src/libcaptive/ps/signal.c

   1 /* $Id$
   2  * UNIX signal handling for processor emulation for support of ntoskrnl of libcaptive
   3  * Copyright (C) 2002 Jan Kratochvil <project-captive@jankratochvil.net>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; exactly version 2 of June 1991 is required
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19
  20 #define _GNU_SOURCE 1   /* for sys/ucontext.h for REG_* */
  21
  22 #include "config.h"
  23
  24 #include "captive/signal.h"     /* self */
  25 #include <glib/gtypes.h>
  26 #include <glib/gmessages.h>
  27 #include <signal.h>
  28 #include "captive/macros.h"
  29 #include <sys/ucontext.h>       /* for struct ucontext */
  30 #include "captive/mm.h" /* for captive_mmap_map_get() */
  31 #include <sys/mman.h>
  32 #include "reactos/internal/mm.h"  /* for PAGE_SIZE */
  33 #include "captive/ldr.h"        /* for captive_ModuleList_patchpoint_find() */
  34 #include "captive/ldr_exports.h"        /* for struct captive_ModuleList_patchpoint */
  35
  36
  37 int _abnormal_termination_orig(void);
  38 extern greg_t fs_KPCR_ExceptionList;
  39
  40 /**
  41  * _abnormal_termination_wrap:
  42  *
  43  * This call can be also accessed as AbnormalTermination() or _abnormal_termination().
  44  * It is a captive wrapper around _abnormal_termination() function.
  45  *
  46  * Returns whether some exception occured in the current #try block we are currently
  47  * #finish -ing. Any functions called from current #finish block will be considered
  48  * for returning zero back again. It is forbidden to call this function outside
  49  * of #finish block, result of such call is undefined.
  50  *
  51  * Exception handlers are registered from W32 binary in stack frames stored in "fs:[0x00000000]"
  52  * value which gets mapped by libcaptive/ps/signal.c to #fs_KPCR_ExceptionList
  53  * variable.
  54  *
  55  * If no exception handler was registered yet this function returns zero.
  56  *
  57  * See also RtlpDispatchException().
  58  *
  59  * Returns: non-zero if some exception is now being handled as pending.
  60  */
  61 int _abnormal_termination_wrap(void)
  62 {
  63         /* No handler registered yet? ntoskrnl _abnormal_termination() does not handle it
  64          * and I do not want to bother with registering toplevel handler.
  65          */
  66         if (fs_KPCR_ExceptionList==(greg_t)-1)
  67                 return 0;
  68
  69         return _abnormal_termination_orig();
  70 }
  71
  72
  73 #if 0
  74
  75 /**
  76  * RtlpDispatchException:
  77  * @ExceptionRecord: Ignored by libcaptive.
  78  * @Context: Ignored by libcaptive.
  79  *
  80  * Function definition to prevent inclusion of real RtlpDispatchException() implementation.
  81  * Currently libcaptive never raises any exception - fix _abnormal_termination() if it changes.
  82  *
  83  * Returns: Never returns. Value %0 if it returns although it is impossible.
