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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, 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
  40 enum debug_event_state { EVENT_QUEUED, EVENT_SENT, EVENT_CONTINUED };
  41
  42 /* debug event */
  43 struct debug_event
  44 {
  45     struct object          obj;       /* object header */
  46     struct list            entry;     /* entry in event queue */
  47     struct thread         *sender;    /* thread which sent this event */
  48     struct thread         *debugger;  /* debugger thread receiving the event */
  49     enum debug_event_state state;     /* event state */
  50     int                    status;    /* continuation status */
  51     debug_event_t          data;      /* event data */
  52     context_t              context;   /* register context */
  53 };
  54
  55 /* debug context */
  56 struct debug_ctx
  57 {
  58     struct object        obj;         /* object header */
  59     struct list          event_queue; /* pending events queue */
  60     int                  kill_on_exit;/* kill debuggees on debugger exit ? */
  61 };
  62
  63
  64 static void debug_event_dump( struct object *obj, int verbose );
  65 static int debug_event_signaled( struct object *obj, struct thread *thread );
  66 static void debug_event_destroy( struct object *obj );
  67
  68 static const struct object_ops debug_event_ops =
  69 {
  70     sizeof(struct debug_event),    /* size */
  71     debug_event_dump,              /* dump */
  72     no_get_type,                   /* get_type */
  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     default_get_sd,                /* get_sd */
  81     default_set_sd,                /* set_sd */
  82     no_lookup_name,                /* lookup_name */
  83     no_open_file,                  /* open_file */
  84     no_close_handle,               /* close_handle */
  85     debug_event_destroy            /* destroy */
  86 };
  87
  88 static void debug_ctx_dump( struct object *obj, int verbose );
  89 static int debug_ctx_signaled( struct object *obj, struct thread *thread );
  90 static void debug_ctx_destroy( struct object *obj );
  91
  92 static const struct object_ops debug_ctx_ops =
  93 {
  94     sizeof(struct debug_ctx),      /* size */
  95     debug_ctx_dump,                /* dump */
  96     no_get_type,                   /* get_type */
  97     add_queue,                     /* add_queue */
  98     remove_queue,                  /* remove_queue */
  99     debug_ctx_signaled,            /* signaled */
 100     no_satisfied,                  /* satisfied */
 101     no_signal,                     /* signal */
 102     no_get_fd,                     /* get_fd */
 103     no_map_access,                 /* map_access */
 104     default_get_sd,                /* get_sd */
 105     default_set_sd,                /* set_sd */
 106     no_lookup_name,                /* lookup_name */
 107     no_open_file,                  /* open_file */
 108     no_close_handle,               /* close_handle */
 109     debug_ctx_destroy              /* destroy */
 110 };
 111
 112
 113 /* routines to build an event according to its type */
 114
 115 static int fill_exception_event( struct debug_event *event, const void *arg )
 116 {
 117     const debug_event_t *data = arg;
 118     event->data.exception = data->exception;
 119     event->data.exception.nb_params = min( event->data.exception.nb_params, EXCEPTION_MAXIMUM_PARAMETERS );
 120     return 1;
 121 }
 122
 123 static int fill_create_thread_event( struct debug_event *event, const void *arg )
 124 {
 125     struct process *debugger = event->debugger->process;
 126     struct thread *thread = event->sender;
 127     const client_ptr_t *entry = arg;
 128     obj_handle_t handle;
 129
 130     /* documented: THREAD_GET_CONTEXT | THREAD_SET_CONTEXT | THREAD_SUSPEND_RESUME */
 131     if (!(handle = alloc_handle( debugger, thread, THREAD_ALL_ACCESS, 0 ))) return 0;
 132     event->data.create_thread.handle = handle;
 133     event->data.create_thread.teb    = thread->teb;
 134     if (entry) event->data.create_thread.start = *entry;
 135     return 1;
 136 }
 137
 138 static int fill_create_process_event( struct debug_event *event, const void *arg )
 139 {
 140     struct process *debugger = event->debugger->process;
 141     struct thread *thread = event->sender;
