Re: "The target is not responding to interrupt requests" after re-attach

[Dmitry Antipov <dantipov@nvidia.com>]

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On 10/19/2017 02:39 PM, Pedro Alves wrote:

> No good reason.  Sounds like you found a bug.

Currently gdbserver installs SIGIO handler just once, in initialize_async_io ()
called from captured_main (), and this handler is removed when remote_desc
is closed in remote_close (). Next, when a new instance of remote_desc is
fetched from accept () and has '\003' arrived, input_interrupt () is never
called because it is not registered as SIGIO handler.

Probably the fix is to (re)install SIGIO handler each time when a new
async-served descriptor gets hooked into an event loop, for example,
in enable_async_notification ().

Dmitry




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diff --git a/gdb/gdbserver/remote-utils.c b/gdb/gdbserver/remote-utils.c
index 66e065225b..f686debeaa 100644
--- a/gdb/gdbserver/remote-utils.c
+++ b/gdb/gdbserver/remote-utils.c
@@ -92,6 +92,7 @@ static int readchar_callback = NOT_SCHEDULED;
 static int readchar (void);
 static void reset_readchar (void);
 static void reschedule (void);
+static void input_interrupt (int);
 
 /* A cache entry for a successfully looked-up symbol.  */
 struct sym_cache
@@ -149,6 +150,10 @@ enable_async_notification (int fd)
   fcntl (fd, F_SETOWN, getpid ());
 #endif
 #endif
+  /* Install SIGIO handler.  */
+#ifndef USE_WIN32API
+  signal (SIGIO, input_interrupt);
+#endif
 }
 
 static int
@@ -859,11 +864,6 @@ initialize_async_io (void)
   /* Make sure that async I/O starts blocked.  */
   async_io_enabled = 1;
   disable_async_io ();
-
-  /* Install the signal handler.  */
-#ifndef USE_WIN32API
-  signal (SIGIO, input_interrupt);
-#endif
 }
 
 /* Internal buffer used by readchar.