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