 142     struct process *process = thread->process;
 143     struct process_dll *exe_module = get_process_exe_module( process );
 144     const client_ptr_t *entry = arg;
 145     obj_handle_t handle;
 146
 147     /* documented: PROCESS_VM_READ | PROCESS_VM_WRITE */
 148     if (!(handle = alloc_handle( debugger, process, PROCESS_ALL_ACCESS, 0 ))) return 0;
 149     event->data.create_process.process = handle;
 150
 151     /* documented: THREAD_GET_CONTEXT | THREAD_SET_CONTEXT | THREAD_SUSPEND_RESUME */
 152     if (!(handle = alloc_handle( debugger, thread, THREAD_ALL_ACCESS, 0 )))
 153     {
 154         close_handle( debugger, event->data.create_process.process );
 155         return 0;
 156     }
 157     event->data.create_process.thread = handle;
 158
 159     handle = 0;
 160     if (exe_module->file &&
 161         /* the doc says write access too, but this doesn't seem a good idea */
 162         !(handle = alloc_handle( debugger, exe_module->file, GENERIC_READ, 0 )))
 163     {
 164         close_handle( debugger, event->data.create_process.process );
 165         close_handle( debugger, event->data.create_process.thread );
 166         return 0;
 167     }
 168     event->data.create_process.file       = handle;
 169     event->data.create_process.teb        = thread->teb;
 170     event->data.create_process.base       = exe_module->base;
 171     event->data.create_process.start      = *entry;
 172     event->data.create_process.dbg_offset = exe_module->dbg_offset;
 173     event->data.create_process.dbg_size   = exe_module->dbg_size;
 174     event->data.create_process.name       = exe_module->name;
 175     event->data.create_process.unicode    = 1;
 176     return 1;
 177 }
 178
 179 static int fill_exit_thread_event( struct debug_event *event, const void *arg )
 180 {
 181     const struct thread *thread = arg;
 182     event->data.exit.exit_code = thread->exit_code;
 183     return 1;
 184 }
 185
 186 static int fill_exit_process_event( struct debug_event *event, const void *arg )
 187 {
 188     const struct process *process = arg;
 189     event->data.exit.exit_code = process->exit_code;
 190     return 1;
 191 }
 192
 193 static int fill_load_dll_event( struct debug_event *event, const void *arg )
 194 {
 195     struct process *debugger = event->debugger->process;
 196     const struct process_dll *dll = arg;
 197     obj_handle_t handle = 0;
 198
 199     if (dll->file && !(handle = alloc_handle( debugger, dll->file, GENERIC_READ, 0 )))
 200         return 0;
 201     event->data.load_dll.handle     = handle;
 202     event->data.load_dll.base       = dll->base;
 203     event->data.load_dll.dbg_offset = dll->dbg_offset;
 204     event->data.load_dll.dbg_size   = dll->dbg_size;
 205     event->data.load_dll.name       = dll->name;
 206     event->data.load_dll.unicode    = 1;
 207     return 1;
 208 }
 209
 210 static int fill_unload_dll_event( struct debug_event *event, const void *arg )
 211 {
 212     const mod_handle_t *base = arg;
 213     event->data.unload_dll.base = *base;
 214     return 1;
 215 }
 216
 217 static int fill_output_debug_string_event( struct debug_event *event, const void *arg )
 218 {
 219     const debug_event_t *data = arg;
 220     event->data.output_string = data->output_string;
 221     return 1;
 222 }
 223
 224 typedef int (*fill_event_func)( struct debug_event *event, const void *arg );
 225
 226 #define NB_DEBUG_EVENTS OUTPUT_DEBUG_STRING_EVENT  /* RIP_EVENT not supported */
 227
 228 static const fill_event_func fill_debug_event[NB_DEBUG_EVENTS] =
 229 {
 230     fill_exception_event,            /* EXCEPTION_DEBUG_EVENT */
 231     fill_create_thread_event,        /* CREATE_THREAD_DEBUG_EVENT */
 232     fill_create_process_event,       /* CREATE_PROCESS_DEBUG_EVENT */
 233     fill_exit_thread_event,          /* EXIT_THREAD_DEBUG_EVENT */
 234     fill_exit_process_event,         /* EXIT_PROCESS_DEBUG_EVENT */
 235     fill_load_dll_event,             /* LOAD_DLL_DEBUG_EVENT */
 236     fill_unload_dll_event,           /* UNLOAD_DLL_DEBUG_EVENT */
 237     fill_output_debug_string_event   /* OUTPUT_DEBUG_STRING_EVENT */
 238 };
 239
 240
 241 /* unlink the first event from the queue */
 242 static void unlink_event( struct debug_ctx *debug_ctx, struct debug_event *event )
 243 {
 244     list_remove( &event->entry );
 245     if (event->sender->debug_event == event) event->sender->debug_event = NULL;
