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
  23 #include <assert.h>
  24 #include <signal.h>
  25 #include <string.h>
  26 #include <stdarg.h>
  27 #include <stdio.h>
  28
  29 #include "ntstatus.h"
  30 #define WIN32_NO_STATUS
  31 #include "windef.h"
  32 #include "winternl.h"
  33
  34 #include "handle.h"
  35 #include "file.h"
  36 #include "process.h"
  37 #include "thread.h"
  38 #include "request.h"
  39
  40 enum debug_event_state { EVENT_QUEUED, EVENT_SENT, EVENT_DELAYED, 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 file           *file;      /* file object for events that need one */
  49     enum debug_event_state state;     /* event state */
  50     int                    status;    /* continuation status */
  51     debug_event_t          data;      /* event data */
  52 };
  53
  54 static const WCHAR debug_obj_name[] = {'D','e','b','u','g','O','b','j','e','c','t'};
  55
  56 struct type_descr debug_obj_type =
  57 {
  58     { debug_obj_name, sizeof(debug_obj_name) },   /* name */
  59     DEBUG_ALL_ACCESS | SYNCHRONIZE,               /* valid_access */
  60     {                                             /* mapping */
  61         STANDARD_RIGHTS_READ | DEBUG_READ_EVENT,
  62         STANDARD_RIGHTS_WRITE | DEBUG_PROCESS_ASSIGN,
  63         STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE,
  64         DEBUG_ALL_ACCESS
  65     },
  66 };
  67
  68 /* debug object */
  69 struct debug_obj
  70 {
  71     struct object        obj;         /* object header */
  72     struct list          event_queue; /* pending events queue */
  73     unsigned int         flags;       /* debug flags */
  74 };
  75
  76
  77 static void debug_event_dump( struct object *obj, int verbose );
  78 static int debug_event_signaled( struct object *obj, struct wait_queue_entry *entry );
  79 static void debug_event_destroy( struct object *obj );
  80
  81 static const struct object_ops debug_event_ops =
  82 {
  83     sizeof(struct debug_event),    /* size */
  84     &no_type,                      /* type */
  85     debug_event_dump,              /* dump */
  86     add_queue,                     /* add_queue */
  87     remove_queue,                  /* remove_queue */
  88     debug_event_signaled,          /* signaled */
  89     no_satisfied,                  /* satisfied */
  90     no_signal,                     /* signal */
  91     no_get_fd,                     /* get_fd */
  92     default_map_access,            /* map_access */
  93     default_get_sd,                /* get_sd */
  94     default_set_sd,                /* set_sd */
  95     no_get_full_name,              /* get_full_name */
  96     no_lookup_name,                /* lookup_name */
  97     no_link_name,                  /* link_name */
  98     NULL,                          /* unlink_name */
  99     no_open_file,                  /* open_file */
 100     no_kernel_obj_list,            /* get_kernel_obj_list */
 101     no_close_handle,               /* close_handle */
 102     debug_event_destroy            /* destroy */
 103 };
 104
 105 static void debug_obj_dump( struct object *obj, int verbose );
 106 static int debug_obj_signaled( struct object *obj, struct wait_queue_entry *entry );
 107 static void debug_obj_destroy( struct object *obj );
 108
 109 static const struct object_ops debug_obj_ops =
 110 {
 111     sizeof(struct debug_obj),      /* size */
 112     &debug_obj_type,               /* type */
 113     debug_obj_dump,                /* dump */
 114     add_queue,                     /* add_queue */
 115     remove_queue,                  /* remove_queue */
 116     debug_obj_signaled,            /* signaled */
 117     no_satisfied,                  /* satisfied */
 118     no_signal,                     /* signal */
 119     no_get_fd,                     /* get_fd */
 120     default_map_access,            /* map_access */
 121     default_get_sd,                /* get_sd */
 122     default_set_sd,                /* set_sd */
 123     default_get_full_name,         /* get_full_name */
 124     no_lookup_name,                /* lookup_name */
 125     directory_link_name,           /* link_name */
 126     default_unlink_name,           /* unlink_name */
 127     no_open_file,                  /* open_file */
 128     no_kernel_obj_list,            /* get_kernel_obj_list */
 129     no_close_handle,               /* close_handle */
 130     debug_obj_destroy              /* destroy */
 131 };
 132
