dlls/ntdll/signal_i386.c

   1 /*
   2  * i386 signal handling routines
   3  *
   4  * Copyright 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 #ifdef __i386__
  22
  23 #include "config.h"
  24 #include "wine/port.h"
  25
  26 #include <errno.h>
  27 #include <signal.h>
  28 #include <stdlib.h>
  29 #include <stdio.h>
  30 #ifdef HAVE_UNISTD_H
  31 # include <unistd.h>
  32 #endif
  33
  34 #ifdef HAVE_SYS_PARAM_H
  35 # include <sys/param.h>
  36 #endif
  37 #ifdef HAVE_SYSCALL_H
  38 # include <syscall.h>
  39 #else
  40 # ifdef HAVE_SYS_SYSCALL_H
  41 #  include <sys/syscall.h>
  42 # endif
  43 #endif
  44
  45 #ifdef HAVE_SYS_VM86_H
  46 # include <sys/vm86.h>
  47 #endif
  48
  49 #ifdef HAVE_SYS_SIGNAL_H
  50 # include <sys/signal.h>
  51 #endif
  52
  53 #include "winternl.h"
  54 #include "winnt.h"
  55 #include "wine/library.h"
  56
  57 #include "selectors.h"
  58
  59 /***********************************************************************
  60  * signal context platform-specific definitions
  61  */
  62
  63 #ifdef linux
  64 typedef struct
  65 {
  66     unsigned short sc_gs, __gsh;
  67     unsigned short sc_fs, __fsh;
  68     unsigned short sc_es, __esh;
  69     unsigned short sc_ds, __dsh;
  70     unsigned long sc_edi;
  71     unsigned long sc_esi;
  72     unsigned long sc_ebp;
  73     unsigned long sc_esp;
  74     unsigned long sc_ebx;
  75     unsigned long sc_edx;
  76     unsigned long sc_ecx;
  77     unsigned long sc_eax;
  78     unsigned long sc_trapno;
  79     unsigned long sc_err;
  80     unsigned long sc_eip;
  81     unsigned short sc_cs, __csh;
  82     unsigned long sc_eflags;
  83     unsigned long esp_at_signal;
  84     unsigned short sc_ss, __ssh;
  85     unsigned long i387;
  86     unsigned long oldmask;
  87     unsigned long cr2;
  88 } SIGCONTEXT;
  89
  90 #define HANDLER_DEF(name) void name( int __signal, SIGCONTEXT __context )
  91 #define HANDLER_CONTEXT (&__context)
  92
  93 /* this is the sigaction structure from the Linux 2.1.20 kernel.  */
  94 struct kernel_sigaction
  95 {
  96     void (*ksa_handler)();
  97     unsigned long ksa_mask;
  98     unsigned long ksa_flags;
  99     void *ksa_restorer;
 100 };
 101
 102 /* Similar to the sigaction function in libc, except it leaves alone the
 103    restorer field, which is used to specify the signal stack address */
 104 static inline int wine_sigaction( int sig, struct kernel_sigaction *new,
 105                                   struct kernel_sigaction *old )
 106 {
 107     __asm__ __volatile__( "pushl %%ebx\n\t"
 108                           "movl %2,%%ebx\n\t"
 109                           "int $0x80\n\t"
 110                           "popl %%ebx"
 111                           : "=a" (sig)
 112                           : "0" (SYS_sigaction), "r" (sig), "c" (new), "d" (old) );
 113     if (sig>=0) return 0;
 114     errno = -sig;
 115     return -1;
 116 }
 117
 118 #ifdef HAVE_SIGALTSTACK
 119 /* direct syscall for sigaltstack to work around glibc 2.0 brain-damage */
 120 static inline int wine_sigaltstack( const struct sigaltstack *new,
 121                                     struct sigaltstack *old )
 122 {
 123     int ret;
 124     __asm__ __volatile__( "pushl %%ebx\n\t"
 125                           "movl %2,%%ebx\n\t"
 126                           "int $0x80\n\t"
 127                           "popl %%ebx"
 128                           : "=a" (ret)
 129                           : "0" (SYS_sigaltstack), "r" (new), "c" (old) );
 130     if (ret >= 0) return 0;
 131     errno = -ret;
 132     return -1;
 133 }
 134 #endif
 135
 136 #define VM86_EAX 0 /* the %eax value while vm86_enter is executing */
 137
 138 int vm86_enter( void **vm86_ptr );
 139 void vm86_return(void);
 140 void vm86_return_end(void);
 141 __ASM_GLOBAL_FUNC(vm86_enter,
 142                   "pushl %ebp\n\t"
 143                   "movl %esp, %ebp\n\t"
 144                   "movl $166,%eax\n\t"  /*SYS_vm86*/
 145                   "movl 8(%ebp),%ecx\n\t" /* vm86_ptr */
 146                   "movl (%ecx),%ecx\n\t"
 147                   "pushl %ebx\n\t"
 148                   "movl $1,%ebx\n\t"    /*VM86_ENTER*/
 149                   "pushl %ecx\n\t"      /* put vm86plus_struct ptr somewhere we can find it */
 150                   "pushl %fs\n\t"
 151                   "int $0x80\n"
 152                   ".globl " __ASM_NAME("vm86_return") "\n\t"
 153                   __ASM_FUNC("vm86_return") "\n"
 154                   __ASM_NAME("vm86_return") ":\n\t"
 155                   "popl %fs\n\t"
 156                   "popl %ecx\n\t"
 157                   "popl %ebx\n\t"
 158                   "popl %ebp\n\t"
 159                   "testl %eax,%eax\n\t"
 160                   "jl 0f\n\t"
 161                   "cmpb $0,%al\n\t" /* VM86_SIGNAL */
 162                   "je " __ASM_NAME("vm86_enter") "\n\t"
 163                   "0:\n\t"
 164                   "movl 4(%esp),%ecx\n\t"  /* vm86_ptr */
