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