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 "file.h"
  37 #include "process.h"
  38 #include "thread.h"
  39 #include "request.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_t              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     no_get_type,                   /* get_type */
  74     add_queue,                     /* add_queue */
  75     remove_queue,                  /* remove_queue */
  76     debug_event_signaled,          /* signaled */
  77     no_satisfied,                  /* satisfied */
  78     no_signal,                     /* signal */
  79     no_get_fd,                     /* get_fd */
  80     no_map_access,                 /* map_access */
  81     default_get_sd,                /* get_sd */
  82     default_set_sd,                /* set_sd */
  83     no_lookup_name,                /* lookup_name */
  84     no_open_file,                  /* open_file */
  85     no_close_handle,               /* close_handle */
  86     debug_event_destroy            /* destroy */
  87 };
  88
  89 static void debug_ctx_dump( struct object *obj, int verbose );
  90 static int debug_ctx_signaled( struct object *obj, struct thread *thread );
  91 static void debug_ctx_destroy( struct object *obj );
  92
  93 static const struct object_ops debug_ctx_ops =
  94 {
  95     sizeof(struct debug_ctx),      /* size */
  96     debug_ctx_dump,                /* dump */
  97     no_get_type,                   /* get_type */
  98     add_queue,                     /* add_queue */
  99     remove_queue,                  /* remove_queue */
 100     debug_ctx_signaled,            /* signaled */
 101     no_satisfied,                  /* satisfied */
 102     no_signal,                     /* signal */
 103     no_get_fd,                     /* get_fd */
 104     no_map_access,                 /* map_access */
 105     default_get_sd,                /* get_sd */
 106     default_set_sd,                /* set_sd */
 107     no_lookup_name,                /* lookup_name */
 108     no_open_file,                  /* open_file */
 109     no_close_handle,               /* close_handle */
 110     debug_ctx_destroy              /* destroy */
 111 };
 112
 113
 114 /* routines to build an event according to its type */
 115
 116 static int fill_exception_event( struct debug_event *event, const void *arg )
 117 {
 118     const debug_event_t *data = arg;
 119     event->data.exception = data->exception;
 120     event->data.exception.nb_params = min( event->data.exception.nb_params, EXCEPTION_MAXIMUM_PARAMETERS );
 121     return 1;
 122 }
 123
 124 static int fill_create_thread_event( struct debug_event *event, const void *arg )
 125 {
 126     struct process *debugger = event->debugger->process;
 127     struct thread *thread = event->sender;
 128     const client_ptr_t *entry = arg;
 129     obj_handle_t handle;
 130
 131     /* documented: THREAD_GET_CONTEXT | THREAD_SET_CONTEXT | THREAD_SUSPEND_RESUME */
 132     if (!(handle = alloc_handle( debugger, thread, THREAD_ALL_ACCESS, 0 ))) return 0;
 133     event->data.create_thread.handle = handle;
 134     event->data.create_thread.teb    = thread->teb;
 135     if (entry) event->data.create_thread.start = *entry;
 136     return 1;
 137 }
 138
 139 static int fill_create_process_event( struct debug_event *event, const void *arg )
 140 {
 141     struct process *debugger = event->debugger->process;
 142     struct thread *thread = event->sender;
 143     struct process *process = thread->process;
 144     struct process_dll *exe_module = get_process_exe_module( process );
 145     const client_ptr_t *entry = arg;
 146     obj_handle_t handle;
 147
 148     /* documented: PROCESS_VM_READ | PROCESS_VM_WRITE */
 149     if (!(handle = alloc_handle( debugger, process, PROCESS_ALL_ACCESS, 0 ))) return 0;
 150     event->data.create_process.process = handle;
 151
 152     /* documented: THREAD_GET_CONTEXT | THREAD_SET_CONTEXT | THREAD_SUSPEND_RESUME */
 153     if (!(handle = alloc_handle( debugger, thread, THREAD_ALL_ACCESS, 0 )))
 154     {
 155         close_handle( debugger, event->data.create_process.process );
 156         return 0;
 157     }
 158     event->data.create_process.thread     = handle;
