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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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 "windef.h"
  31
  32 #include "handle.h"
  33 #include "process.h"
  34 #include "thread.h"
  35 #include "request.h"
  36 #include "console.h"
  37
  38 enum debug_event_state { EVENT_QUEUED, EVENT_SENT, EVENT_CONTINUED };
  39
  40 /* debug event */
  41 struct debug_event
  42 {
  43     struct object          obj;       /* object header */
  44     struct list            entry;     /* entry in event queue */
  45     struct thread         *sender;    /* thread which sent this event */
  46     struct thread         *debugger;  /* debugger thread receiving the event */
  47     enum debug_event_state state;     /* event state */
  48     int                    status;    /* continuation status */
  49     debug_event_t          data;      /* event data */
  50     CONTEXT                context;   /* register context */
  51 };
  52
  53 /* debug context */
  54 struct debug_ctx
  55 {
  56     struct object        obj;         /* object header */
  57     struct list          event_queue; /* pending events queue */
  58     int                  kill_on_exit;/* kill debuggees on debugger exit ? */
  59 };
  60
  61
  62 static void debug_event_dump( struct object *obj, int verbose );
  63 static int debug_event_signaled( struct object *obj, struct thread *thread );
  64 static void debug_event_destroy( struct object *obj );
  65
  66 static const struct object_ops debug_event_ops =
  67 {
  68     sizeof(struct debug_event),    /* size */
  69     debug_event_dump,              /* dump */
  70     add_queue,                     /* add_queue */
  71     remove_queue,                  /* remove_queue */
  72     debug_event_signaled,          /* signaled */
  73     no_satisfied,                  /* satisfied */
  74     no_signal,                     /* signal */
  75     no_get_fd,                     /* get_fd */
  76     no_close_handle,               /* close_handle */
  77     debug_event_destroy            /* destroy */
  78 };
  79
  80 static void debug_ctx_dump( struct object *obj, int verbose );
  81 static int debug_ctx_signaled( struct object *obj, struct thread *thread );
  82 static void debug_ctx_destroy( struct object *obj );
  83
  84 static const struct object_ops debug_ctx_ops =
  85 {
  86     sizeof(struct debug_ctx),      /* size */
  87     debug_ctx_dump,                /* dump */
  88     add_queue,                     /* add_queue */
  89     remove_queue,                  /* remove_queue */
  90     debug_ctx_signaled,            /* signaled */
  91     no_satisfied,                  /* satisfied */
  92     no_signal,                     /* signal */
  93     no_get_fd,                     /* get_fd */
  94     no_close_handle,               /* close_handle */
  95     debug_ctx_destroy              /* destroy */
  96 };
  97
  98
  99 /* routines to build an event according to its type */
 100
 101 static int fill_exception_event( struct debug_event *event, void *arg )
 102 {
 103     memcpy( &event->data.info.exception, arg, sizeof(event->data.info.exception) );
 104     return 1;
 105 }
 106
 107 static int fill_create_thread_event( struct debug_event *event, void *arg )
 108 {
 109     struct process *debugger = event->debugger->process;
 110     struct thread *thread = event->sender;
 111     obj_handle_t handle;
 112
 113     /* documented: THREAD_GET_CONTEXT | THREAD_SET_CONTEXT | THREAD_SUSPEND_RESUME */
 114     if (!(handle = alloc_handle( debugger, thread, THREAD_ALL_ACCESS, FALSE ))) return 0;
 115     event->data.info.create_thread.handle = handle;
 116     event->data.info.create_thread.teb    = thread->teb;
 117     event->data.info.create_thread.start  = arg;
 118     return 1;
 119 }
 120
 121 static int fill_create_process_event( struct debug_event *event, void *arg )
 122 {
 123     struct process *debugger = event->debugger->process;
 124     struct thread *thread = event->sender;
 125     struct process *process = thread->process;
 126     obj_handle_t handle;
 127
 128     /* documented: PROCESS_VM_READ | PROCESS_VM_WRITE */
 129     if (!(handle = alloc_handle( debugger, process, PROCESS_ALL_ACCESS, FALSE ))) return 0;
 130     event->data.info.create_process.process = handle;
 131
 132     /* documented: THREAD_GET_CONTEXT | THREAD_SET_CONTEXT | THREAD_SUSPEND_RESUME */
