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 "ntstatus.h"
  31 #define WIN32_NO_STATUS
  32 #include "windef.h"
  33 #include "winternl.h"
  34
  35 #include "handle.h"
  36 #include "process.h"
  37 #include "thread.h"
  38 #include "request.h"
  39 #include "console.h"
  40
  41 enum debug_event_state { EVENT_QUEUED, EVENT_SENT, 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 thread         *debugger;  /* debugger thread receiving the event */
  50     enum debug_event_state state;     /* event state */
  51     int                    status;    /* continuation status */
  52     debug_event_t          data;      /* event data */
  53     CONTEXT                context;   /* register context */
  54 };
  55
  56 /* debug context */
  57 struct debug_ctx
  58 {
  59     struct object        obj;         /* object header */
  60     struct list          event_queue; /* pending events queue */
  61     int                  kill_on_exit;/* kill debuggees on debugger exit ? */
  62 };
  63
  64
  65 static void debug_event_dump( struct object *obj, int verbose );
  66 static int debug_event_signaled( struct object *obj, struct thread *thread );
  67 static void debug_event_destroy( struct object *obj );
  68
  69 static const struct object_ops debug_event_ops =
  70 {
  71     sizeof(struct debug_event),    /* size */
  72     debug_event_dump,              /* dump */
  73     add_queue,                     /* add_queue */
  74     remove_queue,                  /* remove_queue */
  75     debug_event_signaled,          /* signaled */
  76     no_satisfied,                  /* satisfied */
  77     no_signal,                     /* signal */
  78     no_get_fd,                     /* get_fd */
  79     no_map_access,                 /* map_access */
  80     no_lookup_name,                /* lookup_name */
  81     no_close_handle,               /* close_handle */
  82     debug_event_destroy            /* destroy */
  83 };
  84
  85 static void debug_ctx_dump( struct object *obj, int verbose );
  86 static int debug_ctx_signaled( struct object *obj, struct thread *thread );
  87 static void debug_ctx_destroy( struct object *obj );
  88
  89 static const struct object_ops debug_ctx_ops =
  90 {
  91     sizeof(struct debug_ctx),      /* size */
  92     debug_ctx_dump,                /* dump */
  93     add_queue,                     /* add_queue */
  94     remove_queue,                  /* remove_queue */
  95     debug_ctx_signaled,            /* signaled */
  96     no_satisfied,                  /* satisfied */
  97     no_signal,                     /* signal */
  98     no_get_fd,                     /* get_fd */
  99     no_map_access,                 /* map_access */
 100     no_lookup_name,                /* lookup_name */
 101     no_close_handle,               /* close_handle */
 102     debug_ctx_destroy              /* destroy */
 103 };
 104
 105
 106 /* routines to build an event according to its type */
 107
 108 static int fill_exception_event( struct debug_event *event, void *arg )
 109 {
 110     memcpy( &event->data.info.exception, arg, sizeof(event->data.info.exception) );
 111     return 1;
 112 }
 113
 114 static int fill_create_thread_event( struct debug_event *event, void *arg )
 115 {
 116     struct process *debugger = event->debugger->process;
 117     struct thread *thread = event->sender;
 118     obj_handle_t handle;
 119
 120     /* documented: THREAD_GET_CONTEXT | THREAD_SET_CONTEXT | THREAD_SUSPEND_RESUME */
 121     if (!(handle = alloc_handle( debugger, thread, THREAD_ALL_ACCESS, 0 ))) return 0;
 122     event->data.info.create_thread.handle = handle;
 123     event->data.info.create_thread.teb    = thread->teb;
 124     event->data.info.create_thread.start  = arg;
 125     return 1;
 126 }
 127
 128 static int fill_create_process_event( struct debug_event *event, void *arg )
 129 {
 130     struct process *debugger = event->debugger->process;
 131     struct thread *thread = event->sender;
 132     struct process *process = thread->process;
 133     obj_handle_t handle;
 134
 135     /* documented: PROCESS_VM_READ | PROCESS_VM_WRITE */
 136     if (!(handle = alloc_handle( debugger, process, PROCESS_ALL_ACCESS, 0 ))) return 0;
 137     event->data.info.create_process.process = handle;
 138
 139     /* documented: THREAD_GET_CONTEXT | THREAD_SET_CONTEXT | THREAD_SUSPEND_RESUME */
 140     if (!(handle = alloc_handle( debugger, thread, THREAD_ALL_ACCESS, 0 )))