 246     release_object( event );
 247 }
 248
 249 /* link an event at the end of the queue */
 250 static void link_event( struct debug_event *event )
 251 {
 252     struct debug_ctx *debug_ctx = event->debugger->debug_ctx;
 253
 254     assert( debug_ctx );
 255     grab_object( event );
 256     list_add_tail( &debug_ctx->event_queue, &event->entry );
 257     if (!event->sender->debug_event) wake_up( &debug_ctx->obj, 0 );
 258 }
 259
 260 /* find the next event that we can send to the debugger */
 261 static struct debug_event *find_event_to_send( struct debug_ctx *debug_ctx )
 262 {
 263     struct debug_event *event;
 264
 265     LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 266     {
 267         if (event->state == EVENT_SENT) continue;  /* already sent */
 268         if (event->sender->debug_event) continue;  /* thread busy with another one */
 269         return event;
 270     }
 271     return NULL;
 272 }
 273
 274 static void debug_event_dump( struct object *obj, int verbose )
 275 {
 276     struct debug_event *debug_event = (struct debug_event *)obj;
 277     assert( obj->ops == &debug_event_ops );
 278     fprintf( stderr, "Debug event sender=%p code=%d state=%d\n",
 279              debug_event->sender, debug_event->data.code, debug_event->state );
 280 }
 281
 282 static int debug_event_signaled( struct object *obj, struct thread *thread )
 283 {
 284     struct debug_event *debug_event = (struct debug_event *)obj;
 285     assert( obj->ops == &debug_event_ops );
 286     return debug_event->state == EVENT_CONTINUED;
 287 }
 288
 289 static void debug_event_destroy( struct object *obj )
 290 {
 291     struct debug_event *event = (struct debug_event *)obj;
 292     assert( obj->ops == &debug_event_ops );
 293
 294     /* If the event has been sent already, the handles are now under the */
 295     /* responsibility of the debugger process, so we don't touch them    */
 296     if (event->state == EVENT_QUEUED)
 297     {
 298         struct process *debugger = event->debugger->process;
 299         switch(event->data.code)
 300         {
 301         case CREATE_THREAD_DEBUG_EVENT:
 302             close_handle( debugger, event->data.create_thread.handle );
 303             break;
 304         case CREATE_PROCESS_DEBUG_EVENT:
 305             if (event->data.create_process.file)
 306                 close_handle( debugger, event->data.create_process.file );
 307             close_handle( debugger, event->data.create_process.thread );
 308             close_handle( debugger, event->data.create_process.process );
 309             break;
 310         case LOAD_DLL_DEBUG_EVENT:
 311             if (event->data.load_dll.handle)
 312                 close_handle( debugger, event->data.load_dll.handle );
 313             break;
 314         }
 315     }
 316     if (event->sender->context == &event->context) event->sender->context = NULL;
 317     release_object( event->sender );
 318     release_object( event->debugger );
 319 }
 320
 321 static void debug_ctx_dump( struct object *obj, int verbose )
 322 {
 323     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 324     assert( obj->ops == &debug_ctx_ops );
 325     fprintf( stderr, "Debug context head=%p tail=%p\n",
 326              debug_ctx->event_queue.next, debug_ctx->event_queue.prev );
 327 }
 328
 329 static int debug_ctx_signaled( struct object *obj, struct thread *thread )
 330 {
 331     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 332     assert( obj->ops == &debug_ctx_ops );
 333     return find_event_to_send( debug_ctx ) != NULL;
 334 }
 335
 336 static void debug_ctx_destroy( struct object *obj )
 337 {
 338     struct list *ptr;
 339     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 340     assert( obj->ops == &debug_ctx_ops );
 341
 342     /* free all pending events */
 343     while ((ptr = list_head( &debug_ctx->event_queue )))
 344         unlink_event( debug_ctx, LIST_ENTRY( ptr, struct debug_event, entry ));
 345 }
 346
 347 /* continue a debug event */
 348 static int continue_debug_event( struct process *process, struct thread *thread, int status )
 349 {
 350     struct debug_ctx *debug_ctx = current->debug_ctx;
 351
 352     if (debug_ctx && process->debugger == current && thread->process == process)
 353     {
 354         struct debug_event *event;
 355
 356         /* find the event in the queue */