 133     if (!(handle = alloc_handle( debugger, thread, THREAD_ALL_ACCESS, FALSE )))
 134     {
 135         close_handle( debugger, event->data.info.create_process.process, NULL );
 136         return 0;
 137     }
 138     event->data.info.create_process.thread = handle;
 139
 140     handle = 0;
 141     if (process->exe.file &&
 142         /* the doc says write access too, but this doesn't seem a good idea */
 143         !(handle = alloc_handle( debugger, process->exe.file, GENERIC_READ, FALSE )))
 144     {
 145         close_handle( debugger, event->data.info.create_process.process, NULL );
 146         close_handle( debugger, event->data.info.create_process.thread, NULL );
 147         return 0;
 148     }
 149     event->data.info.create_process.file       = handle;
 150     event->data.info.create_process.teb        = thread->teb;
 151     event->data.info.create_process.base       = process->exe.base;
 152     event->data.info.create_process.start      = arg;
 153     event->data.info.create_process.dbg_offset = process->exe.dbg_offset;
 154     event->data.info.create_process.dbg_size   = process->exe.dbg_size;
 155     event->data.info.create_process.name       = process->exe.name;
 156     event->data.info.create_process.unicode    = 1;
 157     return 1;
 158 }
 159
 160 static int fill_exit_thread_event( struct debug_event *event, void *arg )
 161 {
 162     struct thread *thread = arg;
 163     event->data.info.exit.exit_code = thread->exit_code;
 164     return 1;
 165 }
 166
 167 static int fill_exit_process_event( struct debug_event *event, void *arg )
 168 {
 169     struct process *process = arg;
 170     event->data.info.exit.exit_code = process->exit_code;
 171     return 1;
 172 }
 173
 174 static int fill_load_dll_event( struct debug_event *event, void *arg )
 175 {
 176     struct process *debugger = event->debugger->process;
 177     struct process_dll *dll = arg;
 178     obj_handle_t handle = 0;
 179
 180     if (dll->file && !(handle = alloc_handle( debugger, dll->file, GENERIC_READ, FALSE )))
 181         return 0;
 182     event->data.info.load_dll.handle     = handle;
 183     event->data.info.load_dll.base       = dll->base;
 184     event->data.info.load_dll.dbg_offset = dll->dbg_offset;
 185     event->data.info.load_dll.dbg_size   = dll->dbg_size;
 186     event->data.info.load_dll.name       = dll->name;
 187     event->data.info.load_dll.unicode    = 1;
 188     return 1;
 189 }
 190
 191 static int fill_unload_dll_event( struct debug_event *event, void *arg )
 192 {
 193     event->data.info.unload_dll.base = arg;
 194     return 1;
 195 }
 196
 197 static int fill_output_debug_string_event( struct debug_event *event, void *arg )
 198 {
 199     struct debug_event_output_string *data = arg;
 200     event->data.info.output_string = *data;
 201     return 1;
 202 }
 203
 204 typedef int (*fill_event_func)( struct debug_event *event, void *arg );
 205
 206 #define NB_DEBUG_EVENTS OUTPUT_DEBUG_STRING_EVENT  /* RIP_EVENT not supported */
 207
 208 static const fill_event_func fill_debug_event[NB_DEBUG_EVENTS] =
 209 {
 210     fill_exception_event,            /* EXCEPTION_DEBUG_EVENT */
 211     fill_create_thread_event,        /* CREATE_THREAD_DEBUG_EVENT */
 212     fill_create_process_event,       /* CREATE_PROCESS_DEBUG_EVENT */
 213     fill_exit_thread_event,          /* EXIT_THREAD_DEBUG_EVENT */
 214     fill_exit_process_event,         /* EXIT_PROCESS_DEBUG_EVENT */
 215     fill_load_dll_event,             /* LOAD_DLL_DEBUG_EVENT */
 216     fill_unload_dll_event,           /* UNLOAD_DLL_DEBUG_EVENT */
 217     fill_output_debug_string_event   /* OUTPUT_DEBUG_STRING_EVENT */
 218 };
 219
 220
 221 /* unlink the first event from the queue */
 222 static void unlink_event( struct debug_ctx *debug_ctx, struct debug_event *event )
 223 {
 224     list_remove( &event->entry );
 225     if (event->sender->debug_event == event) event->sender->debug_event = NULL;
 226     release_object( event );
 227 }
 228
 229 /* link an event at the end of the queue */
 230 static void link_event( struct debug_event *event )
 231 {
 232     struct debug_ctx *debug_ctx = event->debugger->debug_ctx;
 233
 234     assert( debug_ctx );
 235     grab_object( event );
 236     list_add_tail( &debug_ctx->event_queue, &event->entry );
 237     if (!event->sender->debug_event) wake_up( &debug_ctx->obj, 0 );
 238 }
 239
 240 /* find the next event that we can send to the debugger */