 165                   "movl $0,(%ecx)\n\t"
 166                   ".globl " __ASM_NAME("vm86_return_end") "\n\t"
 167                   __ASM_FUNC("vm86_return_end") "\n"
 168                   __ASM_NAME("vm86_return_end") ":\n\t"
 169                   "ret" );
 170
 171 #ifdef HAVE_SYS_VM86_H
 172 # define __HAVE_VM86
 173 #endif
 174
 175 #endif  /* linux */
 176
 177 #ifdef BSDI
 178
 179 #define EAX_sig(context)     ((context)->tf_eax)
 180 #define EBX_sig(context)     ((context)->tf_ebx)
 181 #define ECX_sig(context)     ((context)->tf_ecx)
 182 #define EDX_sig(context)     ((context)->tf_edx)
 183 #define ESI_sig(context)     ((context)->tf_esi)
 184 #define EDI_sig(context)     ((context)->tf_edi)
 185 #define EBP_sig(context)     ((context)->tf_ebp)
 186
 187 #define CS_sig(context)      ((context)->tf_cs)
 188 #define DS_sig(context)      ((context)->tf_ds)
 189 #define ES_sig(context)      ((context)->tf_es)
 190 #define SS_sig(context)      ((context)->tf_ss)
 191
 192 #include <machine/frame.h>
 193 typedef struct trapframe SIGCONTEXT;
 194
 195 #define HANDLER_DEF(name) void name( int __signal, int code, SIGCONTEXT *__context )
 196 #define HANDLER_CONTEXT __context
 197
 198 #define EFL_sig(context)     ((context)->tf_eflags)
 199
 200 #define EIP_sig(context)     (*((unsigned long*)&(context)->tf_eip))
 201 #define ESP_sig(context)     (*((unsigned long*)&(context)->tf_esp))
 202
 203 #endif /* bsdi */
 204
 205 #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__)
 206
 207 typedef struct sigcontext SIGCONTEXT;
 208
 209 #define HANDLER_DEF(name) void name( int __signal, int code, SIGCONTEXT *__context )
 210 #define HANDLER_CONTEXT __context
 211
 212 #endif  /* FreeBSD */
 213
 214 #if defined(__svr4__) || defined(_SCO_DS) || defined(__sun)
 215
 216 #ifdef _SCO_DS
 217 #include <sys/regset.h>
 218 #endif
 219 /* Solaris kludge */
 220 #undef ERR
 221 #include <sys/ucontext.h>
 222 #undef ERR
 223 typedef struct ucontext SIGCONTEXT;
 224
 225 #define HANDLER_DEF(name) void name( int __signal, void *__siginfo, SIGCONTEXT *__context )
 226 #define HANDLER_CONTEXT __context
 227
 228 #endif  /* svr4 || SCO_DS */
 229
 230 #ifdef __EMX__
 231
 232 typedef struct
 233 {
 234     unsigned long ContextFlags;
 235     FLOATING_SAVE_AREA sc_float;
 236     unsigned long sc_gs;
 237     unsigned long sc_fs;
 238     unsigned long sc_es;
 239     unsigned long sc_ds;
 240     unsigned long sc_edi;
 241     unsigned long sc_esi;
 242     unsigned long sc_eax;
 243     unsigned long sc_ebx;
 244     unsigned long sc_ecx;
 245     unsigned long sc_edx;
 246     unsigned long sc_ebp;
 247     unsigned long sc_eip;
 248     unsigned long sc_cs;
 249     unsigned long sc_eflags;
 250     unsigned long sc_esp;
 251     unsigned long sc_ss;
 252 } SIGCONTEXT;
 253
 254 #endif  /* __EMX__ */
 255
 256 #ifdef __CYGWIN__
 257
 258 /* FIXME: This section is just here so it can compile, it's most likely
 259  * completely wrong. */
 260
 261 typedef struct
 262 {
 263     unsigned short sc_gs, __gsh;
 264     unsigned short sc_fs, __fsh;
 265     unsigned short sc_es, __esh;
 266     unsigned short sc_ds, __dsh;
 267     unsigned long sc_edi;
 268     unsigned long sc_esi;
 269     unsigned long sc_ebp;
 270     unsigned long sc_esp;
 271     unsigned long sc_ebx;
 272     unsigned long sc_edx;
 273     unsigned long sc_ecx;
 274     unsigned long sc_eax;
 275     unsigned long sc_trapno;
 276     unsigned long sc_err;
 277     unsigned long sc_eip;
 278     unsigned short sc_cs, __csh;
 279     unsigned long sc_eflags;
 280     unsigned long esp_at_signal;
 281     unsigned short sc_ss, __ssh;
 282     unsigned long i387;
 283     unsigned long oldmask;
 284     unsigned long cr2;
 285 } SIGCONTEXT;
 286
 287 #define HANDLER_DEF(name) void name( int __signal, SIGCONTEXT __context )
 288 #define HANDLER_CONTEXT (&__context)
 289
 290 #endif /* __CYGWIN__ */
 291
 292 #if defined(linux) || defined(__NetBSD__) || defined(__FreeBSD__) ||\
 293     defined(__OpenBSD__) || defined(__EMX__) || defined(__CYGWIN__)
 294
 295 #define EAX_sig(context)     ((context)->sc_eax)
 296 #define EBX_sig(context)     ((context)->sc_ebx)
 297 #define ECX_sig(context)     ((context)->sc_ecx)
 298 #define EDX_sig(context)     ((context)->sc_edx)
 299 #define ESI_sig(context)     ((context)->sc_esi)
 300 #define EDI_sig(context)     ((context)->sc_edi)
 301 #define EBP_sig(context)     ((context)->sc_ebp)
 302
 303 #define CS_sig(context)      ((context)->sc_cs)
 304 #define DS_sig(context)      ((context)->sc_ds)
 305 #define ES_sig(context)      ((context)->sc_es)
 306 #define SS_sig(context)      ((context)->sc_ss)
 307
 308 /* FS and GS are now in the sigcontext struct of FreeBSD, but not
 309  * saved by the exception handling. duh.
 310  * Actually they are in -current (have been for a while), and that
 311  * patch now finally has been MFC'd to -stable too (Nov 15 1999).
