[OpenMP] Fix releasing of stack memory

[protze.joachim]

Summary

Starting with 787eb0c637b I got spurious segmentation faults for some testcases. I could nail it down to brel trying to release the "memory" of the node allocated on the stack of __kmpc_omp_wait_deps. With this patch, you will see the assertion triggering for some of the tests in the test suite.

My proposed solution for the issue is to just patch __kmpc_omp_wait_deps:

  __kmp_init_node(&node);
-  node.dn.on_stack = 1;
+  // the stack owns the node
+  __kmp_node_ref(&node);

What do you think?

[protze.joachim]

After harbormaster highlighted the issue, this is the patch to solve the issue.

[protze.joachim]

ping

[AndreyChurbanov]

LGTM

openmp/runtime/src/kmp_taskdeps.cpp

 #if OMPT_SUPPORT
     __ompt_taskwait_dep_finish(current_task, taskwait_task_data);
 #endif /* OMPT_SUPPORT */
     return;
   }
 
   kmp_depnode_t node = {0};
   __kmp_init_node(&node);
+  // the stack owns the node
+  __kmp_node_ref(&node);
 
   if (!__kmp_check_deps(gtid, &node, NULL, &current_task->td_dephash,
                         DEP_BARRIER, ndeps, dep_list, ndeps_noalias,
                         noalias_dep_list)) {
     KA_TRACE(10, ("__kmpc_omp_wait_deps(exit): T#%d has no blocking "
                   "dependencies : loc=%p\n",
                   gtid, loc_ref));
 #if OMPT_SUPPORT