  84  */
  85 ULONG RtlpDispatchException(IN PEXCEPTION_RECORD ExceptionRecord,IN PCONTEXT Context)
  86 {
  87         g_assert_not_reached();
  88         g_return_val_if_reached(0);
  89 }
  90
  91 #endif
  92
  93
  94 /* =='KeGetCurrentKPCR()->ExceptionList';
  95  * libcaptive has reduced KPCR (named 'captive_KPCR') which
  96  * does not contain this field
  97  */
  98 greg_t fs_KPCR_ExceptionList=(greg_t)-1;
  99
 100 /* FIXME */
 101 static greg_t fs_KPCR_Unknown638=0;
 102
 103
 104 static gboolean instr_mov_greg_to_fsmem(int greg,const void *fsmem,struct ucontext *ucontext)
 105 {
 106         if (fsmem==(const void *)0x00000000) {  /* exception stack top pointer */
 107                 /* moving from %esp is required to pass! */
 108                 fs_KPCR_ExceptionList=ucontext->uc_mcontext.gregs[greg];
 109                 return TRUE;
 110                 }
 111         g_return_val_if_reached(FALSE);
 112 }
 113
 114 static gboolean instr_mov_immed_to_fsmem(greg_t immed,const void *fsmem,struct ucontext *ucontext)
 115 {
 116         if (fsmem==(const void *)0x00000000) {  /* exception stack top pointer */
 117                 fs_KPCR_ExceptionList=immed;
 118                 return TRUE;
 119                 }
 120         g_return_val_if_reached(FALSE);
 121 }
 122
 123 static gboolean instr_mov_fsmem_to_greg(const void *fsmem,int greg,struct ucontext *ucontext)
 124 {
 125         if (fsmem==(const void *)0x00000000) {  /* exception stack top pointer */
 126                 /* moving to %esp is required to pass! */
 127                 ucontext->uc_mcontext.gregs[greg]=fs_KPCR_ExceptionList;
 128                 return TRUE;
 129                 }
 130         if (fsmem==(const void *)0x00000051) {  /* =='KeGetCurrentKPCR()->Number' */
 131                 g_return_val_if_fail(greg!=REG_ESP,FALSE);
 132                 ucontext->uc_mcontext.gregs[greg]=(greg_t)0;    /* ==libcaptive version of KeGetCurrentProcessorNumber() */
 133                 return TRUE;
 134                 }
 135         if (fsmem==(const void *)0x00000124) {  /* =='KeGetCurrentKPCR()->CurrentThread' */
 136                 g_return_val_if_fail(greg!=REG_ESP,FALSE);
 137                 ucontext->uc_mcontext.gregs[greg]=(greg_t)captive_KeGetCurrentKPCR()->CurrentThread;
 138                 return TRUE;
 139                 }
 140         g_return_val_if_reached(FALSE);
 141 }
 142
 143 static gboolean instr_push_fsmem(const void *fsmem,struct ucontext *ucontext)
 144 {
 145         if (fsmem==(const void *)0x00000000) {  /* exception stack top pointer */
 146                 ucontext->uc_mcontext.gregs[REG_ESP]-=4;
 147                 *(greg_t *)ucontext->uc_mcontext.gregs[REG_ESP]=fs_KPCR_ExceptionList;
 148                 return TRUE;
 149                 }
 150         g_return_val_if_reached(FALSE);
 151 }
 152
 153 static gboolean instr_pop_fsmem(const void *fsmem,struct ucontext *ucontext)
 154 {
 155         if (fsmem==(const void *)0x00000000) {  /* exception stack top pointer */
 156                 fs_KPCR_ExceptionList=*(greg_t *)ucontext->uc_mcontext.gregs[REG_ESP];
 157                 ucontext->uc_mcontext.gregs[REG_ESP]+=4;
 158                 return TRUE;
 159                 }
 160         g_return_val_if_reached(FALSE);
 161 }
 162
 163 static gboolean instr_incl_fsmem(const void *fsmem,struct ucontext *ucontext)
 164 {
 165         if (fsmem==(const void *)0x00000638) {  /* Unknown638 */
 166                 fs_KPCR_Unknown638++;
 167                 return TRUE;
 168                 }
 169         g_return_val_if_reached(FALSE);
 170 }
 171
 172 static int op_regcode_to_greg(guint8 regcode)
 173 {
 174         switch (regcode) {
 175                 case 0x00: return REG_EAX;
 176                 case 0x01: return REG_ECX;
 177                 case 0x02: return REG_EDX;
 178                 case 0x03: return REG_EBX;
 179                 case 0x04: return REG_ESP;
 180                 case 0x05: return REG_EBP;
 181                 case 0x06: return REG_ESI;
 182                 case 0x07: return REG_EDI;
 183                 }
 184         g_return_val_if_reached(REG_EAX);
 185 }
 186
 187 static void sigaction_SIGSEGV(int signo,siginfo_t *siginfo,struct ucontext *ucontext)
 188 {
 189 guint8 *reg_eip;
 190 const void *reg_eip_aligned;
 191
 192         g_return_if_fail(signo==SIGSEGV);
 193         g_return_if_fail(siginfo->si_signo==SIGSEGV);
 194         /* siginfo->si_code is weird, seen to have value 128 */
 195
 196         reg_eip=(void *)ucontext->uc_mcontext.gregs[REG_EIP];
 197
 198         /* 'reg_eip' is not yet PAGE_SIZE-aligned but we need the aligned ptr for captive_mmap_map_get().