 312  * If you're running a system from the -stable branch older than that,
 313  * like a 3.3-RELEASE, grab the patch from the ports tree:
 314  * ftp://ftp.freebsd.org/pub/FreeBSD/FreeBSD-current/ports/emulators/wine/files/patch-3.3-sys-fsgs
 315  * (If its not yet there when you look, go here:
 316  * http://www.jelal.kn-bremen.de/freebsd/ports/emulators/wine/files/ )
 317  */
 318 #ifdef __FreeBSD__
 319 #define FS_sig(context)      ((context)->sc_fs)
 320 #define GS_sig(context)      ((context)->sc_gs)
 321 #endif
 322
 323 #ifdef linux
 324 #define FS_sig(context)      ((context)->sc_fs)
 325 #define GS_sig(context)      ((context)->sc_gs)
 326 #define CR2_sig(context)     ((context)->cr2)
 327 #define TRAP_sig(context)    ((context)->sc_trapno)
 328 #define ERROR_sig(context)   ((context)->sc_err)
 329 #define FPU_sig(context)     ((FLOATING_SAVE_AREA*)((context)->i387))
 330 #endif
 331
 332 #ifndef __FreeBSD__
 333 #define EFL_sig(context)     ((context)->sc_eflags)
 334 #else
 335 #define EFL_sig(context)     ((context)->sc_efl)
 336 /* FreeBSD, see i386/i386/traps.c::trap_pfault va->err kludge  */
 337 #define CR2_sig(context)     ((context)->sc_err)
 338 #define TRAP_sig(context)    ((context)->sc_trapno)
 339 #endif
 340
 341 #define EIP_sig(context)     (*((unsigned long*)&(context)->sc_eip))
 342 #define ESP_sig(context)     (*((unsigned long*)&(context)->sc_esp))
 343
 344 #endif  /* linux || __NetBSD__ || __FreeBSD__ || __OpenBSD__ */
 345
 346 #if defined(__svr4__) || defined(_SCO_DS) || defined(__sun)
 347
 348 #ifdef _SCO_DS
 349 #define gregs regs
 350 #endif
 351
 352 #define EAX_sig(context)     ((context)->uc_mcontext.gregs[EAX])
 353 #define EBX_sig(context)     ((context)->uc_mcontext.gregs[EBX])
 354 #define ECX_sig(context)     ((context)->uc_mcontext.gregs[ECX])
 355 #define EDX_sig(context)     ((context)->uc_mcontext.gregs[EDX])
 356 #define ESI_sig(context)     ((context)->uc_mcontext.gregs[ESI])
 357 #define EDI_sig(context)     ((context)->uc_mcontext.gregs[EDI])
 358 #define EBP_sig(context)     ((context)->uc_mcontext.gregs[EBP])
 359
 360 #define CS_sig(context)      ((context)->uc_mcontext.gregs[CS])
 361 #define DS_sig(context)      ((context)->uc_mcontext.gregs[DS])
 362 #define ES_sig(context)      ((context)->uc_mcontext.gregs[ES])
 363 #define SS_sig(context)      ((context)->uc_mcontext.gregs[SS])
 364
 365 #define FS_sig(context)      ((context)->uc_mcontext.gregs[FS])
 366 #define GS_sig(context)      ((context)->uc_mcontext.gregs[GS])
 367
 368 #define EFL_sig(context)     ((context)->uc_mcontext.gregs[EFL])
 369
 370 #define EIP_sig(context)     ((context)->uc_mcontext.gregs[EIP])
 371 #ifdef R_ESP
 372 #define ESP_sig(context)     ((context)->uc_mcontext.gregs[R_ESP])
 373 #else
 374 #define ESP_sig(context)     ((context)->uc_mcontext.gregs[ESP])
 375 #endif
 376 #ifdef TRAPNO
 377 #define TRAP_sig(context)     ((context)->uc_mcontext.gregs[TRAPNO])
 378 #endif
 379
 380 #endif  /* svr4 || SCO_DS */
 381
 382
 383 /* exception code definitions (already defined by FreeBSD/NetBSD) */
 384 #if !defined(__FreeBSD__) && !defined(__NetBSD__) /* FIXME: other BSDs? */
 385 #define T_DIVIDE        0   /* Division by zero exception */
 386 #define T_TRCTRAP       1   /* Single-step exception */
 387 #define T_NMI           2   /* NMI interrupt */
 388 #define T_BPTFLT        3   /* Breakpoint exception */
 389 #define T_OFLOW         4   /* Overflow exception */
 390 #define T_BOUND         5   /* Bound range exception */
 391 #define T_PRIVINFLT     6   /* Invalid opcode exception */
 392 #define T_DNA           7   /* Device not available exception */
 393 #define T_DOUBLEFLT     8   /* Double fault exception */
 394 #define T_FPOPFLT       9   /* Coprocessor segment overrun */
 395 #define T_TSSFLT        10  /* Invalid TSS exception */
 396 #define T_SEGNPFLT      11  /* Segment not present exception */
 397 #define T_STKFLT        12  /* Stack fault */
 398 #define T_PROTFLT       13  /* General protection fault */
 399 #define T_PAGEFLT       14  /* Page fault */
 400 #define T_RESERVED      15  /* Unknown exception */
 401 #define T_ARITHTRAP     16  /* Floating point exception */
 402 #define T_ALIGNFLT      17  /* Alignment check exception */
 403 #define T_MCHK          18  /* Machine check exception */
 404 #define T_CACHEFLT      19  /* Cache flush exception */
 405 #endif
 406 #if defined(__NetBSD__)
 407 #define T_MCHK          19  /* Machine check exception */
 408 #endif
 409
 410 #define T_UNKNOWN     (-1)  /* Unknown fault (TRAP_sig not defined) */
 411
 412 #include "wine/exception.h"
 413 #include "stackframe.h"
 414 #include "global.h"
 415 #include "miscemu.h"
 416 #include "syslevel.h"
 417 #include "wine/debug.h"
 418
 419 WINE_DEFAULT_DEBUG_CHANNEL(seh);
 420
 421 typedef int (*wine_signal_handler)(unsigned int sig);
 422
 423 static wine_signal_handler handlers[256];
 424
 425 static sigset_t all_sigs;
 426
 427
 428 /***********************************************************************
 429  *           dispatch_signal
 430  */
 431 inline static int dispatch_signal(unsigned int sig)
 432 {
 433     if (handlers[sig] == NULL) return 0;
 434     return handlers[sig](sig);
 435 }
 436
 437
 438 /***********************************************************************
 439  *           get_trap_code
 440  *
 441  * Get the trap code for a signal.
 442  */
 443 static inline int get_trap_code( const SIGCONTEXT *sigcontext )
 444 {
 445 #ifdef TRAP_sig
 446     return TRAP_sig(sigcontext);
 447 #else
 448     return T_UNKNOWN;  /* unknown trap code */
 449 #endif
 450 }
 451
 452 /***********************************************************************
 453  *           get_error_code
 454  *
 455  * Get the error code for a signal.
 456  */
 457 static inline int get_error_code( const SIGCONTEXT *sigcontext )
 458 {
 459 #ifdef ERROR_sig
 460     return ERROR_sig(sigcontext);
 461 #else
 462     return 0;
 463 #endif
 464 }
 465
 466 /***********************************************************************
 467  *           get_cr2_value
 468  *
 469  * Get the CR2 value for a signal.
 470  */
 471 static inline void *get_cr2_value( const SIGCONTEXT *sigcontext )
 472 {
 473 #ifdef CR2_sig
 474     return (void *)CR2_sig(sigcontext);
 475 #else
 476     return NULL;
 477 #endif
 478 }
 479
 480
 481 #ifdef __HAVE_VM86
 482 /***********************************************************************
 483  *           save_vm86_context
 484  *
 485  * Set the register values from a vm86 structure.
