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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, 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 <stdarg.h>
  30 #include <stdio.h>
  31 #include <sys/types.h>
  32 #ifdef HAVE_UNISTD_H
  33 # include <unistd.h>
  34 #endif
  35
  36 #ifdef HAVE_SYS_PARAM_H
  37 # include <sys/param.h>
  38 #endif
  39 #ifdef HAVE_SYSCALL_H
  40 # include <syscall.h>
  41 #else
  42 # ifdef HAVE_SYS_SYSCALL_H
  43 #  include <sys/syscall.h>
  44 # endif
  45 #endif
  46
  47 #ifdef HAVE_SYS_VM86_H
  48 # include <sys/vm86.h>
  49 #endif
  50
  51 #ifdef HAVE_SYS_SIGNAL_H
  52 # include <sys/signal.h>
  53 #endif
  54 #ifdef HAVE_SYS_SYSCTL_H
  55 # include <sys/sysctl.h>
  56 #endif
  57
  58 #include "windef.h"
  59 #include "thread.h"
  60 #include "wine/library.h"
  61 #include "ntdll_misc.h"
  62 #include "wine/exception.h"
  63 #include "wine/debug.h"
  64
  65 #ifdef HAVE_VALGRIND_MEMCHECK_H
  66 #include <valgrind/memcheck.h>
  67 #endif
  68
  69 #undef ERR  /* Solaris needs to define this */
  70
  71 /* not defined for x86, so copy the x86_64 definition */
  72 typedef struct DECLSPEC_ALIGN(16) _M128A
  73 {
  74     ULONGLONG Low;
  75     LONGLONG High;
  76 } M128A;
  77
  78 typedef struct
  79 {
  80     WORD ControlWord;
  81     WORD StatusWord;
  82     BYTE TagWord;
  83     BYTE Reserved1;
  84     WORD ErrorOpcode;
  85     DWORD ErrorOffset;
  86     WORD ErrorSelector;
  87     WORD Reserved2;
  88     DWORD DataOffset;
  89     WORD DataSelector;
  90     WORD Reserved3;
  91     DWORD MxCsr;
  92     DWORD MxCsr_Mask;
  93     M128A FloatRegisters[8];
  94     M128A XmmRegisters[16];
  95     BYTE Reserved4[96];
  96 } XMM_SAVE_AREA32;
  97
  98 /***********************************************************************
  99  * signal context platform-specific definitions
 100  */
 101
 102 #ifdef linux
 103
 104 typedef ucontext_t SIGCONTEXT;
 105
 106 #define EAX_sig(context)     ((context)->uc_mcontext.gregs[REG_EAX])
 107 #define EBX_sig(context)     ((context)->uc_mcontext.gregs[REG_EBX])
 108 #define ECX_sig(context)     ((context)->uc_mcontext.gregs[REG_ECX])
 109 #define EDX_sig(context)     ((context)->uc_mcontext.gregs[REG_EDX])
 110 #define ESI_sig(context)     ((context)->uc_mcontext.gregs[REG_ESI])
 111 #define EDI_sig(context)     ((context)->uc_mcontext.gregs[REG_EDI])
 112 #define EBP_sig(context)     ((context)->uc_mcontext.gregs[REG_EBP])
 113 #define ESP_sig(context)     ((context)->uc_mcontext.gregs[REG_ESP])
 114
 115 #define CS_sig(context)      ((context)->uc_mcontext.gregs[REG_CS])
 116 #define DS_sig(context)      ((context)->uc_mcontext.gregs[REG_DS])
 117 #define ES_sig(context)      ((context)->uc_mcontext.gregs[REG_ES])
 118 #define SS_sig(context)      ((context)->uc_mcontext.gregs[REG_SS])
 119 #define FS_sig(context)      ((context)->uc_mcontext.gregs[REG_FS])
 120 #define GS_sig(context)      ((context)->uc_mcontext.gregs[REG_GS])
 121
 122 #define EFL_sig(context)     ((context)->uc_mcontext.gregs[REG_EFL])
 123 #define EIP_sig(context)     ((context)->uc_mcontext.gregs[REG_EIP])
 124 #define TRAP_sig(context)    ((context)->uc_mcontext.gregs[REG_TRAPNO])
 125 #define ERROR_sig(context)   ((context)->uc_mcontext.gregs[REG_ERR])
 126
 127 #define FPU_sig(context)     ((FLOATING_SAVE_AREA*)((context)->uc_mcontext.fpregs))
 128 #define FPUX_sig(context)    (FPU_sig(context) && !((context)->uc_mcontext.fpregs->status >> 16) ? (XMM_SAVE_AREA32 *)(FPU_sig(context) + 1) : NULL)
 129
 130 #define VM86_EAX 0 /* the %eax value while vm86_enter is executing */
 131
 132 int vm86_enter( void **vm86_ptr );
 133 void vm86_return(void);
 134 void vm86_return_end(void);
 135 __ASM_GLOBAL_FUNC(vm86_enter,
 136                   "pushl %ebp\n\t"
 137                   "movl %esp, %ebp\n\t"
 138                   "movl $166,%eax\n\t"  /*SYS_vm86*/
 139                   "movl 8(%ebp),%ecx\n\t" /* vm86_ptr */
 140                   "movl (%ecx),%ecx\n\t"
 141                   "pushl %ebx\n\t"
 142                   "movl $1,%ebx\n\t"    /*VM86_ENTER*/
 143                   "pushl %ecx\n\t"      /* put vm86plus_struct ptr somewhere we can find it */
 144                   "pushl %fs\n\t"
 145                   "pushl %gs\n\t"
 146                   "int $0x80\n"
 147                   ".globl " __ASM_NAME("vm86_return") "\n\t"
 148                   __ASM_FUNC("vm86_return") "\n"
 149                   __ASM_NAME("vm86_return") ":\n\t"
 150                   "popl %gs\n\t"
 151                   "popl %fs\n\t"
 152                   "popl %ecx\n\t"
 153                   "popl %ebx\n\t"
 154                   "popl %ebp\n\t"
 155                   "testl %eax,%eax\n\t"
 156                   "jl 0f\n\t"
 157                   "cmpb $0,%al\n\t" /* VM86_SIGNAL */
 158                   "je " __ASM_NAME("vm86_enter") "\n\t"
 159                   "0:\n\t"
 160                   "movl 4(%esp),%ecx\n\t"  /* vm86_ptr */
 161                   "movl $0,(%ecx)\n\t"
 162                   ".globl " __ASM_NAME("vm86_return_end") "\n\t"
 163                   __ASM_FUNC("vm86_return_end") "\n"
 164                   __ASM_NAME("vm86_return_end") ":\n\t"
 165                   "ret" )
 166
 167 #ifdef HAVE_SYS_VM86_H
 168 # define __HAVE_VM86
 169 #endif
 170
 171 #endif  /* linux */
 172
 173 #ifdef BSDI
 174
 175 #include <machine/frame.h>
 176 typedef struct trapframe SIGCONTEXT;
 177
 178 #define EAX_sig(context)     ((context)->tf_eax)
 179 #define EBX_sig(context)     ((context)->tf_ebx)
 180 #define ECX_sig(context)     ((context)->tf_ecx)
 181 #define EDX_sig(context)     ((context)->tf_edx)
 182 #define ESI_sig(context)     ((context)->tf_esi)
 183 #define EDI_sig(context)     ((context)->tf_edi)
 184 #define EBP_sig(context)     ((context)->tf_ebp)
 185
 186 #define CS_sig(context)      ((context)->tf_cs)
 187 #define DS_sig(context)      ((context)->tf_ds)
 188 #define ES_sig(context)      ((context)->tf_es)
 189 #define SS_sig(context)      ((context)->tf_ss)
 190
 191 #define EFL_sig(context)     ((context)->tf_eflags)
 192
 193 #define EIP_sig(context)     (*((unsigned long*)&(context)->tf_eip))
 194 #define ESP_sig(context)     (*((unsigned long*)&(context)->tf_esp))
 195
 196 #define FPU_sig(context)     NULL  /* FIXME */
 197 #define FPUX_sig(context)    NULL  /* FIXME */
 198
 199 #endif /* bsdi */
 200
 201 #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
 202
 203 typedef struct sigcontext SIGCONTEXT;
 204
 205 #define EAX_sig(context)     ((context)->sc_eax)
 206 #define EBX_sig(context)     ((context)->sc_ebx)
 207 #define ECX_sig(context)     ((context)->sc_ecx)
 208 #define EDX_sig(context)     ((context)->sc_edx)
 209 #define ESI_sig(context)     ((context)->sc_esi)
 210 #define EDI_sig(context)     ((context)->sc_edi)
 211 #define EBP_sig(context)     ((context)->sc_ebp)
 212
 213 #define CS_sig(context)      ((context)->sc_cs)
 214 #define DS_sig(context)      ((context)->sc_ds)
 215 #define ES_sig(context)      ((context)->sc_es)
 216 #define FS_sig(context)      ((context)->sc_fs)
 217 #define GS_sig(context)      ((context)->sc_gs)
 218 #define SS_sig(context)      ((context)->sc_ss)
 219
 220 #define TRAP_sig(context)    ((context)->sc_trapno)
 221 #define ERROR_sig(context)   ((context)->sc_err)
 222 #define EFL_sig(context)     ((context)->sc_eflags)
 223
 224 #define EIP_sig(context)     ((context)->sc_eip)
 225 #define ESP_sig(context)     ((context)->sc_esp)
 226
 227 #define FPU_sig(context)     NULL  /* FIXME */
 228 #define FPUX_sig(context)    NULL  /* FIXME */
 229
 230 #endif  /* *BSD */
 231
 232 #if defined(__svr4__) || defined(_SCO_DS) || defined(__sun)
 233
 234 #ifdef _SCO_DS
 235 #include <sys/regset.h>
 236 #endif
 237 #include <sys/ucontext.h>
 238 typedef struct ucontext SIGCONTEXT;
 239
 240 #ifdef _SCO_DS
 241 #define gregs regs
 242 #endif
 243
 244 #define EAX_sig(context)     ((context)->uc_mcontext.gregs[EAX])
 245 #define EBX_sig(context)     ((context)->uc_mcontext.gregs[EBX])
 246 #define ECX_sig(context)     ((context)->uc_mcontext.gregs[ECX])
 247 #define EDX_sig(context)     ((context)->uc_mcontext.gregs[EDX])
 248 #define ESI_sig(context)     ((context)->uc_mcontext.gregs[ESI])