 199          * glib NOTE: YOU MAY NOT STORE POINTERS IN INTEGERS.
 200          */
 201         reg_eip_aligned=(const void *)(((char *)reg_eip)-(GPOINTER_TO_UINT(reg_eip)&(PAGE_SIZE-1)));
 202         g_assert(reg_eip_aligned!=NULL);
 203         g_return_if_fail(!(captive_mmap_map_get(reg_eip_aligned)&PROT_EXEC));
 204
 205         /* all instruction notation comments are written in AT&T 'instr src,dest' syntax! */
 206         if (*reg_eip==0x64) {   /* prefix '%fs:' */
 207                 reg_eip++;
 208                 /* TODO:thread; %fs: is CPU-dependent */
 209                 if (*reg_eip==0x0F) {   /* two-byte opcode */
 210                         reg_eip++;
 211                         if (*reg_eip==0xB6) {   /* ??? */
 212                                 reg_eip++;
 213                                 if (*reg_eip==0x05) {   /* movzbl %fs:{reg_eip[1..4]},%eax */
 214                                         reg_eip++;
 215                                         if (instr_mov_fsmem_to_greg(*(const void **)reg_eip,REG_EAX,ucontext)) {
 216                                                 reg_eip+=4;
 217                                                 goto ok;
 218                                                 }
 219                                         g_assert_not_reached();
 220                                         }
 221                                 g_assert_not_reached();
 222                                 }
 223                         g_assert_not_reached();
 224                         }
 225                 if (*reg_eip==0xA3) {   /* 'mov %eax,%fs:{reg_eip[1..4]}' */
 226                         reg_eip++;
 227                         if (instr_mov_greg_to_fsmem(REG_EAX,*(const void **)reg_eip,ucontext)) {
 228                                 reg_eip+=4;
 229                                 goto ok;
 230                                 }
 231                         g_assert_not_reached();
 232                         }
 233                 if (*reg_eip==0x89) {   /* prefix 0x89 */
 234                         reg_eip++;
 235                         if ((*reg_eip & ~0x38)==0x05)   { /* 'mov %{op_regcode_to_greg(*reg_eip[b3..b5])},%fs:{reg_eip[1..4]} */
 236                                 reg_eip++;
 237                                 if (instr_mov_greg_to_fsmem(op_regcode_to_greg(reg_eip[-1]>>3U),*(const void **)reg_eip,ucontext)) {
 238                                         reg_eip+=4;
 239                                         goto ok;
 240                                         }
 241                                 g_assert_not_reached();
 242                                 }
 243                         g_assert_not_reached();
 244                         }
 245                 if (*reg_eip==0xA1) {   /* 'mov %fs:{reg_eip[1..4]},%eax' */
 246                         reg_eip++;
 247                         if (instr_mov_fsmem_to_greg(*(const void **)reg_eip,REG_EAX,ucontext)) {
 248                                 reg_eip+=4;
 249                                 goto ok;
 250                                 }
 251                         g_assert_not_reached();
 252                         }
 253                 if (*reg_eip==0x8B) {   /* prefix 0x8B */
 254                         reg_eip++;
 255                         if ((*reg_eip & ~0x38)==0x05) { /* 'mov %fs:{reg_eip[1..4]},%{op_regcode_to_greg(*reg_eip[b3..b5])}' */
 256                                 reg_eip++;
 257                                 if (instr_mov_fsmem_to_greg(*(const void **)reg_eip,op_regcode_to_greg(reg_eip[-1]>>3U),ucontext)) {
 258                                         reg_eip+=4;
 259                                         goto ok;
 260                                         }
 261                                 g_assert_not_reached();
 262                                 }
 263                         g_assert_not_reached();
 264                         }
 265                 if (*reg_eip==0xFF) {   /* prefix 0xFF */
 266                         reg_eip++;
 267                         if (*reg_eip==0x05) {   /* 'incl %fs:{reg_eip[1..4]}' */
 268                                 reg_eip++;
