btl/sm: fix crash on put/get to self

This commit fixes an issue that can occur if the sm btl is used to either
get or put to self. In this case there is no smsc endpoint since none is
needed to access the local addess space. Since the smsc endpoint is NULL
the process would SEGV.

Signed-off-by: Nathan Hjelm <hjelmn@google.com>

Author: hjelmn

opal/mca/btl/sm/btl_sm.h

@@ -157,6 +157,10 @@ mca_btl_base_descriptor_t *mca_btl_sm_alloc(struct mca_btl_base_module_t *btl,
  */
 int mca_btl_sm_free(struct mca_btl_base_module_t *btl, mca_btl_base_descriptor_t *des);
 
+static inline bool mca_btl_is_self_endpoint(mca_btl_base_endpoint_t *endpoint) {
+    return endpoint->peer_smp_rank == MCA_BTL_SM_LOCAL_RANK;
+}
+
 END_C_DECLS
 
 #endif

opal/mca/btl/sm/btl_sm_get.c

@@ -4,7 +4,7 @@
  *                         reserved.
  * Copyright (c) 2018      Research Organization for Information Science
  *                         and Technology (RIST).  All rights reserved.
- * Copyright (c) 2019-2021 Google, Inc. All rights reserved.
+ * Copyright (c) 2019-2022 Google, Inc. All rights reserved.
  * Copyright (c) 2020      The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
@@ -36,10 +36,14 @@ int mca_btl_sm_get(mca_btl_base_module_t *btl, mca_btl_base_endpoint_t *endpoint
                    int order, mca_btl_base_rdma_completion_fn_t cbfunc, void *cbcontext,
                    void *cbdata)
 {
-    int ret = MCA_SMSC_CALL(copy_from, endpoint->smsc_endpoint, local_address,
-                            (void *) (intptr_t) remote_address, size, remote_handle);
-    if (OPAL_UNLIKELY(OPAL_SUCCESS != ret)) {
-        return ret;
+    if (!mca_btl_is_self_endpoint(endpoint)) {
+        int ret = MCA_SMSC_CALL(copy_from, endpoint->smsc_endpoint, local_address,
+                                (void *) (intptr_t) remote_address, size, remote_handle);
+        if (OPAL_UNLIKELY(OPAL_SUCCESS != ret)) {
+            return ret;
+        }
+    } else {
+        memcpy(local_address, (void *)(uintptr_t) remote_address, size);
     }
 
     /* always call the callback function */

opal/mca/btl/sm/btl_sm_module.c

@@ -19,7 +19,7 @@
  *                         and Technology (RIST).  All rights reserved.
  * Copyright (c) 2018-2019 Triad National Security, LLC. All rights
  *                         reserved.
- * Copyright (c) 2020-2021 Google, LLC. All rights reserved.
+ * Copyright (c) 2020-2022 Google, LLC. All rights reserved.
  * Copyright (c) 2021      Nanook Consulting.  All rights reserved.
  * $COPYRIGHT$
  *
@@ -167,7 +167,7 @@ static int init_sm_endpoint(struct mca_btl_base_endpoint_t **ep_out, struct opal
 
     ep->peer_smp_rank = peer_local_rank;
 
-    if (peer_local_rank != MCA_BTL_SM_LOCAL_RANK) {
+    if (!mca_btl_is_self_endpoint(ep)) {
         OPAL_MODEX_RECV_IMMEDIATE(rc, &component->super.btl_version, &proc->proc_name,
                                   (void **) &modex, &msg_size);
         if (OPAL_SUCCESS != rc) {

opal/mca/btl/sm/btl_sm_put.c

@@ -4,7 +4,7 @@
  *                         reserved.
  * Copyright (c) 2014-2018 Research Organization for Information Science
  *                         and Technology (RIST).  All rights reserved.
- * Copyright (c) 2019-2021 Google, Inc. All rights reserved.
+ * Copyright (c) 2019-2022 Google, Inc. All rights reserved.
  * Copyright (c) 2020      The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
@@ -36,10 +36,14 @@ int mca_btl_sm_put(mca_btl_base_module_t *btl, mca_btl_base_endpoint_t *endpoint
                    int order, mca_btl_base_rdma_completion_fn_t cbfunc, void *cbcontext,
                    void *cbdata)
 {
-    int ret = MCA_SMSC_CALL(copy_to, endpoint->smsc_endpoint, local_address,
-                            (void *) (intptr_t) remote_address, size, remote_handle);
-    if (OPAL_UNLIKELY(OPAL_SUCCESS != ret)) {
-        return ret;
+    if (!mca_btl_is_self_endpoint(endpoint)) {
+        int ret = MCA_SMSC_CALL(copy_to, endpoint->smsc_endpoint, local_address,
+                                (void *) (intptr_t) remote_address, size, remote_handle);
+        if (OPAL_UNLIKELY(OPAL_SUCCESS != ret)) {
+            return ret;
+        }
+    } else {
+        memcpy((void *)(uintptr_t) remote_address, local_address, size);
     }
 
     /* always call the callback function */