server/debugger.c

   1 /*
   2  * Server-side debugger functions
   3  *
   4  * Copyright (C) 1999 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <assert.h>
  25 #include <signal.h>
  26 #include <string.h>
  27 #include <stdarg.h>
  28 #include <stdio.h>
  29
  30 #include "ntstatus.h"
  31 #define WIN32_NO_STATUS
  32 #include "windef.h"
  33 #include "winternl.h"
  34
  35 #include "handle.h"
  36 #include "file.h"
  37 #include "process.h"
  38 #include "thread.h"
  39 #include "request.h"
  40
  41 enum debug_event_state { EVENT_QUEUED, EVENT_SENT, EVENT_DELAYED, EVENT_CONTINUED };
  42
  43 /* debug event */
  44 struct debug_event
  45 {
  46     struct object          obj;       /* object header */
  47     struct list            entry;     /* entry in event queue */
  48     struct thread         *sender;    /* thread which sent this event */
  49     struct file           *file;      /* file object for events that need one */
  50     enum debug_event_state state;     /* event state */
  51     int                    status;    /* continuation status */
  52     debug_event_t          data;      /* event data */
  53 };
  54
  55 static const WCHAR debug_obj_name[] = {'D','e','b','u','g','O','b','j','e','c','t'};
  56
  57 struct type_descr debug_obj_type =
  58 {
  59     { debug_obj_name, sizeof(debug_obj_name) },   /* name */
  60     DEBUG_ALL_ACCESS | SYNCHRONIZE,               /* valid_access */
  61     {                                             /* mapping */
  62         STANDARD_RIGHTS_READ | DEBUG_READ_EVENT,
  63         STANDARD_RIGHTS_WRITE | DEBUG_PROCESS_ASSIGN,
  64         STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE,
  65         DEBUG_ALL_ACCESS
  66     },
  67 };
  68
  69 /* debug object */
  70 struct debug_obj
  71 {
  72     struct object        obj;         /* object header */
  73     struct list          event_queue; /* pending events queue */
  74     unsigned int         flags;       /* debug flags */
  75 };
  76
  77
  78 static void debug_event_dump( struct object *obj, int verbose );
  79 static int debug_event_signaled( struct object *obj, struct wait_queue_entry *entry );
  80 static void debug_event_destroy( struct object *obj );
  81
  82 static const struct object_ops debug_event_ops =
  83 {
  84     sizeof(struct debug_event),    /* size */
  85     &no_type,                      /* type */
  86     debug_event_dump,              /* dump */
  87     add_queue,                     /* add_queue */
  88     remove_queue,                  /* remove_queue */
  89     debug_event_signaled,          /* signaled */
  90     no_satisfied,                  /* satisfied */
  91     no_signal,                     /* signal */
  92     no_get_fd,                     /* get_fd */
  93     default_map_access,            /* map_access */
  94     default_get_sd,                /* get_sd */
  95     default_set_sd,                /* set_sd */
  96     no_get_full_name,              /* get_full_name */
  97     no_lookup_name,                /* lookup_name */
  98     no_link_name,                  /* link_name */
  99     NULL,                          /* unlink_name */
 100     no_open_file,                  /* open_file */
 101     no_kernel_obj_list,            /* get_kernel_obj_list */
 102     no_close_handle,               /* close_handle */
 103     debug_event_destroy            /* destroy */
 104 };
 105
 106 static void debug_obj_dump( struct object *obj, int verbose );
 107 static int debug_obj_signaled( struct object *obj, struct wait_queue_entry *entry );
 108 static void debug_obj_destroy( struct object *obj );
 109
 110 static const struct object_ops debug_obj_ops =
 111 {
 112     sizeof(struct debug_obj),      /* size */
 113     &debug_obj_type,               /* type */
 114     debug_obj_dump,                /* dump */
 115     add_queue,                     /* add_queue */