 133 /* get a pointer to TEB->ArbitraryUserPointer in the client address space */
 134 static client_ptr_t get_teb_user_ptr( struct thread *thread )
 135 {
 136     unsigned int ptr_size = is_machine_64bit( native_machine ) ? 8 : 4;
 137     return thread->teb + 5 * ptr_size;
 138 }
 139
 140
 141 /* routines to build an event according to its type */
 142
 143 static void fill_exception_event( struct debug_event *event, const void *arg )
 144 {
 145     const debug_event_t *data = arg;
 146     event->data.exception = data->exception;
 147     event->data.exception.nb_params = min( event->data.exception.nb_params, EXCEPTION_MAXIMUM_PARAMETERS );
 148 }
 149
 150 static void fill_create_thread_event( struct debug_event *event, const void *arg )
 151 {
 152     const client_ptr_t *entry = arg;
 153
 154     if (entry) event->data.create_thread.start = *entry;
 155 }
 156
 157 static void fill_create_process_event( struct debug_event *event, const void *arg )
 158 {
 159     const struct memory_view *view = arg;
 160     const pe_image_info_t *image_info = get_view_image_info( view, &event->data.create_process.base );
 161
 162     event->data.create_process.start      = event->data.create_process.base + image_info->entry_point;
 163     event->data.create_process.dbg_offset = image_info->dbg_offset;
 164     event->data.create_process.dbg_size   = image_info->dbg_size;
 165     /* the doc says write access too, but this doesn't seem a good idea */
 166     event->file = get_view_file( view, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE );
 167 }
 168
 169 static void fill_exit_thread_event( struct debug_event *event, const void *arg )
 170 {
 171     const struct thread *thread = arg;
 172     event->data.exit.exit_code = thread->exit_code;
 173 }
 174
 175 static void fill_exit_process_event( struct debug_event *event, const void *arg )
 176 {
 177     const struct process *process = arg;
 178     event->data.exit.exit_code = process->exit_code;
 179 }
 180
 181 static void fill_load_dll_event( struct debug_event *event, const void *arg )
 182 {
 183     const struct memory_view *view = arg;
 184     const pe_image_info_t *image_info = get_view_image_info( view, &event->data.load_dll.base );
 185
 186     event->data.load_dll.dbg_offset = image_info->dbg_offset;
 187     event->data.load_dll.dbg_size   = image_info->dbg_size;
 188     event->data.load_dll.name       = get_teb_user_ptr( event->sender );
 189     event->file = get_view_file( view, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE );
 190 }
 191
 192 static void fill_unload_dll_event( struct debug_event *event, const void *arg )
 193 {
 194     const struct memory_view *view = arg;
 195     get_view_image_info( view, &event->data.unload_dll.base );
 196 }
 197
 198 typedef void (*fill_event_func)( struct debug_event *event, const void *arg );
 199
 200 static const fill_event_func fill_debug_event[] =
 201 {
 202     fill_create_thread_event,  /* DbgCreateThreadStateChange */
 203     fill_create_process_event, /* DbgCreateProcessStateChange */
 204     fill_exit_thread_event,    /* DbgExitThreadStateChange */
 205     fill_exit_process_event,   /* DbgExitProcessStateChange */
 206     fill_exception_event,      /* DbgExceptionStateChange */
 207     fill_exception_event,      /* DbgBreakpointStateChange */
 208     fill_exception_event,      /* DbgSingleStepStateChange */
 209     fill_load_dll_event,       /* DbgLoadDllStateChange */
 210     fill_unload_dll_event      /* DbgUnloadDllStateChange */
 211 };
 212
 213 /* allocate the necessary handles in the event data */
 214 static void alloc_event_handles( struct debug_event *event, struct process *process )
 215 {
 216     switch (event->data.code)
 217     {
 218     case DbgCreateThreadStateChange:
 219         /* documented: THREAD_GET_CONTEXT | THREAD_SET_CONTEXT | THREAD_SUSPEND_RESUME */
 220         event->data.create_thread.handle = alloc_handle( process, event->sender, THREAD_ALL_ACCESS, 0 );
 221         break;
 222     case DbgCreateProcessStateChange:
 223         event->data.create_process.thread = alloc_handle( process, event->sender, THREAD_ALL_ACCESS, 0 );
 224         /* documented: PROCESS_VM_READ | PROCESS_VM_WRITE */
 225         event->data.create_process.process = alloc_handle( process, event->sender->process,
 226                                                            PROCESS_ALL_ACCESS, 0 );
 227         if (event->file)
 228             event->data.create_process.file = alloc_handle( process, event->file, GENERIC_READ, 0 );
 229         break;