 486  */
 487 static void save_vm86_context( CONTEXT *context, const struct vm86plus_struct *vm86 )
 488 {
 489     context->Eax    = vm86->regs.eax;
 490     context->Ebx    = vm86->regs.ebx;
 491     context->Ecx    = vm86->regs.ecx;
 492     context->Edx    = vm86->regs.edx;
 493     context->Esi    = vm86->regs.esi;
 494     context->Edi    = vm86->regs.edi;
 495     context->Esp    = vm86->regs.esp;
 496     context->Ebp    = vm86->regs.ebp;
 497     context->Eip    = vm86->regs.eip;
 498     context->SegCs  = vm86->regs.cs;
 499     context->SegDs  = vm86->regs.ds;
 500     context->SegEs  = vm86->regs.es;
 501     context->SegFs  = vm86->regs.fs;
 502     context->SegGs  = vm86->regs.gs;
 503     context->SegSs  = vm86->regs.ss;
 504     context->EFlags = vm86->regs.eflags;
 505 }
 506
 507
 508 /***********************************************************************
 509  *           restore_vm86_context
 510  *
 511  * Build a vm86 structure from the register values.
 512  */
 513 static void restore_vm86_context( const CONTEXT *context, struct vm86plus_struct *vm86 )
 514 {
 515     vm86->regs.eax    = context->Eax;
 516     vm86->regs.ebx    = context->Ebx;
 517     vm86->regs.ecx    = context->Ecx;
 518     vm86->regs.edx    = context->Edx;
 519     vm86->regs.esi    = context->Esi;
 520     vm86->regs.edi    = context->Edi;
 521     vm86->regs.esp    = context->Esp;
 522     vm86->regs.ebp    = context->Ebp;
 523     vm86->regs.eip    = context->Eip;
 524     vm86->regs.cs     = context->SegCs;
 525     vm86->regs.ds     = context->SegDs;
 526     vm86->regs.es     = context->SegEs;
 527     vm86->regs.fs     = context->SegFs;
 528     vm86->regs.gs     = context->SegGs;
 529     vm86->regs.ss     = context->SegSs;
 530     vm86->regs.eflags = context->EFlags;
 531 }
 532 #endif /* __HAVE_VM86 */
 533
 534
 535 /***********************************************************************
 536  *           save_context
 537  *
 538  * Set the register values from a sigcontext.
 539  */
 540 static void save_context( CONTEXT *context, const SIGCONTEXT *sigcontext )
 541 {
 542     WORD fs;
 543     /* get %fs at time of the fault */
 544 #ifdef FS_sig
 545     fs = FS_sig(sigcontext);
 546 #else
 547     fs = wine_get_fs();
 548 #endif
 549     context->SegFs = fs;
 550
 551     /* now restore a proper %fs for the fault handler */
 552     if (!IS_SELECTOR_SYSTEM(CS_sig(sigcontext)))  /* 16-bit mode */
 553     {
 554         fs = SYSLEVEL_Win16CurrentTeb;
 555     }
 556 #ifdef __HAVE_VM86
 557     else if ((void *)EIP_sig(sigcontext) == vm86_return)  /* vm86 mode */
 558     {
 559         /* fetch the saved %fs on the stack */
 560         fs = *(unsigned int *)ESP_sig(sigcontext);
 561         if (EAX_sig(sigcontext) == VM86_EAX) {
 562             struct vm86plus_struct *vm86;
 563             wine_set_fs(fs);
 564             /* retrieve pointer to vm86plus struct that was stored in vm86_enter
 565              * (but we could also get if from teb->vm86_ptr) */
 566             vm86 = *(struct vm86plus_struct **)(ESP_sig(sigcontext) + sizeof(int));
 567             /* get context from vm86 struct */
 568             save_vm86_context( context, vm86 );
 569             return;
 570         }
 571     }
 572 #endif  /* __HAVE_VM86 */
 573
 574     wine_set_fs(fs);
 575
 576     context->Eax    = EAX_sig(sigcontext);
 577     context->Ebx    = EBX_sig(sigcontext);
 578     context->Ecx    = ECX_sig(sigcontext);
 579     context->Edx    = EDX_sig(sigcontext);
 580     context->Esi    = ESI_sig(sigcontext);
 581     context->Edi    = EDI_sig(sigcontext);
 582     context->Ebp    = EBP_sig(sigcontext);
 583     context->EFlags = EFL_sig(sigcontext);
 584     context->Eip    = EIP_sig(sigcontext);
 585     context->Esp    = ESP_sig(sigcontext);
 586     context->SegCs  = LOWORD(CS_sig(sigcontext));
 587     context->SegDs  = LOWORD(DS_sig(sigcontext));
 588     context->SegEs  = LOWORD(ES_sig(sigcontext));
 589     context->SegSs  = LOWORD(SS_sig(sigcontext));
 590 #ifdef GS_sig
 591     context->SegGs  = LOWORD(GS_sig(sigcontext));
 592 #else
 593     context->SegGs  = wine_get_gs();
 594 #endif
 595 }
 596
 597
 598 /***********************************************************************
 599  *           restore_context
 600  *
 601  * Build a sigcontext from the register values.
 602  */
 603 static void restore_context( const CONTEXT *context, SIGCONTEXT *sigcontext )
 604 {
 605 #ifdef __HAVE_VM86
 606     /* check if exception occurred in vm86 mode */
 607     if ((void *)EIP_sig(sigcontext) == vm86_return &&
 608         IS_SELECTOR_SYSTEM(CS_sig(sigcontext)) &&
 609         EAX_sig(sigcontext) == VM86_EAX)
 610     {
 611         /* retrieve pointer to vm86plus struct that was stored in vm86_enter
 612          * (but we could also get it from teb->vm86_ptr) */
 613         struct vm86plus_struct *vm86 = *(struct vm86plus_struct **)(ESP_sig(sigcontext) + sizeof(int));
 614         restore_vm86_context( context, vm86 );
 615         return;
 616     }
 617 #endif /* __HAVE_VM86 */
 618
 619     EAX_sig(sigcontext) = context->Eax;
 620     EBX_sig(sigcontext) = context->Ebx;
 621     ECX_sig(sigcontext) = context->Ecx;
 622     EDX_sig(sigcontext) = context->Edx;
 623     ESI_sig(sigcontext) = context->Esi;
 624     EDI_sig(sigcontext) = context->Edi;
 625     EBP_sig(sigcontext) = context->Ebp;
 626     EFL_sig(sigcontext) = context->EFlags;
 627     EIP_sig(sigcontext) = context->Eip;
 628     ESP_sig(sigcontext) = context->Esp;
 629     CS_sig(sigcontext)  = context->SegCs;
 630     DS_sig(sigcontext)  = context->SegDs;
 631     ES_sig(sigcontext)  = context->SegEs;
 632     SS_sig(sigcontext)  = context->SegSs;
 633 #ifdef FS_sig
 634     FS_sig(sigcontext)  = context->SegFs;
 635 #else
 636     wine_set_fs( context->SegFs );
 637 #endif
 638 #ifdef GS_sig
 639     GS_sig(sigcontext)  = context->SegGs;
 640 #else
 641     wine_set_gs( context->SegGs );
 642 #endif
 643 }
 644
 645
 646 /***********************************************************************
 647  *           save_fpu
 648  *
 649  * Set the FPU context from a sigcontext.
