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