 116     remove_queue,                  /* remove_queue */
 117     debug_obj_signaled,            /* signaled */
 118     no_satisfied,                  /* satisfied */
 119     no_signal,                     /* signal */
 120     no_get_fd,                     /* get_fd */
 121     default_map_access,            /* map_access */
 122     default_get_sd,                /* get_sd */
 123     default_set_sd,                /* set_sd */
 124     default_get_full_name,         /* get_full_name */
 125     no_lookup_name,                /* lookup_name */
 126     directory_link_name,           /* link_name */
 127     default_unlink_name,           /* unlink_name */
 128     no_open_file,                  /* open_file */
 129     no_kernel_obj_list,            /* get_kernel_obj_list */
 130     no_close_handle,               /* close_handle */
 131     debug_obj_destroy              /* destroy */
 132 };
 133
 134 /* get a pointer to TEB->ArbitraryUserPointer in the client address space */
 135 static client_ptr_t get_teb_user_ptr( struct thread *thread )
 136 {
 137     unsigned int ptr_size = (CPU_FLAG( thread->process->cpu ) & CPU_64BIT_MASK) ? 8 : 4;
 138     return thread->teb + 5 * ptr_size;
 139 }
 140
 141
 142 /* routines to build an event according to its type */
 143
 144 static void fill_exception_event( struct debug_event *event, const void *arg )
 145 {
 146     const debug_event_t *data = arg;
 147     event->data.exception = data->exception;
 148     event->data.exception.nb_params = min( event->data.exception.nb_params, EXCEPTION_MAXIMUM_PARAMETERS );
 149 }
 150
 151 static void fill_create_thread_event( struct debug_event *event, const void *arg )
 152 {
 153     const client_ptr_t *entry = arg;
 154
 155     if (entry) event->data.create_thread.start = *entry;
 156 }
 157
 158 static void fill_create_process_event( struct debug_event *event, const void *arg )
 159 {
 160     const struct memory_view *view = arg;
 161     const pe_image_info_t *image_info = get_view_image_info( view, &event->data.create_process.base );
 162
 163     event->data.create_process.start      = image_info->entry_point;
 164     event->data.create_process.dbg_offset = image_info->dbg_offset;
 165     event->data.create_process.dbg_size   = image_info->dbg_size;
 166     /* the doc says write access too, but this doesn't seem a good idea */
 167     event->file = get_view_file( view, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE );
 168 }
 169
 170 static void fill_exit_thread_event( struct debug_event *event, const void *arg )
 171 {
 172     const struct thread *thread = arg;
 173     event->data.exit.exit_code = thread->exit_code;
 174 }
 175
 176 static void fill_exit_process_event( struct debug_event *event, const void *arg )
 177 {
 178     const struct process *process = arg;
 179     event->data.exit.exit_code = process->exit_code;
 180 }
 181
 182 static void fill_load_dll_event( struct debug_event *event, const void *arg )
 183 {
 184     const struct memory_view *view = arg;
 185     const pe_image_info_t *image_info = get_view_image_info( view, &event->data.load_dll.base );
 186
 187     event->data.load_dll.dbg_offset = image_info->dbg_offset;
 188     event->data.load_dll.dbg_size   = image_info->dbg_size;
 189     event->data.load_dll.name       = get_teb_user_ptr( event->sender );
 190     event->file = get_view_file( view, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE );
 191 }
 192
 193 static void fill_unload_dll_event( struct debug_event *event, const void *arg )
 194 {
 195     const struct memory_view *view = arg;
 196     get_view_image_info( view, &event->data.unload_dll.base );
 197 }
 198
 199 typedef void (*fill_event_func)( struct debug_event *event, const void *arg );
 200
 201 static const fill_event_func fill_debug_event[] =
 202 {
 203     fill_create_thread_event,  /* DbgCreateThreadStateChange */
 204     fill_create_process_event, /* DbgCreateProcessStateChange */