 650  */
 651 inline static void save_fpu( CONTEXT *context, const SIGCONTEXT *sigcontext )
 652 {
 653 #ifdef FPU_sig
 654     if (FPU_sig(sigcontext))
 655     {
 656         context->FloatSave = *FPU_sig(sigcontext);
 657         return;
 658     }
 659 #endif  /* FPU_sig */
 660 #ifdef __GNUC__
 661     __asm__ __volatile__( "fnsave %0; fwait" : "=m" (context->FloatSave) );
 662 #endif  /* __GNUC__ */
 663 }
 664
 665
 666 /***********************************************************************
 667  *           restore_fpu
 668  *
 669  * Restore the FPU context to a sigcontext.
 670  */
 671 inline static void restore_fpu( CONTEXT *context, const SIGCONTEXT *sigcontext )
 672 {
 673     /* reset the current interrupt status */
 674     context->FloatSave.StatusWord &= context->FloatSave.ControlWord | 0xffffff80;
 675 #ifdef FPU_sig
 676     if (FPU_sig(sigcontext))
 677     {
 678         *FPU_sig(sigcontext) = context->FloatSave;
 679         return;
 680     }
 681 #endif  /* FPU_sig */
 682 #ifdef __GNUC__
 683     /* avoid nested exceptions */
 684     __asm__ __volatile__( "frstor %0; fwait" : : "m" (context->FloatSave) );
 685 #endif  /* __GNUC__ */
 686 }
 687
 688
 689 /**********************************************************************
 690  *              get_fpu_code
 691  *
 692  * Get the FPU exception code from the FPU status.
 693  */
 694 static inline DWORD get_fpu_code( const CONTEXT *context )
 695 {
 696     DWORD status = context->FloatSave.StatusWord;
 697
 698     if (status & 0x01)  /* IE */
 699     {
 700         if (status & 0x40)  /* SF */
 701             return EXCEPTION_FLT_STACK_CHECK;
 702         else
 703             return EXCEPTION_FLT_INVALID_OPERATION;
 704     }
 705     if (status & 0x02) return EXCEPTION_FLT_DENORMAL_OPERAND;  /* DE flag */
 706     if (status & 0x04) return EXCEPTION_FLT_DIVIDE_BY_ZERO;    /* ZE flag */
 707     if (status & 0x08) return EXCEPTION_FLT_OVERFLOW;          /* OE flag */
 708     if (status & 0x10) return EXCEPTION_FLT_UNDERFLOW;         /* UE flag */
 709     if (status & 0x20) return EXCEPTION_FLT_INEXACT_RESULT;    /* PE flag */
 710     return EXCEPTION_FLT_INVALID_OPERATION;  /* generic error */
 711 }
 712
 713
 714 /***********************************************************************
 715  *           SIGNAL_Unblock
 716  *
 717  * Unblock signals. Called from EXC_RtlRaiseException.
 718  */
 719 void SIGNAL_Unblock( void )
 720 {
 721     sigprocmask( SIG_UNBLOCK, &all_sigs, NULL );
 722 }
 723
 724
 725 /**********************************************************************
 726  *              do_segv
 727  *
 728  * Implementation of SIGSEGV handler.
 729  */
 730 static void do_segv( CONTEXT *context, int trap_code, void *cr2, int err_code )
 731 {
 732     EXCEPTION_RECORD rec;
 733     DWORD page_fault_code = EXCEPTION_ACCESS_VIOLATION;
 734
 735 #ifdef CR2_sig
 736     /* we want the page-fault case to be fast */
 737     if (trap_code == T_PAGEFLT)
 738         if (!(page_fault_code = VIRTUAL_HandleFault( cr2 ))) return;
 739 #endif
 740
 741     rec.ExceptionRecord  = NULL;
 742     rec.ExceptionFlags   = EXCEPTION_CONTINUABLE;
 743     rec.ExceptionAddress = (LPVOID)context->Eip;
 744     rec.NumberParameters = 0;
 745
 746     switch(trap_code)
 747     {
 748     case T_OFLOW:   /* Overflow exception */
 749         rec.ExceptionCode = EXCEPTION_INT_OVERFLOW;
 750         break;
 751     case T_BOUND:   /* Bound range exception */
 752         rec.ExceptionCode = EXCEPTION_ARRAY_BOUNDS_EXCEEDED;
 753         break;
 754     case T_PRIVINFLT:   /* Invalid opcode exception */
 755         rec.ExceptionCode = EXCEPTION_ILLEGAL_INSTRUCTION;
 756         break;
 757     case T_STKFLT:  /* Stack fault */
 758         rec.ExceptionCode = EXCEPTION_STACK_OVERFLOW;
 759         break;
 760     case T_SEGNPFLT:  /* Segment not present exception */
 761     case T_PROTFLT:   /* General protection fault */
 762     case T_UNKNOWN:   /* Unknown fault code */
 763         if (INSTR_EmulateInstruction( context )) return;
 764         rec.ExceptionCode = EXCEPTION_PRIV_INSTRUCTION;
 765         break;
 766     case T_PAGEFLT:  /* Page fault */
 767 #ifdef CR2_sig
 768         rec.NumberParameters = 2;
 769         rec.ExceptionInformation[0] = (err_code & 2) != 0;
 770         rec.ExceptionInformation[1] = (DWORD)cr2;
 771 #endif /* CR2_sig */
 772         rec.ExceptionCode = page_fault_code;
 773         break;
 774     case T_ALIGNFLT:  /* Alignment check exception */
 775         /* FIXME: pass through exception handler first? */
 776         if (context->EFlags & 0x00040000)
 777         {
 778             /* Disable AC flag, return */
 779             context->EFlags &= ~0x00040000;
 780             return;
 781         }
 782         rec.ExceptionCode = EXCEPTION_DATATYPE_MISALIGNMENT;
 783         break;
 784     default:
 785         ERR( "Got unexpected trap %d\n", trap_code );
 786         /* fall through */
 787     case T_NMI:       /* NMI interrupt */
 788     case T_DNA:       /* Device not available exception */
 789     case T_DOUBLEFLT: /* Double fault exception */
 790     case T_TSSFLT:    /* Invalid TSS exception */
 791     case T_RESERVED:  /* Unknown exception */
 792     case T_MCHK:      /* Machine check exception */
 793 #ifdef T_CACHEFLT
 794     case T_CACHEFLT:  /* Cache flush exception */
 795 #endif
 796         rec.ExceptionCode = EXCEPTION_ILLEGAL_INSTRUCTION;
 797         break;
 798     }
 799     EXC_RtlRaiseException( &rec, context );
 800 }
 801
 802
 803 /**********************************************************************
 804  *              do_trap
 805  *
 806  * Implementation of SIGTRAP handler.
