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* Misaligned read/write of memory by GDB
@ 2004-06-28 21:18 Dave Brolley
  2004-06-28 22:50 ` Dave Brolley
  0 siblings, 1 reply; 7+ messages in thread
From: Dave Brolley @ 2004-06-28 21:18 UTC (permalink / raw)
  To: sid

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Hi,

Some sid components don't support misaligned reads/writes. The current 
cache components are the example which caused my particular problem. 
They punt on misaligned reads/writes, presumably so that they don't have 
to worry about accesses which cross cache line boundaries. This causes a 
problem when GDB attempts to read memory at unaligned addresses.

This patch to gdb::process_get_mem and gdb::process_set_mem forces any 
unaligned requests to use the existing byte-at-a-time method.

I've committed this patch. Let me know if there are any problems.

Dave

[-- Attachment #2: sid-gdb-align.ChangeLog --]
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2004-06-28  Dave Brolley  <brolley@redhat.com>

	* gdb.cxx (process_get_mem): Use byte-at-a-time access for unaligned
	requests.
	(process_set_mem): Ditto.


[-- Attachment #3: sid-gdb.patch.txt --]
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Index: sid/component/consoles/socketio.cxx
===================================================================
RCS file: /cvs/src/src/sid/component/consoles/socketio.cxx,v
retrieving revision 1.5
diff -c -p -r1.5 socketio.cxx
*** sid/component/consoles/socketio.cxx	4 Mar 2002 20:38:56 -0000	1.5
--- sid/component/consoles/socketio.cxx	22 Mar 2004 18:48:32 -0000
***************
*** 1,7 ****
  // socketio.cxx - A console that uses a socket to do its I/O.
  // -*- C++ -*-
  
! // Copyright (C) 1999, 2000, 2002 Red Hat.
  // This file is part of SID and is licensed under the GPL.
  // See the file COPYING.SID for conditions for redistribution.
  
--- 1,7 ----
  // socketio.cxx - A console that uses a socket to do its I/O.
  // -*- C++ -*-
  
! // Copyright (C) 1999-2002, 2004 Red Hat.
  // This file is part of SID and is licensed under the GPL.
  // See the file COPYING.SID for conditions for redistribution.
  
*************** void 
*** 297,302 ****
--- 297,306 ----
  socketio::fini_handler (host_int_4)
  {
    this->poll_control.cancel ();
+ 
+   // Flush out any remaining data
+   if (this->connected_p)
+     this->poll_transmit ();
  
    if (this->connected_p)
      {
Index: sid/component/gdb/gdb.cxx
===================================================================
RCS file: /cvs/src/src/sid/component/gdb/gdb.cxx,v
retrieving revision 1.10
diff -c -p -r1.10 gdb.cxx
*** sid/component/gdb/gdb.cxx	8 May 2002 19:15:30 -0000	1.10
--- sid/component/gdb/gdb.cxx	22 Mar 2004 18:48:32 -0000
***************
*** 1,6 ****
  // gdb.cxx - GDB stub implementation.  -*- C++ -*-
  
! // Copyright (C) 1999-2002 Red Hat.
  // This file is part of SID and is licensed under the GPL.
  // See the file COPYING.SID for conditions for redistribution.
  
--- 1,6 ----
  // gdb.cxx - GDB stub implementation.  -*- C++ -*-
  
! // Copyright (C) 1999-2002, 2004 Red Hat.
  // This file is part of SID and is licensed under the GPL.
  // See the file COPYING.SID for conditions for redistribution.
  
*************** gdb::deinit_handler (host_int_4) 
*** 1550,1556 ****
  {
    // disconnect if needed
    if (this->connected_p)
!     this->remote_rx_eof_handler ();
  }
  
  
--- 1550,1562 ----
  {
    // disconnect if needed
    if (this->connected_p)
!     {
!       // shut down target
!       target_power (false);
!       // signal gdb
!       gdbserv_fromtarget_exit (gdbserv, 0);
!       this->remote_rx_eof_handler ();
!     }
  }
  
  
Index: sid/main/dynamic/commonCfg.cxx
===================================================================
RCS file: /cvs/src/src/sid/main/dynamic/commonCfg.cxx,v
retrieving revision 1.6
diff -c -p -r1.6 commonCfg.cxx
*** sid/main/dynamic/commonCfg.cxx	27 Oct 2003 18:55:34 -0000	1.6
--- sid/main/dynamic/commonCfg.cxx	22 Mar 2004 18:48:34 -0000
*************** SessionCfg::SessionCfg (const string nam
*** 530,536 ****
      tcl_bridge (NULL),
      loader (NULL),
      verbose (false),
!     use_stdio (true)
  {
    add_child (host_sched);
    add_child (sim_sched);
--- 530,538 ----
      tcl_bridge (NULL),
      loader (NULL),
      verbose (false),
!     use_stdio (true),
!     board_count (0),
!     gdb_count (0)
  {
    add_child (host_sched);
    add_child (sim_sched);
*************** void SessionCfg::use_tcl_bridge ()
*** 657,662 ****
--- 659,684 ----
    init_seq->add_output (7, tcl_bridge, "!event");
  }
  