 249 #define EDI_sig(context)     ((context)->uc_mcontext.gregs[EDI])
 250 #define EBP_sig(context)     ((context)->uc_mcontext.gregs[EBP])
 251
 252 #define CS_sig(context)      ((context)->uc_mcontext.gregs[CS])
 253 #define DS_sig(context)      ((context)->uc_mcontext.gregs[DS])
 254 #define ES_sig(context)      ((context)->uc_mcontext.gregs[ES])
 255 #define SS_sig(context)      ((context)->uc_mcontext.gregs[SS])
 256
 257 #define FS_sig(context)      ((context)->uc_mcontext.gregs[FS])
 258 #define GS_sig(context)      ((context)->uc_mcontext.gregs[GS])
 259
 260 #define EFL_sig(context)     ((context)->uc_mcontext.gregs[EFL])
 261
 262 #define EIP_sig(context)     ((context)->uc_mcontext.gregs[EIP])
 263 #ifdef UESP
 264 #define ESP_sig(context)     ((context)->uc_mcontext.gregs[UESP])
 265 #elif defined(R_ESP)
 266 #define ESP_sig(context)     ((context)->uc_mcontext.gregs[R_ESP])
 267 #else
 268 #define ESP_sig(context)     ((context)->uc_mcontext.gregs[ESP])
 269 #endif
 270 #ifdef ERR
 271 #define ERROR_sig(context)   ((context)->uc_mcontext.gregs[ERR])
 272 #endif
 273 #ifdef TRAPNO
 274 #define TRAP_sig(context)     ((context)->uc_mcontext.gregs[TRAPNO])
 275 #endif
 276
 277 #define FPU_sig(context)     NULL  /* FIXME */
 278 #define FPUX_sig(context)    NULL  /* FIXME */
 279
 280 #endif  /* svr4 || SCO_DS */
 281
 282 #ifdef __APPLE__
 283 # include <sys/ucontext.h>
 284
 285 typedef ucontext_t SIGCONTEXT;
 286
 287 /* work around silly renaming of struct members in OS X 10.5 */
 288 #if __DARWIN_UNIX03 && defined(_STRUCT_X86_EXCEPTION_STATE32)
 289 #define EAX_sig(context)     ((context)->uc_mcontext->__ss.__eax)
 290 #define EBX_sig(context)     ((context)->uc_mcontext->__ss.__ebx)
 291 #define ECX_sig(context)     ((context)->uc_mcontext->__ss.__ecx)
 292 #define EDX_sig(context)     ((context)->uc_mcontext->__ss.__edx)
 293 #define ESI_sig(context)     ((context)->uc_mcontext->__ss.__esi)
 294 #define EDI_sig(context)     ((context)->uc_mcontext->__ss.__edi)
 295 #define EBP_sig(context)     ((context)->uc_mcontext->__ss.__ebp)
 296 #define CS_sig(context)      ((context)->uc_mcontext->__ss.__cs)
 297 #define DS_sig(context)      ((context)->uc_mcontext->__ss.__ds)
 298 #define ES_sig(context)      ((context)->uc_mcontext->__ss.__es)
 299 #define FS_sig(context)      ((context)->uc_mcontext->__ss.__fs)
 300 #define GS_sig(context)      ((context)->uc_mcontext->__ss.__gs)
 301 #define SS_sig(context)      ((context)->uc_mcontext->__ss.__ss)
 302 #define EFL_sig(context)     ((context)->uc_mcontext->__ss.__eflags)
 303 #define EIP_sig(context)     (*((unsigned long*)&(context)->uc_mcontext->__ss.__eip))
 304 #define ESP_sig(context)     (*((unsigned long*)&(context)->uc_mcontext->__ss.__esp))
 305 #define TRAP_sig(context)    ((context)->uc_mcontext->__es.__trapno)
 306 #define ERROR_sig(context)   ((context)->uc_mcontext->__es.__err)
 307 #define FPU_sig(context)     NULL
 308 #define FPUX_sig(context)    ((XMM_SAVE_AREA32 *)&(context)->uc_mcontext->__fs.__fpu_fcw)
 309 #else
 310 #define EAX_sig(context)     ((context)->uc_mcontext->ss.eax)
 311 #define EBX_sig(context)     ((context)->uc_mcontext->ss.ebx)
 312 #define ECX_sig(context)     ((context)->uc_mcontext->ss.ecx)
 313 #define EDX_sig(context)     ((context)->uc_mcontext->ss.edx)
 314 #define ESI_sig(context)     ((context)->uc_mcontext->ss.esi)
 315 #define EDI_sig(context)     ((context)->uc_mcontext->ss.edi)
 316 #define EBP_sig(context)     ((context)->uc_mcontext->ss.ebp)
 317 #define CS_sig(context)      ((context)->uc_mcontext->ss.cs)
 318 #define DS_sig(context)      ((context)->uc_mcontext->ss.ds)
 319 #define ES_sig(context)      ((context)->uc_mcontext->ss.es)
 320 #define FS_sig(context)      ((context)->uc_mcontext->ss.fs)
 321 #define GS_sig(context)      ((context)->uc_mcontext->ss.gs)
 322 #define SS_sig(context)      ((context)->uc_mcontext->ss.ss)
 323 #define EFL_sig(context)     ((context)->uc_mcontext->ss.eflags)
 324 #define EIP_sig(context)     (*((unsigned long*)&(context)->uc_mcontext->ss.eip))
 325 #define ESP_sig(context)     (*((unsigned long*)&(context)->uc_mcontext->ss.esp))
 326 #define TRAP_sig(context)    ((context)->uc_mcontext->es.trapno)
 327 #define ERROR_sig(context)   ((context)->uc_mcontext->es.err)
 328 #define FPU_sig(context)     NULL
 329 #define FPUX_sig(context)    ((XMM_SAVE_AREA32 *)&(context)->uc_mcontext->fs.fpu_fcw)
 330 #endif
 331
 332 #endif /* __APPLE__ */
 333
 334 WINE_DEFAULT_DEBUG_CHANNEL(seh);
 335
 336 typedef int (*wine_signal_handler)(unsigned int sig);
 337
 338 static size_t signal_stack_mask;
 339 static size_t signal_stack_size;
 340
 341 static wine_signal_handler handlers[256];
 342
 343 static int fpux_support;  /* whether the CPU support extended fpu context */
 344
 345 extern void DECLSPEC_NORETURN __wine_call_from_32_restore_regs( const CONTEXT *context );
 346
 347 enum i386_trap_code
 348 {
 349     TRAP_x86_UNKNOWN    = -1,  /* Unknown fault (TRAP_sig not defined) */
 350 #if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
 351     TRAP_x86_DIVIDE     = T_DIVIDE,     /* Division by zero exception */
 352     TRAP_x86_TRCTRAP    = T_TRCTRAP,    /* Single-step exception */
 353     TRAP_x86_NMI        = T_NMI,        /* NMI interrupt */
 354     TRAP_x86_BPTFLT     = T_BPTFLT,     /* Breakpoint exception */
 355     TRAP_x86_OFLOW      = T_OFLOW,      /* Overflow exception */
 356     TRAP_x86_BOUND      = T_BOUND,      /* Bound range exception */
 357     TRAP_x86_PRIVINFLT  = T_PRIVINFLT,  /* Invalid opcode exception */
 358     TRAP_x86_DNA        = T_DNA,        /* Device not available exception */
 359     TRAP_x86_DOUBLEFLT  = T_DOUBLEFLT,  /* Double fault exception */
 360     TRAP_x86_FPOPFLT    = T_FPOPFLT,    /* Coprocessor segment overrun */
 361     TRAP_x86_TSSFLT     = T_TSSFLT,     /* Invalid TSS exception */
 362     TRAP_x86_SEGNPFLT   = T_SEGNPFLT,   /* Segment not present exception */
 363     TRAP_x86_STKFLT     = T_STKFLT,     /* Stack fault */
 364     TRAP_x86_PROTFLT    = T_PROTFLT,    /* General protection fault */
 365     TRAP_x86_PAGEFLT    = T_PAGEFLT,    /* Page fault */
 366     TRAP_x86_ARITHTRAP  = T_ARITHTRAP,  /* Floating point exception */
 367     TRAP_x86_ALIGNFLT   = T_ALIGNFLT,   /* Alignment check exception */
 368     TRAP_x86_MCHK       = T_MCHK,       /* Machine check exception */
 369     TRAP_x86_CACHEFLT   = T_XMMFLT      /* Cache flush exception */
 370 #else
 371     TRAP_x86_DIVIDE     = 0,   /* Division by zero exception */
 372     TRAP_x86_TRCTRAP    = 1,   /* Single-step exception */
 373     TRAP_x86_NMI        = 2,   /* NMI interrupt */
 374     TRAP_x86_BPTFLT     = 3,   /* Breakpoint exception */
 375     TRAP_x86_OFLOW      = 4,   /* Overflow exception */
 376     TRAP_x86_BOUND      = 5,   /* Bound range exception */
 377     TRAP_x86_PRIVINFLT  = 6,   /* Invalid opcode exception */
 378     TRAP_x86_DNA        = 7,   /* Device not available exception */
 379     TRAP_x86_DOUBLEFLT  = 8,   /* Double fault exception */
 380     TRAP_x86_FPOPFLT    = 9,   /* Coprocessor segment overrun */
 381     TRAP_x86_TSSFLT     = 10,  /* Invalid TSS exception */
 382     TRAP_x86_SEGNPFLT   = 11,  /* Segment not present exception */
 383     TRAP_x86_STKFLT     = 12,  /* Stack fault */
 384     TRAP_x86_PROTFLT    = 13,  /* General protection fault */
 385     TRAP_x86_PAGEFLT    = 14,  /* Page fault */
 386     TRAP_x86_ARITHTRAP  = 16,  /* Floating point exception */
 387     TRAP_x86_ALIGNFLT   = 17,  /* Alignment check exception */
 388     TRAP_x86_MCHK       = 18,  /* Machine check exception */
 389     TRAP_x86_CACHEFLT   = 19   /* SIMD exception (via SIGFPE) if CPU is SSE capable
 390                                   otherwise Cache flush exception (via SIGSEV) */
 391 #endif
 392 };
 393
 394
 395 /***********************************************************************
 396  *           dispatch_signal
 397  */
 398 static inline int dispatch_signal(unsigned int sig)
 399 {
 400     if (handlers[sig] == NULL) return 0;
 401     return handlers[sig](sig);
 402 }
 403
 404
 405 /***********************************************************************
 406  *           get_trap_code
 407  *
 408  * Get the trap code for a signal.