 807  */
 808 static void do_trap( CONTEXT *context, int trap_code )
 809 {
 810     EXCEPTION_RECORD rec;
 811
 812     rec.ExceptionFlags   = EXCEPTION_CONTINUABLE;
 813     rec.ExceptionRecord  = NULL;
 814     rec.ExceptionAddress = (LPVOID)context->Eip;
 815     rec.NumberParameters = 0;
 816
 817     switch(trap_code)
 818     {
 819     case T_TRCTRAP:  /* Single-step exception */
 820         if (context->EFlags & 0x100)
 821         {
 822             rec.ExceptionCode = EXCEPTION_SINGLE_STEP;
 823             context->EFlags &= ~0x100;  /* clear single-step flag */
 824         }
 825         else
 826         {
 827             /* likely we get this because of a kill(SIGTRAP) on ourself,
 828              * so send a bp exception instead of a single step exception
 829              */
 830             TRACE("Spurious single step trap => breakpoint simulation\n");
 831             rec.ExceptionCode = EXCEPTION_BREAKPOINT;
 832         }
 833         break;
 834     case T_BPTFLT:   /* Breakpoint exception */
 835         rec.ExceptionAddress = (char *)rec.ExceptionAddress - 1;  /* back up over the int3 instruction */
 836         /* fall through */
 837     default:
 838         rec.ExceptionCode = EXCEPTION_BREAKPOINT;
 839         break;
 840     }
 841     EXC_RtlRaiseException( &rec, context );
 842 }
 843
 844
 845 /**********************************************************************
 846  *              do_fpe
 847  *
 848  * Implementation of SIGFPE handler
 849  */
 850 static void do_fpe( CONTEXT *context, int trap_code )
 851 {
 852     EXCEPTION_RECORD rec;
 853
 854     switch(trap_code)
 855     {
 856     case T_DIVIDE:   /* Division by zero exception */
 857         rec.ExceptionCode = EXCEPTION_INT_DIVIDE_BY_ZERO;
 858         break;
 859     case T_FPOPFLT:   /* Coprocessor segment overrun */
 860         rec.ExceptionCode = EXCEPTION_FLT_INVALID_OPERATION;
 861         break;
 862     case T_ARITHTRAP:  /* Floating point exception */
 863     case T_UNKNOWN:    /* Unknown fault code */
 864         rec.ExceptionCode = get_fpu_code( context );
 865         break;
 866     default:
 867         ERR( "Got unexpected trap %d\n", trap_code );
 868         rec.ExceptionCode = EXCEPTION_FLT_INVALID_OPERATION;
 869         break;
 870     }
 871     rec.ExceptionFlags   = EXCEPTION_CONTINUABLE;
 872     rec.ExceptionRecord  = NULL;
 873     rec.ExceptionAddress = (LPVOID)context->Eip;
 874     rec.NumberParameters = 0;
 875     EXC_RtlRaiseException( &rec, context );
 876 }
 877
 878
 879 #ifdef __HAVE_VM86
 880 /**********************************************************************
 881  *              set_vm86_pend
 882  *
 883  * Handler for SIGUSR2, which we use to set the vm86 pending flag.
 884  */
 885 static void set_vm86_pend( CONTEXT *context )
 886 {
 887     EXCEPTION_RECORD rec;
 888     TEB *teb = NtCurrentTeb();
 889     struct vm86plus_struct *vm86 = (struct vm86plus_struct*)(teb->vm86_ptr);
 890
 891     rec.ExceptionCode           = EXCEPTION_VM86_STI;
 892     rec.ExceptionFlags          = EXCEPTION_CONTINUABLE;
 893     rec.ExceptionRecord         = NULL;
 894     rec.NumberParameters        = 1;
 895     rec.ExceptionInformation[0] = 0;
 896
 897     /* __wine_enter_vm86() merges the vm86_pending flag in safely */
 898     teb->vm86_pending |= VIP_MASK;
 899     /* see if we were in VM86 mode */
 900     if (context->EFlags & 0x00020000)
 901     {
 902         /* seems so, also set flag in signal context */
 903         if (context->EFlags & VIP_MASK) return;
 904         context->EFlags |= VIP_MASK;
 905         vm86->regs.eflags |= VIP_MASK; /* no exception recursion */
 906         if (context->EFlags & VIF_MASK) {
 907             /* VIF is set, throw exception */
 908             teb->vm86_pending = 0;
 909             teb->vm86_ptr = NULL;
 910             rec.ExceptionAddress = (LPVOID)context->Eip;
 911             EXC_RtlRaiseException( &rec, context );
 912             teb->vm86_ptr = vm86;
 913         }
 914     }
 915     else if (vm86)
 916     {
 917         /* not in VM86, but possibly setting up for it */
 918         if (vm86->regs.eflags & VIP_MASK) return;
 919         vm86->regs.eflags |= VIP_MASK;
 920         if (((char*)context->Eip >= (char*)vm86_return) &&
 921             ((char*)context->Eip <= (char*)vm86_return_end) &&
 922             (VM86_TYPE(context->Eax) != VM86_SIGNAL)) {
 923             /* exiting from VM86, can't throw */
 924             return;
 925         }
 926         if (vm86->regs.eflags & VIF_MASK) {
 927             /* VIF is set, throw exception */
 928             CONTEXT vcontext;
 929             teb->vm86_pending = 0;
 930             teb->vm86_ptr = NULL;
 931             save_vm86_context( &vcontext, vm86 );
 932             rec.ExceptionAddress = (LPVOID)vcontext.Eip;
 933             EXC_RtlRaiseException( &rec, &vcontext );
 934             teb->vm86_ptr = vm86;
 935             restore_vm86_context( &vcontext, vm86 );
 936         }
 937     }
 938 }
 939
 940
 941 /**********************************************************************
 942  *              usr2_handler
 943  *
 944  * Handler for SIGUSR2.
 945  * We use it to signal that the running __wine_enter_vm86() should
 946  * immediately set VIP_MASK, causing pending events to be handled
 947  * as early as possible.
 948  */
 949 static HANDLER_DEF(usr2_handler)
 950 {
 951     CONTEXT context;
 952
 953     save_context( &context, HANDLER_CONTEXT );
 954     set_vm86_pend( &context );
 955     restore_context( &context, HANDLER_CONTEXT );
 956 }
 957
 958
 959 /**********************************************************************
 960  *              alrm_handler
 961  *
 962  * Handler for SIGALRM.
 963  * Increases the alarm counter and sets the vm86 pending flag.
