Downgrade fatal to warning in linux_async

This commit downgrades a fatal error to a warning in linux_async.
linux_async is called from two different places in gdbserver:

 Via target_async from handle_accept_event.  The argument
   is always zero, so the warning will never be printed here.

 Via start_non_stop from handle_general_set.  This prints
   its own error message to stderr on failure, which will
   be preceded by the warning if it is emitted.

gdb/gdbserver/ChangeLog:

	* linux-low.c (linux_async): Replace fatal with warning.
	Tidy up and return.
	(linux_start_non_stop): Return -1 if linux_async failed.

1 files changed, 12 insertions, 1 deletions

diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index f8b3e68..ec3260e 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -5107,7 +5107,14 @@ linux_async (int enable)
       if (enable)
 	{
 	  if (pipe (linux_event_pipe) == -1)
-	    fatal ("creating event pipe failed.");
+	    {
+	      linux_event_pipe[0] = -1;
+	      linux_event_pipe[1] = -1;
+	      sigprocmask (SIG_UNBLOCK, &mask, NULL);
+
+	      warning ("creating event pipe failed.");
+	      return previous;
+	    }
 
 	  fcntl (linux_event_pipe[0], F_SETFL, O_NONBLOCK);
 	  fcntl (linux_event_pipe[1], F_SETFL, O_NONBLOCK);
@@ -5140,6 +5147,10 @@ linux_start_non_stop (int nonstop)
 {
   /* Register or unregister from event-loop accordingly.  */
   linux_async (nonstop);
+
+  if (target_is_async_p () != (nonstop != 0))
+    return -1;
+
   return 0;
 }