zpool: import: use realloc for realloc, remove strtok

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12094

cmd/zpool/zpool_main.c

@@ -3499,16 +3499,8 @@ zpool_do_import(int argc, char **argv)
 			cachefile = optarg;
 			break;
 		case 'd':
-			if (searchdirs == NULL) {
-				searchdirs = safe_malloc(sizeof (char *));
-			} else {
-				char **tmp = safe_malloc((nsearch + 1) *
-				    sizeof (char *));
-				bcopy(searchdirs, tmp, nsearch *
-				    sizeof (char *));
-				free(searchdirs);
-				searchdirs = tmp;
-			}
+			searchdirs = safe_realloc(searchdirs,
+			    (nsearch + 1) * sizeof (char *));
 			searchdirs[nsearch++] = optarg;
 			break;
 		case 'D':
@@ -3698,24 +3690,16 @@ zpool_do_import(int argc, char **argv)
 	 * Check the environment for the preferred search path.
 	 */
 	if ((searchdirs == NULL) && (env = getenv("ZPOOL_IMPORT_PATH"))) {
-		char *dir;
+		char *dir, *tmp = NULL;
 
 		envdup = strdup(env);
 
-		dir = strtok(envdup, ":");
-		while (dir != NULL) {
-			if (searchdirs == NULL) {
-				searchdirs = safe_malloc(sizeof (char *));
-			} else {
-				char **tmp = safe_malloc((nsearch + 1) *
-				    sizeof (char *));
-				bcopy(searchdirs, tmp, nsearch *
-				    sizeof (char *));
-				free(searchdirs);
-				searchdirs = tmp;
-			}
+		for (dir = strtok_r(envdup, ":", &tmp);
+		    dir != NULL;
+		    dir = strtok_r(NULL, ":", &tmp)) {
+			searchdirs = safe_realloc(searchdirs,
+			    (nsearch + 1) * sizeof (char *));
 			searchdirs[nsearch++] = dir;
-			dir = strtok(NULL, ":");
 		}
 	}
 
@@ -3754,10 +3738,8 @@ zpool_do_import(int argc, char **argv)
 	}
 
 	if (err == 1) {
-		if (searchdirs != NULL)
-			free(searchdirs);
-		if (envdup != NULL)
-			free(envdup);
+		free(searchdirs);
+		free(envdup);
 		nvlist_free(policy);
 		nvlist_free(pools);
 		nvlist_free(props);
@@ -3795,10 +3777,8 @@ zpool_do_import(int argc, char **argv)
 	nvlist_free(props);
 	nvlist_free(pools);
 	nvlist_free(policy);
-	if (searchdirs != NULL)
-		free(searchdirs);
-	if (envdup != NULL)
-		free(envdup);
+	free(searchdirs);
+	free(envdup);
 
 	return (err ? 1 : 0);
 }

cmd/zpool/zpool_util.c

@@ -49,6 +49,22 @@ safe_malloc(size_t size)
 	return (data);
 }
 
+/*
+ * Utility function to guarantee realloc() success.
+ */
+void *
+safe_realloc(void *from, size_t size)
+{
+	void *data;
+
+	if ((data = realloc(from, size)) == NULL) {
+		(void) fprintf(stderr, "internal error: out of memory\n");
+		exit(1);
+	}
+
+	return (data);
+}
+
 /*
  * Display an out of memory error message and abort the current program.
  */

cmd/zpool/zpool_util.h

@@ -39,6 +39,7 @@ extern "C" {
  * Basic utility functions
  */
 void *safe_malloc(size_t);
+void *safe_realloc(void *, size_t);
 void zpool_no_memory(void);
 uint_t num_logs(nvlist_t *nv);
 uint64_t array64_max(uint64_t array[], unsigned int len);