treematch: Fix warnings

Fix two classes of warnings in the treematch code.  First, handle
the error condition for fgets(), which may leave the buffer in an
undefined state in error.  Define the state of the buffer on error
by initializing the first character to a NULL terminator, which
will trip the already existing error handling.

Second, handle errors from a call to hwloc that could cause
very large allocations (due to -1 being cast to a size_t).

Signed-off-by: Brian Barrett <bbarrett@amazon.com>

Author: bwbarrett

3rd-party/treematch/tm_topology.c

@@ -68,7 +68,13 @@ tm_topology_t * tgt_to_tm(char *filename)
     printf("Reading TGT file: %s\n",filename);
 
 
-  fgets(line,1024,pf);
+  if (NULL == fgets(line,1024,pf)) {
+      /* either an error has occurred (and is in an unknown state) or
+         we hit EOF and line is empty.  Either way, make line the
+         empty string to avoid errors later */
+      line[0] = '\0';
+  }
+
   fclose(pf);
 
   s = strstr(line,"tleaf");
@@ -159,7 +165,13 @@ double ** topology_to_arch(hwloc_topology_t topology)
   double **arch = NULL;
 
   nb_proc = hwloc_get_nbobjs_by_type(topology, HWLOC_OBJ_PU);
-  arch = (double**)MALLOC(sizeof(double*)*nb_proc);
+  if (nb_proc < 0) {
+    return NULL;
+  }
+  arch = (double**)malloc(sizeof(double*)*nb_proc);
+  if (NULL == arch) {
+    return NULL;
+  }
   for( i = 0 ; i < nb_proc ; i++ ){
     obj_proc1 = hwloc_get_obj_by_type(topology,HWLOC_OBJ_PU,i);
     arch[obj_proc1->os_index] = (double*)MALLOC(sizeof(double)*nb_proc);
@@ -534,7 +546,9 @@ int  tm_topology_add_binding_constraints(char *constraints_filename, tm_topology
 
   /* compute the size of the array to store the constraints*/
   n = 0;
-  fgets(line, LINE_SIZE, pf);
+  if (NULL == fgets(line, LINE_SIZE, pf)) {
+    line[0] = '\0';
+  }
   l = line;
   while((ptr=strtok(l," \t"))){
     l = NULL;
@@ -545,7 +559,9 @@ int  tm_topology_add_binding_constraints(char *constraints_filename, tm_topology
   tab = (int*)MALLOC(n*sizeof(int));
 
   rewind(pf);
-  fgets(line, LINE_SIZE, pf);
+  if (NULL == fgets(line, LINE_SIZE, pf)) {
+    line[0] = '\0';
+  }
   fclose(pf);
   l = line;
   i = 0;