpthread symbols it means to override.
If it doesn't, that is a user error though.


-- 

jakub at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44661

[Bug libmudflap/44661] Link order (?) might cause threaded libmudflap to assert

[davi dot arnaut at sun dot com]

------- Comment #4 from davi dot arnaut at sun dot com  2010-07-22 10:54 -------
Let's get it documented? One sentence should do. I think it's pertinent because
-lpthread will most of the time come before user supplied compiler flags.


-- 

davi dot arnaut at sun dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|INVALID                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44661

[Bug libmudflap/44661] Link order (?) might cause threaded libmudflap to assert

[g_sauthoff at web dot de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44661

--- Comment #5 from Georg Sauthoff <g_sauthoff at web dot de> 2013-03-02 20:42:25 UTC ---
I can reproduce this issue on Ubuntu 10.04 (gcc 4.4.3).

That means:

$ gcc -o foo foo.c  -fmudflapth -lpthread -lmudflapth
$ ./foo

-> mf: erroneous reentrancy detected in `__mf_check'

$ gcc -o foo foo.c  -fmudflapth -pthread -lmudflapth
$ ./foo

-> foo 1


On Fedora 17 (x86-64) (gcc 4.7.2) the issue is not present:

$ gcc -lpthread -o foo foo.c -fmudflapth -lpthread -lmudflap
$ ./foo

-> foo 1

[Bug libmudflap/44661] Link order (?) might cause threaded libmudflap to assert

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44661

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> 2013-03-02 20:44:20 UTC ---
I bet the issue is that Ubuntu's GCC passes --as-needed by default (non
standard really).

[Bug libmudflap/44661] Link order (?) might cause threaded libmudflap to assert

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44661

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |RESOLVED
         Resolution|---                         |WONTFIX
   Target Milestone|---                         |4.9.0

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
fmudflap support has been removed.