Don't modify argv[] in user tools

argv[] gets modified during string parsing for input arguments. This
is reflected in the live process listing. Don't do that.

Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Giuseppe Di Natale <guss80@gmail.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: DHE <git@dehacked.net>
Closes #7760

cmd/zfs/zfs_main.c

@@ -7041,6 +7041,7 @@ main(int argc, char **argv)
 	int ret = 0;
 	int i = 0;
 	char *cmdname;
+	char **newargv;
 
 	(void) setlocale(LC_ALL, "");
 	(void) textdomain(TEXT_DOMAIN);
@@ -7095,17 +7096,26 @@ main(int argc, char **argv)
 
 	libzfs_print_on_error(g_zfs, B_TRUE);
 
+	/*
+	 * Many commands modify input strings for string parsing reasons.
+	 * We create a copy to protect the original argv.
+	 */
+	newargv = malloc((argc + 1) * sizeof (newargv[0]));
+	for (i = 0; i < argc; i++)
+		newargv[i] = strdup(argv[i]);
+	newargv[argc] = NULL;
+
 	/*
 	 * Run the appropriate command.
 	 */
 	libzfs_mnttab_cache(g_zfs, B_TRUE);
 	if (find_command_idx(cmdname, &i) == 0) {
 		current_command = &command_table[i];
-		ret = command_table[i].func(argc - 1, argv + 1);
+		ret = command_table[i].func(argc - 1, newargv + 1);
 	} else if (strchr(cmdname, '=') != NULL) {
 		verify(find_command_idx("set", &i) == 0);
 		current_command = &command_table[i];
-		ret = command_table[i].func(argc, argv);
+		ret = command_table[i].func(argc, newargv);
 	} else {
 		(void) fprintf(stderr, gettext("unrecognized "
 		    "command '%s'\n"), cmdname);
@@ -7113,6 +7123,10 @@ main(int argc, char **argv)
 		ret = 1;
 	}
 
+	for (i = 0; i < argc; i++)
+		free(newargv[i]);
+	free(newargv);
+
 	if (ret == 0 && log_history)
 		(void) zpool_log_history(g_zfs, history_str);
 

cmd/zpool/zpool_main.c

@@ -7971,6 +7971,7 @@ main(int argc, char **argv)
 	int ret = 0;
 	int i = 0;
 	char *cmdname;
+	char **newargv;
 
 	(void) setlocale(LC_ALL, "");
 	(void) textdomain(TEXT_DOMAIN);
@@ -8005,16 +8006,25 @@ main(int argc, char **argv)
 
 	zfs_save_arguments(argc, argv, history_str, sizeof (history_str));
 
+	/*
+	 * Many commands modify input strings for string parsing reasons.
+	 * We create a copy to protect the original argv.
+	 */
+	newargv = malloc((argc + 1) * sizeof (newargv[0]));
+	for (i = 0; i < argc; i++)
+		newargv[i] = strdup(argv[i]);
+	newargv[argc] = NULL;
+
 	/*
 	 * Run the appropriate command.
 	 */
 	if (find_command_idx(cmdname, &i) == 0) {
 		current_command = &command_table[i];
-		ret = command_table[i].func(argc - 1, argv + 1);
+		ret = command_table[i].func(argc - 1, newargv + 1);
 	} else if (strchr(cmdname, '=')) {
 		verify(find_command_idx("set", &i) == 0);
 		current_command = &command_table[i];
-		ret = command_table[i].func(argc, argv);
+		ret = command_table[i].func(argc, newargv);
 	} else if (strcmp(cmdname, "freeze") == 0 && argc == 3) {
 		/*
 		 * 'freeze' is a vile debugging abomination, so we treat
@@ -8031,6 +8041,10 @@ main(int argc, char **argv)
 		ret = 1;
 	}
 
+	for (i = 0; i < argc; i++)
+		free(newargv[i]);
+	free(newargv);
+
 	if (ret == 0 && log_history)
 		(void) zpool_log_history(g_zfs, history_str);