From 9067f13be067f39f6c8586926b190b7dee0def3d Mon Sep 17 00:00:00 2001
From: Denis Vlasenko <vda.linux@googlemail.com>
Date: Sat, 24 Mar 2007 12:11:17 +0000
Subject: 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.
---
libbb/vfork_daemon_rexec.c | 23 +++++++++--------------
1 file changed, 9 insertions(+), 14 deletions(-)
(limited to 'libbb')
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 */
--
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