Hi, We observe crash during shmem_finalize() (in trunk) with new MCA framework. After investigation, found that MCA tears-down process can access previously released memory. (reproduced with oshmem_hello_c.c test)
0 0x00007fffed3d51d0 in ?? () #1 <signal handler called> #2 <http://bgate.mellanox.com/redmine/issues/2> 0x00007ffff710e21e in var_destructor (var=0x6fa7e0) at mca_base_var.c:1605 #3 <http://bgate.mellanox.com/redmine/issues/3> 0x00007ffff710ae99 in opal_obj_run_destructors (object=0x6fa7e0) at ../../../opal/class/opal_object.h:448 #4 0x00007ffff710ca18 in mca_base_var_finalize () at mca_base_var.c:954 #5 <http://bgate.mellanox.com/redmine/issues/5> 0x00007ffff710a7e2 in mca_base_param_finalize () at mca_base_param.c:643 #6 <http://bgate.mellanox.com/redmine/issues/6> 0x00007ffff70e08e2 in opal_finalize_util () at runtime/opal_finalize.c:77 #7 <http://bgate.mellanox.com/redmine/issues/7> 0x00007ffff7aa5319 in ompi_mpi_finalize () at runtime/ompi_mpi_finalize.c:407 #8 <http://bgate.mellanox.com/redmine/issues/8> 0x00007ffff7d900cc in oshmem_shmem_finalize () at runtime/oshmem_shmem_finalize.c:75 #9 <http://bgate.mellanox.com/redmine/issues/9> 0x00007ffff7d91119 in shmem_finalize () at shmem_finalize.c:24 #10 <http://bgate.mellanox.com/redmine/issues/10> 0x00007ffff7d89b8f in __do_global_dtors_aux () from /install/lib/libshmem.so.0 #11 <http://bgate.mellanox.com/redmine/issues/11> 0x0000000000000000 in ?? () The crash can be resolved by following patch: diff --git a/opal/mca/base/mca_base_var.c b/opal/mca/base/mca_base_var.c index 9966627..48028d8 100644 --- a/opal/mca/base/mca_base_var.c +++ b/opal/mca/base/mca_base_var.c @@ -773,7 +773,7 @@ static int var_find_by_name (const char *full_name, int *index, bool invalidok) (void) var_get ((int)(uintptr_t) tmp, &var, false); - if (invalidok || VAR_IS_VALID(var[0])) { + if (VAR_IS_VALID(var[0])) { *index = (int)(uintptr_t) tmp; return OPAL_SUCCESS; } I`m not sure we understand yet why it fixes the problem and what is a race. Could some` with knowledge of MCA flows look at it and comment? The "invalidok" was introduced by Jeff`s commit. Thanks M