 357         LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 358         {
 359             if (event->state != EVENT_SENT) continue;
 360             if (event->sender == thread)
 361             {
 362                 assert( event->sender->debug_event == event );
 363
 364                 event->status = status;
 365                 event->state  = EVENT_CONTINUED;
 366                 wake_up( &event->obj, 0 );
 367                 unlink_event( debug_ctx, event );
 368                 resume_process( process );
 369                 return 1;
 370             }
 371         }
 372     }
 373     /* not debugging this process, or no such event */
 374     set_error( STATUS_ACCESS_DENIED );  /* FIXME */
 375     return 0;
 376 }
 377
 378 /* alloc a debug event for a debugger */
 379 static struct debug_event *alloc_debug_event( struct thread *thread, int code, const void *arg )
 380 {
 381     struct thread *debugger = thread->process->debugger;
 382     struct debug_event *event;
 383
 384     assert( code > 0 && code <= NB_DEBUG_EVENTS );
 385     /* cannot queue a debug event for myself */
 386     assert( debugger->process != thread->process );
 387
 388     /* build the event */
 389     if (!(event = alloc_object( &debug_event_ops ))) return NULL;
 390     event->state     = EVENT_QUEUED;
 391     event->sender    = (struct thread *)grab_object( thread );
 392     event->debugger  = (struct thread *)grab_object( debugger );
 393     memset( &event->data, 0, sizeof(event->data) );
 394
 395     if (!fill_debug_event[code-1]( event, arg ))
 396     {
 397         event->data.code = -1;  /* make sure we don't attempt to close handles */
 398         release_object( event );
 399         return NULL;
 400     }
 401     event->data.code = code;
 402     return event;
 403 }
 404
 405 /* generate a debug event from inside the server and queue it */
 406 void generate_debug_event( struct thread *thread, int code, const void *arg )
 407 {
 408     if (thread->process->debugger)
 409     {
 410         struct debug_event *event = alloc_debug_event( thread, code, arg );
 411         if (event)
 412         {
 413             link_event( event );
 414             suspend_process( thread->process );
 415             release_object( event );
 416         }
 417     }
 418 }
 419
 420 /* attach a process to a debugger thread and suspend it */
 421 static int debugger_attach( struct process *process, struct thread *debugger )
 422 {
 423     struct thread *thread;
 424
 425     if (process->debugger) goto error;  /* already being debugged */
 426     if (!is_process_init_done( process )) goto error;  /* still starting up */
 427     if (list_empty( &process->thread_list )) goto error;  /* no thread running in the process */
 428
 429     /* make sure we don't create a debugging loop */
 430     for (thread = debugger; thread; thread = thread->process->debugger)
 431         if (thread->process == process) goto error;
 432
 433     /* don't let a debugger debug its console... won't work */
 434     if (debugger->process->console && console_get_renderer(debugger->process->console)->process == process)
 435         goto error;
 436
 437     suspend_process( process );
 438     if (!set_process_debugger( process, debugger ))
 439     {
 440         resume_process( process );
 441         return 0;
 442     }
 443     if (!set_process_debug_flag( process, 1 ))
 444     {
 445         process->debugger = NULL;
 446         resume_process( process );
 447         return 0;
 448     }
 449     return 1;
 450
 451  error:
 452     set_error( STATUS_ACCESS_DENIED );
 453     return 0;
 454 }
 455
 456
 457 /* detach a process from a debugger thread (and resume it ?) */
 458 int debugger_detach( struct process *process, struct thread *debugger )
 459 {
 460     struct debug_event *event, *next;
 461     struct debug_ctx *debug_ctx;
 462
 463     if (!process->debugger || process->debugger != debugger)
 464         goto error;  /* not currently debugged, or debugged by another debugger */
 465     if (!debugger->debug_ctx ) goto error; /* should be a debugger */
 466     /* init should be done, otherwise wouldn't be attached */
 467     assert(is_process_init_done(process));
 468
 469     suspend_process( process );
 470     /* send continue indication for all events */
 471     debug_ctx = debugger->debug_ctx;
 472
 473     /* free all events from this process */
