Merge pull request open-mpi#8475 from awlauria/fix_rdma_accumulate_segv

Fix osc/rdma gcc warnings + possible race

Author: hjelmn

ompi/mca/osc/rdma/osc_rdma_accumulate.c

@@ -192,9 +192,9 @@ static int ompi_osc_rdma_fetch_and_op_cas (ompi_osc_rdma_sync_t *sync, const voi
         new_value = old_value;
 
         if (&ompi_mpi_op_replace.op == op) {
-            memcpy ((void *)((intptr_t) &new_value + offset), origin_addr + dt->super.true_lb, extent);
+            memcpy ((void *)((intptr_t) &new_value + offset), (void *)((intptr_t) origin_addr + dt->super.true_lb), extent);
         } else if (&ompi_mpi_op_no_op.op != op) {
-            ompi_op_reduce (op, (void *) origin_addr + dt->super.true_lb, (void*)((intptr_t) &new_value + offset), 1, dt);
+            ompi_op_reduce (op, (void *) ((intptr_t) origin_addr + dt->super.true_lb), (void*)((intptr_t) &new_value + offset), 1, dt);
         }
 
         ret = ompi_osc_rdma_btl_cswap (module, peer->data_endpoint, address, target_handle,
@@ -219,7 +219,7 @@ static int ompi_osc_rdma_acc_single_atomic (ompi_osc_rdma_sync_t *sync, const vo
 {
     ompi_osc_rdma_module_t *module = sync->module;
     int32_t atomic_flags = module->selected_btl->btl_atomic_flags;
-    int ret, btl_op, flags;
+    int btl_op, flags;
     int64_t origin;
 
     if (!(module->selected_btl->btl_flags & MCA_BTL_FLAGS_ATOMIC_OPS)) {
@@ -261,7 +261,6 @@ static inline int ompi_osc_rdma_gacc_amo (ompi_osc_rdma_module_t *module, ompi_o
     const bool use_amo = module->acc_use_amo;
     const size_t dt_size = datatype->super.size;
     void *to_free = NULL;
-    uint64_t offset = 0;
     int ret;
 
     OSC_RDMA_VERBOSE(MCA_BASE_VERBOSE_TRACE, "using network atomics for accumulate operation with count %d", count);
@@ -339,7 +338,7 @@ static inline int ompi_osc_rdma_gacc_contig (ompi_osc_rdma_sync_t *sync, const v
     /* if the datatype is small enough (and the count is 1) then try to directly use the hardware to execute
      * the atomic operation. this should be safe in all cases as either 1) the user has assured us they will
      * never use atomics with count > 1, 2) we have the accumulate lock, or 3) we have an exclusive lock */
-    if (target_datatype->super.size <= 8 && target_count <= module->network_amo_max_count) {
+    if ((target_datatype->super.size <= 8) && (((unsigned long) target_count) <= module->network_amo_max_count)) {
         ret = ompi_osc_rdma_gacc_amo (module, sync, source, result, result_count, result_datatype, result_convertor,
                                       peer, target_address, target_handle, target_count, target_datatype, op, request);
         if (OPAL_LIKELY(OMPI_SUCCESS == ret)) {
@@ -867,7 +866,7 @@ int ompi_osc_rdma_rget_accumulate_internal (ompi_win_t *win, const void *origin_
     ompi_osc_rdma_module_t *module = GET_MODULE(win);
     mca_btl_base_registration_handle_t *target_handle;
     uint64_t target_address;
-    ptrdiff_t lb, target_lb, target_span;
+    ptrdiff_t target_lb, target_span;
     ompi_osc_rdma_request_t *rdma_request = NULL;
     bool lock_acquired = false;
     ompi_osc_rdma_sync_t *sync;

ompi/mca/osc/rdma/osc_rdma_dynamic.c

@@ -168,7 +168,7 @@ int ompi_osc_rdma_attach (struct ompi_win_t *win, void *base, size_t len)
     ompi_osc_rdma_handle_t *rdma_region_handle;
     osc_rdma_counter_t region_count;
     osc_rdma_counter_t region_id;
-    intptr_t bound, aligned_base, aligned_bound;
+    intptr_t aligned_base, aligned_bound;
     intptr_t page_size = opal_getpagesize ();
     int region_index, ret;
     size_t aligned_len;
@@ -185,6 +185,7 @@ int ompi_osc_rdma_attach (struct ompi_win_t *win, void *base, size_t len)
     OSC_RDMA_VERBOSE(MCA_BASE_VERBOSE_TRACE, "attach: %s, %p, %lu", win->w_name, base, (unsigned long) len);
 