 409  */
 410 static inline enum i386_trap_code get_trap_code( const SIGCONTEXT *sigcontext )
 411 {
 412 #ifdef TRAP_sig
 413     return TRAP_sig(sigcontext);
 414 #else
 415     return TRAP_x86_UNKNOWN;  /* unknown trap code */
 416 #endif
 417 }
 418
 419 /***********************************************************************
 420  *           get_error_code
 421  *
 422  * Get the error code for a signal.
 423  */
 424 static inline WORD get_error_code( const SIGCONTEXT *sigcontext )
 425 {
 426 #ifdef ERROR_sig
 427     return ERROR_sig(sigcontext);
 428 #else
 429     return 0;
 430 #endif
 431 }
 432
 433 /***********************************************************************
 434  *           get_signal_stack
 435  *
 436  * Get the base of the signal stack for the current thread.
 437  */
 438 static inline void *get_signal_stack(void)
 439 {
 440     return (char *)NtCurrentTeb() + 4096;
 441 }
 442
 443
 444 /***********************************************************************
 445  *           get_current_teb
 446  *
 447  * Get the current teb based on the stack pointer.
 448  */
 449 static inline TEB *get_current_teb(void)
 450 {
 451     unsigned long esp;
 452     __asm__("movl %%esp,%0" : "=g" (esp) );
 453     return (TEB *)(esp & ~signal_stack_mask);
 454 }
 455
 456
 457 #ifdef __HAVE_VM86
 458 /***********************************************************************
 459  *           save_vm86_context
 460  *
 461  * Set the register values from a vm86 structure.
 462  */
 463 static void save_vm86_context( CONTEXT *context, const struct vm86plus_struct *vm86 )
 464 {
 465     context->ContextFlags = CONTEXT_FULL;
 466     context->Eax    = vm86->regs.eax;
 467     context->Ebx    = vm86->regs.ebx;
 468     context->Ecx    = vm86->regs.ecx;
 469     context->Edx    = vm86->regs.edx;
 470     context->Esi    = vm86->regs.esi;
 471     context->Edi    = vm86->regs.edi;
 472     context->Esp    = vm86->regs.esp;
 473     context->Ebp    = vm86->regs.ebp;
 474     context->Eip    = vm86->regs.eip;
 475     context->SegCs  = vm86->regs.cs;
 476     context->SegDs  = vm86->regs.ds;
 477     context->SegEs  = vm86->regs.es;
 478     context->SegFs  = vm86->regs.fs;
 479     context->SegGs  = vm86->regs.gs;
 480     context->SegSs  = vm86->regs.ss;
 481     context->EFlags = vm86->regs.eflags;
 482 }
 483
 484
 485 /***********************************************************************
 486  *           restore_vm86_context
 487  *
 488  * Build a vm86 structure from the register values.
 489  */
 490 static void restore_vm86_context( const CONTEXT *context, struct vm86plus_struct *vm86 )
 491 {
 492     vm86->regs.eax    = context->Eax;
 493     vm86->regs.ebx    = context->Ebx;
 494     vm86->regs.ecx    = context->Ecx;
 495     vm86->regs.edx    = context->Edx;
 496     vm86->regs.esi    = context->Esi;
 497     vm86->regs.edi    = context->Edi;
 498     vm86->regs.esp    = context->Esp;
 499     vm86->regs.ebp    = context->Ebp;
 500     vm86->regs.eip    = context->Eip;
 501     vm86->regs.cs     = context->SegCs;
 502     vm86->regs.ds     = context->SegDs;
 503     vm86->regs.es     = context->SegEs;
 504     vm86->regs.fs     = context->SegFs;
 505     vm86->regs.gs     = context->SegGs;
 506     vm86->regs.ss     = context->SegSs;
 507     vm86->regs.eflags = context->EFlags;
 508 }
 509
 510
 511 /**********************************************************************
 512  *              merge_vm86_pending_flags
 513  *
 514  * Merges TEB.vm86_ptr and TEB.vm86_pending VIP flags and
 515  * raises exception if there are pending events and VIF flag
 516  * has been turned on.
 517  *
 518  * Called from __wine_enter_vm86 because vm86_enter
 519  * doesn't check for pending events.
 520  *
 521  * Called from raise_vm86_sti_exception to check for
 522  * pending events in a signal safe way.
 523  */
 524 static void merge_vm86_pending_flags( EXCEPTION_RECORD *rec )
 525 {
 526     BOOL check_pending = TRUE;
 527     struct vm86plus_struct *vm86 =
 528         (struct vm86plus_struct*)(ntdll_get_thread_data()->vm86_ptr);
 529
 530     /*
 531      * In order to prevent a race when SIGUSR2 occurs while
 532      * we are returning from exception handler, pending events
 533      * will be rechecked after each raised exception.
 534      */
 535     while (check_pending && NtCurrentTeb()->vm86_pending)
 536     {
 537         check_pending = FALSE;
 538         ntdll_get_thread_data()->vm86_ptr = NULL;
 539
 540         /*
 541          * If VIF is set, throw exception.
 542          * Note that SIGUSR2 may turn VIF flag off so
 543          * VIF check must occur only when TEB.vm86_ptr is NULL.
 544          */
 545         if (vm86->regs.eflags & VIF_MASK)
 546         {
 547             CONTEXT vcontext;
 548             save_vm86_context( &vcontext, vm86 );
 549
 550             rec->ExceptionCode    = EXCEPTION_VM86_STI;
 551             rec->ExceptionFlags   = EXCEPTION_CONTINUABLE;
 552             rec->ExceptionRecord  = NULL;
 553             rec->NumberParameters = 0;
 554             rec->ExceptionAddress = (LPVOID)vcontext.Eip;
 555
 556             vcontext.EFlags &= ~VIP_MASK;
 557             NtCurrentTeb()->vm86_pending = 0;
 558             __regs_RtlRaiseException( rec, &vcontext );
 559
 560             restore_vm86_context( &vcontext, vm86 );
 561             check_pending = TRUE;
 562         }
 563
 564         ntdll_get_thread_data()->vm86_ptr = vm86;
 565     }
 566
 567     /*
 568      * Merge VIP flags in a signal safe way. This requires
 569      * that the following operation compiles into atomic
 570      * instruction.
 571      */
 572     vm86->regs.eflags |= NtCurrentTeb()->vm86_pending;
 573 }
 574 #endif /* __HAVE_VM86 */
 575
 576
 577 typedef void (WINAPI *raise_func)( EXCEPTION_RECORD *rec, CONTEXT *context );
 578
 579
 580 /***********************************************************************
 581  *           init_handler
 582  *
 583  * Handler initialization when the full context is not needed.
 584  */
 585 static inline void *init_handler( const SIGCONTEXT *sigcontext, WORD *fs, WORD *gs )
 586 {
 587     void *stack = (void *)(ESP_sig(sigcontext) & ~3);
 588     TEB *teb = get_current_teb();
 589     struct ntdll_thread_data *thread_data = (struct ntdll_thread_data *)teb->SystemReserved2;
 590
 591     /* get %fs and %gs at time of the fault */
 592 #ifdef FS_sig
 593     *fs = LOWORD(FS_sig(sigcontext));
 594 #else
 595     *fs = wine_get_fs();
 596 #endif
 597 #ifdef GS_sig
 598     *gs = LOWORD(GS_sig(sigcontext));
 599 #else
 600     *gs = wine_get_gs();
 601 #endif
 602
 603     wine_set_fs( thread_data->fs );
 604
 605     /* now restore a proper %gs for the fault handler */
 606     if (!wine_ldt_is_system(CS_sig(sigcontext)) ||
 607         !wine_ldt_is_system(SS_sig(sigcontext)))  /* 16-bit mode */
 608     {
 609         /*
 610          * Win16 or DOS protected mode. Note that during switch
 611          * from 16-bit mode to linear mode, CS may be set to system
 612          * segment before FS is restored. Fortunately, in this case
 613          * SS is still non-system segment. This is why both CS and SS
 614          * are checked.