 230     case DbgLoadDllStateChange:
 231         if (event->file)
 232             event->data.load_dll.handle = alloc_handle( process, event->file, GENERIC_READ, 0 );
 233         break;
 234     }
 235     clear_error();  /* ignore errors, simply set handles to 0 */
 236 }
 237
 238 /* unlink the first event from the queue */
 239 static void unlink_event( struct debug_obj *debug_obj, struct debug_event *event )
 240 {
 241     list_remove( &event->entry );
 242     if (event->sender->process->debug_event == event) event->sender->process->debug_event = NULL;
 243     release_object( event );
 244 }
 245
 246 /* link an event at the end of the queue */
 247 static void link_event( struct debug_obj *debug_obj, struct debug_event *event )
 248 {
 249     grab_object( event );
 250     list_add_tail( &debug_obj->event_queue, &event->entry );
 251     if (!event->sender->process->debug_event)
 252     {
 253         /* grab reference since debugger could be killed while trying to wake up */
 254         grab_object( debug_obj );
 255         wake_up( &debug_obj->obj, 0 );
 256         release_object( debug_obj );
 257     }
 258 }
 259
 260 /* resume a delayed debug event already in the queue */
 261 static void resume_event( struct debug_obj *debug_obj, struct debug_event *event )
 262 {
 263     event->state = EVENT_QUEUED;
 264     if (!event->sender->process->debug_event)
 265     {
 266         grab_object( debug_obj );
 267         wake_up( &debug_obj->obj, 0 );
 268         release_object( debug_obj );
 269     }
 270 }
 271
 272 /* delay a debug event already in the queue to be replayed when thread wakes up */
 273 static void delay_event( struct debug_obj *debug_obj, struct debug_event *event )
 274 {
 275     event->state = EVENT_DELAYED;
 276     if (event->sender->process->debug_event == event) event->sender->process->debug_event = NULL;
 277 }
 278
 279 /* find the next event that we can send to the debugger */
 280 static struct debug_event *find_event_to_send( struct debug_obj *debug_obj )
 281 {
 282     struct debug_event *event;
 283
 284     LIST_FOR_EACH_ENTRY( event, &debug_obj->event_queue, struct debug_event, entry )
 285     {
 286         if (event->state == EVENT_SENT) continue;  /* already sent */
 287         if (event->state == EVENT_DELAYED) continue;  /* delayed until thread resumes */
 288         if (event->sender->process->debug_event) continue;  /* process busy with another one */
 289         return event;
 290     }
 291     return NULL;
 292 }
 293
 294 static void debug_event_dump( struct object *obj, int verbose )
 295 {
 296     struct debug_event *debug_event = (struct debug_event *)obj;
 297     assert( obj->ops == &debug_event_ops );
 298     fprintf( stderr, "Debug event sender=%p code=%d state=%d\n",
 299              debug_event->sender, debug_event->data.code, debug_event->state );
 300 }
 301
 302 static int debug_event_signaled( struct object *obj, struct wait_queue_entry *entry )
 303 {
 304     struct debug_event *debug_event = (struct debug_event *)obj;
 305     assert( obj->ops == &debug_event_ops );
 306     return debug_event->state == EVENT_CONTINUED;
 307 }
 308
 309 static void debug_event_destroy( struct object *obj )
 310 {
 311     struct debug_event *event = (struct debug_event *)obj;
 312     assert( obj->ops == &debug_event_ops );
 313
 314     if (event->file) release_object( event->file );
 315     release_object( event->sender );
 316 }
 317
 318 static void debug_obj_dump( struct object *obj, int verbose )
 319 {
 320     struct debug_obj *debug_obj = (struct debug_obj *)obj;
 321     assert( obj->ops == &debug_obj_ops );
 322     fprintf( stderr, "Debug context head=%p tail=%p\n",
 323              debug_obj->event_queue.next, debug_obj->event_queue.prev );
 324 }
 325
 326 static int debug_obj_signaled( struct object *obj, struct wait_queue_entry *entry )
 327 {
 328     struct debug_obj *debug_obj = (struct debug_obj *)obj;
 329     assert( obj->ops == &debug_obj_ops );
 330     return find_event_to_send( debug_obj ) != NULL;
 331 }
 332
 333 static void debug_obj_destroy( struct object *obj )
 334 {
 335     struct list *ptr;
 336     struct debug_obj *debug_obj = (struct debug_obj *)obj;
 337     assert( obj->ops == &debug_obj_ops );
 338
 339     detach_debugged_processes( debug_obj,
 340                                (debug_obj->flags & DEBUG_KILL_ON_CLOSE) ? STATUS_DEBUGGER_INACTIVE : 0 );
 341
 342     /* free all pending events */
 343     while ((ptr = list_head( &debug_obj->event_queue )))
