*: introduce and use xvfork()

function                                             old     new   delta
time_main                                           1052    1285    +233
crontab_main                                         623     856    +233
ifupdown_main                                       2202    2403    +201
xvfork                                                 -      20     +20
passwd_main                                         1049    1053      +4
grave                                               1068    1066      -2
script_main                                          935     921     -14
vfork_or_die                                          20       -     -20
vfork_compressor                                     206     175     -31
open_as_user                                         109       -    -109
popen2                                               218       -    -218
edit_file                                            910     690    -220
run_command                                          268       -    -268
------------------------------------------------------------------------------
(add/remove: 1/4 grow/shrink: 4/4 up/down: 691/-882)         Total: -191 bytes

2 files changed, 3 insertions, 15 deletions

diff --git a/networking/ifupdown.c b/networking/ifupdown.c
index c12391863..8caff3f4d 100644
--- a/networking/ifupdown.c
+++ b/networking/ifupdown.c
@@ -1008,12 +1008,9 @@ static int popen2(FILE **in, FILE **out, char *command, char *param)
         xpiped_pair(outfd);
 
         fflush(NULL);
-        pid = vfork();
+        pid = xvfork();
 
-        switch (pid) {
-        case -1:  /* failure */
-                bb_perror_msg_and_die("vfork");
-        case 0:  /* child */
+        if (pid == 0) { /* child */
                 /* NB: close _first_, then move fds! */
                 close(infd.wr);
                 close(outfd.rd);
diff --git a/networking/sendmail.c b/networking/sendmail.c
index 1c23ca290..c195cc021 100644
--- a/networking/sendmail.c
+++ b/networking/sendmail.c
@@ -120,15 +120,6 @@ static void signal_handler(int signo)
 #undef err
 }
 
-/* libbb candidate */
-static pid_t vfork_or_die(void)
-{
-        pid_t pid = vfork();
-        if (pid < 0)
-                bb_perror_msg_and_die("vfork");
-        return pid;
-}
-
 static void launch_helper(const char **argv)
 {
         // setup vanilla unidirectional pipes interchange
@@ -137,7 +128,7 @@ static void launch_helper(const char **argv)
 
         xpipe(pipes);
         xpipe(pipes+2);
-        helper_pid = vfork_or_die();
+        helper_pid = xvfork();
         idx = (!helper_pid) * 2;
         xdup2(pipes[idx], STDIN_FILENO);
         xdup2(pipes[3-idx], STDOUT_FILENO);