 474     LIST_FOR_EACH_ENTRY_SAFE( event, next, &debug_ctx->event_queue, struct debug_event, entry )
 475     {
 476         if (event->sender->process != process) continue;
 477
 478         assert( event->state != EVENT_CONTINUED );
 479         event->status = DBG_CONTINUE;
 480         event->state  = EVENT_CONTINUED;
 481         wake_up( &event->obj, 0 );
 482         unlink_event( debug_ctx, event );
 483         /* from queued debug event */
 484         resume_process( process );
 485     }
 486
 487     /* remove relationships between process and its debugger */
 488     process->debugger = NULL;
 489     if (!set_process_debug_flag( process, 0 )) clear_error();  /* ignore error */
 490
 491     /* from this function */
 492     resume_process( process );
 493     return 0;
 494
 495  error:
 496     set_error( STATUS_ACCESS_DENIED );
 497     return 0;
 498 }
 499
 500 /* generate all startup events of a given process */
 501 void generate_startup_debug_events( struct process *process, client_ptr_t entry )
 502 {
 503     struct list *ptr;
 504     struct thread *thread, *first_thread = get_process_first_thread( process );
 505
 506     /* generate creation events */
 507     LIST_FOR_EACH_ENTRY( thread, &process->thread_list, struct thread, proc_entry )
 508     {
 509         if (thread == first_thread)
 510             generate_debug_event( thread, CREATE_PROCESS_DEBUG_EVENT, &entry );
 511         else
 512             generate_debug_event( thread, CREATE_THREAD_DEBUG_EVENT, NULL );
 513     }
 514
 515     /* generate dll events (in loading order, i.e. reverse list order) */
 516     ptr = list_tail( &process->dlls );
 517     while (ptr)
 518     {
 519         struct process_dll *dll = LIST_ENTRY( ptr, struct process_dll, entry );
 520         generate_debug_event( first_thread, LOAD_DLL_DEBUG_EVENT, dll );
 521         ptr = list_prev( &process->dlls, ptr );
 522     }
 523 }
 524
 525 /* set the debugger of a given process */
 526 int set_process_debugger( struct process *process, struct thread *debugger )
 527 {
 528     struct debug_ctx *debug_ctx;
 529
 530     assert( !process->debugger );
 531
 532     if (!debugger->debug_ctx)  /* need to allocate a context */
 533     {
 534         if (!(debug_ctx = alloc_object( &debug_ctx_ops ))) return 0;
 535         debug_ctx->kill_on_exit = 1;
 536         list_init( &debug_ctx->event_queue );
 537         debugger->debug_ctx = debug_ctx;
 538     }
 539     process->debugger = debugger;
 540     return 1;
 541 }
 542
 543 /* a thread is exiting */
 544 void debug_exit_thread( struct thread *thread )
 545 {
 546     if (thread->debug_ctx)  /* this thread is a debugger */
 547     {
 548         if (thread->debug_ctx->kill_on_exit)
 549         {
 550             /* kill all debugged processes */
 551             kill_debugged_processes( thread, STATUS_DEBUGGER_INACTIVE );
 552         }
 553         else
 554         {
 555             detach_debugged_processes( thread );
 556         }
 557         release_object( thread->debug_ctx );
 558         thread->debug_ctx = NULL;
 559     }
 560 }
 561
 562 /* Wait for a debug event */
 563 DECL_HANDLER(wait_debug_event)
 564 {
 565     struct debug_ctx *debug_ctx = current->debug_ctx;
 566     struct debug_event *event;
 567
 568     if (!debug_ctx)  /* current thread is not a debugger */
 569     {
 570         set_error( STATUS_INVALID_HANDLE );
 571         return;
 572     }
 573     reply->wait = 0;
 574     if ((event = find_event_to_send( debug_ctx )))
 575     {
 576         data_size_t size = get_reply_max_size();
 577         event->state = EVENT_SENT;
 578         event->sender->debug_event = event;
 579         reply->pid = get_process_id( event->sender->process );
 580         reply->tid = get_thread_id( event->sender );
 581         if (size > sizeof(debug_event_t)) size = sizeof(debug_event_t);
 582         set_reply_data( &event->data, size );
 583     }
 584     else  /* no event ready */
 585     {
 586         reply->pid  = 0;
 587         reply->tid  = 0;
 588         if (req->get_handle)
 589             reply->wait = alloc_handle( current->process, debug_ctx, SYNCHRONIZE, 0 );
 590     }
 591 }
 592
 593 /* Continue a debug event */
 594 DECL_HANDLER(continue_debug_event)
 595 {
 596     struct process *process = get_process_from_id( req->pid );
 597     if (process)
 598     {
 599         struct thread *thread = get_thread_from_id( req->tid );