 344         unlink_event( debug_obj, LIST_ENTRY( ptr, struct debug_event, entry ));
 345 }
 346
 347 struct debug_obj *get_debug_obj( struct process *process, obj_handle_t handle, unsigned int access )
 348 {
 349     return (struct debug_obj *)get_handle_obj( process, handle, access, &debug_obj_ops );
 350 }
 351
 352 static struct debug_obj *create_debug_obj( struct object *root, const struct unicode_str *name,
 353                                            unsigned int attr, unsigned int flags,
 354                                            const struct security_descriptor *sd )
 355 {
 356     struct debug_obj *debug_obj;
 357
 358     if ((debug_obj = create_named_object( root, &debug_obj_ops, name, attr, sd )))
 359     {
 360         if (get_error() != STATUS_OBJECT_NAME_EXISTS)
 361         {
 362             debug_obj->flags = flags;
 363             list_init( &debug_obj->event_queue );
 364         }
 365     }
 366     return debug_obj;
 367 }
 368
 369 /* continue a debug event */
 370 static int continue_debug_event( struct debug_obj *debug_obj, struct process *process,
 371                                  struct thread *thread, int status )
 372 {
 373     if (process->debug_obj == debug_obj && thread->process == process)
 374     {
 375         struct debug_event *event;
 376
 377         if (status == DBG_REPLY_LATER)
 378         {
 379             /* if thread is suspended, delay all its events and resume process
 380              * if not, reset the event for immediate replay */
 381             LIST_FOR_EACH_ENTRY( event, &debug_obj->event_queue, struct debug_event, entry )
 382             {
 383                 if (event->sender != thread) continue;
 384                 if (thread->suspend)
 385                 {
 386                     delay_event( debug_obj, event );
 387                     resume_process( process );
 388                 }
 389                 else if (event->state == EVENT_SENT)
 390                 {
 391                     assert( event->sender->process->debug_event == event );
 392                     event->sender->process->debug_event = NULL;
 393                     resume_event( debug_obj, event );
 394                     return 1;
 395                 }
 396             }
 397             return 1;
 398         }
 399
 400         /* find the event in the queue */
 401         LIST_FOR_EACH_ENTRY( event, &debug_obj->event_queue, struct debug_event, entry )
 402         {
 403             if (event->state != EVENT_SENT) continue;
 404             if (event->sender == thread)
 405             {
 406                 assert( event->sender->process->debug_event == event );
 407                 event->status = status;
 408                 event->state  = EVENT_CONTINUED;
 409                 wake_up( &event->obj, 0 );
 410                 unlink_event( debug_obj, event );
 411                 resume_process( process );
 412                 return 1;
 413             }
 414         }
 415     }
 416     /* not debugging this process, or no such event */
 417     set_error( STATUS_ACCESS_DENIED );  /* FIXME */
 418     return 0;
 419 }
 420
 421 /* alloc a debug event for a debugger */
 422 static struct debug_event *alloc_debug_event( struct thread *thread, int code, const void *arg )
 423 {
 424     struct debug_event *event;
 425
 426     assert( code >= DbgCreateThreadStateChange && code <= DbgUnloadDllStateChange );
 427
 428     /* build the event */
 429     if (!(event = alloc_object( &debug_event_ops ))) return NULL;
 430     event->state     = EVENT_QUEUED;
 431     event->sender    = (struct thread *)grab_object( thread );
 432     event->file      = NULL;
 433     memset( &event->data, 0, sizeof(event->data) );
 434     fill_debug_event[code - DbgCreateThreadStateChange]( event, arg );
 435     event->data.code = code;
 436     return event;
 437 }
 438
 439 /* generate a debug event from inside the server and queue it */
 440 void generate_debug_event( struct thread *thread, int code, const void *arg )
 441 {
 442     struct debug_obj *debug_obj = thread->process->debug_obj;
 443
 444     if (debug_obj)
 445     {
 446         struct debug_event *event = alloc_debug_event( thread, code, arg );
 447         if (event)
 448         {
 449             link_event( debug_obj, event );
 450             suspend_process( thread->process );
 451             release_object( event );
 452         }
 453         clear_error();  /* ignore errors */
 454     }
 455 }
 456