 159     event->data.create_process.file       = 0;
 160     event->data.create_process.teb        = thread->teb;
 161     event->data.create_process.base       = exe_module->base;
 162     event->data.create_process.start      = *entry;
 163     event->data.create_process.dbg_offset = exe_module->dbg_offset;
 164     event->data.create_process.dbg_size   = exe_module->dbg_size;
 165     event->data.create_process.name       = exe_module->name;
 166     event->data.create_process.unicode    = 1;
 167
 168     if (exe_module->mapping)  /* the doc says write access too, but this doesn't seem a good idea */
 169         event->data.create_process.file = open_mapping_file( debugger, exe_module->mapping, GENERIC_READ,
 170                                                              FILE_SHARE_READ | FILE_SHARE_WRITE );
 171     return 1;
 172 }
 173
 174 static int fill_exit_thread_event( struct debug_event *event, const void *arg )
 175 {
 176     const struct thread *thread = arg;
 177     event->data.exit.exit_code = thread->exit_code;
 178     return 1;
 179 }
 180
 181 static int fill_exit_process_event( struct debug_event *event, const void *arg )
 182 {
 183     const struct process *process = arg;
 184     event->data.exit.exit_code = process->exit_code;
 185     return 1;
 186 }
 187
 188 static int fill_load_dll_event( struct debug_event *event, const void *arg )
 189 {
 190     struct process *debugger = event->debugger->process;
 191     const struct process_dll *dll = arg;
 192
 193     event->data.load_dll.handle     = 0;
 194     event->data.load_dll.base       = dll->base;
 195     event->data.load_dll.dbg_offset = dll->dbg_offset;
 196     event->data.load_dll.dbg_size   = dll->dbg_size;
 197     event->data.load_dll.name       = dll->name;
 198     event->data.load_dll.unicode    = 1;
 199     if (dll->mapping)
 200         event->data.load_dll.handle = open_mapping_file( debugger, dll->mapping, GENERIC_READ,
 201                                                          FILE_SHARE_READ | FILE_SHARE_WRITE );
 202     return 1;
 203 }
 204
 205 static int fill_unload_dll_event( struct debug_event *event, const void *arg )
 206 {
 207     const mod_handle_t *base = arg;
 208     event->data.unload_dll.base = *base;
 209     return 1;
 210 }
 211
 212 static int fill_output_debug_string_event( struct debug_event *event, const void *arg )
 213 {
 214     const debug_event_t *data = arg;
 215     event->data.output_string = data->output_string;
 216     return 1;
 217 }
 218
 219 typedef int (*fill_event_func)( struct debug_event *event, const void *arg );
 220
 221 #define NB_DEBUG_EVENTS OUTPUT_DEBUG_STRING_EVENT  /* RIP_EVENT not supported */
 222
 223 static const fill_event_func fill_debug_event[NB_DEBUG_EVENTS] =
 224 {
 225     fill_exception_event,            /* EXCEPTION_DEBUG_EVENT */
 226     fill_create_thread_event,        /* CREATE_THREAD_DEBUG_EVENT */
 227     fill_create_process_event,       /* CREATE_PROCESS_DEBUG_EVENT */
 228     fill_exit_thread_event,          /* EXIT_THREAD_DEBUG_EVENT */
 229     fill_exit_process_event,         /* EXIT_PROCESS_DEBUG_EVENT */
 230     fill_load_dll_event,             /* LOAD_DLL_DEBUG_EVENT */
 231     fill_unload_dll_event,           /* UNLOAD_DLL_DEBUG_EVENT */
 232     fill_output_debug_string_event   /* OUTPUT_DEBUG_STRING_EVENT */
 233 };
 234
 235
 236 /* unlink the first event from the queue */
 237 static void unlink_event( struct debug_ctx *debug_ctx, struct debug_event *event )
 238 {
 239     list_remove( &event->entry );
 240     if (event->sender->debug_event == event) event->sender->debug_event = NULL;
 241     release_object( event );
 242 }
 243
 244 /* link an event at the end of the queue */
 245 static void link_event( struct debug_event *event )
 246 {
 247     struct debug_ctx *debug_ctx = event->debugger->debug_ctx;
 248
 249     assert( debug_ctx );
 250     grab_object( event );
 251     list_add_tail( &debug_ctx->event_queue, &event->entry );
 252     if (!event->sender->debug_event) wake_up( &debug_ctx->obj, 0 );
 253 }
 254
 255 /* find the next event that we can send to the debugger */
 256 static struct debug_event *find_event_to_send( struct debug_ctx *debug_ctx )