 205     fill_exit_thread_event,    /* DbgExitThreadStateChange */
 206     fill_exit_process_event,   /* DbgExitProcessStateChange */
 207     fill_exception_event,      /* DbgExceptionStateChange */
 208     fill_exception_event,      /* DbgBreakpointStateChange */
 209     fill_exception_event,      /* DbgSingleStepStateChange */
 210     fill_load_dll_event,       /* DbgLoadDllStateChange */
 211     fill_unload_dll_event      /* DbgUnloadDllStateChange */
 212 };
 213
 214 /* allocate the necessary handles in the event data */
 215 static void alloc_event_handles( struct debug_event *event, struct process *process )
 216 {
 217     switch (event->data.code)
 218     {
 219     case DbgCreateThreadStateChange:
 220         /* documented: THREAD_GET_CONTEXT | THREAD_SET_CONTEXT | THREAD_SUSPEND_RESUME */
 221         event->data.create_thread.handle = alloc_handle( process, event->sender, THREAD_ALL_ACCESS, 0 );
 222         break;
 223     case DbgCreateProcessStateChange:
 224         event->data.create_process.thread = alloc_handle( process, event->sender, THREAD_ALL_ACCESS, 0 );
 225         /* documented: PROCESS_VM_READ | PROCESS_VM_WRITE */
 226         event->data.create_process.process = alloc_handle( process, event->sender->process,
 227                                                            PROCESS_ALL_ACCESS, 0 );
 228         if (event->file)
 229             event->data.create_process.file = alloc_handle( process, event->file, GENERIC_READ, 0 );
 230         break;
 231     case DbgLoadDllStateChange:
 232         if (event->file)
 233             event->data.load_dll.handle = alloc_handle( process, event->file, GENERIC_READ, 0 );
 234         break;
 235     }
 236     clear_error();  /* ignore errors, simply set handles to 0 */
 237 }
 238
 239 /* unlink the first event from the queue */
 240 static void unlink_event( struct debug_obj *debug_obj, struct debug_event *event )
 241 {
 242     list_remove( &event->entry );
 243     if (event->sender->process->debug_event == event) event->sender->process->debug_event = NULL;
 244     release_object( event );
 245 }
 246
 247 /* link an event at the end of the queue */
 248 static void link_event( struct debug_obj *debug_obj, struct debug_event *event )
 249 {
 250     grab_object( event );
 251     list_add_tail( &debug_obj->event_queue, &event->entry );
 252     if (!event->sender->process->debug_event)
 253     {
 254         /* grab reference since debugger could be killed while trying to wake up */
 255         grab_object( debug_obj );
 256         wake_up( &debug_obj->obj, 0 );
 257         release_object( debug_obj );
 258     }
 259 }
 260
 261 /* resume a delayed debug event already in the queue */
 262 static void resume_event( struct debug_obj *debug_obj, struct debug_event *event )
 263 {
 264     event->state = EVENT_QUEUED;
 265     if (!event->sender->process->debug_event)
 266     {
 267         grab_object( debug_obj );
 268         wake_up( &debug_obj->obj, 0 );
 269         release_object( debug_obj );
 270     }
 271 }
 272
 273 /* delay a debug event already in the queue to be replayed when thread wakes up */
 274 static void delay_event( struct debug_obj *debug_obj, struct debug_event *event )
 275 {
 276     event->state = EVENT_DELAYED;
 277     if (event->sender->process->debug_event == event) event->sender->process->debug_event = NULL;
 278 }
 279
 280 /* find the next event that we can send to the debugger */
 281 static struct debug_event *find_event_to_send( struct debug_obj *debug_obj )
 282 {
 283     struct debug_event *event;
 284
 285     LIST_FOR_EACH_ENTRY( event, &debug_obj->event_queue, struct debug_event, entry )
 286     {
 287         if (event->state == EVENT_SENT) continue;  /* already sent */
 288         if (event->state == EVENT_DELAYED) continue;  /* delayed until thread resumes */
