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     struct process_dll *exe_module = get_process_exe_module( process );
 134     obj_handle_t handle;
 135
 136     /* documented: PROCESS_VM_READ | PROCESS_VM_WRITE */
 137     if (!(handle = alloc_handle( debugger, process, PROCESS_ALL_ACCESS, 0 ))) return 0;
 138     event->data.info.create_process.process = handle;
 139
 140     /* documented: THREAD_GET_CONTEXT | THREAD_SET_CONTEXT | THREAD_SUSPEND_RESUME */
 141     if (!(handle = alloc_handle( debugger, thread, THREAD_ALL_ACCESS, 0 )))
 142     {
 143         close_handle( debugger, event->data.info.create_process.process, NULL );
 144         return 0;
 145     }
 146     event->data.info.create_process.thread = handle;
 147
 148     handle = 0;
 149     if (exe_module->file &&
 150         /* the doc says write access too, but this doesn't seem a good idea */
 151         !(handle = alloc_handle( debugger, exe_module->file, GENERIC_READ, 0 )))
 152     {
 153         close_handle( debugger, event->data.info.create_process.process, NULL );
 154         close_handle( debugger, event->data.info.create_process.thread, NULL );
 155         return 0;
 156     }
 157     event->data.info.create_process.file       = handle;
 158     event->data.info.create_process.teb        = thread->teb;
 159     event->data.info.create_process.base       = exe_module->base;
 160     event->data.info.create_process.start      = arg;
 161     event->data.info.create_process.dbg_offset = exe_module->dbg_offset;
 162     event->data.info.create_process.dbg_size   = exe_module->dbg_size;
 163     event->data.info.create_process.name       = exe_module->name;
 164     event->data.info.create_process.unicode    = 1;
 165     return 1;
 166 }
 167
 168 static int fill_exit_thread_event( struct debug_event *event, void *arg )
 169 {
 170     struct thread *thread = arg;
 171     event->data.info.exit.exit_code = thread->exit_code;
 172     return 1;
 173 }
 174
 175 static int fill_exit_process_event( struct debug_event *event, void *arg )
 176 {
 177     struct process *process = arg;
 178     event->data.info.exit.exit_code = process->exit_code;
 179     return 1;
 180 }
 181
 182 static int fill_load_dll_event( struct debug_event *event, void *arg )
 183 {
 184     struct process *debugger = event->debugger->process;
 185     struct process_dll *dll = arg;
 186     obj_handle_t handle = 0;
 187
 188     if (dll->file && !(handle = alloc_handle( debugger, dll->file, GENERIC_READ, 0 )))
 189         return 0;
 190     event->data.info.load_dll.handle     = handle;
 191     event->data.info.load_dll.base       = dll->base;
 192     event->data.info.load_dll.dbg_offset = dll->dbg_offset;
 193     event->data.info.load_dll.dbg_size   = dll->dbg_size;
 194     event->data.info.load_dll.name       = dll->name;
 195     event->data.info.load_dll.unicode    = 1;
 196     return 1;
 197 }
 198
 199 static int fill_unload_dll_event( struct debug_event *event, void *arg )
 200 {
 201     event->data.info.unload_dll.base = arg;
 202     return 1;
 203 }
 204
 205 static int fill_output_debug_string_event( struct debug_event *event, void *arg )
 206 {
 207     struct debug_event_output_string *data = arg;
 208     event->data.info.output_string = *data;
 209     return 1;
 210 }
 211
 212 typedef int (*fill_event_func)( struct debug_event *event, void *arg );
 213
 214 #define NB_DEBUG_EVENTS OUTPUT_DEBUG_STRING_EVENT  /* RIP_EVENT not supported */
 215
 216 static const fill_event_func fill_debug_event[NB_DEBUG_EVENTS] =
 217 {
 218     fill_exception_event,            /* EXCEPTION_DEBUG_EVENT */
 219     fill_create_thread_event,        /* CREATE_THREAD_DEBUG_EVENT */
 220     fill_create_process_event,       /* CREATE_PROCESS_DEBUG_EVENT */
 221     fill_exit_thread_event,          /* EXIT_THREAD_DEBUG_EVENT */
 222     fill_exit_process_event,         /* EXIT_PROCESS_DEBUG_EVENT */
 223     fill_load_dll_event,             /* LOAD_DLL_DEBUG_EVENT */
 224     fill_unload_dll_event,           /* UNLOAD_DLL_DEBUG_EVENT */
 225     fill_output_debug_string_event   /* OUTPUT_DEBUG_STRING_EVENT */
 226 };
 227
 228
 229 /* unlink the first event from the queue */
 230 static void unlink_event( struct debug_ctx *debug_ctx, struct debug_event *event )
 231 {
 232     list_remove( &event->entry );
 233     if (event->sender->debug_event == event) event->sender->debug_event = NULL;
 234     release_object( event );
 235 }
 236
 237 /* link an event at the end of the queue */
 238 static void link_event( struct debug_event *event )
