Index: gdb-7.4.50.20120602/gdb/linux-nat.c

===================================================================

--- gdb-7.4.50.20120602.orig/gdb/linux-nat.c	2012-06-02 20:54:30.000000000 +0200

+++ gdb-7.4.50.20120602/gdb/linux-nat.c	2012-06-02 20:56:03.966493352 +0200

@@ -1816,8 +1816,22 @@ get_pending_status (struct lwp_info *lp,

 			    gdb_signal_to_string (signo));

     }

-  if (*status == 0 && GET_PID (lp->ptid) == pid_was_stopped)

-    *status = W_STOPCODE (SIGSTOP);

+  /* Workaround RHEL-5 kernel which has unreliable PTRACE_DETACH, SIGSTOP (that

+     many TIDs are left unstopped).  See RH Bug 496732.  */

+  if (GET_PID (lp->ptid) == pid_was_stopped)

+    {

+      int err;

+

+      errno = 0;

+      err = kill_lwp (GET_LWP (lp->ptid), SIGSTOP);

+      if (debug_linux_nat)

+	{

+	  fprintf_unfiltered (gdb_stdlog,

+			      "SC:  lwp kill %d %s\n",

+			      err,

+			      errno ? safe_strerror (errno) : "ERRNO-OK");

+	}

+    }

   return 0;

 }