 615          */
 616         wine_set_gs( thread_data->gs );
 617         stack = teb->WOW32Reserved;
 618     }
 619 #ifdef __HAVE_VM86
 620     else if ((void *)EIP_sig(sigcontext) == vm86_return)  /* vm86 mode */
 621     {
 622         unsigned int *int_stack = stack;
 623         /* fetch the saved %gs from the stack */
 624         wine_set_gs( int_stack[0] );
 625     }
 626 #endif
 627     else  /* 32-bit mode */
 628     {
 629 #ifdef GS_sig
 630         wine_set_gs( GS_sig(sigcontext) );
 631 #endif
 632     }
 633     return stack;
 634 }
 635
 636
 637 /***********************************************************************
 638  *           save_fpu
 639  *
 640  * Save the thread FPU context.
 641  */
 642 static inline void save_fpu( CONTEXT *context )
 643 {
 644 #ifdef __GNUC__
 645     context->ContextFlags |= CONTEXT_FLOATING_POINT;
 646     __asm__ __volatile__( "fnsave %0; fwait" : "=m" (context->FloatSave) );
 647 #endif
 648 }
 649
 650
 651 /***********************************************************************
 652  *           save_fpux
 653  *
 654  * Save the thread FPU extended context.
 655  */
 656 static inline void save_fpux( CONTEXT *context )
 657 {
 658 #ifdef __GNUC__
 659     /* we have to enforce alignment by hand */
 660     char buffer[sizeof(XMM_SAVE_AREA32) + 16];
 661     XMM_SAVE_AREA32 *state = (XMM_SAVE_AREA32 *)(((ULONG_PTR)buffer + 15) & ~15);
 662
 663     __asm__ __volatile__( "fxsave %0" : "=m" (*state) );
 664     context->ContextFlags |= CONTEXT_EXTENDED_REGISTERS;
 665     memcpy( context->ExtendedRegisters, state, sizeof(*state) );
 666 #endif
 667 }
 668
 669
 670 /***********************************************************************
 671  *           restore_fpu
 672  *
 673  * Restore the FPU context to a sigcontext.
 674  */
 675 static inline void restore_fpu( const CONTEXT *context )
 676 {
 677     FLOATING_SAVE_AREA float_status = context->FloatSave;
 678     /* reset the current interrupt status */
 679     float_status.StatusWord &= float_status.ControlWord | 0xffffff80;
 680 #ifdef __GNUC__
 681     __asm__ __volatile__( "frstor %0; fwait" : : "m" (float_status) );
 682 #endif  /* __GNUC__ */
 683 }
 684
 685
 686 /***********************************************************************
 687  *           restore_fpux
 688  *
 689  * Restore the FPU extended context to a sigcontext.
 690  */
 691 static inline void restore_fpux( const CONTEXT *context )
 692 {
 693 #ifdef __GNUC__
 694     /* we have to enforce alignment by hand */
 695     char buffer[sizeof(XMM_SAVE_AREA32) + 16];
 696     XMM_SAVE_AREA32 *state = (XMM_SAVE_AREA32 *)(((ULONG_PTR)buffer + 15) & ~15);
 697
 698     memcpy( state, context->ExtendedRegisters, sizeof(*state) );
 699     /* reset the current interrupt status */
 700     state->StatusWord &= state->ControlWord | 0xff80;
 701     __asm__ __volatile__( "fxrstor %0" : : "m" (*state) );
 702 #endif
 703 }
 704
 705
 706 /***********************************************************************
 707  *           fpux_to_fpu
 708  *
 709  * Build a standard FPU context from an extended one.
 710  */
 711 static void fpux_to_fpu( FLOATING_SAVE_AREA *fpu, const XMM_SAVE_AREA32 *fpux )
 712 {
 713     unsigned int i, tag, stack_top;
 714
 715     fpu->ControlWord   = fpux->ControlWord | 0xffff0000;
 716     fpu->StatusWord    = fpux->StatusWord | 0xffff0000;
 717     fpu->ErrorOffset   = fpux->ErrorOffset;
 718     fpu->ErrorSelector = fpux->ErrorSelector | (fpux->ErrorOpcode << 16);
 719     fpu->DataOffset    = fpux->DataOffset;
 720     fpu->DataSelector  = fpux->DataSelector;
 721     fpu->Cr0NpxState   = fpux->StatusWord | 0xffff0000;
 722
 723     stack_top = (fpux->StatusWord >> 11) & 7;
 724     fpu->TagWord = 0xffff0000;
 725     for (i = 0; i < 8; i++)
 726     {
 727         memcpy( &fpu->RegisterArea[10 * i], &fpux->FloatRegisters[i], 10 );
 728         if (!(fpux->TagWord & (1 << i))) tag = 3;  /* empty */
 729         else
 730         {
 731             const M128A *reg = &fpux->FloatRegisters[(i - stack_top) & 7];
 732             if ((reg->High & 0x7fff) == 0x7fff)  /* exponent all ones */
 733             {
 734                 tag = 2;  /* special */
 735             }
 736             else if (!(reg->High & 0x7fff))  /* exponent all zeroes */
 737             {
 738                 if (reg->Low) tag = 2;  /* special */
 739                 else tag = 1;  /* zero */
 740             }
 741             else
 742             {
 743                 if (reg->Low >> 63) tag = 0;  /* valid */
 744                 else tag = 2;  /* special */
 745             }
 746         }
 747         fpu->TagWord |= tag << (2 * i);
 748     }
 749 }
 750
 751
 752 /***********************************************************************
 753  *           save_context
 754  *
 755  * Build a context structure from the signal info.
 756  */
 757 static inline void save_context( CONTEXT *context, const SIGCONTEXT *sigcontext, WORD fs, WORD gs )
 758 {
 759     struct ntdll_thread_regs * const regs = ntdll_get_thread_regs();
 760     FLOATING_SAVE_AREA *fpu = FPU_sig(sigcontext);
 761     XMM_SAVE_AREA32 *fpux = FPUX_sig(sigcontext);
 762
 763     memset(context, 0, sizeof(*context));
 764     context->ContextFlags = CONTEXT_FULL | CONTEXT_DEBUG_REGISTERS;
 765     context->Eax          = EAX_sig(sigcontext);
 766     context->Ebx          = EBX_sig(sigcontext);
 767     context->Ecx          = ECX_sig(sigcontext);
 768     context->Edx          = EDX_sig(sigcontext);
 769     context->Esi          = ESI_sig(sigcontext);
 770     context->Edi          = EDI_sig(sigcontext);
 771     context->Ebp          = EBP_sig(sigcontext);
 772     context->EFlags       = EFL_sig(sigcontext);
 773     context->Eip          = EIP_sig(sigcontext);
 774     context->Esp          = ESP_sig(sigcontext);
 775     context->SegCs        = LOWORD(CS_sig(sigcontext));
 776     context->SegDs        = LOWORD(DS_sig(sigcontext));
 777     context->SegEs        = LOWORD(ES_sig(sigcontext));
 778     context->SegFs        = fs;
 779     context->SegGs        = gs;
 780     context->SegSs        = LOWORD(SS_sig(sigcontext));
 781     context->Dr0          = regs->dr0;
 782     context->Dr1          = regs->dr1;
 783     context->Dr2          = regs->dr2;
 784     context->Dr3          = regs->dr3;
 785     context->Dr6          = regs->dr6;
 786     context->Dr7          = regs->dr7;
 787
 788     if (fpu)
 789     {
 790         context->ContextFlags |= CONTEXT_FLOATING_POINT;
 791         context->FloatSave = *fpu;
 792     }
 793     if (fpux)
 794     {
 795         context->ContextFlags |= CONTEXT_FLOATING_POINT | CONTEXT_EXTENDED_REGISTERS;
 796         memcpy( context->ExtendedRegisters, fpux, sizeof(*fpux) );
 797         fpux_support = 1;
 798         if (!fpu) fpux_to_fpu( &context->FloatSave, fpux );
 799     }
 800     if (!fpu && !fpux) save_fpu( context );
 801 }
 802
 803
 804 /***********************************************************************
 805  *           restore_context
 806  *
 807  * Restore the signal info from the context.