 239 {
 240     struct debug_ctx *debug_ctx = event->debugger->debug_ctx;
 241
 242     assert( debug_ctx );
 243     grab_object( event );
 244     list_add_tail( &debug_ctx->event_queue, &event->entry );
 245     if (!event->sender->debug_event) wake_up( &debug_ctx->obj, 0 );
 246 }
 247
 248 /* find the next event that we can send to the debugger */
 249 static struct debug_event *find_event_to_send( struct debug_ctx *debug_ctx )
 250 {
 251     struct debug_event *event;
 252
 253     LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 254     {
 255         if (event->state == EVENT_SENT) continue;  /* already sent */
 256         if (event->sender->debug_event) continue;  /* thread busy with another one */
 257         return event;
 258     }
 259     return NULL;
 260 }
 261
 262 static void debug_event_dump( struct object *obj, int verbose )
 263 {
 264     struct debug_event *debug_event = (struct debug_event *)obj;
 265     assert( obj->ops == &debug_event_ops );
 266     fprintf( stderr, "Debug event sender=%p code=%d state=%d\n",
 267              debug_event->sender, debug_event->data.code, debug_event->state );
 268 }
 269
 270 static int debug_event_signaled( struct object *obj, struct thread *thread )
 271 {
 272     struct debug_event *debug_event = (struct debug_event *)obj;
 273     assert( obj->ops == &debug_event_ops );
 274     return debug_event->state == EVENT_CONTINUED;
 275 }
 276
 277 static void debug_event_destroy( struct object *obj )
 278 {
 279     struct debug_event *event = (struct debug_event *)obj;
 280     assert( obj->ops == &debug_event_ops );
 281
 282     /* If the event has been sent already, the handles are now under the */
 283     /* responsibility of the debugger process, so we don't touch them    */
 284     if (event->state == EVENT_QUEUED)
 285     {
 286         struct process *debugger = event->debugger->process;
 287         switch(event->data.code)
 288         {
 289         case CREATE_THREAD_DEBUG_EVENT:
 290             close_handle( debugger, event->data.info.create_thread.handle, NULL );
 291             break;
 292         case CREATE_PROCESS_DEBUG_EVENT:
 293             if (event->data.info.create_process.file)
 294                 close_handle( debugger, event->data.info.create_process.file, NULL );
 295             close_handle( debugger, event->data.info.create_process.thread, NULL );
 296             close_handle( debugger, event->data.info.create_process.process, NULL );
 297             break;
 298         case LOAD_DLL_DEBUG_EVENT:
 299             if (event->data.info.load_dll.handle)
 300                 close_handle( debugger, event->data.info.load_dll.handle, NULL );
 301             break;
 302         }
 303     }
 304     if (event->sender->context == &event->context) event->sender->context = NULL;
 305     release_object( event->sender );
 306     release_object( event->debugger );
 307 }
 308
 309 static void debug_ctx_dump( struct object *obj, int verbose )
 310 {
 311     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 312     assert( obj->ops == &debug_ctx_ops );
 313     fprintf( stderr, "Debug context head=%p tail=%p\n",
 314              debug_ctx->event_queue.next, debug_ctx->event_queue.prev );
 315 }
 316
 317 static int debug_ctx_signaled( struct object *obj, struct thread *thread )
 318 {
 319     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 320     assert( obj->ops == &debug_ctx_ops );
 321     return find_event_to_send( debug_ctx ) != NULL;
 322 }
 323
 324 static void debug_ctx_destroy( struct object *obj )
 325 {
 326     struct list *ptr;
 327     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 328     assert( obj->ops == &debug_ctx_ops );
 329
 330     /* free all pending events */
 331     while ((ptr = list_head( &debug_ctx->event_queue )))
 332         unlink_event( debug_ctx, LIST_ENTRY( ptr, struct debug_event, entry ));
 333 }
 334
 335 /* continue a debug event */
 336 static int continue_debug_event( struct process *process, struct thread *thread, int status )
 337 {
 338     struct debug_ctx *debug_ctx = current->debug_ctx;
 339
 340     if (debug_ctx && process->debugger == current && thread->process == process)
 341     {
 342         struct debug_event *event;
 343
 344         /* find the event in the queue */
 345         LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 346         {
 347             if (event->state != EVENT_SENT) continue;
 348             if (event->sender == thread)
 349             {