+ void SessionCfg::write_config (Writer &w)
+ {
+   AggregateCfg::write_config (w);
+ 
+   // Stop the host scheduler if all of the GDB stubs are stopped
+   if (gdb_count)
+     {
+       assert (host_sched);
+       Setting (host_sched, "yield-host-time-threshold",
+ 	       sidutil::make_attribute (gdb_count)).write_to (w);
+       Setting (host_sched, "yield-host-time?", "0").write_to (w);
+     }
+ 
+   // Stop the sim scheduler if any of the GDB stubs are stopped
+   assert (sim_sched);
+   Setting (sim_sched, "enable-threshold",
+ 	   sidutil::make_attribute (board_count)).write_to (w);
+   Setting (sim_sched, "enabled?",
+ 	   sidutil::make_attribute (board_count)).write_to (w);
+ }
  
  // LoaderCfg 
  LoaderCfg::~LoaderCfg () {}
*************** void BoardCfg::set_gdb (const string por
*** 920,925 ****
--- 942,948 ----
    gdb = new GdbCfg ("gdb", port, cpu, this, sess);
    add_child (gdb);
    sess->use_no_stdio ();
+   sess->add_gdb ();
  }
  
  
Index: sid/main/dynamic/commonCfg.h
===================================================================
RCS file: /cvs/src/src/sid/main/dynamic/commonCfg.h,v
retrieving revision 1.3
diff -c -p -r1.3 commonCfg.h
*** sid/main/dynamic/commonCfg.h	21 Oct 2003 21:39:04 -0000	1.3
--- sid/main/dynamic/commonCfg.h	22 Mar 2004 18:48:34 -0000
*************** struct UlogCfg
*** 182,187 ****
--- 182,188 ----
  
  // you should really only make one of these, with an empty name,
  // unless you want some crazy multi-session support.
+ class BoardCfg;
  class LoaderCfg;
  
  struct SessionCfg :
*************** struct SessionCfg :
*** 214,219 ****
--- 215,226 ----
    bool use_stdio;
    void add_ulog_file (const string filename);
    map<const string, AtomicCfg *> ulog_map;
+   void add_gdb () { ++gdb_count; }
+   void add_board (ComponentCfg *b) { ++board_count; add_child (b); }
+   virtual void write_config (Writer &w);
+ private:
+   sid::host_int_4 board_count;
+   sid::host_int_4 gdb_count;
  };
  
  class CpuCfg :
*************** public:
*** 277,283 ****
    virtual ~GprofCfg ();
  };
  
- class BoardCfg;
  class GdbCfg :
    virtual public AggregateCfg
  {
--- 284,289 ----
Index: sid/main/dynamic/mainDynamic.cxx
===================================================================
RCS file: /cvs/src/src/sid/main/dynamic/mainDynamic.cxx,v
retrieving revision 1.5
diff -c -p -r1.5 mainDynamic.cxx
*** sid/main/dynamic/mainDynamic.cxx	21 Oct 2003 21:39:04 -0000	1.5
--- sid/main/dynamic/mainDynamic.cxx	22 Mar 2004 18:48:34 -0000
*************** main(int argc, char* argv[])
*** 617,623 ****
  	      {
  		need_sess (sess);
  		if (curr_board)
! 		  sess->add_child (curr_board);
  		curr_board = NULL;
  		string new_board_type = optstring();
  		string new_board_name (new_board_type + "-" + 
--- 617,623 ----
  	      {
  		need_sess (sess);
  		if (curr_board)
! 		  sess->add_board (curr_board);
  		curr_board = NULL;
  		string new_board_type = optstring();
  		string new_board_name (new_board_type + "-" + 
*************** main(int argc, char* argv[])
*** 878,884 ****
      }
  
    if (sess && curr_board)
!     sess->add_child (curr_board);
  
    if (persistent_p)
      config_items.push_back (make_pair (false, string("set main persistent? true")));
--- 878,884 ----
      }
  
    if (sess && curr_board)
!     sess->add_board (curr_board);
  
    if (persistent_p)
      config_items.push_back (make_pair (false, string("set main persistent? true")));

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2004-07-01 17:02 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-06-28 21:18 Misaligned read/write of memory by GDB Dave Brolley
2004-06-28 22:50 ` Dave Brolley
2004-06-29 18:27   ` Frank Ch. Eigler
2004-06-29 19:14     ` Dave Brolley
2004-06-29 19:18       ` Frank Ch. Eigler
2004-06-29 20:40         ` Dave Brolley
2004-07-01 17:02           ` Dave Brolley

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