 269                                 if (instr_incl_fsmem(*(const void **)reg_eip,ucontext)) {
 270                                         reg_eip+=4;
 271                                         goto ok;
 272                                         }
 273                                 g_assert_not_reached();
 274                                 }
 275                         if (*reg_eip==0x35) {   /* 'pushl %fs:{reg_eip[1..4]}' */
 276                                 reg_eip++;
 277                                 if (instr_push_fsmem(*(const void **)reg_eip,ucontext)) {
 278                                         reg_eip+=4;
 279                                         goto ok;
 280                                         }
 281                                 g_assert_not_reached();
 282                                 }
 283                         g_assert_not_reached();
 284                         }
 285                 if (*reg_eip==0x8F) {   /* prefix 0x0F */
 286                         reg_eip++;
 287                         if (*reg_eip==0x05) {   /* 'popl %fs:{reg_eip[1..4]}' */
 288                                 reg_eip++;
 289                                 if (instr_pop_fsmem(*(const void **)reg_eip,ucontext)) {
 290                                         reg_eip+=4;
 291                                         goto ok;
 292                                         }
 293                                 g_assert_not_reached();
 294                                 }
 295                         g_assert_not_reached();
 296                         }
 297                 if (*reg_eip==0xC7) {   /* prefix 0xC7 */
 298                         reg_eip++;
 299                         if (*reg_eip==0x05) {   /* 'movl ${reg_eip[5..8]},%fs:{reg_eip[1..4]}' */
 300                                 reg_eip++;
 301                                 if (instr_mov_immed_to_fsmem(((greg_t *)reg_eip)[1],*(const void **)reg_eip,ucontext)) {
 302                                         reg_eip+=4+4;
 303                                         goto ok;
 304                                         }
 305                                 g_assert_not_reached();
 306                                 }
 307                         g_assert_not_reached();
 308                         }
 309                 g_assert_not_reached();
 310                 }
 311
 312         /* all instruction notation comments are written in AT&T 'instr src,dest' syntax! */
 313         if (*reg_eip==0x66) {   /* prefix '%fs:' */
 314                 reg_eip++;
 315                 /* TODO:thread; %fs: is CPU-dependent */
 316                 if (*reg_eip==0x8E) {   /* two-byte opcode */
 317                         reg_eip++;
 318                         if (*reg_eip==0xE3) {   /* 'mov %bx,%fs' */
 319                                 reg_eip++;
 320                                 g_assert(0x30==(0xFFFF&ucontext->uc_mcontext.gregs[REG_EBX]));
 321                                 /* 'reload' of %fs can be ignored */
 322                                 goto ok;
 323                                 }
 324                         g_assert_not_reached();
 325                         }
 326                 g_assert_not_reached();
 327                 }
 328
 329         if (*reg_eip==0xF4) {   /* hlt; from captive_ModuleList_patch() */
 330 struct captive_ModuleList_patchpoint *patchpoint;
 331 const gchar *funcname_disabled;
 332
 333                 g_log(G_LOG_DOMAIN,G_LOG_LEVEL_DEBUG,"%s: reg_eip=%p; 0xF4 hit",G_STRLOC,reg_eip);
 334
 335                 if ((funcname_disabled=captive_ModuleList_function_disable_find(
 336                                                 reg_eip)))      { /* ExportAddress */
 337                         g_error("%s: Reached disabled W32 function: %s",G_STRLOC,funcname_disabled);
 338                         g_assert_not_reached();
 339                         }
 340                 patchpoint=captive_ModuleList_patchpoint_find(
 341                                 reg_eip);       /* ExportAddress */
 342                 g_assert(patchpoint!=NULL);
 343                 if (reg_eip==patchpoint->orig_w32_func) {
 344                         g_assert(0xF4 /* hlt */ ==*patchpoint->orig_w32_func);