 350                 assert( event->sender->debug_event == event );
 351
 352                 event->status = status;
 353                 event->state  = EVENT_CONTINUED;
 354                 wake_up( &event->obj, 0 );
 355                 unlink_event( debug_ctx, event );
 356                 resume_process( process );
 357                 return 1;
 358             }
 359         }
 360     }
 361     /* not debugging this process, or no such event */
 362     set_error( STATUS_ACCESS_DENIED );  /* FIXME */
 363     return 0;
 364 }
 365
 366 /* alloc a debug event for a debugger */
 367 static struct debug_event *alloc_debug_event( struct thread *thread, int code,
 368                                               void *arg, const CONTEXT *context )
 369 {
 370     struct thread *debugger = thread->process->debugger;
 371     struct debug_event *event;
 372
 373     assert( code > 0 && code <= NB_DEBUG_EVENTS );
 374     /* cannot queue a debug event for myself */
 375     assert( debugger->process != thread->process );
 376
 377     /* build the event */
 378     if (!(event = alloc_object( &debug_event_ops ))) return NULL;
 379     event->state     = EVENT_QUEUED;
 380     event->sender    = (struct thread *)grab_object( thread );
 381     event->debugger  = (struct thread *)grab_object( debugger );
 382     event->data.code = code;
 383
 384     if (!fill_debug_event[code-1]( event, arg ))
 385     {
 386         event->data.code = -1;  /* make sure we don't attempt to close handles */
 387         release_object( event );
 388         return NULL;
 389     }
 390     if (context)
 391     {
 392         memcpy( &event->context, context, sizeof(event->context) );
 393         thread->context = &event->context;
 394     }
 395     return event;
 396 }
 397
 398 /* generate a debug event from inside the server and queue it */
 399 void generate_debug_event( struct thread *thread, int code, void *arg )
 400 {
 401     if (thread->process->debugger)
 402     {
 403         struct debug_event *event = alloc_debug_event( thread, code, arg, NULL );
 404         if (event)
 405         {
 406             link_event( event );
 407             suspend_process( thread->process );
 408             release_object( event );
 409         }
 410     }
 411 }
 412
 413 /* attach a process to a debugger thread and suspend it */
 414 static int debugger_attach( struct process *process, struct thread *debugger )
 415 {
 416     struct thread *thread;
 417
 418     if (process->debugger) goto error;  /* already being debugged */
 419     if (!is_process_init_done( process )) goto error;  /* still starting up */
 420     if (list_empty( &process->thread_list )) goto error;  /* no thread running in the process */
 421
 422     /* make sure we don't create a debugging loop */
 423     for (thread = debugger; thread; thread = thread->process->debugger)
 424         if (thread->process == process) goto error;
 425
 426     /* don't let a debugger debug its console... won't work */
 427     if (debugger->process->console && debugger->process->console->renderer->process == process)
 428         goto error;
 429
 430     suspend_process( process );
 431     if (!attach_process( process ) || !set_process_debugger( process, debugger ))
 432     {
 433         resume_process( process );
 434         return 0;
 435     }
 436     if (!set_process_debug_flag( process, 1 ))
 437     {
 438         process->debugger = NULL;
 439         resume_process( process );
 440         return 0;
 441     }
 442     return 1;
 443
 444  error:
 445     set_error( STATUS_ACCESS_DENIED );
 446     return 0;
 447 }
 448
 449
 450 /* detach a process from a debugger thread (and resume it ?) */
 451 int debugger_detach( struct process *process, struct thread *debugger )
 452 {
 453     struct debug_event *event;
 454     struct debug_ctx *debug_ctx;
 455
 456     if (!process->debugger || process->debugger != debugger)
 457         goto error;  /* not currently debugged, or debugged by another debugger */
 458     if (!debugger->debug_ctx ) goto error; /* should be a debugger */
 459     /* init should be done, otherwise wouldn't be attached */
 460     assert(is_process_init_done(process));
 461
 462     suspend_process( process );
 463     /* send continue indication for all events */
 464     debug_ctx = debugger->debug_ctx;
 465
 466     /* find the event in the queue
 467      * FIXME: could loop on process' threads and look the debug_event field */
 468     LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 469     {