 457 void resume_delayed_debug_events( struct thread *thread )
 458 {
 459     struct debug_obj *debug_obj = thread->process->debug_obj;
 460     struct debug_event *event;
 461
 462     if (debug_obj)
 463     {
 464         LIST_FOR_EACH_ENTRY( event, &debug_obj->event_queue, struct debug_event, entry )
 465         {
 466             if (event->sender != thread) continue;
 467             if (event->state != EVENT_DELAYED) continue;
 468             resume_event( debug_obj, event );
 469             suspend_process( thread->process );
 470         }
 471     }
 472 }
 473
 474 /* attach a process to a debugger thread and suspend it */
 475 static int debugger_attach( struct process *process, struct thread *debugger, struct debug_obj *debug_obj )
 476 {
 477     if (debugger->process == process) goto error;
 478     if (!is_process_init_done( process )) goto error;  /* still starting up */
 479     if (list_empty( &process->thread_list )) goto error;  /* no thread running in the process */
 480     /* don't let a debugger debug its console... won't work */
 481     if (debugger->process->console)
 482     {
 483         struct thread *renderer = console_get_renderer(debugger->process->console);
 484         if (renderer && renderer->process == process) goto error;
 485     }
 486
 487     suspend_process( process );
 488
 489     if (!set_process_debug_flag( process, 1 ))
 490     {
 491         resume_process( process );
 492         return 0;
 493     }
 494     process->debug_obj = debug_obj;
 495     process->debug_children = 0;
 496     generate_startup_debug_events( process );
 497     resume_process( process );
 498     return 1;
 499
 500  error:
 501     set_error( STATUS_ACCESS_DENIED );
 502     return 0;
 503 }
 504
 505
 506 /* detach a process from a debugger thread (and resume it) */
 507 void debugger_detach( struct process *process, struct debug_obj *debug_obj )
 508 {
 509     struct debug_event *event, *next;
 510
 511     suspend_process( process );
 512
 513     /* send continue indication for all events */
 514     LIST_FOR_EACH_ENTRY_SAFE( event, next, &debug_obj->event_queue, struct debug_event, entry )
 515     {
 516         if (event->sender->process != process) continue;
 517
 518         assert( event->state != EVENT_CONTINUED );
 519         event->status = DBG_CONTINUE;
 520         event->state  = EVENT_CONTINUED;
 521         wake_up( &event->obj, 0 );
 522         unlink_event( debug_obj, event );
 523         /* from queued debug event */
 524         resume_process( process );
 525     }
 526
 527     /* remove relationships between process and its debugger */
 528     process->debug_obj = NULL;
 529     if (!set_process_debug_flag( process, 0 )) clear_error();  /* ignore error */
 530
 531     resume_process( process );
 532 }
 533
 534 /* create a debug object */
 535 DECL_HANDLER(create_debug_obj)
 536 {
 537     struct debug_obj *debug_obj;
 538     struct unicode_str name;
 539     struct object *root;
 540     const struct security_descriptor *sd;
 541     const struct object_attributes *objattr = get_req_object_attributes( &sd, &name, &root );
 542
 543     if (!objattr) return;
 544     if ((debug_obj = create_debug_obj( root, &name, objattr->attributes, req->flags, sd )))
 545     {
 546         if (get_error() == STATUS_OBJECT_NAME_EXISTS)
 547             reply->handle = alloc_handle( current->process, debug_obj, req->access, objattr->attributes );
 548         else
 549             reply->handle = alloc_handle_no_access_check( current->process, debug_obj,
 550                                                           req->access, objattr->attributes );
 551         release_object( debug_obj );
 552     }
 553     if (root) release_object( root );
 554 }
 555
 556 /* Wait for a debug event */
 557 DECL_HANDLER(wait_debug_event)
 558 {
 559     struct debug_obj *debug_obj;
 560     struct debug_event *event;
 561
 562     if (!(debug_obj = get_debug_obj( current->process, req->debug, DEBUG_READ_EVENT ))) return;
 563
 564     if ((event = find_event_to_send( debug_obj )))
 565     {
 566         event->state = EVENT_SENT;
 567         event->sender->process->debug_event = event;
 568         reply->pid = get_process_id( event->sender->process );
 569         reply->tid = get_thread_id( event->sender );
 570         alloc_event_handles( event, current->process );
 571         set_reply_data( &event->data, min( get_reply_max_size(), sizeof(event->data) ));
 572     }
 573     else
 574     {