 289         if (event->sender->process->debug_event) continue;  /* process busy with another one */
 290         return event;
 291     }
 292     return NULL;
 293 }
 294
 295 static void debug_event_dump( struct object *obj, int verbose )
 296 {
 297     struct debug_event *debug_event = (struct debug_event *)obj;
 298     assert( obj->ops == &debug_event_ops );
 299     fprintf( stderr, "Debug event sender=%p code=%d state=%d\n",
 300              debug_event->sender, debug_event->data.code, debug_event->state );
 301 }
 302
 303 static int debug_event_signaled( struct object *obj, struct wait_queue_entry *entry )
 304 {
 305     struct debug_event *debug_event = (struct debug_event *)obj;
 306     assert( obj->ops == &debug_event_ops );
 307     return debug_event->state == EVENT_CONTINUED;
 308 }
 309
 310 static void debug_event_destroy( struct object *obj )
 311 {
 312     struct debug_event *event = (struct debug_event *)obj;
 313     assert( obj->ops == &debug_event_ops );
 314
 315     if (event->file) release_object( event->file );
 316     release_object( event->sender );
 317 }
 318
 319 static void debug_obj_dump( struct object *obj, int verbose )
 320 {
 321     struct debug_obj *debug_obj = (struct debug_obj *)obj;
 322     assert( obj->ops == &debug_obj_ops );
 323     fprintf( stderr, "Debug context head=%p tail=%p\n",
 324              debug_obj->event_queue.next, debug_obj->event_queue.prev );
 325 }
 326
 327 static int debug_obj_signaled( struct object *obj, struct wait_queue_entry *entry )
 328 {
 329     struct debug_obj *debug_obj = (struct debug_obj *)obj;
 330     assert( obj->ops == &debug_obj_ops );
 331     return find_event_to_send( debug_obj ) != NULL;
 332 }
 333
 334 static void debug_obj_destroy( struct object *obj )
 335 {
 336     struct list *ptr;
 337     struct debug_obj *debug_obj = (struct debug_obj *)obj;
 338     assert( obj->ops == &debug_obj_ops );
 339
 340     detach_debugged_processes( debug_obj,
 341                                (debug_obj->flags & DEBUG_KILL_ON_CLOSE) ? STATUS_DEBUGGER_INACTIVE : 0 );
 342
 343     /* free all pending events */
 344     while ((ptr = list_head( &debug_obj->event_queue )))
 345         unlink_event( debug_obj, LIST_ENTRY( ptr, struct debug_event, entry ));
 346 }
 347
 348 struct debug_obj *get_debug_obj( struct process *process, obj_handle_t handle, unsigned int access )
 349 {
 350     return (struct debug_obj *)get_handle_obj( process, handle, access, &debug_obj_ops );
 351 }
 352
 353 static struct debug_obj *create_debug_obj( struct object *root, const struct unicode_str *name,
 354                                            unsigned int attr, unsigned int flags,
 355                                            const struct security_descriptor *sd )
 356 {
 357     struct debug_obj *debug_obj;
 358
 359     if ((debug_obj = create_named_object( root, &debug_obj_ops, name, attr, sd )))
 360     {
 361         if (get_error() != STATUS_OBJECT_NAME_EXISTS)
 362         {
 363             debug_obj->flags = flags;
 364             list_init( &debug_obj->event_queue );
 365         }
 366     }
 367     return debug_obj;
 368 }
 369
 370 /* continue a debug event */
 371 static int continue_debug_event( struct debug_obj *debug_obj, struct process *process,
 372                                  struct thread *thread, int status )
 373 {
 374     if (process->debug_obj == debug_obj && thread->process == process)
 375     {
 376         struct debug_event *event;
 377
 378         if (status == DBG_REPLY_LATER)
 379         {
 380             /* if thread is suspended, delay all its events and resume process
 381              * if not, reset the event for immediate replay */
 382             LIST_FOR_EACH_ENTRY( event, &debug_obj->event_queue, struct debug_event, entry )
 383             {
 384                 if (event->sender != thread) continue;
 385                 if (thread->suspend)
 386                 {