 141     {
 142         close_handle( debugger, event->data.info.create_process.process, NULL );
 143         return 0;
 144     }
 145     event->data.info.create_process.thread = handle;
 146
 147     handle = 0;
 148     if (process->exe.file &&
 149         /* the doc says write access too, but this doesn't seem a good idea */
 150         !(handle = alloc_handle( debugger, process->exe.file, GENERIC_READ, 0 )))
 151     {
 152         close_handle( debugger, event->data.info.create_process.process, NULL );
 153         close_handle( debugger, event->data.info.create_process.thread, NULL );
 154         return 0;
 155     }
 156     event->data.info.create_process.file       = handle;
 157     event->data.info.create_process.teb        = thread->teb;
 158     event->data.info.create_process.base       = process->exe.base;
 159     event->data.info.create_process.start      = arg;
 160     event->data.info.create_process.dbg_offset = process->exe.dbg_offset;
 161     event->data.info.create_process.dbg_size   = process->exe.dbg_size;
 162     event->data.info.create_process.name       = process->exe.name;
 163     event->data.info.create_process.unicode    = 1;
 164     return 1;
 165 }
 166
 167 static int fill_exit_thread_event( struct debug_event *event, void *arg )
 168 {
 169     struct thread *thread = arg;
 170     event->data.info.exit.exit_code = thread->exit_code;
 171     return 1;
 172 }
 173
 174 static int fill_exit_process_event( struct debug_event *event, void *arg )
 175 {
 176     struct process *process = arg;
 177     event->data.info.exit.exit_code = process->exit_code;
 178     return 1;
 179 }
 180
 181 static int fill_load_dll_event( struct debug_event *event, void *arg )
 182 {
 183     struct process *debugger = event->debugger->process;
 184     struct process_dll *dll = arg;
 185     obj_handle_t handle = 0;
 186
 187     if (dll->file && !(handle = alloc_handle( debugger, dll->file, GENERIC_READ, 0 )))
 188         return 0;
 189     event->data.info.load_dll.handle     = handle;
 190     event->data.info.load_dll.base       = dll->base;
 191     event->data.info.load_dll.dbg_offset = dll->dbg_offset;
 192     event->data.info.load_dll.dbg_size   = dll->dbg_size;
 193     event->data.info.load_dll.name       = dll->name;
 194     event->data.info.load_dll.unicode    = 1;
 195     return 1;
 196 }
 197
 198 static int fill_unload_dll_event( struct debug_event *event, void *arg )
 199 {
 200     event->data.info.unload_dll.base = arg;
 201     return 1;
 202 }
 203
 204 static int fill_output_debug_string_event( struct debug_event *event, void *arg )
 205 {
 206     struct debug_event_output_string *data = arg;
 207     event->data.info.output_string = *data;
 208     return 1;
 209 }
 210
 211 typedef int (*fill_event_func)( struct debug_event *event, void *arg );
 212
 213 #define NB_DEBUG_EVENTS OUTPUT_DEBUG_STRING_EVENT  /* RIP_EVENT not supported */
 214
 215 static const fill_event_func fill_debug_event[NB_DEBUG_EVENTS] =
 216 {
 217     fill_exception_event,            /* EXCEPTION_DEBUG_EVENT */
 218     fill_create_thread_event,        /* CREATE_THREAD_DEBUG_EVENT */
 219     fill_create_process_event,       /* CREATE_PROCESS_DEBUG_EVENT */
 220     fill_exit_thread_event,          /* EXIT_THREAD_DEBUG_EVENT */
 221     fill_exit_process_event,         /* EXIT_PROCESS_DEBUG_EVENT */
 222     fill_load_dll_event,             /* LOAD_DLL_DEBUG_EVENT */
 223     fill_unload_dll_event,           /* UNLOAD_DLL_DEBUG_EVENT */
 224     fill_output_debug_string_event   /* OUTPUT_DEBUG_STRING_EVENT */
 225 };
 226
 227
 228 /* unlink the first event from the queue */
 229 static void unlink_event( struct debug_ctx *debug_ctx, struct debug_event *event )
 230 {
 231     list_remove( &event->entry );
 232     if (event->sender->debug_event == event) event->sender->debug_event = NULL;
 233     release_object( event );
 234 }
 235
 236 /* link an event at the end of the queue */
 237 static void link_event( struct debug_event *event )
 238 {
 239     struct debug_ctx *debug_ctx = event->debugger->debug_ctx;
 240
 241     assert( debug_ctx );
 242     grab_object( event );
 243     list_add_tail( &debug_ctx->event_queue, &event->entry );
 244     if (!event->sender->debug_event) wake_up( &debug_ctx->obj, 0 );
 245 }
 246
 247 /* find the next event that we can send to the debugger */
