[Powerpc-utils-devel] [PATCH] drmgr: Combine the init_node() and examine_child() routines

[Nathan F. <nf...@li...>]

The complexity of the init_node() and examine_child() routines that call
each other recursively is causing drmgr to segfault in odd and sometimes
slightly differing ways. Each instance does involve drmgr segfaulting in
libc malloc code.

This patch re-writes these two routines to combine them into a single
routine that is called recursively. The result is cleaner code that no
longer segfaults.

Signed-off-by: Nathan Fontenot <nf...@li...>
---
 src/drmgr/common_pci.c |  100 ++++++++++++++++--------------------------------
 1 file changed, 34 insertions(+), 66 deletions(-)

diff --git a/src/drmgr/common_pci.c b/src/drmgr/common_pci.c
index 04a8a35..590c9b2 100644
--- a/src/drmgr/common_pci.c
+++ b/src/drmgr/common_pci.c
@@ -304,11 +304,6 @@ add_child_node(struct dr_node *parent, char *child_path)
 	parent->children = child;
 }
 
-/* This forward declaration is needed because init_node and examine_child
- * call each other.
- */
-static int examine_child(struct dr_node *, char *);
-
 /**
  * init_node
  *
@@ -318,82 +313,55 @@ static int examine_child(struct dr_node *, char *);
 static int
 init_node(struct dr_node *node)
 {
-	struct dirent **de_list, *de;
-	char *newpath;
-	int count;
-	int rc, i;
+	DIR *d;
+	struct dirent *de;
+	char child_path[DR_PATH_MAX];
+	uint32_t my_drc_index;
+	int rc;
 
 	if (node->is_owned)
 		find_ofdt_dname(node, node->ofdt_path);
 
-	count = scandir(node->ofdt_path, &de_list, 0, alphasort);
-	for (i = 0; i < count; i++) {
-		de = de_list[i];
+	d = opendir(node->ofdt_path);
+	if (!d)
+		return -1;
+
+	rc = 0;
+	while ((de = readdir(d)) != NULL) {
 		if ((de->d_type != DT_DIR) || is_dot_dir(de->d_name))
 			continue;
 
-		newpath = zalloc(strlen(node->ofdt_path) +
-				 strlen(de->d_name) + 2);
-		if (newpath == NULL) {
-			say(ERROR, "Could not allocate path for node at "
-			    "%s/%s\n", node->ofdt_path, de->d_name);
-			return 1;
-		}
-
-		sprintf(newpath, "%s/%s", node->ofdt_path, de->d_name);
-		rc = examine_child(node, newpath);
-		if (rc)
-			return rc;
-	}
-
-	return 0;
-}
-
-/**
- * examine_children
- *
- * @param node
- * @param child_path
- * @returns 0 on success, !0 otherwise
- */
-static int
-examine_child(struct dr_node *node, char *child_path)
-{
-	uint32_t my_drc_index;
-	int used = 0;
-	int rc = 0;
+		sprintf(child_path, "%s/%s", node->ofdt_path, de->d_name);
 
-	if (get_my_drc_index(child_path, &my_drc_index))
-		goto done;
+		if (get_my_drc_index(child_path, &my_drc_index))
+			continue;
 
-	if (node->dev_type == PCI_HP_DEV) {
-		if (node->drc_index == my_drc_index) {
-			/* Add hotplug children */
-			add_child_node(node, child_path);
-			used = 1;
-		}
-	} else {
-		if (! node->is_owned) {
+		if (node->dev_type == PCI_HP_DEV) {
 			if (node->drc_index == my_drc_index) {
-				/* Update node path */
-				snprintf(node->ofdt_path, DR_PATH_MAX, "%s",
-					 child_path);
-				node->is_owned = 1;
-				used = 1;
-
-				/* Populate w/ children */
-				rc = init_node(node);
+				/* Add hotplug children */
+				add_child_node(node, child_path);
 			}
 		} else {
-			/* Add all DR-capable children */
-			add_child_node(node, child_path);
-			used = 1;
+			if (!node->is_owned) {
+				if (node->drc_index == my_drc_index) {
+					/* Update node path */
+					snprintf(node->ofdt_path, DR_PATH_MAX,
+						 "%s", child_path);
+					node->is_owned = 1;
+
+					/* Populate w/ children */
+					rc = init_node(node);
+					if (rc)
+						break;
+				}
+			} else {
+				/* Add all DR-capable children */
+				add_child_node(node, child_path);
+			}
 		}
 	}
-done:
-	if (! used)
-		free(child_path);
 
+	closedir(d);
 	return rc;
 }