5 files changed, 20 insertions, 14 deletions

diff --git a/debianutils/start_stop_daemon.c b/debianutils/start_stop_daemon.c
index d8a0d7d46..cf792709c 100644
--- a/debianutils/start_stop_daemon.c
+++ b/debianutils/start_stop_daemon.c
@@ -14,6 +14,8 @@
 #include <getopt.h>
 #include <sys/resource.h>
 
+/* Override ENABLE_FEATURE_PIDFILE */
+#define WANT_PIDFILE 1
 #include "libbb.h"
 
 static int signal_nr = 15;
@@ -46,7 +48,7 @@ static int pid_is_exec(pid_t pid, const char *name)
         n = strcmp(execbuf, name);
         if (ENABLE_FEATURE_CLEAN_UP)
                 free(execbuf);
-        return ~n; /* nonzero (true) if execbuf == name */
+        return !n; /* nonzero (true) if execbuf == name */
 }
 
 static int pid_is_user(int pid, int uid)
@@ -301,10 +303,14 @@ int start_stop_daemon_main(int argc, char **argv)
                 pid_t pid = vfork();
                 if (pid < 0) /* error */
                         bb_perror_msg_and_die("vfork");
-                if (pid == 0) /* parent */
-                        return 0;
+                if (pid != 0) {
+                        /* parent */
+                        /* why _exit? the child may have changed the stack,
+                         * so "return 0" may do bad things */
+                        _exit(0);
                 }
                 /* 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(
@@ -316,11 +322,7 @@ int start_stop_daemon_main(int argc, char **argv)
         }
         if (opt & OPT_MAKEPID) {
                 /* user wants _us_ to make the pidfile */
-                FILE *pidf = xfopen(pidfile, "w");
-
-                pid_t pidt = getpid();
-                fprintf(pidf, "%d\n", pidt);
-                fclose(pidf);
+                write_pidfile(pidfile);
         }
         if (opt & OPT_c) {
                 struct bb_uidgid_t ugid;
diff --git a/include/libbb.h b/include/libbb.h
index 547b8f798..1cbcb41e4 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -619,8 +619,9 @@ llist_t *llist_rev(llist_t *list);
  *   llist_t *llist_add_to(llist_t *old_head, void *data)
  * etc does not result in smaller code... */
 
-
-#if ENABLE_FEATURE_PIDFILE
+/* start_stop_daemon and (udhcpc with ifupdown) are special - they want to
+ * create pidfiles regardless of FEATURE_PIDFILE. */
+#if ENABLE_FEATURE_PIDFILE || defined(WANT_PIDFILE)
 int write_pidfile(const char *path);
 #define remove_pidfile(f) ((void)unlink(f))
 #else
diff --git a/libbb/pidfile.c b/libbb/pidfile.c
index 79c3108fc..50af91f4e 100644
--- a/libbb/pidfile.c
+++ b/libbb/pidfile.c
@@ -6,9 +6,11 @@
  *
  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
+
+/* Override ENABLE_FEATURE_PIDFILE */
+#define WANT_PIDFILE 1
 #include "libbb.h"
 
-#if ENABLE_FEATURE_PIDFILE
 int write_pidfile(const char *path)
 {
         int pid_fd;
@@ -26,4 +28,3 @@ int write_pidfile(const char *path)
         close(pid_fd);
         return 1;
 }
-#endif
diff --git a/networking/ifupdown.c b/networking/ifupdown.c
index a15e1411e..040bbe389 100644
--- a/networking/ifupdown.c
+++ b/networking/ifupdown.c
@@ -536,8 +536,8 @@ static int manual_up_down(struct interface_defn_t *ifd, execfn *exec)
 static int bootp_up(struct interface_defn_t *ifd, execfn *exec)
 {
         return execute("bootpc[[ --bootfile %bootfile%]] --dev %iface%"
-                        "[[ --server %server%]][[ --hwaddr %hwaddr%]] "
-                        "--returniffail --serverbcast", ifd, exec);
+                        "[[ --server %server%]][[ --hwaddr %hwaddr%]]"
+                        " --returniffail --serverbcast", ifd, exec);
 }
 
 static int ppp_up(struct interface_defn_t *ifd, execfn *exec)
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index b84a6785a..4bb90c2da 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -11,6 +11,8 @@
 #include <getopt.h>
 #include <syslog.h>
 
+/* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
+#define WANT_PIDFILE 1
 #include "common.h"
 #include "dhcpd.h"
 #include "dhcpc.h"