 248 static struct debug_event *find_event_to_send( struct debug_ctx *debug_ctx )
 249 {
 250     struct debug_event *event;
 251
 252     LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 253     {
 254         if (event->state == EVENT_SENT) continue;  /* already sent */
 255         if (event->sender->debug_event) continue;  /* thread busy with another one */
 256         return event;
 257     }
 258     return NULL;
 259 }
 260
 261 static void debug_event_dump( struct object *obj, int verbose )
 262 {
 263     struct debug_event *debug_event = (struct debug_event *)obj;
 264     assert( obj->ops == &debug_event_ops );
 265     fprintf( stderr, "Debug event sender=%p code=%d state=%d\n",
 266              debug_event->sender, debug_event->data.code, debug_event->state );
 267 }
 268
 269 static int debug_event_signaled( struct object *obj, struct thread *thread )
 270 {
 271     struct debug_event *debug_event = (struct debug_event *)obj;
 272     assert( obj->ops == &debug_event_ops );
 273     return debug_event->state == EVENT_CONTINUED;
 274 }
 275
 276 static void debug_event_destroy( struct object *obj )
 277 {
 278     struct debug_event *event = (struct debug_event *)obj;
 279     assert( obj->ops == &debug_event_ops );
 280
 281     /* If the event has been sent already, the handles are now under the */
 282     /* responsibility of the debugger process, so we don't touch them    */
 283     if (event->state == EVENT_QUEUED)
 284     {
 285         struct process *debugger = event->debugger->process;
 286         switch(event->data.code)
 287         {
 288         case CREATE_THREAD_DEBUG_EVENT:
 289             close_handle( debugger, event->data.info.create_thread.handle, NULL );
 290             break;
 291         case CREATE_PROCESS_DEBUG_EVENT:
 292             if (event->data.info.create_process.file)
 293                 close_handle( debugger, event->data.info.create_process.file, NULL );
 294             close_handle( debugger, event->data.info.create_process.thread, NULL );
 295             close_handle( debugger, event->data.info.create_process.process, NULL );
 296             break;
 297         case LOAD_DLL_DEBUG_EVENT:
 298             if (event->data.info.load_dll.handle)
 299                 close_handle( debugger, event->data.info.load_dll.handle, NULL );
 300             break;
 301         }
 302     }
 303     if (event->sender->context == &event->context) event->sender->context = NULL;
 304     release_object( event->sender );
 305     release_object( event->debugger );
 306 }
 307
 308 static void debug_ctx_dump( struct object *obj, int verbose )
 309 {
 310     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 311     assert( obj->ops == &debug_ctx_ops );
 312     fprintf( stderr, "Debug context head=%p tail=%p\n",
 313              debug_ctx->event_queue.next, debug_ctx->event_queue.prev );
 314 }
 315
 316 static int debug_ctx_signaled( struct object *obj, struct thread *thread )
 317 {
 318     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 319     assert( obj->ops == &debug_ctx_ops );
 320     return find_event_to_send( debug_ctx ) != NULL;
 321 }
 322
 323 static void debug_ctx_destroy( struct object *obj )
 324 {
 325     struct list *ptr;
 326     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 327     assert( obj->ops == &debug_ctx_ops );
 328
 329     /* free all pending events */
 330     while ((ptr = list_head( &debug_ctx->event_queue )))
 331         unlink_event( debug_ctx, LIST_ENTRY( ptr, struct debug_event, entry ));
 332 }
 333
 334 /* continue a debug event */
 335 static int continue_debug_event( struct process *process, struct thread *thread, int status )
 336 {
 337     struct debug_ctx *debug_ctx = current->debug_ctx;
 338
 339     if (debug_ctx && process->debugger == current && thread->process == process)
 340     {
 341         struct debug_event *event;
 342
 343         /* find the event in the queue */
 344         LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 345         {
 346             if (event->state != EVENT_SENT) continue;
 347             if (event->sender == thread)
 348             {
 349                 assert( event->sender->debug_event == event );
 350
 351                 event->status = status;
 352                 event->state  = EVENT_CONTINUED;
 353                 wake_up( &event->obj, 0 );
 354                 unlink_event( debug_ctx, event );
 355                 resume_process( process );