 241 static struct debug_event *find_event_to_send( struct debug_ctx *debug_ctx )
 242 {
 243     struct debug_event *event;
 244
 245     LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 246     {
 247         if (event->state == EVENT_SENT) continue;  /* already sent */
 248         if (event->sender->debug_event) continue;  /* thread busy with another one */
 249         return event;
 250     }
 251     return NULL;
 252 }
 253
 254 static void debug_event_dump( struct object *obj, int verbose )
 255 {
 256     struct debug_event *debug_event = (struct debug_event *)obj;
 257     assert( obj->ops == &debug_event_ops );
 258     fprintf( stderr, "Debug event sender=%p code=%d state=%d\n",
 259              debug_event->sender, debug_event->data.code, debug_event->state );
 260 }
 261
 262 static int debug_event_signaled( struct object *obj, struct thread *thread )
 263 {
 264     struct debug_event *debug_event = (struct debug_event *)obj;
 265     assert( obj->ops == &debug_event_ops );
 266     return debug_event->state == EVENT_CONTINUED;
 267 }
 268
 269 static void debug_event_destroy( struct object *obj )
 270 {
 271     struct debug_event *event = (struct debug_event *)obj;
 272     assert( obj->ops == &debug_event_ops );
 273
 274     /* If the event has been sent already, the handles are now under the */
 275     /* responsibility of the debugger process, so we don't touch them    */
 276     if (event->state == EVENT_QUEUED)
 277     {
 278         struct process *debugger = event->debugger->process;
 279         switch(event->data.code)
 280         {
 281         case CREATE_THREAD_DEBUG_EVENT:
 282             close_handle( debugger, event->data.info.create_thread.handle, NULL );
 283             break;
 284         case CREATE_PROCESS_DEBUG_EVENT:
 285             if (event->data.info.create_process.file)
 286                 close_handle( debugger, event->data.info.create_process.file, NULL );
 287             close_handle( debugger, event->data.info.create_process.thread, NULL );
 288             close_handle( debugger, event->data.info.create_process.process, NULL );
 289             break;
 290         case LOAD_DLL_DEBUG_EVENT:
 291             if (event->data.info.load_dll.handle)
 292                 close_handle( debugger, event->data.info.load_dll.handle, NULL );
 293             break;
 294         }
 295     }
 296     if (event->sender->context == &event->context) event->sender->context = NULL;
 297     release_object( event->sender );
 298     release_object( event->debugger );
 299 }
 300
 301 static void debug_ctx_dump( struct object *obj, int verbose )
 302 {
 303     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 304     assert( obj->ops == &debug_ctx_ops );
 305     fprintf( stderr, "Debug context head=%p tail=%p\n",
 306              debug_ctx->event_queue.next, debug_ctx->event_queue.prev );
 307 }
 308
 309 static int debug_ctx_signaled( struct object *obj, struct thread *thread )
 310 {
 311     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 312     assert( obj->ops == &debug_ctx_ops );
 313     return find_event_to_send( debug_ctx ) != NULL;
 314 }
 315
 316 static void debug_ctx_destroy( struct object *obj )
 317 {
 318     struct list *ptr;
 319     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 320     assert( obj->ops == &debug_ctx_ops );
 321
 322     /* free all pending events */
 323     while ((ptr = list_head( &debug_ctx->event_queue )))
 324         unlink_event( debug_ctx, LIST_ENTRY( ptr, struct debug_event, entry ));
 325 }
 326
 327 /* continue a debug event */
 328 static int continue_debug_event( struct process *process, struct thread *thread, int status )
 329 {
 330     struct debug_ctx *debug_ctx = current->debug_ctx;
 331
 332     if (debug_ctx && process->debugger == current && thread->process == process)
 333     {
 334         struct debug_event *event;
 335
 336         /* find the event in the queue */
 337         LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 338         {
 339             if (event->state != EVENT_SENT) continue;
 340             if (event->sender == thread)
 341             {
 342                 assert( event->sender->debug_event == event );
 343
 344                 event->status = status;
 345                 event->state  = EVENT_CONTINUED;
 346                 wake_up( &event->obj, 0 );
 347                 unlink_event( debug_ctx, event );