 575         int state = list_empty( &debug_obj->event_queue ) ? DbgIdle : DbgReplyPending;
 576         set_reply_data( &state, min( get_reply_max_size(), sizeof(state) ));
 577     }
 578     release_object( debug_obj );
 579 }
 580
 581 /* Continue a debug event */
 582 DECL_HANDLER(continue_debug_event)
 583 {
 584     struct debug_obj *debug_obj;
 585     struct process *process;
 586
 587     if (req->status != DBG_EXCEPTION_NOT_HANDLED &&
 588         req->status != DBG_EXCEPTION_HANDLED &&
 589         req->status != DBG_CONTINUE &&
 590         req->status != DBG_REPLY_LATER)
 591     {
 592         set_error( STATUS_INVALID_PARAMETER );
 593         return;
 594     }
 595
 596     if (!(debug_obj = get_debug_obj( current->process, req->debug, DEBUG_READ_EVENT ))) return;
 597
 598     if ((process = get_process_from_id( req->pid )))
 599     {
 600         struct thread *thread = get_thread_from_id( req->tid );
 601         if (thread)
 602         {
 603             continue_debug_event( debug_obj, process, thread, req->status );
 604             release_object( thread );
 605         }
 606         release_object( process );
 607     }
 608     release_object( debug_obj );
 609 }
 610
 611 /* start or stop debugging an existing process */
 612 DECL_HANDLER(debug_process)
 613 {
 614     struct debug_obj *debug_obj;
 615     struct process *process = get_process_from_handle( req->handle,
 616                                             PROCESS_VM_READ | PROCESS_VM_WRITE | PROCESS_SUSPEND_RESUME );
 617
 618     if (!process) return;
 619     if ((debug_obj = get_debug_obj( current->process, req->debug, DEBUG_PROCESS_ASSIGN )))
 620     {
 621         if (req->attach)
 622         {
 623             if (!process->debug_obj) debugger_attach( process, current, debug_obj );
 624             else set_error( STATUS_ACCESS_DENIED );
 625         }
 626         else
 627         {
 628             if (process->debug_obj == debug_obj) debugger_detach( process, debug_obj );
 629             else set_error( STATUS_ACCESS_DENIED );
 630         }
 631         release_object( debug_obj );
 632     }
 633     release_object( process );
 634 }
 635
 636 /* queue an exception event */
 637 DECL_HANDLER(queue_exception_event)
 638 {
 639     struct debug_obj *debug_obj = current->process->debug_obj;
 640
 641     reply->handle = 0;
 642     if (debug_obj)
 643     {
 644         debug_event_t data;
 645         struct debug_event *event;
 646         struct thread *thread = current;
 647
 648         if ((req->len % sizeof(client_ptr_t)) != 0 ||
 649             req->len > get_req_data_size() ||
 650             req->len > EXCEPTION_MAXIMUM_PARAMETERS * sizeof(client_ptr_t))
 651         {
 652             set_error( STATUS_INVALID_PARAMETER );
 653             return;
 654         }
 655         memset( &data, 0, sizeof(data) );
 656         data.exception.first     = req->first;
 657         data.exception.exc_code  = req->code;
 658         data.exception.flags     = req->flags;
 659         data.exception.record    = req->record;
 660         data.exception.address   = req->address;
 661         data.exception.nb_params = req->len / sizeof(client_ptr_t);
 662         memcpy( data.exception.params, get_req_data(), req->len );
 663
 664         if ((event = alloc_debug_event( thread, DbgExceptionStateChange, &data )))
 665         {
 666             if ((reply->handle = alloc_handle( thread->process, event, SYNCHRONIZE, 0 )))
 667             {
 668                 link_event( debug_obj, event );
 669                 suspend_process( thread->process );
 670             }
 671             release_object( event );
 672         }
 673     }
 674 }
 675
 676 /* retrieve the status of an exception event */
 677 DECL_HANDLER(get_exception_status)
 678 {
 679     struct debug_event *event;
 680
 681     if ((event = (struct debug_event *)get_handle_obj( current->process, req->handle,
 682                                                        0, &debug_event_ops )))
 683     {
 684         close_handle( current->process, req->handle );
 685         set_error( event->state == EVENT_CONTINUED ? event->status : STATUS_PENDING );
 686         release_object( event );
 687     }
 688 }
 689
 690 /* set debug object information */
 691 DECL_HANDLER(set_debug_obj_info)
 692 {
 693     struct debug_obj *debug_obj;
 694
 695     if (!(debug_obj = get_debug_obj( current->process, req->debug, DEBUG_SET_INFORMATION ))) return;
 696     debug_obj->flags = req->flags;
 697     release_object( debug_obj );
 698 }