[Bug libgcc/98390] New: AIX: exceptions in threads: IOT/Abort trap(coredump)

[Bug libgcc/98390] New: AIX: exceptions in threads: IOT/Abort trap(coredump)

[stefan at bytereef dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98390

            Bug ID: 98390
           Summary: AIX: exceptions in threads: IOT/Abort trap(coredump)
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgcc
          Assignee: unassigned at gcc dot gnu.org
          Reporter: stefan at bytereef dot org
  Target Milestone: ---

The following test case is extracted from a larger program. When repeated
often enough, it terminates with: IOT/Abort trap(coredump)

Confirmed with g++ (GCC) 7.2.0 and g++ (GCC) 10.2.0 on gcc119.fsffrance.org.


test.cc:
========================================================================
#include <stdexcept>
#include <thread>
#include <vector>


class suntime_error : public std::runtime_error {
  using std::runtime_error::runtime_error;
};

static void
doit()
{
    try {
        throw suntime_error("this is an error");
    }
    catch (const suntime_error& err) {
        (void)err;
    }
}

static void
do_threads()
{
    const size_t n = 100;
    std::vector<std::thread> t(n);

    for (size_t k = 0; k < n; k++) {
        t[k] = std::thread(doit);
    }

    for (size_t k = 0; k < n; k++) {
        t[k].join();
    }
}

int
main()
{
    do_threads();
    return 0;
}
========================================================================


doit.sh:
========================================================================
#!/bin/sh

while ./test; do
    :
done
========================================================================



$ g++ -pthread -Wall -Wextra -std=gnu++11 -pedantic -O0 -g -o test test.cc

$ ./doit.sh
./doit.sh[3]: 14484092 IOT/Abort trap(coredump)

$ gdb ./test core
[...]
Program terminated with signal SIGABRT, Aborted.
#0  0xd058f3ec in pthread_kill () from /usr/lib/libpthreads.a(shr_xpg5.o)
(gdb) bt
#0  0xd058f3ec in pthread_kill () from /usr/lib/libpthreads.a(shr_xpg5.o)
#1  0xd058e7cc in _p_raise () from /usr/lib/libpthreads.a(shr_xpg5.o)
#2  0xd0123608 in raise () from /usr/lib/libc.a(shr.o)
#3  0xd0189ebc in abort () from /usr/lib/libc.a(shr.o)
#4  0xd08741a4 in uw_init_context_1 () from
/opt/freeware/lib/gcc/powerpc-ibm-aix7.2.0.0/7.2.0/pthread/libgcc_s.a(shr.o)
#5  0xd0874e50 in _Unwind_RaiseException () from
/opt/freeware/lib/gcc/powerpc-ibm-aix7.2.0.0/7.2.0/pthread/libgcc_s.a(shr.o)
#6  0xd17cd2cc in __cxa_throw () from
/opt/freeware/lib/gcc/powerpc-ibm-aix7.2.0.0/7.2.0/pthread/libstdc++.a(libstdc++.so.6)
#7  0x100006dc in doit () at test.cc:14
#8  0x100021fc in void std::__invoke_impl<void, void
(*)()>(std::__invoke_other, void (*&&)()) (__f=<incomplete type>)
#9  0x100020c4 in std::__invoke_result<void (*)()>::type std::__invoke<void
(*)()>(void (*&&)()) (__fn=<incomplete type>)
#10 0x10002cd4 in decltype (__invoke((_S_declval<0ul>)()))
std::thread::_Invoker<std::tuple<void (*)()>
>::_M_invoke<0ul>(std::_Index_tuple<0ul>) (this=<incomplete type>)
#11 0x10002c2c in std::thread::_Invoker<std::tuple<void (*)()> >::operator()
(this=<incomplete type>)
#12 0x10002b8c in
std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (*)()> >
>::_M_run (this=<incomplete type>)
#13 0xd18964d8 in execute_native_thread_routine () from
/opt/freeware/lib/gcc/powerpc-ibm-aix7.2.0.0/7.2.0/pthread/libstdc++.a(libstdc++.so.6)
#14 0xd0572f68 in _pthread_body () from /usr/lib/libpthreads.a(shr_xpg5.o)
#15 0x00000000 in ?? ()

[Bug target/98390] AIX: exceptions in threads: IOT/Abort trap(coredump)

[stefan at bytereef dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98390

--- Comment #1 from Stefan Krah <stefan at bytereef dot org> ---

The issue can still be reproduced with a gcc-14 snapshot. ibm-clang++ does not
have this problem. The LLVM unwinder has been reworked for AIX:

https://www.mail-archive.com/cfe-commits@lists.llvm.org/msg275024.html


Would it be possible for gcc to use the LLVM libunwind on AIX? It would be
great if IBM unlocked some funding for this.

gcc often produces faster binaries than clang and this is literally the only
gcc issue on AIX that I've come across after many long running tests. It would
be worth fixing --- both AIX and gcc (except for this issue) are very stable.