svm: asan: fix asan support

 - restrict the unittests SVM address space to what is supported by ASan
 - mark SVM mmap()ed address space accessible for ASan
 - SVM shared memory heap scheme means some allocation can happen
   outside the current process. Lazily mark those accessible for ASan

Type: fix

Change-Id: I7c196c80b2a5297651d0afa54f1a8e478fcf59b1
Signed-off-by: Benoît Ganne <bganne@cisco.com>
diff --git a/src/svm/svm.c b/src/svm/svm.c
index 6249a34..20f4b7a 100644
--- a/src/svm/svm.c
+++ b/src/svm/svm.c
@@ -329,6 +329,7 @@
 	  return -3;
 	}
       close (fd);
+      CLIB_MEM_UNPOISON (rp->data_base, map_size);
       rp->backing_file = (char *) format (0, "%s\0", a->backing_file);
       rp->flags |= SVM_FLAGS_FILE;
     }
@@ -414,6 +415,7 @@
 	  return -3;
 	}
       close (fd);
+      CLIB_MEM_UNPOISON (rp->data_base, map_size);
     }
   return 0;
 }
@@ -607,6 +609,7 @@
 	  return (0);
 	}
       close (svm_fd);
+      CLIB_MEM_UNPOISON (rp, a->size);
 
       svm_region_init_mapped_region (a, rp);
 
@@ -663,6 +666,9 @@
 	  clib_warning ("mmap");
 	  return (0);
 	}
+
+      CLIB_MEM_UNPOISON (rp, MMAP_PAGESIZE);
+
       /*
        * We lost the footrace to create this region; make sure
        * the winner has crossed the finish line.
@@ -699,6 +705,8 @@
 
       close (svm_fd);
 
+      CLIB_MEM_UNPOISON (rp, a->size);
+
       if ((uword) rp != rp->virtual_base)
 	{
 	  clib_warning ("mmap botch");
@@ -1042,6 +1050,7 @@
   oldheap = svm_push_pvt_heap (rp);	/* nb vec_delete() in the loop */
 
   /* Remove the caller from the list of mappers */
+  CLIB_MEM_UNPOISON (rp->client_pids, vec_bytes (rp->client_pids));
   for (i = 0; i < vec_len (rp->client_pids); i++)
     {
       if (rp->client_pids[i] == mypid)
@@ -1174,6 +1183,7 @@
   virtual_base = root_rp->virtual_base;
   virtual_size = root_rp->virtual_size;
 
+  CLIB_MEM_UNPOISON (root_rp->client_pids, vec_bytes (root_rp->client_pids));
   for (i = 0; i < vec_len (root_rp->client_pids); i++)
     {
       if (root_rp->client_pids[i] == mypid)