 348                 resume_process( process );
 349                 return 1;
 350             }
 351         }
 352     }
 353     /* not debugging this process, or no such event */
 354     set_error( STATUS_ACCESS_DENIED );  /* FIXME */
 355     return 0;
 356 }
 357
 358 /* alloc a debug event for a debugger */
 359 static struct debug_event *alloc_debug_event( struct thread *thread, int code,
 360                                               void *arg, const CONTEXT *context )
 361 {
 362     struct thread *debugger = thread->process->debugger;
 363     struct debug_event *event;
 364
 365     assert( code > 0 && code <= NB_DEBUG_EVENTS );
 366     /* cannot queue a debug event for myself */
 367     assert( debugger->process != thread->process );
 368
 369     /* build the event */
 370     if (!(event = alloc_object( &debug_event_ops ))) return NULL;
 371     event->state     = EVENT_QUEUED;
 372     event->sender    = (struct thread *)grab_object( thread );
 373     event->debugger  = (struct thread *)grab_object( debugger );
 374     event->data.code = code;
 375
 376     if (!fill_debug_event[code-1]( event, arg ))
 377     {
 378         event->data.code = -1;  /* make sure we don't attempt to close handles */
 379         release_object( event );
 380         return NULL;
 381     }
 382     if (context)
 383     {
 384         memcpy( &event->context, context, sizeof(event->context) );
 385         thread->context = &event->context;
 386     }
 387     return event;
 388 }
 389
 390 /* generate a debug event from inside the server and queue it */
 391 void generate_debug_event( struct thread *thread, int code, void *arg )
 392 {
 393     if (thread->process->debugger)
 394     {
 395         struct debug_event *event = alloc_debug_event( thread, code, arg, NULL );
 396         if (event)
 397         {
 398             link_event( event );
 399             suspend_process( thread->process );
 400             release_object( event );
 401         }
 402     }
 403 }
 404
 405 /* attach a process to a debugger thread and suspend it */
 406 static int debugger_attach( struct process *process, struct thread *debugger )
 407 {
 408     struct thread *thread;
 409
 410     if (process->debugger) goto error;  /* already being debugged */
 411     if (!is_process_init_done( process )) goto error;  /* still starting up */
 412     if (list_empty( &process->thread_list )) goto error;  /* no thread running in the process */
 413
 414     /* make sure we don't create a debugging loop */
 415     for (thread = debugger; thread; thread = thread->process->debugger)
 416         if (thread->process == process) goto error;
 417
 418     /* don't let a debugger debug its console... won't work */
 419     if (debugger->process->console && debugger->process->console->renderer->process == process)
 420         goto error;
 421
 422     suspend_process( process );
 423     if (!attach_process( process ) || !set_process_debugger( process, debugger ))
 424     {
 425         resume_process( process );
 426         return 0;
 427     }
 428     if (!set_process_debug_flag( process, 1 ))
 429     {
 430         process->debugger = NULL;
 431         resume_process( process );
 432         return 0;
 433     }
 434     return 1;
 435
 436  error:
 437     set_error( STATUS_ACCESS_DENIED );
 438     return 0;
 439 }
 440
 441
 442 /* detach a process from a debugger thread (and resume it ?) */
 443 int debugger_detach( struct process *process, struct thread *debugger )
 444 {
 445     struct debug_event *event;
 446     struct debug_ctx *debug_ctx;
 447
 448     if (!process->debugger || process->debugger != debugger)
 449         goto error;  /* not currently debugged, or debugged by another debugger */
 450     if (!debugger->debug_ctx ) goto error; /* should be a debugger */
 451     /* init should be done, otherwise wouldn't be attached */
 452     assert(is_process_init_done(process));
 453
 454     suspend_process( process );
 455     /* send continue indication for all events */
 456     debug_ctx = debugger->debug_ctx;
 457
 458     /* find the event in the queue
 459      * FIXME: could loop on process' threads and look the debug_event field */
 460     LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 461     {
 462         if (event->state != EVENT_QUEUED) continue;
 463
 464         if (event->sender->process == process)
 465         {
 466             assert( event->sender->debug_event == event );