 964  */
 965 static HANDLER_DEF(alrm_handler)
 966 {
 967     CONTEXT context;
 968
 969     save_context( &context, HANDLER_CONTEXT );
 970     NtCurrentTeb()->alarms++;
 971     set_vm86_pend( &context );
 972     restore_context( &context, HANDLER_CONTEXT );
 973 }
 974 #endif /* __HAVE_VM86 */
 975
 976
 977 /**********************************************************************
 978  *              segv_handler
 979  *
 980  * Handler for SIGSEGV and related errors.
 981  */
 982 static HANDLER_DEF(segv_handler)
 983 {
 984     CONTEXT context;
 985     save_context( &context, HANDLER_CONTEXT );
 986     do_segv( &context, get_trap_code(HANDLER_CONTEXT),
 987              get_cr2_value(HANDLER_CONTEXT), get_error_code(HANDLER_CONTEXT) );
 988     restore_context( &context, HANDLER_CONTEXT );
 989 }
 990
 991
 992 /**********************************************************************
 993  *              trap_handler
 994  *
 995  * Handler for SIGTRAP.
 996  */
 997 static HANDLER_DEF(trap_handler)
 998 {
 999     CONTEXT context;
1000     save_context( &context, HANDLER_CONTEXT );
1001     do_trap( &context, get_trap_code(HANDLER_CONTEXT) );
1002     restore_context( &context, HANDLER_CONTEXT );
1003 }
1004
1005
1006 /**********************************************************************
1007  *              fpe_handler
1008  *
1009  * Handler for SIGFPE.
1010  */
1011 static HANDLER_DEF(fpe_handler)
1012 {
1013     CONTEXT context;
1014     save_fpu( &context, HANDLER_CONTEXT );
1015     save_context( &context, HANDLER_CONTEXT );
1016     do_fpe( &context, get_trap_code(HANDLER_CONTEXT) );
1017     restore_context( &context, HANDLER_CONTEXT );
1018     restore_fpu( &context, HANDLER_CONTEXT );
1019 }
1020
1021
1022 /**********************************************************************
1023  *              int_handler
1024  *
1025  * Handler for SIGINT.
1026  */
1027 static HANDLER_DEF(int_handler)
1028 {
1029     if (!dispatch_signal(SIGINT))
1030     {
1031         EXCEPTION_RECORD rec;
1032         CONTEXT context;
1033
1034         save_context( &context, HANDLER_CONTEXT );
1035         rec.ExceptionCode    = CONTROL_C_EXIT;
1036         rec.ExceptionFlags   = EXCEPTION_CONTINUABLE;
1037         rec.ExceptionRecord  = NULL;
1038         rec.ExceptionAddress = (LPVOID)context.Eip;
1039         rec.NumberParameters = 0;
1040         EXC_RtlRaiseException( &rec, &context );
1041         restore_context( &context, HANDLER_CONTEXT );
1042     }
1043 }
1044
1045 /**********************************************************************
1046  *              abrt_handler
1047  *
1048  * Handler for SIGABRT.
1049  */
1050 static HANDLER_DEF(abrt_handler)
1051 {
1052     EXCEPTION_RECORD rec;
1053     CONTEXT context;
1054
1055     save_context( &context, HANDLER_CONTEXT );
1056     rec.ExceptionCode    = EXCEPTION_WINE_ASSERTION;
1057     rec.ExceptionFlags   = EH_NONCONTINUABLE;
1058     rec.ExceptionRecord  = NULL;
1059     rec.ExceptionAddress = (LPVOID)context.Eip;
1060     rec.NumberParameters = 0;
1061     EXC_RtlRaiseException( &rec, &context ); /* Should never return.. */
1062     restore_context( &context, HANDLER_CONTEXT );
1063 }
1064
1065
1066 /***********************************************************************
1067  *           set_handler
1068  *
1069  * Set a signal handler
1070  */
1071 static int set_handler( int sig, int have_sigaltstack, void (*func)() )
1072 {
1073     struct sigaction sig_act;
1074
1075 #ifdef linux
1076     if (!have_sigaltstack && NtCurrentTeb()->signal_stack)
1077     {
1078         struct kernel_sigaction sig_act;
1079         sig_act.ksa_handler = func;
1080         sig_act.ksa_flags   = SA_RESTART;
1081         sig_act.ksa_mask    = (1 << (SIGINT-1)) |
1082                               (1 << (SIGALRM-1));
1083         /* point to the top of the stack */
1084         sig_act.ksa_restorer = (char *)NtCurrentTeb()->signal_stack + SIGNAL_STACK_SIZE;
1085         return wine_sigaction( sig, &sig_act, NULL );
1086     }
1087 #endif  /* linux */
1088     sig_act.sa_handler = func;
1089     sigemptyset( &sig_act.sa_mask );
1090     sigaddset( &sig_act.sa_mask, SIGINT );
1091     sigaddset( &sig_act.sa_mask, SIGALRM );
1092
1093 #ifdef linux
1094     sig_act.sa_flags = SA_RESTART;
1095 #elif defined (__svr4__) || defined(_SCO_DS)
1096     sig_act.sa_flags = SA_SIGINFO | SA_RESTART;
1097 #else
1098     sig_act.sa_flags = 0;
1099 #endif
1100
1101 #ifdef SA_ONSTACK
1102     if (have_sigaltstack) sig_act.sa_flags |= SA_ONSTACK;
1103 #endif
1104     return sigaction( sig, &sig_act, NULL );
1105 }
1106
1107
1108 /***********************************************************************
1109  *           __wine_set_signal_handler   (NTDLL.@)
1110  */
1111 int __wine_set_signal_handler(unsigned int sig, wine_signal_handler wsh)
1112 {
1113     if (sig > sizeof(handlers) / sizeof(handlers[0])) return -1;
1114     if (handlers[sig] != NULL) return -2;
1115     handlers[sig] = wsh;
1116     return 0;
1117 }
1118
1119
1120 /**********************************************************************
1121  *              SIGNAL_Init
1122  */
1123 BOOL SIGNAL_Init(void)
1124 {
1125     int have_sigaltstack = 0;
1126
1127 #ifdef HAVE_SIGALTSTACK
1128     struct sigaltstack ss;
1129     if ((ss.ss_sp = NtCurrentTeb()->signal_stack))
1130     {
1131         ss.ss_size  = SIGNAL_STACK_SIZE;
1132         ss.ss_flags = 0;
1133         if (!sigaltstack(&ss, NULL)) have_sigaltstack = 1;
1134 #ifdef linux
1135         /* sigaltstack may fail because the kernel is too old, or
1136            because glibc is brain-dead. In the latter case a
1137            direct system call should succeed. */
1138         else if (!wine_sigaltstack(&ss, NULL)) have_sigaltstack = 1;
1139 #endif  /* linux */
1140     }
1141 #endif  /* HAVE_SIGALTSTACK */
1142
1143     sigfillset( &all_sigs );