 356                 return 1;
 357             }
 358         }
 359     }
 360     /* not debugging this process, or no such event */
 361     set_error( STATUS_ACCESS_DENIED );  /* FIXME */
 362     return 0;
 363 }
 364
 365 /* alloc a debug event for a debugger */
 366 static struct debug_event *alloc_debug_event( struct thread *thread, int code,
 367                                               void *arg, const CONTEXT *context )
 368 {
 369     struct thread *debugger = thread->process->debugger;
 370     struct debug_event *event;
 371
 372     assert( code > 0 && code <= NB_DEBUG_EVENTS );
 373     /* cannot queue a debug event for myself */
 374     assert( debugger->process != thread->process );
 375
 376     /* build the event */
 377     if (!(event = alloc_object( &debug_event_ops ))) return NULL;
 378     event->state     = EVENT_QUEUED;
 379     event->sender    = (struct thread *)grab_object( thread );
 380     event->debugger  = (struct thread *)grab_object( debugger );
 381     event->data.code = code;
 382
 383     if (!fill_debug_event[code-1]( event, arg ))
 384     {
 385         event->data.code = -1;  /* make sure we don't attempt to close handles */
 386         release_object( event );
 387         return NULL;
 388     }
 389     if (context)
 390     {
 391         memcpy( &event->context, context, sizeof(event->context) );
 392         thread->context = &event->context;
 393     }
 394     return event;
 395 }
 396
 397 /* generate a debug event from inside the server and queue it */
 398 void generate_debug_event( struct thread *thread, int code, void *arg )
 399 {
 400     if (thread->process->debugger)
 401     {
 402         struct debug_event *event = alloc_debug_event( thread, code, arg, NULL );
 403         if (event)
 404         {
 405             link_event( event );
 406             suspend_process( thread->process );
 407             release_object( event );
 408         }
 409     }
 410 }
 411
 412 /* attach a process to a debugger thread and suspend it */
 413 static int debugger_attach( struct process *process, struct thread *debugger )
 414 {
 415     struct thread *thread;
 416
 417     if (process->debugger) goto error;  /* already being debugged */
 418     if (!is_process_init_done( process )) goto error;  /* still starting up */
 419     if (list_empty( &process->thread_list )) goto error;  /* no thread running in the process */
 420
 421     /* make sure we don't create a debugging loop */
 422     for (thread = debugger; thread; thread = thread->process->debugger)
 423         if (thread->process == process) goto error;
 424
 425     /* don't let a debugger debug its console... won't work */
 426     if (debugger->process->console && debugger->process->console->renderer->process == process)
 427         goto error;
 428
 429     suspend_process( process );
 430     if (!attach_process( process ) || !set_process_debugger( process, debugger ))
 431     {
 432         resume_process( process );
 433         return 0;
 434     }
 435     if (!set_process_debug_flag( process, 1 ))
 436     {
 437         process->debugger = NULL;
 438         resume_process( process );
 439         return 0;
 440     }
 441     return 1;
 442
 443  error:
 444     set_error( STATUS_ACCESS_DENIED );
 445     return 0;
 446 }
 447
 448
 449 /* detach a process from a debugger thread (and resume it ?) */
 450 int debugger_detach( struct process *process, struct thread *debugger )
 451 {
 452     struct debug_event *event;
 453     struct debug_ctx *debug_ctx;
 454
 455     if (!process->debugger || process->debugger != debugger)
 456         goto error;  /* not currently debugged, or debugged by another debugger */
 457     if (!debugger->debug_ctx ) goto error; /* should be a debugger */
 458     /* init should be done, otherwise wouldn't be attached */
 459     assert(is_process_init_done(process));
 460
 461     suspend_process( process );
 462     /* send continue indication for all events */
 463     debug_ctx = debugger->debug_ctx;
 464
 465     /* find the event in the queue
 466      * FIXME: could loop on process' threads and look the debug_event field */
 467     LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 468     {
 469         if (event->state != EVENT_QUEUED) continue;
 470
 471         if (event->sender->process == process)
 472         {
 473             assert( event->sender->debug_event == event );
