gdb/linux-nat.c:
- Workaround RHEL-5 kernels for detaching SIGSTOPped processes (BZ 498595).

--- gdb-6.8/gdb-orig/symfile.c	2008-08-21 00:06:50.000000000 +0200
+++ gdb-6.8/gdb/symfile.c	2008-08-21 22:31:00.000000000 +0200
@@ -1456,8 +1456,10 @@ find_separate_debug_file (struct objfile
       /* Prevent looping on a stripped .debug file.  */
       if (build_id_name != NULL && strcmp (build_id_name, objfile->name) == 0)
         {
+#if 0 /* RHEL-5 backward behavior compatibility.  */
 	  warning (_("\"%s\": separate debug info file has no debug info"),
 		   build_id_name);
+#endif
 	  xfree (build_id_name);
 	}
       else if (build_id_name != NULL)
--- gdb-7.0-orig/gdb/linux-nat.c	2009-12-19 20:53:46.000000000 +0100
+++ gdb-7.0/gdb/linux-nat.c	2009-12-19 20:55:02.000000000 +0100
@@ -1604,8 +1604,22 @@ GPT: lwp %s had signal %s, but it is in 
 	*status = lp->status;
     }
 
-  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;
 }