 257 {
 258     struct debug_event *event;
 259
 260     LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 261     {
 262         if (event->state == EVENT_SENT) continue;  /* already sent */
 263         if (event->sender->debug_event) continue;  /* thread busy with another one */
 264         return event;
 265     }
 266     return NULL;
 267 }
 268
 269 static void debug_event_dump( struct object *obj, int verbose )
 270 {
 271     struct debug_event *debug_event = (struct debug_event *)obj;
 272     assert( obj->ops == &debug_event_ops );
 273     fprintf( stderr, "Debug event sender=%p code=%d state=%d\n",
 274              debug_event->sender, debug_event->data.code, debug_event->state );
 275 }
 276
 277 static int debug_event_signaled( struct object *obj, struct thread *thread )
 278 {
 279     struct debug_event *debug_event = (struct debug_event *)obj;
 280     assert( obj->ops == &debug_event_ops );
 281     return debug_event->state == EVENT_CONTINUED;
 282 }
 283
 284 static void debug_event_destroy( struct object *obj )
 285 {
 286     struct debug_event *event = (struct debug_event *)obj;
 287     assert( obj->ops == &debug_event_ops );
 288
 289     /* If the event has been sent already, the handles are now under the */
 290     /* responsibility of the debugger process, so we don't touch them    */
 291     if (event->state == EVENT_QUEUED)
 292     {
 293         struct process *debugger = event->debugger->process;
 294         switch(event->data.code)
 295         {
 296         case CREATE_THREAD_DEBUG_EVENT:
 297             close_handle( debugger, event->data.create_thread.handle );
 298             break;
 299         case CREATE_PROCESS_DEBUG_EVENT:
 300             if (event->data.create_process.file)
 301                 close_handle( debugger, event->data.create_process.file );
 302             close_handle( debugger, event->data.create_process.thread );
 303             close_handle( debugger, event->data.create_process.process );
 304             break;
 305         case LOAD_DLL_DEBUG_EVENT:
 306             if (event->data.load_dll.handle)
 307                 close_handle( debugger, event->data.load_dll.handle );
 308             break;
 309         }
 310     }
 311     if (event->sender->context == &event->context)
 312     {
 313         event->sender->context = NULL;
 314         stop_thread_if_suspended( event->sender );
 315     }
 316     release_object( event->sender );
 317     release_object( event->debugger );
 318 }
 319
 320 static void debug_ctx_dump( struct object *obj, int verbose )
 321 {
 322     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 323     assert( obj->ops == &debug_ctx_ops );
 324     fprintf( stderr, "Debug context head=%p tail=%p\n",
 325              debug_ctx->event_queue.next, debug_ctx->event_queue.prev );
 326 }
 327
 328 static int debug_ctx_signaled( struct object *obj, struct thread *thread )
 329 {
 330     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 331     assert( obj->ops == &debug_ctx_ops );
 332     return find_event_to_send( debug_ctx ) != NULL;
 333 }
 334
 335 static void debug_ctx_destroy( struct object *obj )
 336 {
 337     struct list *ptr;
 338     struct debug_ctx *debug_ctx = (struct debug_ctx *)obj;
 339     assert( obj->ops == &debug_ctx_ops );
 340
 341     /* free all pending events */
 342     while ((ptr = list_head( &debug_ctx->event_queue )))
 343         unlink_event( debug_ctx, LIST_ENTRY( ptr, struct debug_event, entry ));
 344 }
 345
 346 /* continue a debug event */
 347 static int continue_debug_event( struct process *process, struct thread *thread, int status )
 348 {
 349     struct debug_ctx *debug_ctx = current->debug_ctx;
 350
 351     if (debug_ctx && process->debugger == current && thread->process == process)
 352     {
 353         struct debug_event *event;
 354
 355         /* find the event in the queue */
 356         LIST_FOR_EACH_ENTRY( event, &debug_ctx->event_queue, struct debug_event, entry )
 357         {
 358             if (event->state != EVENT_SENT) continue;
 359             if (event->sender == thread)
 360             {
 361                 assert( event->sender->debug_event == event );