 470         if (event->state != EVENT_QUEUED) continue;
 471
 472         if (event->sender->process == process)
 473         {
 474             assert( event->sender->debug_event == event );
 475             event->status = DBG_CONTINUE;
 476             event->state  = EVENT_CONTINUED;
 477             wake_up( &event->obj, 0 );
 478             unlink_event( debug_ctx, event );
 479             /* from queued debug event */
 480             resume_process( process );
 481             break;
 482         }
 483     }
 484
 485     /* remove relationships between process and its debugger */
 486     process->debugger = NULL;
 487     if (!set_process_debug_flag( process, 0 )) clear_error();  /* ignore error */
 488     detach_process( process );
 489
 490     /* from this function */
 491     resume_process( process );
 492     return 0;
 493
 494  error:
 495     set_error( STATUS_ACCESS_DENIED );
 496     return 0;
 497 }
 498
 499 /* generate all startup events of a given process */
 500 void generate_startup_debug_events( struct process *process, void *entry )
 501 {
 502     struct list *ptr;
 503     struct thread *thread, *first_thread = get_process_first_thread( process );
 504
 505     /* generate creation events */
 506     LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
 507     {
 508         if (thread == first_thread)
 509             generate_debug_event( thread, CREATE_PROCESS_DEBUG_EVENT, entry );
 510         else
 511             generate_debug_event( thread, CREATE_THREAD_DEBUG_EVENT, NULL );
 512     }
 513
 514     /* generate dll events (in loading order, i.e. reverse list order) */
 515     ptr = list_tail( &process->dlls );
 516     while (ptr)
 517     {
 518         struct process_dll *dll = LIST_ENTRY( ptr, struct process_dll, entry );
 519         generate_debug_event( first_thread, LOAD_DLL_DEBUG_EVENT, dll );
 520         ptr = list_prev( &process->dlls, ptr );
 521     }
 522 }
 523
 524 /* set the debugger of a given process */
 525 int set_process_debugger( struct process *process, struct thread *debugger )
 526 {
 527     struct debug_ctx *debug_ctx;
 528
 529     assert( !process->debugger );
 530
 531     if (!debugger->debug_ctx)  /* need to allocate a context */
 532     {
 533         if (!(debug_ctx = alloc_object( &debug_ctx_ops ))) return 0;
 534         debug_ctx->kill_on_exit = 1;
 535         list_init( &debug_ctx->event_queue );
 536         debugger->debug_ctx = debug_ctx;
 537     }
 538     process->debugger = debugger;
 539     return 1;
 540 }
 541
 542 /* a thread is exiting */
 543 void debug_exit_thread( struct thread *thread )
 544 {
 545     if (thread->debug_ctx)  /* this thread is a debugger */
 546     {
 547         if (thread->debug_ctx->kill_on_exit)
 548         {
 549             /* kill all debugged processes */
 550             kill_debugged_processes( thread, thread->exit_code );
 551         }
 552         else
 553         {
 554             detach_debugged_processes( thread );
 555         }
 556         release_object( thread->debug_ctx );
 557         thread->debug_ctx = NULL;
 558     }
 559 }
 560
 561 /* Wait for a debug event */
 562 DECL_HANDLER(wait_debug_event)
 563 {
 564     struct debug_ctx *debug_ctx = current->debug_ctx;
 565     struct debug_event *event;
 566
 567     if (!debug_ctx)  /* current thread is not a debugger */
 568     {
 569         set_error( STATUS_INVALID_HANDLE );
 570         return;
 571     }
 572     reply->wait = 0;
 573     if ((event = find_event_to_send( debug_ctx )))
 574     {
 575         size_t size = get_reply_max_size();
 576         event->state = EVENT_SENT;
 577         event->sender->debug_event = event;
 578         reply->pid = get_process_id( event->sender->process );
 579         reply->tid = get_thread_id( event->sender );
 580         if (size > sizeof(debug_event_t)) size = sizeof(debug_event_t);
 581         set_reply_data( &event->data, size );
 582     }
 583     else  /* no event ready */
 584     {
 585         reply->pid  = 0;
 586         reply->tid  = 0;
 587         if (req->get_handle)
 588             reply->wait = alloc_handle( current->process, debug_ctx, SYNCHRONIZE, 0 );
 589     }
 590 }
 591
 592 /* Continue a debug event */
 593 DECL_HANDLER(continue_debug_event)
 594 {
 595     struct process *process = get_process_from_id( req->pid );
 596     if (process)
 597     {
 598         struct thread *thread = get_thread_from_id( req->tid );
 599         if (thread)
 600         {
 601             continue_debug_event( process, thread, req->status );
