diff --git a/arch/sim/src/sim/up_heap.c b/arch/sim/src/sim/up_heap.c
index acc8f17ac55..0baf3ca4e5f 100644
--- a/arch/sim/src/sim/up_heap.c
+++ b/arch/sim/src/sim/up_heap.c
@@ -410,6 +410,7 @@ void mm_extend(FAR struct mm_heap_s *heap, FAR void *mem, size_t size,
 int mm_mallinfo(FAR struct mm_heap_s *heap, FAR struct mallinfo *info)
 {
   memset(info, 0, sizeof(struct mallinfo));
+  host_mallinfo(&info->aordblks, &info->uordblks);
   return 0;
 }
 
diff --git a/arch/sim/src/sim/up_hostmemory.c b/arch/sim/src/sim/up_hostmemory.c
index 82a38dbebf5..6d69cedb150 100644
--- a/arch/sim/src/sim/up_hostmemory.c
+++ b/arch/sim/src/sim/up_hostmemory.c
@@ -28,6 +28,7 @@
 #include <string.h>
 #include <malloc.h>
 #include <stdlib.h>
+#include <stdatomic.h>
 
 #include <sys/mman.h>
 #include <sys/stat.h>
@@ -40,6 +41,13 @@
 
 #include "up_internal.h"
 
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static atomic_int g_aordblks;
+static atomic_int g_uordblks;
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -145,28 +153,59 @@ void *host_memalign(size_t alignment, size_t size)
       return NULL;
     }
 
+  size = host_malloc_size(p);
+  g_aordblks += 1;
+  g_uordblks += size;
+
   return p;
 }
 
 void host_free(void *mem)
 {
+  size_t size;
+
+  if (mem == NULL)
+    {
+      return;
+    }
+
+  size = host_malloc_size(mem);
+  g_aordblks -= 1;
+  g_uordblks -= size;
   free(mem);
 }
 
 void *host_realloc(void *oldmem, size_t size)
 {
-  return realloc(oldmem, size);
+  size_t oldsize;
+  void *mem;
+
+  if (size == 0)
+    {
+      host_free(oldmem);
+      return NULL;
+    }
+  else if (oldmem == NULL)
+    {
+      return host_memalign(sizeof(void *), size);
+    }
+
+  oldsize = host_malloc_size(oldmem);
+  mem = realloc(oldmem, size);
+  if (mem == NULL)
+    {
+      return NULL;
+    }
+
+  size = host_malloc_size(mem);
+  g_uordblks -= oldsize;
+  g_uordblks += size;
+
+  return mem;
 }
 
-void host_mallinfo(struct host_mallinfo *info)
+void host_mallinfo(int *aordblks, int *uordblks)
 {
-  struct mallinfo tmp;
-
-  tmp = mallinfo();
-  info->arena = tmp.arena;
-  info->ordblks = tmp.ordblks;
-  info->aordblks = tmp.hblks;
-  info->mxordblk = tmp.usmblks;
-  info->uordblks = tmp.uordblks;
-  info->fordblks = tmp.fordblks;
+  *aordblks = g_aordblks;
+  *uordblks = g_uordblks;
 }
diff --git a/arch/sim/src/sim/up_internal.h b/arch/sim/src/sim/up_internal.h
index e9e21f585d4..1fc0743818e 100644
--- a/arch/sim/src/sim/up_internal.h
+++ b/arch/sim/src/sim/up_internal.h
@@ -94,21 +94,6 @@ struct qspi_dev_s;
 struct ioexpander_dev_s;
 struct i2c_master_s;
 
-/* This describes the information about memory allocations */
-
-struct host_mallinfo
-{
-  int arena;    /* This is the total size of memory allocated
-                 * for use by malloc in bytes. */
-  int ordblks;  /* This is the number of free (not in use) chunks */
-  int aordblks; /* This is the number of allocated (in use) chunks */
-  int mxordblk; /* Size of the largest free (not in use) chunk */
-  int uordblks; /* This is the total size of memory occupied by
-                 * chunks handed out by malloc. */
-  int fordblks; /* This is the total size of memory occupied
-                 * by free (not in use) chunks. */
-};
-
 /****************************************************************************
  * Public Data
  ****************************************************************************/
@@ -163,6 +148,7 @@ size_t host_malloc_size(void *mem);
 void *host_memalign(size_t alignment, size_t size);
 void host_free(void *mem);
 void *host_realloc(void *oldmem, size_t size);
+void host_mallinfo(int *aordblks, int *uordblks);
 
 /* up_hosttime.c ************************************************************/