[patch] Fix linux-nat.c new_lp dropped status

[Jan Kratochvil <jan.kratochvil@redhat.com>]

Hi,

while reading the code it seems to me it can drop non-SIGSTOP status in this
case.  It can happen only during some racy case while creating a thread,
I have not tried to exploit it.

Does the patch make sense?  I have no dependency on it, I just have seen it.

No regressions on {x86_64,x86_64-m32,i686}-fedora12-linux-gnu.


Thanks,
Jan


--- a/gdb/linux-nat.c
+++ b/gdb/linux-nat.c
@@ -2288,6 +2288,23 @@ linux_handle_extended_wait (struct lwp_info *lp, int status,
 	      linux_ops->to_resume (linux_ops, pid_to_ptid (new_pid),
 				    0, signo);
 	    }
+	  else
+	    {
+	      if (status != 0)
+		{
+		  /* We created NEW_LP so it cannot yet contain STATUS.  */
+		  gdb_assert (new_lp->status == 0);
+
+		  /* Save the wait status to report later.  */
+		  if (debug_linux_nat)
+		    fprintf_unfiltered (gdb_stdlog,
+					"LHEW: waitpid of new LWP %ld, "
+					"saving status %s\n",
+					(long) GET_LWP (new_lp->ptid),
+					status_to_str (status));
+		  new_lp->status = status;
+		}
+	    }
 
 	  if (debug_linux_nat)
 	    fprintf_unfiltered (gdb_stdlog,