 467             event->status = DBG_CONTINUE;
 468             event->state  = EVENT_CONTINUED;
 469             wake_up( &event->obj, 0 );
 470             unlink_event( debug_ctx, event );
 471             /* from queued debug event */
 472             resume_process( process );
 473             break;
 474         }
 475     }
 476
 477     /* remove relationships between process and its debugger */
 478     process->debugger = NULL;
 479     if (!set_process_debug_flag( process, 0 )) clear_error();  /* ignore error */
 480     detach_process( process );
 481
 482     /* from this function */
 483     resume_process( process );
 484     return 0;
 485
 486  error:
 487     set_error( STATUS_ACCESS_DENIED );
 488     return 0;
 489 }
 490
 491 /* generate all startup events of a given process */
 492 void generate_startup_debug_events( struct process *process, void *entry )
 493 {
 494     struct list *ptr;
 495     struct thread *thread, *first_thread = get_process_first_thread( process );
 496
 497     /* generate creation events */
 498     LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
 499     {
 500         if (thread == first_thread)
 501             generate_debug_event( thread, CREATE_PROCESS_DEBUG_EVENT, entry );
 502         else
 503             generate_debug_event( thread, CREATE_THREAD_DEBUG_EVENT, NULL );
 504     }
 505
 506     /* generate dll events (in loading order, i.e. reverse list order) */
 507     ptr = list_tail( &process->dlls );
 508     while (ptr)
 509     {
 510         struct process_dll *dll = LIST_ENTRY( ptr, struct process_dll, entry );
 511         generate_debug_event( first_thread, LOAD_DLL_DEBUG_EVENT, dll );
 512         ptr = list_prev( &process->dlls, ptr );
 513     }
 514 }
 515
 516 /* set the debugger of a given process */
 517 int set_process_debugger( struct process *process, struct thread *debugger )
 518 {
 519     struct debug_ctx *debug_ctx;
 520
 521     assert( !process->debugger );
 522
 523     if (!debugger->debug_ctx)  /* need to allocate a context */
 524     {
 525         if (!(debug_ctx = alloc_object( &debug_ctx_ops ))) return 0;
 526         debug_ctx->kill_on_exit = 1;
 527         list_init( &debug_ctx->event_queue );
 528         debugger->debug_ctx = debug_ctx;
 529     }
 530     process->debugger = debugger;
 531     return 1;
 532 }
 533
 534 /* a thread is exiting */
 535 void debug_exit_thread( struct thread *thread )
 536 {
 537     if (thread->debug_ctx)  /* this thread is a debugger */
 538     {
 539         if (thread->debug_ctx->kill_on_exit)
 540         {
 541             /* kill all debugged processes */
 542             kill_debugged_processes( thread, thread->exit_code );
 543         }
 544         else
 545         {
 546             detach_debugged_processes( thread );
 547         }
 548         release_object( thread->debug_ctx );
 549         thread->debug_ctx = NULL;
 550     }
 551 }
 552
 553 /* Wait for a debug event */
 554 DECL_HANDLER(wait_debug_event)
 555 {
 556     struct debug_ctx *debug_ctx = current->debug_ctx;
 557     struct debug_event *event;
 558
 559     if (!debug_ctx)  /* current thread is not a debugger */
 560     {
 561         set_error( STATUS_INVALID_HANDLE );
 562         return;
 563     }
 564     reply->wait = 0;
 565     if ((event = find_event_to_send( debug_ctx )))
 566     {
 567         size_t size = get_reply_max_size();
 568         event->state = EVENT_SENT;
 569         event->sender->debug_event = event;
 570         reply->pid = get_process_id( event->sender->process );
 571         reply->tid = get_thread_id( event->sender );
 572         if (size > sizeof(debug_event_t)) size = sizeof(debug_event_t);
 573         set_reply_data( &event->data, size );
 574     }
 575     else  /* no event ready */
 576     {
 577         reply->pid  = 0;
 578         reply->tid  = 0;
 579         if (req->get_handle)
 580             reply->wait = alloc_handle( current->process, debug_ctx, SYNCHRONIZE, FALSE );
 581     }
 582 }
 583
 584 /* Continue a debug event */
 585 DECL_HANDLER(continue_debug_event)
 586 {
 587     struct process *process = get_process_from_id( req->pid );
 588     if (process)
 589     {
 590         struct thread *thread = get_thread_from_id( req->tid );
 591         if (thread)
 592         {
 593             continue_debug_event( process, thread, req->status );
 594             release_object( thread );