 808  */
 809 static inline void restore_context( const CONTEXT *context, SIGCONTEXT *sigcontext )
 810 {
 811     struct ntdll_thread_regs * const regs = ntdll_get_thread_regs();
 812     FLOATING_SAVE_AREA *fpu = FPU_sig(sigcontext);
 813     XMM_SAVE_AREA32 *fpux = FPUX_sig(sigcontext);
 814
 815     regs->dr0 = context->Dr0;
 816     regs->dr1 = context->Dr1;
 817     regs->dr2 = context->Dr2;
 818     regs->dr3 = context->Dr3;
 819     regs->dr6 = context->Dr6;
 820     regs->dr7 = context->Dr7;
 821     EAX_sig(sigcontext) = context->Eax;
 822     EBX_sig(sigcontext) = context->Ebx;
 823     ECX_sig(sigcontext) = context->Ecx;
 824     EDX_sig(sigcontext) = context->Edx;
 825     ESI_sig(sigcontext) = context->Esi;
 826     EDI_sig(sigcontext) = context->Edi;
 827     EBP_sig(sigcontext) = context->Ebp;
 828     EFL_sig(sigcontext) = context->EFlags;
 829     EIP_sig(sigcontext) = context->Eip;
 830     ESP_sig(sigcontext) = context->Esp;
 831     CS_sig(sigcontext)  = context->SegCs;
 832     DS_sig(sigcontext)  = context->SegDs;
 833     ES_sig(sigcontext)  = context->SegEs;
 834     SS_sig(sigcontext)  = context->SegSs;
 835 #ifdef GS_sig
 836     GS_sig(sigcontext)  = context->SegGs;
 837 #else
 838     wine_set_gs( context->SegGs );
 839 #endif
 840 #ifdef FS_sig
 841     FS_sig(sigcontext)  = context->SegFs;
 842 #else
 843     wine_set_fs( context->SegFs );
 844 #endif
 845
 846     if (fpu) *fpu = context->FloatSave;
 847     if (fpux) memcpy( fpux, context->ExtendedRegisters, sizeof(*fpux) );
 848     if (!fpu && !fpux) restore_fpu( context );
 849 }
 850
 851
 852 /***********************************************************************
 853  *              get_cpu_context
 854  *
 855  * Register function to get the context of the current thread.
 856  */
 857 void WINAPI __regs_get_cpu_context( CONTEXT *context, CONTEXT *regs )
 858 {
 859     *context = *regs;
 860     if (fpux_support) save_fpux( context );
 861     else save_fpu( context );
 862 }
 863 DEFINE_REGS_ENTRYPOINT( get_cpu_context, 4, 4 )
 864
 865
 866 /***********************************************************************
 867  *           set_cpu_context
 868  *
 869  * Set the new CPU context. Used by NtSetContextThread.
 870  */
 871 void set_cpu_context( const CONTEXT *context )
 872 {
 873     DWORD flags = context->ContextFlags & ~CONTEXT_i386;
 874
 875     if ((flags & CONTEXT_EXTENDED_REGISTERS) && fpux_support) restore_fpux( context );
 876     else if (flags & CONTEXT_FLOATING_POINT) restore_fpu( context );
 877
 878     if (flags & CONTEXT_DEBUG_REGISTERS)
 879     {
 880         struct ntdll_thread_regs * const regs = ntdll_get_thread_regs();
 881         regs->dr0 = context->Dr0;
 882         regs->dr1 = context->Dr1;
 883         regs->dr2 = context->Dr2;
 884         regs->dr3 = context->Dr3;
 885         regs->dr6 = context->Dr6;
 886         regs->dr7 = context->Dr7;
 887     }
 888     if (flags & CONTEXT_FULL)
 889     {
 890         if (!(flags & CONTEXT_CONTROL))
 891             FIXME( "setting partial context (%x) not supported\n", flags );
 892         else if (flags & CONTEXT_SEGMENTS)
 893             __wine_call_from_32_restore_regs( context );
 894         else
 895         {
 896             CONTEXT newcontext = *context;
 897             newcontext.SegDs = wine_get_ds();
 898             newcontext.SegEs = wine_get_es();
 899             newcontext.SegFs = wine_get_fs();
 900             newcontext.SegGs = wine_get_gs();
 901             __wine_call_from_32_restore_regs( &newcontext );
 902         }
 903     }
 904 }
 905
 906
 907 /***********************************************************************
 908  *           is_privileged_instr
 909  *
 910  * Check if the fault location is a privileged instruction.
 911  * Based on the instruction emulation code in dlls/kernel/instr.c.
 912  */
 913 static inline DWORD is_privileged_instr( CONTEXT86 *context )
 914 {
 915     const BYTE *instr;
 916     unsigned int prefix_count = 0;
 917
 918     if (!wine_ldt_is_system( context->SegCs )) return 0;
 919     instr = (BYTE *)context->Eip;
 920
 921     for (;;) switch(*instr)
 922     {
 923     /* instruction prefixes */
 924     case 0x2e:  /* %cs: */
 925     case 0x36:  /* %ss: */
 926     case 0x3e:  /* %ds: */
 927     case 0x26:  /* %es: */
 928     case 0x64:  /* %fs: */
 929     case 0x65:  /* %gs: */
 930     case 0x66:  /* opcode size */
 931     case 0x67:  /* addr size */
 932     case 0xf0:  /* lock */
 933     case 0xf2:  /* repne */
 934     case 0xf3:  /* repe */
 935         if (++prefix_count >= 15) return EXCEPTION_ILLEGAL_INSTRUCTION;
 936         instr++;
 937         continue;
 938
 939     case 0x0f: /* extended instruction */
 940         switch(instr[1])
 941         {
 942         case 0x20: /* mov crX, reg */
 943         case 0x21: /* mov drX, reg */
 944         case 0x22: /* mov reg, crX */
 945         case 0x23: /* mov reg drX */
 946             return EXCEPTION_PRIV_INSTRUCTION;
 947         }
 948         return 0;
 949     case 0x6c: /* insb (%dx) */
 950     case 0x6d: /* insl (%dx) */
 951     case 0x6e: /* outsb (%dx) */
 952     case 0x6f: /* outsl (%dx) */
 953     case 0xcd: /* int $xx */
 954     case 0xe4: /* inb al,XX */
 955     case 0xe5: /* in (e)ax,XX */
 956     case 0xe6: /* outb XX,al */
 957     case 0xe7: /* out XX,(e)ax */
 958     case 0xec: /* inb (%dx),%al */
 959     case 0xed: /* inl (%dx),%eax */
 960     case 0xee: /* outb %al,(%dx) */
 961     case 0xef: /* outl %eax,(%dx) */
 962     case 0xf4: /* hlt */
 963     case 0xfa: /* cli */
 964     case 0xfb: /* sti */
 965         return EXCEPTION_PRIV_INSTRUCTION;
 966     default:
 967         return 0;
 968     }
 969 }
 970
 971
 972 #include "pshpack1.h"
 973 struct atl_thunk
 974 {
 975     DWORD movl;  /* movl this,4(%esp) */
 976     DWORD this;
 977     BYTE  jmp;   /* jmp func */
 978     int   func;
 979 };
 980 #include "poppack.h"
 981
 982 /**********************************************************************
 983  *              check_atl_thunk
 984  *
 985  * Check if code destination is an ATL thunk, and emulate it if so.
 986  */
 987 static BOOL check_atl_thunk( EXCEPTION_RECORD *rec, CONTEXT *context )
 988 {
 989     const struct atl_thunk *thunk = (const struct atl_thunk *)rec->ExceptionInformation[1];
 990     BOOL ret = FALSE;
 991
 992     __TRY
 993     {
 994         if (thunk->movl == 0x042444c7 && thunk->jmp == 0xe9)
 995         {
 996             *((DWORD *)context->Esp + 1) = thunk->this;
 997             context->Eip = (DWORD_PTR)(&thunk->func + 1) + thunk->func;
 998             TRACE( "emulating ATL thunk at %p, func=%08x arg=%08x\n",
 999                    thunk, context->Eip, *((DWORD *)context->Esp + 1) );
1000             ret = TRUE;
1001         }
1002     }
1003     __EXCEPT_PAGE_FAULT
1004     {
1005         return FALSE;
1006     }
1007     __ENDTRY
1008     return ret;
1009 }
1010
1011
1012 /***********************************************************************
1013  *           setup_exception
1014  *
1015  * Setup a proper stack frame for the raise function, and modify the
1016  * sigcontext so that the return from the signal handler will call
1017  * the raise function.
