[mpich2-dev] [PATCH 1/1] Fix uses of MPI_Aint in mpich2 tests

[Douglas Miller]

Fix several problems related to having MPI_Aint larger than (void *).
1. In copy_fn() the cast-and-dereference of attribute_val_out will
overwrite the stack in MPIR_Attr_dup_list() as that function only
provides a void * for attribute_val_out.

2. In delete_fn() do not promote values to MPI_Aint for comparing,
especially since neither are MPI_Aint to begin with.

3. Also in delete_fn(), the error path will segfault because it tries
to dereference attribute_val which is not a pointer.

4. Other uses of MPI_Aint are arbitrary and complicate the test.
Since attribute values in this program start out as ints and are
stored as void * within attributes, it seems confusing to be casting
them to/from MPI_Aint in between. This also avoids 64-bit manipulations
on 32-bit architectures.

-----

diff --git a/lib/mpi/mpich2/test/mpi/attr/attric.c
b/lib/mpi/mpich2/test/mpi/attr/attric.c
index 6b87a4e..56738e9 100644
--- a/lib/mpi/mpich2/test/mpi/attr/attric.c
+++ b/lib/mpi/mpich2/test/mpi/attr/attric.c
@@ -41,24 +41,24 @@ int main( int argc, char **argv )
 int copy_fn( MPI_Comm oldcomm, int keyval, void *extra_state,
             void *attribute_val_in, void *attribute_val_out, int *flag)
 {
     /* Note that if (sizeof(int) < sizeof(void *), just setting the int
        part of attribute_val_out may leave some dirty bits
     */
-    *(MPI_Aint *)attribute_val_out = (MPI_Aint)attribute_val_in;
+    *(void **)attribute_val_out = attribute_val_in;
     *flag = 1;
     return MPI_SUCCESS;
 }

 int delete_fn( MPI_Comm comm, int keyval, void *attribute_val,
               void *extra_state)
 {
     int world_rank;
     MPI_Comm_rank( MPI_COMM_WORLD, &world_rank );
-    if ((MPI_Aint)attribute_val != (MPI_Aint)world_rank) {
-       printf( "incorrect attribute value %d\n", *(int*)attribute_val );
+    if (attribute_val != (void *)world_rank) {
+       printf( "incorrect attribute value %ld\n", (long)attribute_val );
        MPI_Abort(MPI_COMM_WORLD, 1005 );
     }
     return MPI_SUCCESS;
 }

 int test_communicators( void )
@@ -68,13 +68,13 @@ int test_communicators( void )
     int flag, world_rank, world_size, key_1, key_3;
     int errs = 0;
     /*      integer n, ,
            .        key_2

     */
-    MPI_Aint value;
+    int      value;
     int      isLeft;

     MPI_Comm_rank( MPI_COMM_WORLD, &world_rank );
     MPI_Comm_size( MPI_COMM_WORLD, &world_size );
 #ifdef DEBUG
     if (world_rank == 0) {
@@ -105,25 +105,25 @@ int test_communicators( void )
        MPI_Keyval_create(MPI_NULL_COPY_FN, MPI_NULL_DELETE_FN,
                          &key_3, &value );

        /* This may generate a compilation warning; it is, however, an
           easy way to cache a value instead of a pointer */
        /* printf( "key1 = %x key3 = %x\n", key_1, key_3 ); */
-       MPI_Attr_put(comm, key_1, (void *) (MPI_Aint) world_rank );
+       MPI_Attr_put(comm, key_1, (void *)world_rank );
        /*         MPI_Attr_put(lo_comm, key_2, world_size ) */
        MPI_Attr_put(comm, key_3, (void *)0 );

        MPI_Comm_dup(comm, &dup_comm );

        /* Note that if sizeof(int) < sizeof(void *), we can't use
           (void **)&value to get the value we passed into Attr_put.  To
avoid
           problems (e.g., alignment errors), we recover the value into
           a (void *) and cast to int. Note that this may generate warning
           messages from the compiler.  */
        MPI_Attr_get(dup_comm, key_1, (void **)&vvalue, &flag );
-       value = (MPI_Aint)vvalue;
+       value = (int)vvalue;

        if (! flag) {
            errs++;
            printf( "dup_comm key_1 not found on %d\n", world_rank );
            fflush( stdout );
            MPI_Abort(MPI_COMM_WORLD, 3004 );
@@ -148,13 +148,13 @@ int test_communicators( void )
              printf( "dup_comm key_2 value incorrect: %d\n", value );
             fflush( stdout );
              MPI_Abort(MPI_COMM_WORLD, 3007 );
           }
        */
        MPI_Attr_get(dup_comm, key_3, (void **)&vvalue, &flag );
-       value = (MPI_Aint)vvalue;
+       value = (int)vvalue;
        if (flag) {
            errs++;
            printf( "dup_comm key_3 found!\n" );
            fflush( stdout );
            MPI_Abort(MPI_COMM_WORLD, 3008 );
        }