 595         }
 596         release_object( process );
 597     }
 598 }
 599
 600 /* Start debugging an existing process */
 601 DECL_HANDLER(debug_process)
 602 {
 603     struct process *process = get_process_from_id( req->pid );
 604     if (!process) return;
 605
 606     if (!req->attach)
 607     {
 608         debugger_detach( process, current );
 609     }
 610     else if (debugger_attach( process, current ))
 611     {
 612         struct debug_event_exception data;
 613         struct thread *thread = get_process_first_thread( process );
 614
 615         generate_startup_debug_events( process, NULL );
 616         resume_process( process );
 617
 618         data.record.ExceptionCode    = EXCEPTION_BREAKPOINT;
 619         data.record.ExceptionFlags   = EXCEPTION_CONTINUABLE;
 620         data.record.ExceptionRecord  = NULL;
 621         data.record.ExceptionAddress = get_thread_ip( thread );
 622         data.record.NumberParameters = 0;
 623         data.first = 1;
 624         generate_debug_event( thread, EXCEPTION_DEBUG_EVENT, &data );
 625     }
 626     release_object( process );
 627 }
 628
 629 /* queue an exception event */
 630 DECL_HANDLER(queue_exception_event)
 631 {
 632     reply->handle = 0;
 633     if (current->process->debugger)
 634     {
 635         struct debug_event_exception data;
 636         struct debug_event *event;
 637         const CONTEXT *context = get_req_data();
 638         const EXCEPTION_RECORD *rec = (const EXCEPTION_RECORD *)(context + 1);
 639
 640         if (get_req_data_size() < sizeof(*rec) + sizeof(*context))
 641         {
 642             set_error( STATUS_INVALID_PARAMETER );
 643             return;
 644         }
 645         data.record = *rec;
 646         data.first  = req->first;
 647         if ((event = alloc_debug_event( current, EXCEPTION_DEBUG_EVENT, &data, context )))
 648         {
 649             if ((reply->handle = alloc_handle( current->process, event, SYNCHRONIZE, FALSE )))
 650             {
 651                 link_event( event );
 652                 suspend_process( current->process );
 653             }
 654             release_object( event );
 655         }
 656     }
 657 }
 658
 659 /* retrieve the status of an exception event */
 660 DECL_HANDLER(get_exception_status)
 661 {
 662     struct debug_event *event;
 663
 664     reply->status = 0;
 665     if ((event = (struct debug_event *)get_handle_obj( current->process, req->handle,
 666                                                        0, &debug_event_ops )))
 667     {
 668         if (event->state == EVENT_CONTINUED)
 669         {
 670             reply->status = event->status;
 671             if (current->context == &event->context)
 672             {
 673                 size_t size = min( sizeof(CONTEXT), get_reply_max_size() );
 674                 set_reply_data( &event->context, size );
 675                 current->context = NULL;
 676             }
 677         }
 678         else set_error( STATUS_PENDING );
 679         release_object( event );
 680     }
 681 }
 682
 683 /* send an output string to the debugger */
 684 DECL_HANDLER(output_debug_string)
 685 {
 686     struct debug_event_output_string data;
 687
 688     data.string  = req->string;
 689     data.unicode = req->unicode;
 690     data.length  = req->length;
 691     generate_debug_event( current, OUTPUT_DEBUG_STRING_EVENT, &data );
 692 }
 693
 694 /* simulate a breakpoint in a process */
 695 DECL_HANDLER(debug_break)
 696 {
 697     struct process *process;
 698
 699     reply->self = 0;
 700     if (!(process = get_process_from_handle( req->handle, PROCESS_SET_INFORMATION /*FIXME*/ )))
 701         return;
 702     if (process != current->process)
 703     {
 704         /* find a suitable thread to signal */
 705         struct thread *thread;
 706         LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
 707         {
 708             if (send_thread_signal( thread, SIGTRAP )) goto done;
 709         }
 710         set_error( STATUS_ACCESS_DENIED );
 711     }
 712     else reply->self = 1;
 713
 714 done:
 715     release_object( process );
 716 }
 717
 718 /* set debugger kill on exit flag */
 719 DECL_HANDLER(set_debugger_kill_on_exit)
 720 {
 721     if (!current->debug_ctx)
 722     {
 723         set_error( STATUS_ACCESS_DENIED );
 724         return;
 725     }
 726     current->debug_ctx->kill_on_exit = req->kill_on_exit;
 727 }