 600         if (thread)
 601         {
 602             continue_debug_event( process, thread, req->status );
 603             release_object( thread );
 604         }
 605         release_object( process );
 606     }
 607 }
 608
 609 /* Start debugging an existing process */
 610 DECL_HANDLER(debug_process)
 611 {
 612     struct process *process = get_process_from_id( req->pid );
 613     if (!process) return;
 614
 615     if (!req->attach)
 616     {
 617         debugger_detach( process, current );
 618     }
 619     else if (debugger_attach( process, current ))
 620     {
 621         generate_startup_debug_events( process, 0 );
 622         break_process( process );
 623         resume_process( process );
 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         debug_event_t data;
 635         struct debug_event *event;
 636
 637         if ((req->len % sizeof(client_ptr_t)) != 0 ||
 638             req->len > get_req_data_size() ||
 639             req->len > EXCEPTION_MAXIMUM_PARAMETERS * sizeof(client_ptr_t))
 640         {
 641             set_error( STATUS_INVALID_PARAMETER );
 642             return;
 643         }
 644         memset( &data, 0, sizeof(data) );
 645         data.exception.first     = req->first;
 646         data.exception.exc_code  = req->code;
 647         data.exception.flags     = req->flags;
 648         data.exception.record    = req->record;
 649         data.exception.address   = req->address;
 650         data.exception.nb_params = req->len / sizeof(client_ptr_t);
 651         memcpy( data.exception.params, get_req_data(), req->len );
 652
 653         if ((event = alloc_debug_event( current, EXCEPTION_DEBUG_EVENT, &data )))
 654         {
 655             const context_t *context = (const context_t *)((char *)get_req_data() + req->len);
 656             data_size_t size = get_req_data_size() - req->len;
 657
 658             memset( &event->context, 0, sizeof(event->context) );
 659             memcpy( &event->context, context, min( sizeof(event->context), size ) );
 660             current->context = &event->context;
 661
 662             if ((reply->handle = alloc_handle( current->process, event, SYNCHRONIZE, 0 )))
 663             {
 664                 link_event( event );
 665                 suspend_process( current->process );
 666             }
 667             release_object( event );
 668         }
 669     }
 670 }
 671
 672 /* retrieve the status of an exception event */
 673 DECL_HANDLER(get_exception_status)
 674 {
 675     struct debug_event *event;
 676
 677     if ((event = (struct debug_event *)get_handle_obj( current->process, req->handle,
 678                                                        0, &debug_event_ops )))
 679     {
 680         close_handle( current->process, req->handle );
 681         if (event->state == EVENT_CONTINUED)
 682         {
 683             if (current->context == &event->context)
 684             {
 685                 data_size_t size = min( sizeof(context_t), get_reply_max_size() );
 686                 set_reply_data( &event->context, size );
 687                 current->context = NULL;
 688             }
 689             set_error( event->status );
 690         }
 691         else set_error( STATUS_PENDING );
 692         release_object( event );
 693     }
 694 }
 695
 696 /* send an output string to the debugger */
 697 DECL_HANDLER(output_debug_string)
 698 {
 699     debug_event_t data;
 700
 701     data.output_string.string  = req->string;
 702     data.output_string.unicode = req->unicode;
 703     data.output_string.length  = req->length;
 704     generate_debug_event( current, OUTPUT_DEBUG_STRING_EVENT, &data );
 705 }
 706
 707 /* simulate a breakpoint in a process */
 708 DECL_HANDLER(debug_break)
 709 {
 710     struct process *process;
 711
 712     reply->self = 0;
 713     if ((process = get_process_from_handle( req->handle, PROCESS_SET_INFORMATION /*FIXME*/ )))
 714     {
 715         if (process != current->process) break_process( process );
 716         else reply->self = 1;
 717         release_object( process );
 718     }
 719 }
 720
 721 /* set debugger kill on exit flag */
 722 DECL_HANDLER(set_debugger_kill_on_exit)
 723 {
 724     if (!current->debug_ctx)
 725     {
 726         set_error( STATUS_ACCESS_DENIED );
 727         return;
 728     }
 729     current->debug_ctx->kill_on_exit = req->kill_on_exit;
 730 }