     OPAL_THREAD_LOCK(&module->lock);
+    ompi_osc_rdma_lock_acquire_exclusive (module, my_peer, offsetof (ompi_osc_rdma_state_t, regions_lock));
 
     region_count = module->state->region_count & 0xffffffffL;
     region_id    = module->state->region_count >> 32;
@@ -197,7 +198,6 @@ int ompi_osc_rdma_attach (struct ompi_win_t *win, void *base, size_t len)
 
     /* it is wasteful to register less than a page. this may allow the remote side to access more
      * memory but the MPI standard covers this with calling the calling behavior erroneous */
-    bound = (intptr_t) base + len;
     aligned_bound = OPAL_ALIGN((intptr_t) base + len, page_size, intptr_t);
     aligned_base = (intptr_t) base & ~(page_size - 1);
     aligned_len = (size_t)(aligned_bound - aligned_base);
@@ -209,16 +209,11 @@ int ompi_osc_rdma_attach (struct ompi_win_t *win, void *base, size_t len)
         /* validates that the region does not overlap with an existing region even if they are on the same page */
         ret = ompi_osc_rdma_add_attachment (module->dynamic_handles[region_index], (intptr_t) base, len);
         OPAL_THREAD_UNLOCK(&module->lock);
+        ompi_osc_rdma_lock_release_exclusive (module, my_peer, offsetof (ompi_osc_rdma_state_t, regions_lock));
         /* no need to invalidate remote caches */
         return ret;
     }
 
-    /* region is in flux */
-    module->state->region_count = -1;
-    opal_atomic_wmb ();
-
-    ompi_osc_rdma_lock_acquire_exclusive (module, my_peer, offsetof (ompi_osc_rdma_state_t, regions_lock));
-
     /* do a binary seach for where the region should be inserted */
     if (region_count) {
         region = find_insertion_point ((ompi_osc_rdma_region_t *) module->state->regions, 0, region_count - 1,
@@ -239,7 +234,7 @@ int ompi_osc_rdma_attach (struct ompi_win_t *win, void *base, size_t len)
     region->len  = aligned_len;
 
     OSC_RDMA_VERBOSE(MCA_BASE_VERBOSE_DEBUG, "attaching dynamic memory region {%p, %p} aligned {%p, %p}, at index %d",
-                     base, (void *) bound, (void *) aligned_base, (void *) aligned_bound, region_index);
+                     base, (void *) ((intptr_t) base + len), (void *) aligned_base, (void *) aligned_bound, region_index);
 
     /* add RDMA region handle to track this region */
     rdma_region_handle = OBJ_NEW(ompi_osc_rdma_handle_t);
@@ -253,6 +248,7 @@ int ompi_osc_rdma_attach (struct ompi_win_t *win, void *base, size_t len)
         if (OPAL_UNLIKELY(OMPI_SUCCESS != ret)) {
             OPAL_THREAD_UNLOCK(&module->lock);
             OBJ_RELEASE(rdma_region_handle);
+            ompi_osc_rdma_lock_release_exclusive (module, my_peer, offsetof (ompi_osc_rdma_state_t, regions_lock));
             return OMPI_ERR_RMA_ATTACH;
         }
 
@@ -275,9 +271,9 @@ int ompi_osc_rdma_attach (struct ompi_win_t *win, void *base, size_t len)
     }
 #endif
 
-    opal_atomic_mb ();
     /* the region state has changed */
     module->state->region_count = ((region_id + 1) << 32) | (region_count + 1);
+    opal_atomic_wmb ();
 
     ompi_osc_rdma_lock_release_exclusive (module, my_peer, offsetof (ompi_osc_rdma_state_t, regions_lock));
     OPAL_THREAD_UNLOCK(&module->lock);
@@ -304,6 +300,9 @@ int ompi_osc_rdma_detach (struct ompi_win_t *win, const void *base)
 
     OPAL_THREAD_LOCK(&module->lock);
 