1018  */
1019 static EXCEPTION_RECORD *setup_exception( SIGCONTEXT *sigcontext, raise_func func )
1020 {
1021     struct stack_layout
1022     {
1023         void             *ret_addr;      /* return address from raise_func */
1024         EXCEPTION_RECORD *rec_ptr;       /* first arg for raise_func */
1025         CONTEXT          *context_ptr;   /* second arg for raise_func */
1026         CONTEXT           context;
1027         EXCEPTION_RECORD  rec;
1028         DWORD             ebp;
1029         DWORD             eip;
1030     } *stack;
1031
1032     WORD fs, gs;
1033
1034     stack = init_handler( sigcontext, &fs, &gs );
1035
1036     /* stack sanity checks */
1037
1038     if ((char *)stack >= (char *)get_signal_stack() &&
1039         (char *)stack < (char *)get_signal_stack() + signal_stack_size)
1040     {
1041         WINE_ERR( "nested exception on signal stack in thread %04x eip %08x esp %08x stack %p-%p\n",
1042                   GetCurrentThreadId(), (unsigned int) EIP_sig(sigcontext),
1043                   (unsigned int) ESP_sig(sigcontext), NtCurrentTeb()->Tib.StackLimit,
1044                   NtCurrentTeb()->Tib.StackBase );
1045         server_abort_thread(1);
1046     }
1047
1048     if (stack - 1 > stack || /* check for overflow in subtraction */
1049         (char *)(stack - 1) < (char *)NtCurrentTeb()->Tib.StackLimit ||
1050         (char *)stack > (char *)NtCurrentTeb()->Tib.StackBase)
1051     {
1052         UINT diff = (char *)NtCurrentTeb()->Tib.StackLimit - (char *)stack;
1053         if (diff < 4096)
1054         {
1055             WINE_ERR( "stack overflow %u bytes in thread %04x eip %08x esp %08x stack %p-%p\n",
1056                       diff, GetCurrentThreadId(), (unsigned int) EIP_sig(sigcontext),
1057                       (unsigned int) ESP_sig(sigcontext), NtCurrentTeb()->Tib.StackLimit,
1058                       NtCurrentTeb()->Tib.StackBase );
1059             server_abort_thread(1);
1060         }
1061         else WARN( "exception outside of stack limits in thread %04x eip %08x esp %08x stack %p-%p\n",
1062                    GetCurrentThreadId(), (unsigned int) EIP_sig(sigcontext),
1063                    (unsigned int) ESP_sig(sigcontext), NtCurrentTeb()->Tib.StackLimit,
1064                    NtCurrentTeb()->Tib.StackBase );
1065     }
1066
1067     stack--;  /* push the stack_layout structure */
1068 #if defined(VALGRIND_MAKE_MEM_UNDEFINED)
1069     VALGRIND_MAKE_MEM_UNDEFINED(stack, sizeof(*stack));
1070 #elif defined(VALGRIND_MAKE_WRITABLE)
1071     VALGRIND_MAKE_WRITABLE(stack, sizeof(*stack));
1072 #endif
1073     stack->ret_addr     = (void *)0xdeadbabe;  /* raise_func must not return */
1074     stack->rec_ptr      = &stack->rec;
1075     stack->context_ptr  = &stack->context;
1076
1077     stack->rec.ExceptionRecord  = NULL;
1078     stack->rec.ExceptionFlags   = EXCEPTION_CONTINUABLE;
1079     stack->rec.ExceptionAddress = (LPVOID)EIP_sig(sigcontext);
1080     stack->rec.NumberParameters = 0;
1081
1082     save_context( &stack->context, sigcontext, fs, gs );
1083
1084     /* now modify the sigcontext to return to the raise function */
1085     ESP_sig(sigcontext) = (DWORD)stack;
1086     EIP_sig(sigcontext) = (DWORD)func;
1087     /* clear single-step and align check flag */
1088     EFL_sig(sigcontext) &= ~(0x100|0x40000);
1089     CS_sig(sigcontext)  = wine_get_cs();
1090     DS_sig(sigcontext)  = wine_get_ds();
1091     ES_sig(sigcontext)  = wine_get_es();
1092     FS_sig(sigcontext)  = wine_get_fs();
1093     GS_sig(sigcontext)  = wine_get_gs();
1094     SS_sig(sigcontext)  = wine_get_ss();
1095
1096     return stack->rec_ptr;
1097 }
1098
1099
1100 /***********************************************************************
1101  *           get_exception_context
1102  *
1103  * Get a pointer to the context built by setup_exception.
1104  */
1105 static inline CONTEXT *get_exception_context( EXCEPTION_RECORD *rec )
1106 {
1107     return (CONTEXT *)rec - 1;  /* cf. stack_layout structure */
1108 }
1109
1110
1111 /**********************************************************************
1112  *              get_fpu_code
1113  *
1114  * Get the FPU exception code from the FPU status.
1115  */
1116 static inline DWORD get_fpu_code( const CONTEXT *context )
1117 {
1118     DWORD status = context->FloatSave.StatusWord;
1119
1120     if (status & 0x01)  /* IE */
1121     {
1122         if (status & 0x40)  /* SF */
1123             return EXCEPTION_FLT_STACK_CHECK;
1124         else
1125             return EXCEPTION_FLT_INVALID_OPERATION;
1126     }
1127     if (status & 0x02) return EXCEPTION_FLT_DENORMAL_OPERAND;  /* DE flag */
1128     if (status & 0x04) return EXCEPTION_FLT_DIVIDE_BY_ZERO;    /* ZE flag */
1129     if (status & 0x08) return EXCEPTION_FLT_OVERFLOW;          /* OE flag */
1130     if (status & 0x10) return EXCEPTION_FLT_UNDERFLOW;         /* UE flag */
1131     if (status & 0x20) return EXCEPTION_FLT_INEXACT_RESULT;    /* PE flag */
1132     return EXCEPTION_FLT_INVALID_OPERATION;  /* generic error */
1133 }
1134
1135
1136 /**********************************************************************
1137  *              raise_segv_exception
1138  */
1139 static void WINAPI raise_segv_exception( EXCEPTION_RECORD *rec, CONTEXT *context )
1140 {
1141     switch(rec->ExceptionCode)
1142     {
1143     case EXCEPTION_ACCESS_VIOLATION:
1144         if (rec->NumberParameters == 2)
1145         {
1146             if (rec->ExceptionInformation[0] == EXCEPTION_EXECUTE_FAULT && check_atl_thunk( rec, context ))
1147                 goto done;
1148             rec->ExceptionCode = VIRTUAL_HandleFault( (void *)rec->ExceptionInformation[1] );
1149         }
1150         break;
1151     case EXCEPTION_DATATYPE_MISALIGNMENT:
1152         /* FIXME: pass through exception handler first? */
1153         if (context->EFlags & 0x00040000)
1154         {
1155             /* Disable AC flag, return */
1156             context->EFlags &= ~0x00040000;
1157             goto done;
1158         }
1159         break;
1160     }
1161     __regs_RtlRaiseException( rec, context );
1162 done:
1163     NtSetContextThread( GetCurrentThread(), context );
1164 }
1165
1166
1167 /**********************************************************************
1168  *              raise_trap_exception
1169  */
1170 static void WINAPI raise_trap_exception( EXCEPTION_RECORD *rec, CONTEXT *context )
1171 {
1172     if (rec->ExceptionCode == EXCEPTION_SINGLE_STEP)
1173     {
1174         struct ntdll_thread_regs * const regs = ntdll_get_thread_regs();
1175
1176         /* when single stepping can't tell whether this is a hw bp or a
1177          * single step interrupt. try to avoid as much overhead as possible
1178          * and only do a server call if there is any hw bp enabled. */
1179
1180         if( !(context->EFlags & 0x100) || (regs->dr7 & 0xff) )
1181         {
1182             /* (possible) hardware breakpoint, fetch the debug registers */
1183             context->ContextFlags = CONTEXT_DEBUG_REGISTERS;
1184             NtGetContextThread(GetCurrentThread(), context);
1185             context->ContextFlags |= CONTEXT_FULL;  /* restore flags */
1186         }
1187
1188         context->EFlags &= ~0x100;  /* clear single-step flag */
1189     }
1190
1191     __regs_RtlRaiseException( rec, context );
1192     NtSetContextThread( GetCurrentThread(), context );
1193 }
1194
1195
1196 /**********************************************************************
1197  *              raise_exception
1198  *
1199  * Generic raise function for exceptions that don't need special treatment.
1200  */
1201 static void WINAPI raise_exception( EXCEPTION_RECORD *rec, CONTEXT *context )
1202 {
1203     __regs_RtlRaiseException( rec, context );
1204     NtSetContextThread( GetCurrentThread(), context );
1205 }
1206
1207
1208 #ifdef __HAVE_VM86
1209 /**********************************************************************
1210  *              raise_vm86_sti_exception
1211  */
1212 static void WINAPI raise_vm86_sti_exception( EXCEPTION_RECORD *rec, CONTEXT *context )
1213 {
1214     /* merge_vm86_pending_flags merges the vm86_pending flag in safely */
1215     NtCurrentTeb()->vm86_pending |= VIP_MASK;
1216
1217     if (ntdll_get_thread_data()->vm86_ptr)
1218     {
1219         if (((char*)context->Eip >= (char*)vm86_return) &&
1220             ((char*)context->Eip <= (char*)vm86_return_end) &&
1221             (VM86_TYPE(context->Eax) != VM86_SIGNAL)) {
1222             /* exiting from VM86, can't throw */
1223             goto done;
1224         }
1225         merge_vm86_pending_flags( rec );
1226     }
1227     else if (NtCurrentTeb()->dpmi_vif &&
1228              !wine_ldt_is_system(context->SegCs) &&
1229              !wine_ldt_is_system(context->SegSs))
1230     {
1231         /* Executing DPMI code and virtual interrupts are enabled. */
1232         NtCurrentTeb()->vm86_pending = 0;
1233         __regs_RtlRaiseException( rec, context );
1234     }
1235 done:
1236     NtSetContextThread( GetCurrentThread(), context );
1237 }
1238
1239
1240 /**********************************************************************
1241  *              usr2_handler
1242  *
1243  * Handler for SIGUSR2.
1244  * We use it to signal that the running __wine_enter_vm86() should
1245  * immediately set VIP_MASK, causing pending events to be handled
1246  * as early as possible.
1247  */
1248 static void usr2_handler( int signal, siginfo_t *siginfo, void *sigcontext )
1249 {
1250     EXCEPTION_RECORD *rec = setup_exception( sigcontext, raise_vm86_sti_exception );
1251     rec->ExceptionCode = EXCEPTION_VM86_STI;
1252 }
1253 #endif /* __HAVE_VM86 */
1254
1255
1256 /**********************************************************************
1257  *              segv_handler
1258  *
1259  * Handler for SIGSEGV and related errors.
