From: Andrey Alekseenko <al42and@gmail.com>
Date: Mon, 18 Oct 2021 13:16:49 +0000 (+0000)
Subject: Fix UB when generating local indices for constraints
X-Git-Url: http://biod.pnpi.spb.ru/gitweb/?p=alexxy%2Fgromacs.git;a=commitdiff_plain;h=750108f507ae426359e41a81f10104df330829cf

Fix UB when generating local indices for constraints
---

diff --git a/src/gromacs/essentialdynamics/edsam.cpp b/src/gromacs/essentialdynamics/edsam.cpp
index ad5e7d9295..48dafd3d0a 100644
--- a/src/gromacs/essentialdynamics/edsam.cpp
+++ b/src/gromacs/essentialdynamics/edsam.cpp
@@ -3062,14 +3062,15 @@ std::unique_ptr<gmx::EssentialDynamics> init_edsam(const gmx::MDLogger&        m
 
     } /* end of MASTER only section */
 
-    if (PAR(cr))
+    if (haveDDAtomOrdering(*cr))
     {
-        /* Broadcast the essential dynamics / flooding data to all nodes */
+        /* Broadcast the essential dynamics / flooding data to all nodes.
+         * In a single-rank case, only the necessary memory allocation is done. */
         broadcast_ed_data(cr, ed);
     }
     else
     {
-        /* In the single-CPU case, point the local atom numbers pointers to the global
+        /* In the non-DD case, point the local atom numbers pointers to the global
          * one, so that we can use the same notation in serial and parallel case: */
         /* Loop over all ED data sets (usually only one, though) */
         for (auto edi = ed->edpar.begin(); edi != ed->edpar.end(); ++edi)
diff --git a/src/gromacs/mdlib/groupcoord.cpp b/src/gromacs/mdlib/groupcoord.cpp
index ac84c96273..adbf364c89 100644
--- a/src/gromacs/mdlib/groupcoord.cpp
+++ b/src/gromacs/mdlib/groupcoord.cpp
@@ -62,6 +62,7 @@ void dd_make_local_group_indices(const gmx_ga2la_t* ga2la,
                                  int coll_ind[]) /* OUT (opt): Where is this position found in the collective array? */
 {
     GMX_ASSERT(ga2la, "We need a valid ga2la object");
+    GMX_RELEASE_ASSERT(anrs != *anrs_loc, "Can not update indices in-place");
 
     /* Loop over all the atom indices of the group to check
      * which ones are on the local node */