+    /* lock the region so it can't change while a peer is reading it */
+    ompi_osc_rdma_lock_acquire_exclusive (module, &my_peer->super, offsetof (ompi_osc_rdma_state_t, regions_lock));
+
     /* the upper 4 bytes of the region count are an instance counter */
     region_count = module->state->region_count & 0xffffffffL;
     region_id    = module->state->region_count >> 32;
@@ -327,23 +326,22 @@ int ompi_osc_rdma_detach (struct ompi_win_t *win, const void *base)
     if (region_index == region_count) {
         OSC_RDMA_VERBOSE(MCA_BASE_VERBOSE_INFO, "could not find dynamic memory attachment for %p", base);
         OPAL_THREAD_UNLOCK(&module->lock);
+        ompi_osc_rdma_lock_release_exclusive (module, &my_peer->super, offsetof (ompi_osc_rdma_state_t, regions_lock));
         return OMPI_ERR_BASE;
     }
 
     if (!opal_list_is_empty (&rdma_region_handle->attachments)) {
         /* another region is referencing this attachment */
+        OPAL_THREAD_UNLOCK(&module->lock);
+        ompi_osc_rdma_lock_release_exclusive (module, &my_peer->super, offsetof (ompi_osc_rdma_state_t, regions_lock));
         return OMPI_SUCCESS;
     }
 
-    /* lock the region so it can't change while a peer is reading it */
-    ompi_osc_rdma_lock_acquire_exclusive (module, &my_peer->super, offsetof (ompi_osc_rdma_state_t, regions_lock));
-
     OSC_RDMA_VERBOSE(MCA_BASE_VERBOSE_DEBUG, "detaching dynamic memory region {%p, %p} from index %d",
                      base, (void *)((intptr_t) base + region->len), region_index);
 
     if (module->selected_btl->btl_register_mem) {
         ompi_osc_rdma_deregister (module, rdma_region_handle->btl_handle);
-
     }
 
     if (region_index < region_count - 1) {
@@ -358,6 +356,7 @@ int ompi_osc_rdma_detach (struct ompi_win_t *win, const void *base)
     module->dynamic_handles[region_count - 1] = NULL;
 
     module->state->region_count = ((region_id + 1) << 32) | (region_count - 1);
+    opal_atomic_wmb ();
 
     ompi_osc_rdma_lock_release_exclusive (module, &my_peer->super, offsetof (ompi_osc_rdma_state_t, regions_lock));
 
@@ -461,14 +460,18 @@ int ompi_osc_rdma_find_dynamic_region (ompi_osc_rdma_module_t *module, ompi_osc_
     ompi_osc_rdma_peer_dynamic_t *dy_peer = (ompi_osc_rdma_peer_dynamic_t *) peer;
     intptr_t bound = (intptr_t) base + len;
     ompi_osc_rdma_region_t *regions;
-    int ret, region_count;
+    int ret = OMPI_SUCCESS, region_count;
 
     OSC_RDMA_VERBOSE(MCA_BASE_VERBOSE_TRACE, "locating dynamic memory region matching: {%" PRIx64 ", %" PRIx64 "}"
                      " (len %lu)", base, base + len, (unsigned long) len);
 
+    OPAL_THREAD_LOCK(&module->lock);
+    // Make sure region isn't being touched.
+    ompi_osc_rdma_lock_acquire_exclusive (module, peer, offsetof (ompi_osc_rdma_state_t, regions_lock));
     if (!ompi_osc_rdma_peer_local_state (peer)) {
         ret = ompi_osc_rdma_refresh_dynamic_region (module, dy_peer);
         if (OMPI_SUCCESS != ret) {
+            ompi_osc_rdma_lock_release_exclusive (module, peer, offsetof (ompi_osc_rdma_state_t, regions_lock));
             return ret;
         }
 
@@ -482,9 +485,11 @@ int ompi_osc_rdma_find_dynamic_region (ompi_osc_rdma_module_t *module, ompi_osc_
 
     *region = ompi_osc_rdma_find_region_containing (regions, 0, region_count - 1, (intptr_t) base, bound, module->region_size, NULL);
     if (!*region) {
-        return OMPI_ERR_RMA_RANGE;
+        ret = OMPI_ERR_RMA_RANGE;
     }
+    OPAL_THREAD_UNLOCK(&module->lock);
+    ompi_osc_rdma_lock_release_exclusive (module, peer, offsetof (ompi_osc_rdma_state_t, regions_lock));
 
     /* round a matching region */
-    return OMPI_SUCCESS;
+    return ret;
 }