 474             event->status = DBG_CONTINUE;
 475             event->state  = EVENT_CONTINUED;
 476             wake_up( &event->obj, 0 );
 477             unlink_event( debug_ctx, event );
 478             /* from queued debug event */
 479             resume_process( process );
 480             break;
 481         }
 482     }
 483
 484     /* remove relationships between process and its debugger */
 485     process->debugger = NULL;
 486     if (!set_process_debug_flag( process, 0 )) clear_error();  /* ignore error */
 487     detach_process( process );
 488
 489     /* from this function */
 490     resume_process( process );
 491     return 0;
 492
 493  error:
 494     set_error( STATUS_ACCESS_DENIED );
 495     return 0;
 496 }
 497
 498 /* generate all startup events of a given process */
 499 void generate_startup_debug_events( struct process *process, void *entry )
 500 {
 501     struct list *ptr;
 502     struct thread *thread, *first_thread = get_process_first_thread( process );
 503
 504     /* generate creation events */
 505     LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
 506     {
 507         if (thread == first_thread)
 508             generate_debug_event( thread, CREATE_PROCESS_DEBUG_EVENT, entry );
 509         else
 510             generate_debug_event( thread, CREATE_THREAD_DEBUG_EVENT, NULL );
 511     }
 512
 513     /* generate dll events (in loading order, i.e. reverse list order) */
 514     ptr = list_tail( &process->dlls );
 515     while (ptr)
 516     {
 517         struct process_dll *dll = LIST_ENTRY( ptr, struct process_dll, entry );
 518         generate_debug_event( first_thread, LOAD_DLL_DEBUG_EVENT, dll );
 519         ptr = list_prev( &process->dlls, ptr );
 520     }
 521 }
 522
 523 /* set the debugger of a given process */
 524 int set_process_debugger( struct process *process, struct thread *debugger )
 525 {
 526     struct debug_ctx *debug_ctx;
 527
 528     assert( !process->debugger );
 529
 530     if (!debugger->debug_ctx)  /* need to allocate a context */
 531     {
 532         if (!(debug_ctx = alloc_object( &debug_ctx_ops ))) return 0;
 533         debug_ctx->kill_on_exit = 1;
 534         list_init( &debug_ctx->event_queue );
 535         debugger->debug_ctx = debug_ctx;
 536     }
 537     process->debugger = debugger;
 538     return 1;
 539 }
 540
 541 /* a thread is exiting */
 542 void debug_exit_thread( struct thread *thread )
 543 {
 544     if (thread->debug_ctx)  /* this thread is a debugger */
 545     {
 546         if (thread->debug_ctx->kill_on_exit)
 547         {
 548             /* kill all debugged processes */
 549             kill_debugged_processes( thread, thread->exit_code );
 550         }
 551         else
 552         {
 553             detach_debugged_processes( thread );
 554         }
 555         release_object( thread->debug_ctx );
 556         thread->debug_ctx = NULL;
 557     }
 558 }
 559
 560 /* Wait for a debug event */
 561 DECL_HANDLER(wait_debug_event)
 562 {
 563     struct debug_ctx *debug_ctx = current->debug_ctx;
 564     struct debug_event *event;
 565
 566     if (!debug_ctx)  /* current thread is not a debugger */
 567     {
 568         set_error( STATUS_INVALID_HANDLE );
 569         return;
 570     }
 571     reply->wait = 0;
 572     if ((event = find_event_to_send( debug_ctx )))
 573     {
 574         size_t size = get_reply_max_size();
 575         event->state = EVENT_SENT;
 576         event->sender->debug_event = event;
 577         reply->pid = get_process_id( event->sender->process );
 578         reply->tid = get_thread_id( event->sender );
 579         if (size > sizeof(debug_event_t)) size = sizeof(debug_event_t);
 580         set_reply_data( &event->data, size );
 581     }
 582     else  /* no event ready */
 583     {
 584         reply->pid  = 0;
 585         reply->tid  = 0;
 586         if (req->get_handle)
 587             reply->wait = alloc_handle( current->process, debug_ctx, SYNCHRONIZE, 0 );
 588     }
 589 }
 590
 591 /* Continue a debug event */
 592 DECL_HANDLER(continue_debug_event)
 593 {
 594     struct process *process = get_process_from_id( req->pid );
 595     if (process)
 596     {
 597         struct thread *thread = get_thread_from_id( req->tid );
 598         if (thread)
 599         {
 600             continue_debug_event( process, thread, req->status );
 601             release_object( thread );
 602         }