 345                         g_assert(patchpoint->orig_w32_2ndinstr_byte ==*patchpoint->orig_w32_2ndinstr);
 346                         if (patchpoint->through_w32_func) {
 347                                 *patchpoint->orig_w32_func=patchpoint->orig_w32_func_byte;
 348                                 *patchpoint->orig_w32_2ndinstr=0xF4;    /* hlt */
 349                                 }
 350                         else {  /* !patchpoint->through_w32_func */
 351                                 reg_eip=(guint8 *)patchpoint->wrap_wrap_func;
 352                                 }
 353                         goto ok;
 354                         }
 355                 if (reg_eip==patchpoint->orig_w32_2ndinstr) {
 356                         g_assert(patchpoint->orig_w32_func_byte ==*patchpoint->orig_w32_func);
 357                         g_assert(0xF4 /* hlt */ ==*patchpoint->orig_w32_2ndinstr);
 358                         g_assert(patchpoint->through_w32_func==TRUE);
 359                         *patchpoint->orig_w32_func=0xF4;        /* hlt */
 360                         *patchpoint->orig_w32_2ndinstr=patchpoint->orig_w32_2ndinstr_byte;
 361                         patchpoint->through_w32_func=FALSE;
 362                         goto ok;
 363                         }
 364                 g_assert_not_reached();
 365                 }
 366
 367         if (*reg_eip==0xFA) {   /* cli */
 368                 g_log(G_LOG_DOMAIN,G_LOG_LEVEL_DEBUG,"%s: reg_eip=%p; CLI neutralized",G_STRLOC,reg_eip);
 369                 *reg_eip=0x90;  /* nop */
 370                 goto ok;
 371                 }
 372
 373         if (*reg_eip==0xFB) {   /* sti */
 374                 g_log(G_LOG_DOMAIN,G_LOG_LEVEL_DEBUG,"%s: reg_eip=%p; STI neutralized",G_STRLOC,reg_eip);
 375                 *reg_eip=0x90;  /* nop */
 376                 goto ok;
 377                 }
 378
 379         g_assert_not_reached();
 380
 381 ok:
 382         ucontext->uc_mcontext.gregs[REG_EIP]=(greg_t)reg_eip;
 383         /* success */
 384 }
 385
 386 /**
 387  * captive_signal_init:
 388  *
 389  * Initialize UNIX signal handling to be able to emulate foreign W32
 390  * instructions. These instructions must be located inside address
 391  * space of foreign W32 binary code which is identified by successful
 392  * call to captive_mmap_map_get() returning #PROT_EXEC bit set.
 393  * This bit should be set from MmAllocateSection() called from
 394  * ntoskrnl/ldr/loader.c/LdrPEProcessModule().
 395  *
 396  * Currently emulated set is the access to %fs register offset %0
 397  * where the exception stack top pointer is located.
 398  *
 399  * Returns: %TRUE if successful.
 400  */
 401 gboolean captive_signal_init(void)
 402 {
 403 gint errint;
 404 struct sigaction sigaction_struct;
 405 sigset_t sigset;
 406
 407         CAPTIVE_MEMZERO(&sigaction_struct);     /* this structure may have unpredictable fields */
 408
 409         /* Init 'sigaction_struct.sa_mask'. */
 410         errint=sigemptyset(&sigaction_struct.sa_mask);
 411         g_return_val_if_fail(errint==0,FALSE);
 412         errint=sigaddset(&sigaction_struct.sa_mask,SIGSEGV);
 413         g_return_val_if_fail(errint==0,FALSE);
 414
 415         /* Set the signal sigaction handler. */
 416         sigaction_struct.sa_sigaction=(void (*)(int,siginfo_t *,void *))sigaction_SIGSEGV;
 417         sigaction_struct.sa_flags=0
 418                         |SA_SIGINFO;    /* Use 'sa_sigaction' (not 'sa_handler') */
 419         errint=sigaction(SIGSEGV,
 420                         &sigaction_struct,      /* act */
 421                         NULL);  /* oldact */
 422         g_return_val_if_fail(errint==0,FALSE);
 423
 424         /* Enable SIGSEGV signal (should be default). */
 425         errint=sigemptyset(&sigset);
 426         g_return_val_if_fail(errint==0,FALSE);
 427         errint=sigaddset(&sigset,SIGSEGV);
 428         g_return_val_if_fail(errint==0,FALSE);
 429         errint=sigprocmask(SIG_UNBLOCK,
 430                         &sigset,        /* set */
 431                         NULL);  /* oldset */
 432         g_return_val_if_fail(errint==0,FALSE);
 433
 434         return TRUE;
 435 }