1260  */
1261 static void segv_handler( int signal, siginfo_t *siginfo, void *sigcontext )
1262 {
1263     SIGCONTEXT *context = sigcontext;
1264     EXCEPTION_RECORD *rec = setup_exception( context, raise_segv_exception );
1265
1266     switch(get_trap_code(context))
1267     {
1268     case TRAP_x86_OFLOW:   /* Overflow exception */
1269         rec->ExceptionCode = EXCEPTION_INT_OVERFLOW;
1270         break;
1271     case TRAP_x86_BOUND:   /* Bound range exception */
1272         rec->ExceptionCode = EXCEPTION_ARRAY_BOUNDS_EXCEEDED;
1273         break;
1274     case TRAP_x86_PRIVINFLT:   /* Invalid opcode exception */
1275         rec->ExceptionCode = EXCEPTION_ILLEGAL_INSTRUCTION;
1276         break;
1277     case TRAP_x86_STKFLT:  /* Stack fault */
1278         rec->ExceptionCode = EXCEPTION_STACK_OVERFLOW;
1279         break;
1280     case TRAP_x86_SEGNPFLT:  /* Segment not present exception */
1281     case TRAP_x86_PROTFLT:   /* General protection fault */
1282     case TRAP_x86_UNKNOWN:   /* Unknown fault code */
1283         {
1284             WORD err = get_error_code(context);
1285             if (!err && (rec->ExceptionCode = is_privileged_instr( get_exception_context(rec) ))) break;
1286             rec->ExceptionCode = EXCEPTION_ACCESS_VIOLATION;
1287             rec->NumberParameters = 2;
1288             rec->ExceptionInformation[0] = 0;
1289             /* if error contains a LDT selector, use that as fault address */
1290             if ((err & 7) == 4 && !wine_ldt_is_system( err | 7 ))
1291                 rec->ExceptionInformation[1] = err & ~7;
1292             else
1293                 rec->ExceptionInformation[1] = 0xffffffff;
1294         }
1295         break;
1296     case TRAP_x86_PAGEFLT:  /* Page fault */
1297         rec->ExceptionCode = EXCEPTION_ACCESS_VIOLATION;
1298         rec->NumberParameters = 2;
1299         rec->ExceptionInformation[0] = (get_error_code(context) >> 1) & 0x09;
1300         rec->ExceptionInformation[1] = (ULONG_PTR)siginfo->si_addr;
1301         break;
1302     case TRAP_x86_ALIGNFLT:  /* Alignment check exception */
1303         rec->ExceptionCode = EXCEPTION_DATATYPE_MISALIGNMENT;
1304         break;
1305     default:
1306         WINE_ERR( "Got unexpected trap %d\n", get_trap_code(context) );
1307         /* fall through */
1308     case TRAP_x86_NMI:       /* NMI interrupt */
1309     case TRAP_x86_DNA:       /* Device not available exception */
1310     case TRAP_x86_DOUBLEFLT: /* Double fault exception */
1311     case TRAP_x86_TSSFLT:    /* Invalid TSS exception */
1312     case TRAP_x86_MCHK:      /* Machine check exception */
1313     case TRAP_x86_CACHEFLT:  /* Cache flush exception */
1314         rec->ExceptionCode = EXCEPTION_ILLEGAL_INSTRUCTION;
1315         break;
1316     }
1317 }
1318
1319
1320 /**********************************************************************
1321  *              trap_handler
1322  *
1323  * Handler for SIGTRAP.
1324  */
1325 static void trap_handler( int signal, siginfo_t *siginfo, void *sigcontext )
1326 {
1327     SIGCONTEXT *context = sigcontext;
1328     EXCEPTION_RECORD *rec = setup_exception( context, raise_trap_exception );
1329
1330     switch(get_trap_code(context))
1331     {
1332     case TRAP_x86_TRCTRAP:  /* Single-step exception */
1333         rec->ExceptionCode = EXCEPTION_SINGLE_STEP;
1334         break;
1335     case TRAP_x86_BPTFLT:   /* Breakpoint exception */
1336         rec->ExceptionAddress = (char *)rec->ExceptionAddress - 1;  /* back up over the int3 instruction */
1337         /* fall through */
1338     default:
1339         rec->ExceptionCode = EXCEPTION_BREAKPOINT;
1340         break;
1341     }
1342 }
1343
1344
1345 /**********************************************************************
1346  *              fpe_handler
1347  *
1348  * Handler for SIGFPE.
1349  */
1350 static void fpe_handler( int signal, siginfo_t *siginfo, void *sigcontext )
1351 {
1352     CONTEXT *win_context;
1353     SIGCONTEXT *context = sigcontext;
1354     EXCEPTION_RECORD *rec = setup_exception( context, raise_exception );
1355
1356     win_context = get_exception_context( rec );
1357
1358     switch(get_trap_code(context))
1359     {
1360     case TRAP_x86_DIVIDE:   /* Division by zero exception */
1361         rec->ExceptionCode = EXCEPTION_INT_DIVIDE_BY_ZERO;
1362         break;
1363     case TRAP_x86_FPOPFLT:   /* Coprocessor segment overrun */
1364         rec->ExceptionCode = EXCEPTION_FLT_INVALID_OPERATION;
1365         break;
1366     case TRAP_x86_ARITHTRAP:  /* Floating point exception */
1367     case TRAP_x86_UNKNOWN:    /* Unknown fault code */
1368         rec->ExceptionCode = get_fpu_code( win_context );
1369         break;
1370     case TRAP_x86_CACHEFLT:  /* SIMD exception */
1371         /* TODO:
1372          * Behaviour only tested for divide-by-zero exceptions
1373          * Check for other SIMD exceptions as well */
1374         if(siginfo->si_code != FPE_FLTDIV)
1375             FIXME("untested SIMD exception: %#x. Might not work correctly\n",
1376                   siginfo->si_code);
1377
1378         rec->ExceptionCode = STATUS_FLOAT_MULTIPLE_TRAPS;
1379         rec->NumberParameters = 1;
1380         /* no idea what meaning is actually behind this but that's what native does */
1381         rec->ExceptionInformation[0] = 0;
1382         break;
1383     default:
1384         WINE_ERR( "Got unexpected trap %d\n", get_trap_code(context) );
1385         rec->ExceptionCode = EXCEPTION_FLT_INVALID_OPERATION;
1386         break;
1387     }
1388 }
1389
1390
1391 /**********************************************************************
1392  *              int_handler
1393  *
1394  * Handler for SIGINT.
1395  *
1396  * FIXME: should not be calling external functions on the signal stack.
1397  */
1398 static void int_handler( int signal, siginfo_t *siginfo, void *sigcontext )
1399 {
1400     WORD fs, gs;
1401     init_handler( sigcontext, &fs, &gs );
1402     if (!dispatch_signal(SIGINT))
1403     {
1404         EXCEPTION_RECORD *rec = setup_exception( sigcontext, raise_exception );
1405         rec->ExceptionCode = CONTROL_C_EXIT;
1406     }
1407 }
1408
1409 /**********************************************************************
1410  *              abrt_handler
1411  *
1412  * Handler for SIGABRT.
1413  */
1414 static void abrt_handler( int signal, siginfo_t *siginfo, void *sigcontext )
1415 {
1416     EXCEPTION_RECORD *rec = setup_exception( sigcontext, raise_exception );
1417     rec->ExceptionCode  = EXCEPTION_WINE_ASSERTION;
1418     rec->ExceptionFlags = EH_NONCONTINUABLE;
1419 }
1420
1421
1422 /**********************************************************************
1423  *              quit_handler
1424  *
1425  * Handler for SIGQUIT.
1426  */
1427 static void quit_handler( int signal, siginfo_t *siginfo, void *sigcontext )
1428 {
1429     WORD fs, gs;
1430     init_handler( sigcontext, &fs, &gs );
1431     server_abort_thread(0);
1432 }
1433
1434
1435 /**********************************************************************
1436  *              usr1_handler
1437  *
1438  * Handler for SIGUSR1, used to signal a thread that it got suspended.
1439  */
1440 static void usr1_handler( int signal, siginfo_t *siginfo, void *sigcontext )
1441 {
1442     CONTEXT context;
1443     WORD fs, gs;
1444
1445     init_handler( sigcontext, &fs, &gs );
1446     save_context( &context, sigcontext, fs, gs );
1447     wait_suspend( &context );
1448     restore_context( &context, sigcontext );
1449 }
1450
1451
1452 /**********************************************************************
1453  *              get_signal_stack_total_size
1454  *
1455  * Retrieve the size to allocate for the signal stack, including the TEB at the bottom.
1456  * Must be a power of two.
