From 6bdfbc4cb5470f63d4905e89f89a9829af354316 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Thu, 18 Feb 2021 23:30:24 +0100 Subject: libbb: fix '--help' handling in FEATURE_SH_NOFORK=y Most BusyBox applets respond to the '--help' option by printing a usage message. This is normally handled by busybox_main() so applet main routines don't have support for '--help'. In standalone shell mode with FEATURE_SH_NOFORK enabled nofork applets are invoked directly, bypassing busybox_main(). This results in inconsistent handling of '--help': - applets which call getopt() report "unrecognized option '--help'" and print help anyway; - realpath says "--help: No such file or directory" and doesn't print help; - usleep says "invalid number '--help'" and doesn't print help. Avoid inconsistency by checking for '--help' in run_nofork_applet(). Bug found by Ron Yorston. function old new delta show_usage_if_dash_dash_help - 70 +70 run_nofork_applet 347 362 +15 run_applet_no_and_exit 432 365 -67 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 1/1 up/down: 85/-67) Total: 18 bytes Signed-off-by: Denys Vlasenko --- libbb/vfork_daemon_rexec.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'libbb/vfork_daemon_rexec.c') diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c index 65271e84f..a49fe8e01 100644 --- a/libbb/vfork_daemon_rexec.c +++ b/libbb/vfork_daemon_rexec.c @@ -109,8 +109,13 @@ int FAST_FUNC run_nofork_applet(int applet_no, char **argv) char *tmp_argv[argc+1]; memcpy(tmp_argv, argv, (argc+1) * sizeof(tmp_argv[0])); applet_name = tmp_argv[0]; + + /* longjmp's (instead of returning) if --help is seen */ + show_usage_if_dash_dash_help(applet_no, argv); + /* Finally we can call NOFORK applet's main() */ rc = applet_main[applet_no](argc, tmp_argv); + /* Important for shells: `which CMD` was failing */ fflush_all(); } else { -- cgit v1.2.3