 387                     delay_event( debug_obj, event );
 388                     resume_process( process );
 389                 }
 390                 else if (event->state == EVENT_SENT)
 391                 {
 392                     assert( event->sender->process->debug_event == event );
 393                     event->sender->process->debug_event = NULL;
 394                     resume_event( debug_obj, event );
 395                     return 1;
 396                 }
 397             }
 398             return 1;
 399         }
 400
 401         /* find the event in the queue */
 402         LIST_FOR_EACH_ENTRY( event, &debug_obj->event_queue, struct debug_event, entry )
 403         {
 404             if (event->state != EVENT_SENT) continue;
 405             if (event->sender == thread)
 406             {
 407                 assert( event->sender->process->debug_event == event );
 408                 event->status = status;
 409                 event->state  = EVENT_CONTINUED;
 410                 wake_up( &event->obj, 0 );
 411                 unlink_event( debug_obj, event );
 412                 resume_process( process );
 413                 return 1;
 414             }
 415         }
 416     }
 417     /* not debugging this process, or no such event */
 418     set_error( STATUS_ACCESS_DENIED );  /* FIXME */
 419     return 0;
 420 }
 421
 422 /* alloc a debug event for a debugger */
 423 static struct debug_event *alloc_debug_event( struct thread *thread, int code, const void *arg )
 424 {
 425     struct debug_event *event;
 426
 427     assert( code >= DbgCreateThreadStateChange && code <= DbgUnloadDllStateChange );
 428
 429     /* build the event */
 430     if (!(event = alloc_object( &debug_event_ops ))) return NULL;
 431     event->state     = EVENT_QUEUED;
 432     event->sender    = (struct thread *)grab_object( thread );
 433     event->file      = NULL;
 434     memset( &event->data, 0, sizeof(event->data) );
 435     fill_debug_event[code - DbgCreateThreadStateChange]( event, arg );
 436     event->data.code = code;
 437     return event;
 438 }
 439
 440 /* generate a debug event from inside the server and queue it */
 441 void generate_debug_event( struct thread *thread, int code, const void *arg )
 442 {
 443     struct debug_obj *debug_obj = thread->process->debug_obj;
 444
 445     if (debug_obj)
 446     {
 447         struct debug_event *event = alloc_debug_event( thread, code, arg );
 448         if (event)
 449         {
 450             link_event( debug_obj, event );
 451             suspend_process( thread->process );
 452             release_object( event );
 453         }
 454         clear_error();  /* ignore errors */
 455     }
 456 }
 457
 458 void resume_delayed_debug_events( struct thread *thread )
 459 {
 460     struct debug_obj *debug_obj = thread->process->debug_obj;
 461     struct debug_event *event;
 462
 463     if (debug_obj)
 464     {
 465         LIST_FOR_EACH_ENTRY( event, &debug_obj->event_queue, struct debug_event, entry )
 466         {
 467             if (event->sender != thread) continue;
 468             if (event->state != EVENT_DELAYED) continue;
 469             resume_event( debug_obj, event );
 470             suspend_process( thread->process );
 471         }
 472     }
 473 }
 474
 475 /* attach a process to a debugger thread and suspend it */
 476 static int debugger_attach( struct process *process, struct thread *debugger, struct debug_obj *debug_obj )
 477 {
 478     if (debugger->process == process) goto error;
 479     if (!is_process_init_done( process )) goto error;  /* still starting up */
 480     if (list_empty( &process->thread_list )) goto error;  /* no thread running in the process */
 481     /* don't let a debugger debug its console... won't work */
 482     if (debugger->process->console)
 483     {
 484         struct thread *renderer = console_get_renderer(debugger->process->console);
