[Bug libgomp/103444] New: Fortran async IO is broken on FreeBSD

[Bug libgomp/103444] New: Fortran async IO is broken on FreeBSD

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103444

            Bug ID: 103444
           Summary: Fortran async IO is broken on FreeBSD
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgomp
          Assignee: unassigned at gcc dot gnu.org
          Reporter: kargl at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org
  Target Milestone: ---

[Bug libgomp/103444] Fortran async IO is broken on FreeBSD

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103444

--- Comment #1 from kargl at gcc dot gnu.org ---


                === libgomp Summary ===

# of expected passes            7743
# of unexpected failures        31
# of expected failures          72
# of unsupported tests          227

Each of async_io_1.f90, async_io_2.f90, async_io_3.f90
async_io_4.f90, async_io_8.f90, and async_io_9.f90
produce the same error.



Program received signal SIGBUS: Access to an undefined portion
of a memory object.

Backtrace for this error:
#0  0x200693bbd in handle_signal
        at /usr/src/lib/libthr/thread/thr_sig.c:303
#1  0x20069321b in thr_sighandler
        at /usr/src/lib/libthr/thread/thr_sig.c:246
#2  0x7ffffffff002 in ???
#3  0x20156872a in _Unwind_ForcedUnwind
        at ../../../gccx/libgcc/unwind.inc:215
#4  0x20068ae6b in _Unwind_ForcedUnwind
        at /usr/src/lib/libthr/thread/thr_exit.c:109
#5  0x20068ae6b in thread_unwind
        at /usr/src/lib/libthr/thread/thr_exit.c:175
#6  0x20068addb in _pthread_exit_mask
        at /usr/src/lib/libthr/thread/thr_exit.c:257
#7  0x20068ac8a in _Tthr_exit
        at /usr/src/lib/libthr/thread/thr_exit.c:209
#8  0x20068a77f in thread_start
        at /usr/src/lib/libthr/thread/thr_create.c:292
#9  0xffffffffffffffff in ???

[Bug libgomp/103444] Fortran async IO is broken on FreeBSD

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103444

--- Comment #2 from kargl at gcc dot gnu.org ---
% gfcx -o z -fopenmp -g async_io_1.f90
% gdb ./z
(gdb) run
Starting program: /home/kargl/tmp/z 
[New LWP 118209 of process 77440]

Thread 2 received signal SIGBUS, Bus error.
[Switching to LWP 118209 of process 77440]
0x0000000800f1815a in _Unwind_ForcedUnwind (exc=0x801a12738, stop=0x8006910b0, 
    stop_argument=0x0) at ../../../gcc/libgcc/unwind.inc:215
215       exc->private_1 = (_Unwind_Ptr) stop;
(gdb) bt
#0  0x0000000800f1815a in _Unwind_ForcedUnwind (exc=0x801a12738, 
    stop=0x8006910b0, stop_argument=0x0) at ../../../gcc/libgcc/unwind.inc:215
#1  0x0000000800690efc in ?? () from /lib/libthr.so.3
#2  0x0000000800690e70 in ?? () from /lib/libthr.so.3
#3  0x0000000800690d1b in pthread_exit () from /lib/libthr.so.3
#4  0x0000000800690833 in ?? () from /lib/libthr.so.3
#5  0x0000000000000000 in ?? ()
Backtrace stopped: Cannot access memory at address 0x7fffdfffe000

Not sure where to go from here.

[Bug libgomp/103444] Fortran async IO is broken on FreeBSD

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103444

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
https://groups.google.com/g/bsdmailinglist/c/PnRU5wlAAWw/m/o1DiaXuWAQAJ?pli=1

But PR 82635 has been fixed for a while now.
Otherwise maybe it is the stack size problem as mentioned in that freebsd bug.

[Bug libgomp/103444] Fortran async IO is broken on FreeBSD

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103444

--- Comment #4 from kargl at gcc dot gnu.org ---
This is as far as I have gotten on this bug.  I don't know if
this is a race condition in libgfortran's async_close(), a 
problem with gcc internal threading modeling (i.e., __gthrw_),
and problem with FreeBSD libthr.  Pointers on how to go to
the next step appreciated.  I assume something in __threadid
below is amiss.

% gfcx -o z -fopenmp -g async_io_9.f90 && ./z

% gdb ./z

(gdb) b async.c:479
Breakpoint 1 at 0x200a77ff0: file ../../../gccx/libgfortran/io/async.c, line
479.
(gdb) run
Thread 1 hit Breakpoint 1, _gfortrani_async_close (au=0x201a49000)
    at ../../../gccx/libgfortran/io/async.c:479
479       if (au == NULL)
(gdb) p *au
$1 = {io_lock = 0x2006da908, lock = 0x2006da888, empty = true, id = {
    waiting = -1, low = 1, high = 1, done = {pending = 0, 
      signal = 0x201a230a0}}, work = {pending = 0, signal = 0x201a23060}, 
  emptysignal = {pending = 0, signal = 0x201a23080}, pdt = 0x201a4e000, 
  thread = 0x201a12700, head = 0x0, tail = 0x0, error = {message = 0x0, 
    cmp = 0x0, has_error = false, last_good_id = 0, family = 0, 
    fatal_error = false}}
(gdb) n
483       enqueue_close (au);
(gdb) n
484       T_ERROR (__gthread_join, au->thread, NULL);
(gdb) 

