From b182e9ad6011909fdb76358431d23d195febaf54 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 4 Aug 2017 23:04:17 +0200 Subject: libbb: use _exit, not exit, in bb_daemonize_or_rexec() By the time we reach exit in parent, child already exited or execed. We should not re-run libc cleanup code. While at it, introduce bb_daemon_helper() and add a few comments. Signed-off-by: Denys Vlasenko --- debianutils/start_stop_daemon.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'debianutils') diff --git a/debianutils/start_stop_daemon.c b/debianutils/start_stop_daemon.c index 9d60b2c7f..07c104baa 100644 --- a/debianutils/start_stop_daemon.c +++ b/debianutils/start_stop_daemon.c @@ -516,6 +516,11 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv) /* DAEMON_DEVNULL_STDIO is superfluous - * it's always done by bb_daemonize() */ #else + /* Daemons usually call bb_daemonize_or_rexec(), but SSD can do + * without: SSD is not itself a daemon, it _execs_ a daemon. + * The usual NOMMU problem of "child can't run indefinitely, + * it must exec" does not bite us: we exec anyway. + */ pid_t pid = xvfork(); if (pid != 0) { /* parent */ @@ -525,12 +530,8 @@ int start_stop_daemon_main(int argc UNUSED_PARAM, char **argv) } /* Child */ setsid(); /* detach from controlling tty */ - /* Redirect stdio to /dev/null, close extra FDs. - * We do not actually daemonize because of DAEMON_ONLY_SANITIZE */ - bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO - + DAEMON_CLOSE_EXTRA_FDS - + DAEMON_ONLY_SANITIZE, - NULL /* argv, unused */ ); + /* Redirect stdio to /dev/null, close extra FDs */ + bb_daemon_helper(DAEMON_DEVNULL_STDIO + DAEMON_CLOSE_EXTRA_FDS); #endif } if (opt & OPT_MAKEPID) { -- cgit v1.2.3