 485         if (renderer && renderer->process == process) goto error;
 486     }
 487
 488     suspend_process( process );
 489
 490     if (!set_process_debug_flag( process, 1 ))
 491     {
 492         resume_process( process );
 493         return 0;
 494     }
 495     process->debug_obj = debug_obj;
 496     process->debug_children = 0;
 497     generate_startup_debug_events( process );
 498     resume_process( process );
 499     return 1;
 500
 501  error:
 502     set_error( STATUS_ACCESS_DENIED );
 503     return 0;
 504 }
 505
 506
 507 /* detach a process from a debugger thread (and resume it) */
 508 void debugger_detach( struct process *process, struct debug_obj *debug_obj )
 509 {
 510     struct debug_event *event, *next;
 511
 512     suspend_process( process );
 513
 514     /* send continue indication for all events */
 515     LIST_FOR_EACH_ENTRY_SAFE( event, next, &debug_obj->event_queue, struct debug_event, entry )
 516     {
 517         if (event->sender->process != process) continue;
 518
 519         assert( event->state != EVENT_CONTINUED );
 520         event->status = DBG_CONTINUE;
 521         event->state  = EVENT_CONTINUED;
 522         wake_up( &event->obj, 0 );
 523         unlink_event( debug_obj, event );
 524         /* from queued debug event */
 525         resume_process( process );
 526     }
 527
 528     /* remove relationships between process and its debugger */
 529     process->debug_obj = NULL;
 530     if (!set_process_debug_flag( process, 0 )) clear_error();  /* ignore error */
 531
 532     resume_process( process );
 533 }
 534
 535 /* create a debug object */
 536 DECL_HANDLER(create_debug_obj)
 537 {
 538     struct debug_obj *debug_obj;
 539     struct unicode_str name;
 540     struct object *root;
 541     const struct security_descriptor *sd;
 542     const struct object_attributes *objattr = get_req_object_attributes( &sd, &name, &root );
 543
 544     if (!objattr) return;
 545     if ((debug_obj = create_debug_obj( root, &name, objattr->attributes, req->flags, sd )))
 546     {
 547         if (get_error() == STATUS_OBJECT_NAME_EXISTS)
 548             reply->handle = alloc_handle( current->process, debug_obj, req->access, objattr->attributes );
 549         else
 550             reply->handle = alloc_handle_no_access_check( current->process, debug_obj,
 551                                                           req->access, objattr->attributes );
 552         release_object( debug_obj );
 553     }
 554     if (root) release_object( root );
 555 }
 556
 557 /* Wait for a debug event */
 558 DECL_HANDLER(wait_debug_event)
 559 {
 560     struct debug_obj *debug_obj;
 561     struct debug_event *event;
 562
 563     if (!(debug_obj = get_debug_obj( current->process, req->debug, DEBUG_READ_EVENT ))) return;
 564
 565     if ((event = find_event_to_send( debug_obj )))
 566     {
 567         event->state = EVENT_SENT;
 568         event->sender->process->debug_event = event;
 569         reply->pid = get_process_id( event->sender->process );
 570         reply->tid = get_thread_id( event->sender );
 571         alloc_event_handles( event, current->process );
 572         set_reply_data( &event->data, min( get_reply_max_size(), sizeof(event->data) ));
 573     }
 574     else
 575     {
 576         int state = list_empty( &debug_obj->event_queue ) ? DbgIdle : DbgReplyPending;
 577         set_reply_data( &state, min( get_reply_max_size(), sizeof(state) ));
 578     }
 579     release_object( debug_obj );
 580 }
 581
 582 /* Continue a debug event */
 583 DECL_HANDLER(continue_debug_event)
 584 {
 585     struct debug_obj *debug_obj;
 586     struct process *process;
 587
 588     if (req->status != DBG_EXCEPTION_NOT_HANDLED &&
 589         req->status != DBG_EXCEPTION_HANDLED &&
 590         req->status != DBG_CONTINUE &&
 591         req->status != DBG_REPLY_LATER)
 592     {
 593         set_error( STATUS_INVALID_PARAMETER );