Thread 2 received signal SIGBUS, Bus error.
[Switching to LWP 180470 of process 18692]
0x0000000200f1ad6a in _Unwind_ForcedUnwind (exc=0x201a12938, 
    stop=0x20068a030 <thread_unwind_stop>, stop_argument=0x0)
    at ../../../gccx/libgcc/unwind.inc:215
215       exc->private_1 = (_Unwind_Ptr) stop;


(gdb) run 
Thread 1 hit Breakpoint 1, _gfortrani_async_close (au=0x201a49000)
    at ../../../gccx/libgfortran/io/async.c:479
479       if (au == NULL)
(gdb) n
483       enqueue_close (au);
(gdb) n
484       T_ERROR (__gthread_join, au->thread, NULL);
(gdb) s
__gthread_join (__value_ptr=0x0, __threadid=0x201a12700)
    at ../libgcc/gthr-default.h:669
669       return __gthrw_(pthread_join) (__threadid, __value_ptr);
(gdb) p __value_ptr
$2 = (void **) 0x0
(gdb) p __threadid
$3 = (__gthread_t) 0x201a12700
(gdb) p *__threadid
$4 = {tid = 180471, lock = {m_owner = 0, m_flags = 0, m_ceilings = {0, 0}, 
    m_rb_lnk = 0, m_spare = {0, 0}}, cycle = 0, locklevel = 0, 
  critical_count = 0, sigblock = 0, fsigblock = 0, tle = {
    tqe_next = 0x201a12000, tqe_prev = 0x200699900 <_thread_list>}, gcle = {
    tqe_next = 0x0, tqe_prev = 0x0}, hle = {le_next = 0x0, 
    le_prev = 0x20069a128}, wle = {tqe_next = 0x0, tqe_prev = 0x201a19080}, 
  refcount = 1, start_routine = 0x200a764d0 <async_io>, arg = 0x201a1df00, 
  attr = {sched_policy = 2, sched_inherit = 4, prio = 0, suspend = 0, 
    flags = 2, stackaddr_attr = 0x7fffbfdfe000, stacksize_attr = 2097152, 
    guardsize_attr = 4096, cpuset = 0x0, cpusetsize = 0}, cancel_enable = 1, 
  cancel_pending = 0, cancel_point = 1, no_cancel = 0, cancel_async = 0, 
  cancelling = 0, sigmask = {__bits = {0, 0, 0, 0}}, unblock_sigcancel = 0, 
  in_sigsuspend = 0, deferred_siginfo = {si_signo = 0, si_errno = 0, 
    si_code = 0, si_pid = 0, si_uid = 0, si_status = 0, si_addr = 0x0, 
    si_value = {sival_int = 0, sival_ptr = 0x0, sigval_int = 0, 
      sigval_ptr = 0x0}, _reason = {_fault = {_trapno = 0}, _timer = {
        _timerid = 0, _overrun = 0}, _mesgq = {_mqd = 0}, _poll = {_band = 0}, 
      _capsicum = {_syscall = 0}, __spare__ = {__spare1__ = 0, __spare2__ = {
          0, 0, 0, 0, 0, 0, 0}}}}, deferred_sigmask = {__bits = {0, 0, 0, 0}}, 
  deferred_sigact = {__sigaction_u = {__sa_handler = 0x0, 
      __sa_sigaction = 0x0}, sa_flags = 0, sa_mask = {__bits = {0, 0, 0, 0}}}, 
  deferred_run = 0, force_exit = 0, state = PS_RUNNING, error = 0, 
  joiner = 0x0, flags = 0, tlflags = 2, mq = {{tqh_first = 0x0, 
      tqh_last = 0x201a128a8}, {tqh_first = 0x0, tqh_last = 0x201a128b8}, {
      tqh_first = 0x0, tqh_last = 0x201a128c8}, {tqh_first = 0x0, 
      tqh_last = 0x201a128d8}, {tqh_first = 0x0, tqh_last = 0x201a128e8}, {
      tqh_first = 0x0, tqh_last = 0x201a128f8}}, ret = 0x0, specific = 0x0, 
  specific_data_count = 0, rdlock_count = 0, rtld_bits = 0, tcb = 0x2006bc1c0, 
  cleanup = 0x0, ex = {exception_class = 0, exception_cleanup = 0x0, 
    private_1 = 0, private_2 = 0}, unwind_stackend = 0x7fffbfffe000, 
  unwind_disabled = 0, magic = 3499860245, report_events = 0, event_mask = 0, 
  event_buf = {event = TD_EVENT_NONE, th_p = 0, data = 0}, wchan = 0x0, 
  mutex_obj = 0x2006da888, will_sleep = 0, nwaiter_defer = 0, 
  robust_inited = 0, robust_list = 0, priv_robust_list = 0, inact_mtx = 0, 
  defer_waiters = {0x20069a428, 0x0 <repeats 49 times>}, 
  wake_addr = 0x200637000, sleepqueue = 0x201a19080, name = 0x0, 
  dlerror_msg = '\000' <repeats 511 times>, dlerror_seen = 0}
(gdb) s

Thread 2 received signal SIGBUS, Bus error.
[Switching to LWP 180472 of process 18709]
0x0000000200f1ad6a in _Unwind_ForcedUnwind (exc=0x201a12938, 
    stop=0x20068a030 <thread_unwind_stop>, stop_argument=0x0)
    at ../../../gccx/libgcc/unwind.inc:215
215       exc->private_1 = (_Unwind_Ptr) stop;