 602             release_object( thread );
 603         }
 604         release_object( process );
 605     }
 606 }
 607
 608 /* Start debugging an existing process */
 609 DECL_HANDLER(debug_process)
 610 {
 611     struct process *process = get_process_from_id( req->pid );
 612     if (!process) return;
 613
 614     if (!req->attach)
 615     {
 616         debugger_detach( process, current );
 617     }
 618     else if (debugger_attach( process, current ))
 619     {
 620         struct debug_event_exception data;
 621         struct thread *thread = get_process_first_thread( process );
 622
 623         generate_startup_debug_events( process, NULL );
 624         resume_process( process );
 625
 626         data.record.ExceptionCode    = EXCEPTION_BREAKPOINT;
 627         data.record.ExceptionFlags   = EXCEPTION_CONTINUABLE;
 628         data.record.ExceptionRecord  = NULL;
 629         data.record.ExceptionAddress = get_thread_ip( thread );
 630         data.record.NumberParameters = 0;
 631         data.first = 1;
 632         generate_debug_event( thread, EXCEPTION_DEBUG_EVENT, &data );
 633     }
 634     release_object( process );
 635 }
 636
 637 /* queue an exception event */
 638 DECL_HANDLER(queue_exception_event)
 639 {
 640     reply->handle = 0;
 641     if (current->process->debugger)
 642     {
 643         struct debug_event_exception data;
 644         struct debug_event *event;
 645         const CONTEXT *context = get_req_data();
 646         const EXCEPTION_RECORD *rec = (const EXCEPTION_RECORD *)(context + 1);
 647
 648         if (get_req_data_size() < sizeof(*rec) + sizeof(*context))
 649         {
 650             set_error( STATUS_INVALID_PARAMETER );
 651             return;
 652         }
 653         data.record = *rec;
 654         data.first  = req->first;
 655         if ((event = alloc_debug_event( current, EXCEPTION_DEBUG_EVENT, &data, context )))
 656         {
 657             if ((reply->handle = alloc_handle( current->process, event, SYNCHRONIZE, 0 )))
 658             {
 659                 link_event( event );
 660                 suspend_process( current->process );
 661             }
 662             release_object( event );
 663         }
 664     }
 665 }
 666
 667 /* retrieve the status of an exception event */
 668 DECL_HANDLER(get_exception_status)
 669 {
 670     struct debug_event *event;
 671
 672     if ((event = (struct debug_event *)get_handle_obj( current->process, req->handle,
 673                                                        0, &debug_event_ops )))
 674     {
 675         close_handle( current->process, req->handle, NULL );
 676         if (event->state == EVENT_CONTINUED)
 677         {
 678             if (current->context == &event->context)
 679             {
 680                 size_t size = min( sizeof(CONTEXT), get_reply_max_size() );
 681                 set_reply_data( &event->context, size );
 682                 current->context = NULL;
 683             }
 684             set_error( event->status );
 685         }
 686         else set_error( STATUS_PENDING );
 687         release_object( event );
 688     }
 689 }
 690
 691 /* send an output string to the debugger */
 692 DECL_HANDLER(output_debug_string)
 693 {
 694     struct debug_event_output_string data;
 695
 696     data.string  = req->string;
 697     data.unicode = req->unicode;
 698     data.length  = req->length;
 699     generate_debug_event( current, OUTPUT_DEBUG_STRING_EVENT, &data );
 700 }
 701
 702 /* simulate a breakpoint in a process */
 703 DECL_HANDLER(debug_break)
 704 {
 705     struct process *process;
 706
 707     reply->self = 0;
 708     if (!(process = get_process_from_handle( req->handle, PROCESS_SET_INFORMATION /*FIXME*/ )))
 709         return;
 710     if (process != current->process)
 711     {
 712         /* find a suitable thread to signal */
 713         struct thread *thread;
 714         LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
 715         {
 716             if (send_thread_signal( thread, SIGTRAP )) goto done;
 717         }
 718         set_error( STATUS_ACCESS_DENIED );
 719     }
 720     else reply->self = 1;
 721
 722 done:
 723     release_object( process );
 724 }
 725
 726 /* set debugger kill on exit flag */
 727 DECL_HANDLER(set_debugger_kill_on_exit)
 728 {
 729     if (!current->debug_ctx)
 730     {
 731         set_error( STATUS_ACCESS_DENIED );
 732         return;
 733     }
 734     current->debug_ctx->kill_on_exit = req->kill_on_exit;
 735 }