 362
 363                 event->status = status;
 364                 event->state  = EVENT_CONTINUED;
 365                 wake_up( &event->obj, 0 );
 366                 unlink_event( debug_ctx, event );
 367                 resume_process( process );
 368                 return 1;
 369             }
 370         }
 371     }
 372     /* not debugging this process, or no such event */
 373     set_error( STATUS_ACCESS_DENIED );  /* FIXME */
 374     return 0;
 375 }
 376
 377 /* alloc a debug event for a debugger */
 378 static struct debug_event *alloc_debug_event( struct thread *thread, int code, const void *arg )
 379 {
 380     struct thread *debugger = thread->process->debugger;
 381     struct debug_event *event;
 382
 383     assert( code > 0 && code <= NB_DEBUG_EVENTS );
 384     /* cannot queue a debug event for myself */
 385     assert( debugger->process != thread->process );
 386
 387     /* build the event */
 388     if (!(event = alloc_object( &debug_event_ops ))) return NULL;
 389     event->state     = EVENT_QUEUED;
 390     event->sender    = (struct thread *)grab_object( thread );
 391     event->debugger  = (struct thread *)grab_object( debugger );
 392     memset( &event->data, 0, sizeof(event->data) );
 393
 394     if (!fill_debug_event[code-1]( event, arg ))
 395     {
 396         event->data.code = -1;  /* make sure we don't attempt to close handles */
 397         release_object( event );
 398         return NULL;
 399     }
 400     event->data.code = code;
 401     return event;
 402 }
 403
 404 /* generate a debug event from inside the server and queue it */
 405 void generate_debug_event( struct thread *thread, int code, const void *arg )
 406 {
 407     if (thread->process->debugger)
 408     {
 409         struct debug_event *event = alloc_debug_event( thread, code, arg );
 410         if (event)
 411         {
 412             link_event( event );
 413             suspend_process( thread->process );
 414             release_object( event );
 415         }
 416         clear_error();  /* ignore errors */
 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     if (process->debugger) goto error;  /* already being debugged */
 424     if (debugger->process == process) goto error;
 425     if (!is_process_init_done( process )) goto error;  /* still starting up */
 426     if (list_empty( &process->thread_list )) goto error;  /* no thread running in the process */
 427
 428     /* don't let a debugger debug its console... won't work */
 429     if (debugger->process->console)
 430     {
 431         struct thread *renderer = console_get_renderer(debugger->process->console);
 432         if (renderer && renderer->process == process)
 433             goto error;
 434     }
 435
 436     suspend_process( process );
 437     if (!set_process_debugger( process, debugger ))
 438     {
 439         resume_process( process );
 440         return 0;
 441     }
 442     if (!set_process_debug_flag( process, 1 ))
 443     {
 444         process->debugger = NULL;
 445         resume_process( process );
 446         return 0;
 447     }
 448     return 1;
 449
 450  error:
 451     set_error( STATUS_ACCESS_DENIED );
 452     return 0;
 453 }
 454
 455
 456 /* detach a process from a debugger thread (and resume it ?) */
 457 int debugger_detach( struct process *process, struct thread *debugger )
 458 {
 459     struct debug_event *event, *next;
 460     struct debug_ctx *debug_ctx;
 461
 462     if (!process->debugger || process->debugger != debugger)
 463         goto error;  /* not currently debugged, or debugged by another debugger */
 464     if (!debugger->debug_ctx ) goto error; /* should be a debugger */
 465     /* init should be done, otherwise wouldn't be attached */
 466     assert(is_process_init_done(process));
 467
 468     suspend_process( process );
 469     /* send continue indication for all events */
 470     debug_ctx = debugger->debug_ctx;
 471
 472     /* free all events from this process */
 473     LIST_FOR_EACH_ENTRY_SAFE( event, next, &debug_ctx->event_queue, struct debug_event, entry )
 474     {
 475         if (event->sender->process != process) continue;
 476
