From: Arthur de Jong <arthur@arthurdejong.org>
Subject: Avoid signal race condition on start-up

This only restores the signal mask after signal handlers are in place
and the daemon has completely daemonised to avoid a race condition in
the start-up phase of nslcd where a signal could be sent to nslcd
causing it to quit or fail to write information to the parent process.

This also block signals sooner in an attempt to avoid race conditions.

Origin: upstream, http://arthurdejong.org/git/nss-pam-ldapd/commit/?id=1d3b19b1ecd3b10f36e8925e8a752a28e3e74b56
Origin: upstream, http://arthurdejong.org/git/nss-pam-ldapd/commit/?id=530cc24c83dd5d2d347acb40d64c3ae06a43a293
Bug-Debian: http://bugs.debian.org/759544

--- a/nslcd/nslcd.c
+++ b/nslcd/nslcd.c
@@ -648,6 +648,17 @@ int main(int argc, char *argv[])
 #ifdef HAVE_PTHREAD_TIMEDJOIN_NP
   struct timespec ts;
 #endif /* HAVE_PTHREAD_TIMEDJOIN_NP */
+  /* block all these signals so our worker threads won't handle them */
+  sigemptyset(&signalmask);
+  sigaddset(&signalmask, SIGHUP);
+  sigaddset(&signalmask, SIGINT);
+  sigaddset(&signalmask, SIGQUIT);
+  sigaddset(&signalmask, SIGABRT);
+  sigaddset(&signalmask, SIGPIPE);
+  sigaddset(&signalmask, SIGTERM);
+  sigaddset(&signalmask, SIGUSR1);
+  sigaddset(&signalmask, SIGUSR2);
+  pthread_sigmask(SIG_BLOCK, &signalmask, &oldmask);
   /* close all file descriptors (except stdin/out/err) */
   daemonize_closefds();
   /* parse the command line */
@@ -785,17 +796,6 @@ int main(int argc, char *argv[])
     }
     log_log(LOG_DEBUG, "setuid(%d) done", (int)nslcd_cfg->uid);
   }
-  /* block all these signals so our worker threads won't handle them */
-  sigemptyset(&signalmask);
-  sigaddset(&signalmask, SIGHUP);
-  sigaddset(&signalmask, SIGINT);
-  sigaddset(&signalmask, SIGQUIT);
-  sigaddset(&signalmask, SIGABRT);
-  sigaddset(&signalmask, SIGPIPE);
-  sigaddset(&signalmask, SIGTERM);
-  sigaddset(&signalmask, SIGUSR1);
-  sigaddset(&signalmask, SIGUSR2);
-  pthread_sigmask(SIG_BLOCK, &signalmask, &oldmask);
   /* start worker threads */
   log_log(LOG_INFO, "accepting connections");
   nslcd_threads = (pthread_t *)malloc(nslcd_cfg->threads * sizeof(pthread_t));
@@ -815,8 +815,7 @@ int main(int argc, char *argv[])
       exit(EXIT_FAILURE);
     }
   }
-  pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
-  /* install signalhandlers for some signals */
+  /* install signal handlers for some signals */
   install_sighandler(SIGHUP, sig_handler);
   install_sighandler(SIGINT, sig_handler);
   install_sighandler(SIGQUIT, sig_handler);
@@ -827,6 +826,8 @@ int main(int argc, char *argv[])
   install_sighandler(SIGUSR2, SIG_IGN);
   /* signal the starting process to exit because we can provide services now */
   daemonize_ready(EXIT_SUCCESS, NULL);
+  /* enable receiving of signals */
+  pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
   /* wait until we received a signal */
   while ((nslcd_receivedsignal == 0) || (nslcd_receivedsignal == SIGUSR1))
   {