 603         release_object( process );
 604     }
 605 }
 606
 607 /* Start debugging an existing process */
 608 DECL_HANDLER(debug_process)
 609 {
 610     struct process *process = get_process_from_id( req->pid );
 611     if (!process) return;
 612
 613     if (!req->attach)
 614     {
 615         debugger_detach( process, current );
 616     }
 617     else if (debugger_attach( process, current ))
 618     {
 619         struct debug_event_exception data;
 620         struct thread *thread = get_process_first_thread( process );
 621
 622         generate_startup_debug_events( process, NULL );
 623         resume_process( process );
 624
 625         data.record.ExceptionCode    = EXCEPTION_BREAKPOINT;
 626         data.record.ExceptionFlags   = EXCEPTION_CONTINUABLE;
 627         data.record.ExceptionRecord  = NULL;
 628         data.record.ExceptionAddress = get_thread_ip( thread );
 629         data.record.NumberParameters = 0;
 630         data.first = 1;
 631         generate_debug_event( thread, EXCEPTION_DEBUG_EVENT, &data );
 632     }
 633     release_object( process );
 634 }
 635
 636 /* queue an exception event */
 637 DECL_HANDLER(queue_exception_event)
 638 {
 639     reply->handle = 0;
 640     if (current->process->debugger)
 641     {
 642         struct debug_event_exception data;
 643         struct debug_event *event;
 644         const CONTEXT *context = get_req_data();
 645         const EXCEPTION_RECORD *rec = (const EXCEPTION_RECORD *)(context + 1);
 646
 647         if (get_req_data_size() < sizeof(*rec) + sizeof(*context))
 648         {
 649             set_error( STATUS_INVALID_PARAMETER );
 650             return;
 651         }
 652         data.record = *rec;
 653         data.first  = req->first;
 654         if ((event = alloc_debug_event( current, EXCEPTION_DEBUG_EVENT, &data, context )))
 655         {
 656             if ((reply->handle = alloc_handle( current->process, event, SYNCHRONIZE, 0 )))
 657             {
 658                 link_event( event );
 659                 suspend_process( current->process );
 660             }
 661             release_object( event );
 662         }
 663     }
 664 }
 665
 666 /* retrieve the status of an exception event */
 667 DECL_HANDLER(get_exception_status)
 668 {
 669     struct debug_event *event;
 670
 671     if ((event = (struct debug_event *)get_handle_obj( current->process, req->handle,
 672                                                        0, &debug_event_ops )))
 673     {
 674         close_handle( current->process, req->handle, NULL );
 675         if (event->state == EVENT_CONTINUED)
 676         {
 677             if (current->context == &event->context)
 678             {
 679                 size_t size = min( sizeof(CONTEXT), get_reply_max_size() );
 680                 set_reply_data( &event->context, size );
 681                 current->context = NULL;
 682             }
 683             set_error( event->status );
 684         }
 685         else set_error( STATUS_PENDING );
 686         release_object( event );
 687     }
 688 }
 689
 690 /* send an output string to the debugger */
 691 DECL_HANDLER(output_debug_string)
 692 {
 693     struct debug_event_output_string data;
 694
 695     data.string  = req->string;
 696     data.unicode = req->unicode;
 697     data.length  = req->length;
 698     generate_debug_event( current, OUTPUT_DEBUG_STRING_EVENT, &data );
 699 }
 700
 701 /* simulate a breakpoint in a process */
 702 DECL_HANDLER(debug_break)
 703 {
 704     struct process *process;
 705
 706     reply->self = 0;
 707     if (!(process = get_process_from_handle( req->handle, PROCESS_SET_INFORMATION /*FIXME*/ )))
 708         return;
 709     if (process != current->process)
 710     {
 711         /* find a suitable thread to signal */
 712         struct thread *thread;
 713         LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
 714         {
 715             if (send_thread_signal( thread, SIGTRAP )) goto done;
 716         }
 717         set_error( STATUS_ACCESS_DENIED );
 718     }
 719     else reply->self = 1;
 720
 721 done:
 722     release_object( process );
 723 }
 724
 725 /* set debugger kill on exit flag */
 726 DECL_HANDLER(set_debugger_kill_on_exit)
 727 {
 728     if (!current->debug_ctx)
 729     {
 730         set_error( STATUS_ACCESS_DENIED );
 731         return;
 732     }
 733     current->debug_ctx->kill_on_exit = req->kill_on_exit;
 734 }