 477         assert( event->state != EVENT_CONTINUED );
 478         event->status = DBG_CONTINUE;
 479         event->state  = EVENT_CONTINUED;
 480         wake_up( &event->obj, 0 );
 481         unlink_event( debug_ctx, event );
 482         /* from queued debug event */
 483         resume_process( process );
 484     }
 485
 486     /* remove relationships between process and its debugger */
 487     process->debugger = NULL;
 488     process->debug_children = 0;
 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 != list_head( &process->dlls ))
 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         struct thread *thread = current;
 637
 638         if ((req->len % sizeof(client_ptr_t)) != 0 ||
 639             req->len > get_req_data_size() ||
 640             req->len > EXCEPTION_MAXIMUM_PARAMETERS * sizeof(client_ptr_t))
 641         {
 642             set_error( STATUS_INVALID_PARAMETER );
 643             return;
 644         }
 645         memset( &data, 0, sizeof(data) );
 646         data.exception.first     = req->first;
 647         data.exception.exc_code  = req->code;
 648         data.exception.flags     = req->flags;
 649         data.exception.record    = req->record;
 650         data.exception.address   = req->address;
 651         data.exception.nb_params = req->len / sizeof(client_ptr_t);
 652         memcpy( data.exception.params, get_req_data(), req->len );
 653
 654         if ((event = alloc_debug_event( thread, EXCEPTION_DEBUG_EVENT, &data )))
 655         {
 656             const context_t *context = (const context_t *)((const char *)get_req_data() + req->len);
 657             data_size_t size = get_req_data_size() - req->len;
 658
 659             memset( &event->context, 0, sizeof(event->context) );
 660             memcpy( &event->context, context, min( sizeof(event->context), size ) );
 661             thread->context = &event->context;
 662
 663             if ((reply->handle = alloc_handle( thread->process, event, SYNCHRONIZE, 0 )))
 664             {
 665                 link_event( event );
 666                 suspend_process( thread->process );
 667             }
 668             release_object( event );
 669         }
 670     }
 671 }
 672
 673 /* retrieve the status of an exception event */
 674 DECL_HANDLER(get_exception_status)
 675 {
 676     struct debug_event *event;
 677
 678     if ((event = (struct debug_event *)get_handle_obj( current->process, req->handle,
 679                                                        0, &debug_event_ops )))
 680     {
 681         close_handle( current->process, req->handle );
 682         if (event->state == EVENT_CONTINUED)
 683         {
 684             if (current->context == &event->context)
 685             {
 686                 data_size_t size = min( sizeof(context_t), get_reply_max_size() );
 687                 set_reply_data( &event->context, size );
 688                 current->context = NULL;
 689                 stop_thread_if_suspended( current );
 690             }
 691             set_error( event->status );
 692         }
 693         else set_error( STATUS_PENDING );
 694         release_object( event );
 695     }
 696 }
 697
 698 /* send an output string to the debugger */
 699 DECL_HANDLER(output_debug_string)
 700 {
 701     debug_event_t data;
 702
 703     data.output_string.string  = req->string;
 704     data.output_string.length  = req->length;
 705     generate_debug_event( current, OUTPUT_DEBUG_STRING_EVENT, &data );
 706 }
 707
 708 /* simulate a breakpoint in a process */
 709 DECL_HANDLER(debug_break)
 710 {
 711     struct process *process;
 712
 713     reply->self = 0;
 714     if ((process = get_process_from_handle( req->handle, PROCESS_SET_INFORMATION /*FIXME*/ )))
 715     {
 716         if (process != current->process) break_process( process );
 717         else reply->self = 1;
 718         release_object( process );
 719     }
 720 }
 721
 722 /* set debugger kill on exit flag */
 723 DECL_HANDLER(set_debugger_kill_on_exit)
 724 {
 725     if (!current->debug_ctx)
 726     {
 727         set_error( STATUS_ACCESS_DENIED );
 728         return;
 729     }
 730     current->debug_ctx->kill_on_exit = req->kill_on_exit;
 731 }