1144
1145     if (set_handler( SIGINT,  have_sigaltstack, (void (*)())int_handler ) == -1) goto error;
1146     if (set_handler( SIGFPE,  have_sigaltstack, (void (*)())fpe_handler ) == -1) goto error;
1147     if (set_handler( SIGSEGV, have_sigaltstack, (void (*)())segv_handler ) == -1) goto error;
1148     if (set_handler( SIGILL,  have_sigaltstack, (void (*)())segv_handler ) == -1) goto error;
1149     if (set_handler( SIGABRT, have_sigaltstack, (void (*)())abrt_handler ) == -1) goto error;
1150 #ifdef SIGBUS
1151     if (set_handler( SIGBUS,  have_sigaltstack, (void (*)())segv_handler ) == -1) goto error;
1152 #endif
1153 #ifdef SIGTRAP
1154     if (set_handler( SIGTRAP, have_sigaltstack, (void (*)())trap_handler ) == -1) goto error;
1155 #endif
1156
1157 #ifdef __HAVE_VM86
1158     if (set_handler( SIGALRM, have_sigaltstack, (void (*)())alrm_handler ) == -1) goto error;
1159     if (set_handler( SIGUSR2, have_sigaltstack, (void (*)())usr2_handler ) == -1) goto error;
1160 #endif
1161
1162     return TRUE;
1163
1164  error:
1165     perror("sigaction");
1166     return FALSE;
1167 }
1168
1169
1170 /**********************************************************************
1171  *              SIGNAL_Reset
1172  */
1173 void SIGNAL_Reset(void)
1174 {
1175     sigset_t block_set;
1176
1177     /* block the async signals */
1178     sigemptyset( &block_set );
1179     sigaddset( &block_set, SIGALRM );
1180     sigaddset( &block_set, SIGIO );
1181     sigaddset( &block_set, SIGHUP );
1182     sigaddset( &block_set, SIGUSR2 );
1183     sigprocmask( SIG_BLOCK, &block_set, NULL );
1184
1185     /* restore default handlers */
1186     signal( SIGINT, SIG_DFL );
1187     signal( SIGFPE, SIG_DFL );
1188     signal( SIGSEGV, SIG_DFL );
1189     signal( SIGILL, SIG_DFL );
1190 #ifdef SIGBUS
1191     signal( SIGBUS, SIG_DFL );
1192 #endif
1193 #ifdef SIGTRAP
1194     signal( SIGTRAP, SIG_DFL );
1195 #endif
1196 }
1197
1198
1199 #ifdef __HAVE_VM86
1200 /**********************************************************************
1201  *              __wine_enter_vm86   (NTDLL.@)
1202  *
1203  * Enter vm86 mode with the specified register context.
1204  */
1205 void __wine_enter_vm86( CONTEXT *context )
1206 {
1207     EXCEPTION_RECORD rec;
1208     TEB *teb = NtCurrentTeb();
1209     int res;
1210     struct vm86plus_struct vm86;
1211
1212     memset( &vm86, 0, sizeof(vm86) );
1213     for (;;)
1214     {
1215         restore_vm86_context( context, &vm86 );
1216         /* Linux doesn't preserve pending flag (VIP_MASK) on return,
1217          * so save it on entry, just in case */
1218         teb->vm86_pending |= (context->EFlags & VIP_MASK);
1219         /* Work around race conditions with signal handler
1220          * (avoiding sigprocmask for performance reasons) */
1221         teb->vm86_ptr = &vm86;
1222         vm86.regs.eflags |= teb->vm86_pending;
1223         /* Check for VIF|VIP here, since vm86_enter doesn't */
1224         if ((vm86.regs.eflags & (VIF_MASK|VIP_MASK)) == (VIF_MASK|VIP_MASK)) {
1225             teb->vm86_ptr = NULL;
1226             teb->vm86_pending = 0;
1227             context->EFlags |= VIP_MASK;
1228             rec.ExceptionCode = EXCEPTION_VM86_STI;
1229             rec.ExceptionInformation[0] = 0;
1230             goto cancel_vm86;
1231         }
1232
1233         do
1234         {
1235             res = vm86_enter( &teb->vm86_ptr ); /* uses and clears teb->vm86_ptr */
1236             if (res < 0)
1237             {
1238                 errno = -res;
1239                 return;
1240             }
1241         } while (VM86_TYPE(res) == VM86_SIGNAL);
1242
1243         save_vm86_context( context, &vm86 );
1244         context->EFlags |= teb->vm86_pending;
1245
1246         switch(VM86_TYPE(res))
1247         {
1248         case VM86_UNKNOWN: /* unhandled GP fault - IO-instruction or similar */
1249             do_segv( context, T_PROTFLT, 0, 0 );
1250             continue;
1251         case VM86_TRAP: /* return due to DOS-debugger request */
1252             do_trap( context, VM86_ARG(res) );
1253             continue;
1254         case VM86_INTx: /* int3/int x instruction (ARG = x) */
1255             rec.ExceptionCode = EXCEPTION_VM86_INTx;
1256             break;
1257         case VM86_STI: /* sti/popf/iret instruction enabled virtual interrupts */
1258             teb->vm86_pending = 0;
1259             rec.ExceptionCode = EXCEPTION_VM86_STI;
1260             break;
1261         case VM86_PICRETURN: /* return due to pending PIC request */
1262             rec.ExceptionCode = EXCEPTION_VM86_PICRETURN;
1263             break;
1264         default:
1265             ERR( "unhandled result from vm86 mode %x\n", res );
1266             continue;
1267         }
1268         rec.ExceptionInformation[0] = VM86_ARG(res);
1269 cancel_vm86:
1270         rec.ExceptionFlags          = EXCEPTION_CONTINUABLE;
1271         rec.ExceptionRecord         = NULL;
1272         rec.ExceptionAddress        = (LPVOID)context->Eip;
1273         rec.NumberParameters        = 1;
1274         EXC_RtlRaiseException( &rec, context );
1275     }
1276 }
1277
1278 #else /* __HAVE_VM86 */
1279 /**********************************************************************
1280  *              __wine_enter_vm86   (NTDLL.@)
1281  */
1282 void __wine_enter_vm86( CONTEXT *context )
1283 {
1284     MESSAGE("vm86 mode not supported on this platform\n");
1285 }
1286 #endif /* __HAVE_VM86 */
1287
1288 /**********************************************************************
1289  *              DbgBreakPoint   (NTDLL.@)
1290  */
1291 __ASM_GLOBAL_FUNC( DbgBreakPoint, "int $3; ret");
1292
1293 /**********************************************************************
1294  *              DbgUserBreakPoint   (NTDLL.@)
1295  */
1296 __ASM_GLOBAL_FUNC( DbgUserBreakPoint, "int $3; ret");
1297
1298 #endif  /* __i386__ */