 594         return;
 595     }
 596
 597     if (!(debug_obj = get_debug_obj( current->process, req->debug, DEBUG_READ_EVENT ))) return;
 598
 599     if ((process = get_process_from_id( req->pid )))
 600     {
 601         struct thread *thread = get_thread_from_id( req->tid );
 602         if (thread)
 603         {
 604             continue_debug_event( debug_obj, process, thread, req->status );
 605             release_object( thread );
 606         }
 607         release_object( process );
 608     }
 609     release_object( debug_obj );
 610 }
 611
 612 /* start or stop debugging an existing process */
 613 DECL_HANDLER(debug_process)
 614 {
 615     struct debug_obj *debug_obj;
 616     struct process *process = get_process_from_handle( req->handle,
 617                                             PROCESS_VM_READ | PROCESS_VM_WRITE | PROCESS_SUSPEND_RESUME );
 618
 619     if (!process) return;
 620     if ((debug_obj = get_debug_obj( current->process, req->debug, DEBUG_PROCESS_ASSIGN )))
 621     {
 622         if (req->attach)
 623         {
 624             if (!process->debug_obj) debugger_attach( process, current, debug_obj );
 625             else set_error( STATUS_ACCESS_DENIED );
 626         }
 627         else
 628         {
 629             if (process->debug_obj == debug_obj) debugger_detach( process, debug_obj );
 630             else set_error( STATUS_ACCESS_DENIED );
 631         }
 632         release_object( debug_obj );
 633     }
 634     release_object( process );
 635 }
 636
 637 /* queue an exception event */
 638 DECL_HANDLER(queue_exception_event)
 639 {
 640     struct debug_obj *debug_obj = current->process->debug_obj;
 641
 642     reply->handle = 0;
 643     if (debug_obj)
 644     {
 645         debug_event_t data;
 646         struct debug_event *event;
 647         struct thread *thread = current;
 648
 649         if ((req->len % sizeof(client_ptr_t)) != 0 ||
 650             req->len > get_req_data_size() ||
 651             req->len > EXCEPTION_MAXIMUM_PARAMETERS * sizeof(client_ptr_t))
 652         {
 653             set_error( STATUS_INVALID_PARAMETER );
 654             return;
 655         }
 656         memset( &data, 0, sizeof(data) );
 657         data.exception.first     = req->first;
 658         data.exception.exc_code  = req->code;
 659         data.exception.flags     = req->flags;
 660         data.exception.record    = req->record;
 661         data.exception.address   = req->address;
 662         data.exception.nb_params = req->len / sizeof(client_ptr_t);
 663         memcpy( data.exception.params, get_req_data(), req->len );
 664
 665         if ((event = alloc_debug_event( thread, DbgExceptionStateChange, &data )))
 666         {
 667             if ((reply->handle = alloc_handle( thread->process, event, SYNCHRONIZE, 0 )))
 668             {
 669                 link_event( debug_obj, event );
 670                 suspend_process( thread->process );
 671             }
 672             release_object( event );
 673         }
 674     }
 675 }
 676
 677 /* retrieve the status of an exception event */
 678 DECL_HANDLER(get_exception_status)
 679 {
 680     struct debug_event *event;
 681
 682     if ((event = (struct debug_event *)get_handle_obj( current->process, req->handle,
 683                                                        0, &debug_event_ops )))
 684     {
 685         close_handle( current->process, req->handle );
 686         set_error( event->state == EVENT_CONTINUED ? event->status : STATUS_PENDING );
 687         release_object( event );
 688     }
 689 }
 690
 691 /* set debug object information */
 692 DECL_HANDLER(set_debug_obj_info)
 693 {
 694     struct debug_obj *debug_obj;
 695
 696     if (!(debug_obj = get_debug_obj( current->process, req->debug, DEBUG_SET_INFORMATION ))) return;
 697     debug_obj->flags = req->flags;
 698     release_object( debug_obj );
 699 }