1457  */
1458 size_t get_signal_stack_total_size(void)
1459 {
1460     static const size_t teb_size = 4096;  /* we reserve one page for the TEB */
1461
1462     if (!signal_stack_size)
1463     {
1464         size_t size = 8192, min_size = teb_size + max( MINSIGSTKSZ, 8192 );
1465         /* find the first power of two not smaller than min_size */
1466         while (size < min_size) size *= 2;
1467         signal_stack_mask = size - 1;
1468         signal_stack_size = size - teb_size;
1469     }
1470     return signal_stack_size + teb_size;
1471 }
1472
1473
1474 /***********************************************************************
1475  *           __wine_set_signal_handler   (NTDLL.@)
1476  */
1477 int __wine_set_signal_handler(unsigned int sig, wine_signal_handler wsh)
1478 {
1479     if (sig >= sizeof(handlers) / sizeof(handlers[0])) return -1;
1480     if (handlers[sig] != NULL) return -2;
1481     handlers[sig] = wsh;
1482     return 0;
1483 }
1484
1485
1486 /**********************************************************************
1487  *              SIGNAL_Init
1488  */
1489 BOOL SIGNAL_Init(void)
1490 {
1491     struct sigaction sig_act;
1492
1493 #ifdef HAVE_SIGALTSTACK
1494     stack_t ss;
1495
1496 #ifdef __APPLE__
1497     int mib[2], val = 1;
1498
1499     mib[0] = CTL_KERN;
1500     mib[1] = KERN_THALTSTACK;
1501     sysctl( mib, 2, NULL, NULL, &val, sizeof(val) );
1502 #endif
1503
1504     ss.ss_sp    = get_signal_stack();
1505     ss.ss_size  = signal_stack_size;
1506     ss.ss_flags = 0;
1507     if (sigaltstack(&ss, NULL) == -1)
1508     {
1509         perror( "sigaltstack" );
1510         return FALSE;
1511     }
1512 #endif  /* HAVE_SIGALTSTACK */
1513
1514     sig_act.sa_mask = server_block_set;
1515     sig_act.sa_flags = SA_SIGINFO | SA_RESTART;
1516 #ifdef SA_ONSTACK
1517     sig_act.sa_flags |= SA_ONSTACK;
1518 #endif
1519
1520     sig_act.sa_sigaction = int_handler;
1521     if (sigaction( SIGINT, &sig_act, NULL ) == -1) goto error;
1522     sig_act.sa_sigaction = fpe_handler;
1523     if (sigaction( SIGFPE, &sig_act, NULL ) == -1) goto error;
1524     sig_act.sa_sigaction = abrt_handler;
1525     if (sigaction( SIGABRT, &sig_act, NULL ) == -1) goto error;
1526     sig_act.sa_sigaction = quit_handler;
1527     if (sigaction( SIGQUIT, &sig_act, NULL ) == -1) goto error;
1528     sig_act.sa_sigaction = usr1_handler;
1529     if (sigaction( SIGUSR1, &sig_act, NULL ) == -1) goto error;
1530
1531     sig_act.sa_sigaction = segv_handler;
1532     if (sigaction( SIGSEGV, &sig_act, NULL ) == -1) goto error;
1533     if (sigaction( SIGILL, &sig_act, NULL ) == -1) goto error;
1534 #ifdef SIGBUS
1535     if (sigaction( SIGBUS, &sig_act, NULL ) == -1) goto error;
1536 #endif
1537
1538 #ifdef SIGTRAP
1539     sig_act.sa_sigaction = trap_handler;
1540     if (sigaction( SIGTRAP, &sig_act, NULL ) == -1) goto error;
1541 #endif
1542
1543 #ifdef __HAVE_VM86
1544     sig_act.sa_sigaction = usr2_handler;
1545     if (sigaction( SIGUSR2, &sig_act, NULL ) == -1) goto error;
1546 #endif
1547
1548     return TRUE;
1549
1550  error:
1551     perror("sigaction");
1552     return FALSE;
1553 }
1554
1555
1556 #ifdef __HAVE_VM86
1557 /**********************************************************************
1558  *              __wine_enter_vm86   (NTDLL.@)
1559  *
1560  * Enter vm86 mode with the specified register context.
1561  */
1562 void __wine_enter_vm86( CONTEXT *context )
1563 {
1564     EXCEPTION_RECORD rec;
1565     int res;
1566     struct vm86plus_struct vm86;
1567
1568     memset( &vm86, 0, sizeof(vm86) );
1569     for (;;)
1570     {
1571         restore_vm86_context( context, &vm86 );
1572
1573         ntdll_get_thread_data()->vm86_ptr = &vm86;
1574         merge_vm86_pending_flags( &rec );
1575
1576         res = vm86_enter( &ntdll_get_thread_data()->vm86_ptr ); /* uses and clears teb->vm86_ptr */
1577         if (res < 0)
1578         {
1579             errno = -res;
1580             return;
1581         }
1582
1583         save_vm86_context( context, &vm86 );
1584
1585         rec.ExceptionFlags   = EXCEPTION_CONTINUABLE;
1586         rec.ExceptionRecord  = NULL;
1587         rec.ExceptionAddress = (LPVOID)context->Eip;
1588         rec.NumberParameters = 0;
1589
1590         switch(VM86_TYPE(res))
1591         {
1592         case VM86_UNKNOWN: /* unhandled GP fault - IO-instruction or similar */
1593             rec.ExceptionCode = EXCEPTION_PRIV_INSTRUCTION;
1594             break;
1595         case VM86_TRAP: /* return due to DOS-debugger request */
1596             switch(VM86_ARG(res))
1597             {
1598             case TRAP_x86_TRCTRAP:  /* Single-step exception */
1599                 rec.ExceptionCode = EXCEPTION_SINGLE_STEP;
1600                 break;
1601             case TRAP_x86_BPTFLT:   /* Breakpoint exception */
1602                 rec.ExceptionAddress = (char *)rec.ExceptionAddress - 1;  /* back up over the int3 instruction */
1603                 /* fall through */
1604             default:
1605                 rec.ExceptionCode = EXCEPTION_BREAKPOINT;
1606                 break;
1607             }
1608             break;
1609         case VM86_INTx: /* int3/int x instruction (ARG = x) */
1610             rec.ExceptionCode = EXCEPTION_VM86_INTx;
1611             rec.NumberParameters = 1;
1612             rec.ExceptionInformation[0] = VM86_ARG(res);
1613             break;
1614         case VM86_STI: /* sti/popf/iret instruction enabled virtual interrupts */
1615             context->EFlags |= VIF_MASK;
1616             context->EFlags &= ~VIP_MASK;
1617             NtCurrentTeb()->vm86_pending = 0;
1618             rec.ExceptionCode = EXCEPTION_VM86_STI;
1619             break;
1620         case VM86_PICRETURN: /* return due to pending PIC request */
1621             rec.ExceptionCode = EXCEPTION_VM86_PICRETURN;
1622             break;
1623         case VM86_SIGNAL: /* cannot happen because vm86_enter handles this case */
1624         default:
1625             WINE_ERR( "unhandled result from vm86 mode %x\n", res );
1626             continue;
1627         }
1628         __regs_RtlRaiseException( &rec, context );
1629     }
1630 }
1631
1632 #else /* __HAVE_VM86 */
1633 /**********************************************************************
1634  *              __wine_enter_vm86   (NTDLL.@)
1635  */
1636 void __wine_enter_vm86( CONTEXT *context )
1637 {
1638     MESSAGE("vm86 mode not supported on this platform\n");
1639 }
1640 #endif /* __HAVE_VM86 */
1641
1642 /**********************************************************************
1643  *              DbgBreakPoint   (NTDLL.@)
1644  */
1645 __ASM_GLOBAL_FUNC( DbgBreakPoint, "int $3; ret")
1646
1647 /**********************************************************************
1648  *              DbgUserBreakPoint   (NTDLL.@)
1649  */
1650 __ASM_GLOBAL_FUNC( DbgUserBreakPoint, "int $3; ret")
1651
1652
1653 /**********************************************************************
1654  *              EXC_CallHandler   (internal)
1655  *
1656  * Some exception handlers depend on EBP to have a fixed position relative to
1657  * the exception frame.
1658  * Shrinker depends on (*1) doing what it does,
1659  * (*2) being the exact instruction it is and (*3) beginning with 0x64
1660  * (i.e. the %fs prefix to the movl instruction). It also depends on the
1661  * function calling the handler having only 5 parameters (*4).
1662  */
1663 __ASM_GLOBAL_FUNC( EXC_CallHandler,
1664 "       pushl   %ebp\n"
1665 "       movl    %esp, %ebp\n"
1666 "       pushl   %ebx\n"
1667 "       movl    28(%ebp), %edx\n" /* ugly hack to pass the 6th param needed because of Shrinker */
1668 "       pushl   24(%ebp)\n"
1669 "       pushl   20(%ebp)\n"
1670 "       pushl   16(%ebp)\n"
1671 "       pushl   12(%ebp)\n"
1672 "       pushl   8(%ebp)\n"
1673 "       call    " __ASM_NAME("call_exception_handler") "\n"
1674 "       popl    %ebx\n"
1675 "       leave\n"
1676 "       ret\n"
1677 )
1678 __ASM_GLOBAL_FUNC(call_exception_handler,
1679 "       pushl   %ebp\n"
1680 "       movl    %esp, %ebp\n"
1681 "       subl    $12,%esp\n"
1682 "       pushl   12(%ebp)\n"       /* make any exceptions in this... */
1683 "       pushl   %edx\n"           /* handler be handled by... */
1684 "       .byte   0x64\n"
1685 "       pushl   (0)\n"            /* nested_handler (passed in edx). */
1686 "       .byte   0x64\n"
1687 "       movl    %esp,(0)\n"       /* push the new exception frame onto the exception stack. */
1688 "       pushl   20(%ebp)\n"
1689 "       pushl   16(%ebp)\n"
1690 "       pushl   12(%ebp)\n"
1691 "       pushl   8(%ebp)\n"
1692 "       movl    24(%ebp), %ecx\n" /* (*1) */
1693 "       call    *%ecx\n"          /* call handler. (*2) */
1694 "       .byte   0x64\n"
1695 "       movl    (0), %esp\n"      /* restore previous... (*3) */
1696 "       .byte   0x64\n"
1697 "       popl    (0)\n"            /* exception frame. */
1698 "       movl    %ebp, %esp\n"     /* restore saved stack, in case it was corrupted */
1699 "       popl    %ebp\n"
1700 "       ret     $20\n"            /* (*4) */
1701 )
1702 #endif  /* __i386__ */