NOMMU re-exec trick shuld not depend on existence of "don't daemonize"

option for every affected applet (and dnsd, for example, don't have one).
Thus rework re-exec support to not require it. Code got smaller too.


git-svn-id: svn://busybox.net/trunk/busybox@18219 69ca8d6d-28ef-0310-b511-8ec308f3f277

1 files changed, 9 insertions, 14 deletions

diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index 26d1826e0..3185f2d39 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -19,19 +19,18 @@
 #include "libbb.h"
 
 #ifdef BB_NOMMU
-void vfork_daemon_rexec(int nochdir, int noclose,
-                int argc, char **argv, char *foreground_opt)
+void vfork_daemon_rexec(int nochdir, int noclose, char **argv)
 {
         int fd;
-        char **vfork_args;
-        int a = 0;
 
         setsid();
 
         if (!nochdir)
                 xchdir("/");
 
-        if (!noclose && (fd = open(bb_dev_null, O_RDWR, 0)) != -1) {
+        if (!noclose) {
+                /* if "/dev/null" doesn't exist, bail out! */
+                fd = xopen(bb_dev_null, O_RDWR);
                 dup2(fd, STDIN_FILENO);
                 dup2(fd, STDOUT_FILENO);
                 dup2(fd, STDERR_FILENO);
@@ -39,21 +38,17 @@ void vfork_daemon_rexec(int nochdir, int noclose,
                         close(fd--);
         }
 
-        vfork_args = xzalloc(sizeof(char *) * (argc + 3));
-        vfork_args[a++] = CONFIG_BUSYBOX_EXEC_PATH;
-        while (*argv) {
-                vfork_args[a++] = *argv;
-                argv++;
-        }
-        vfork_args[a] = foreground_opt;
         switch (vfork()) {
         case 0: /* child */
                 /* Make certain we are not a session leader, or else we
                  * might reacquire a controlling terminal */
                 if (vfork())
                         _exit(0);
-                execv(vfork_args[0], vfork_args);
-                bb_perror_msg_and_die("execv %s", vfork_args[0]);
+                /* High-order bit of first char in argv[0] is a hidden
+                 * "we have (alrealy) re-execed, don't do it again" flag */
+                argv[0][0] |= 0x80;
+                execv(CONFIG_BUSYBOX_EXEC_PATH, argv);
+                bb_perror_msg_and_die("exec %s", CONFIG_BUSYBOX_EXEC_PATH);
         case -1: /* error */
                 bb_perror_msg_and_die("vfork");
         default: /* parent */