src/unexw32.c

   1 /* unexec for GNU Emacs on Windows NT.
   2    Copyright (C) 1994 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Emacs 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
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Emacs; see the file COPYING.  If not, write to
  18 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.
  20
  21    Geoff Voelker (voelker@cs.washington.edu)                         8-12-94
  22 */
  23
  24 #include <stdlib.h>     /* _fmode */
  25 #include <stdio.h>
  26 #include <fcntl.h>
  27 #include <windows.h>
  28
  29 extern BOOL ctrl_c_handler (unsigned long type);
  30
  31 #include "w32heap.h"
  32
  33 /* A convenient type for keeping all the info about a mapped file together.  */
  34 typedef struct file_data {
  35     char          *name;
  36     unsigned long  size;
  37     HANDLE         file;
  38     HANDLE         file_mapping;
  39     unsigned char *file_base;
  40 } file_data;
  41
  42 /* Force zero initialized variables to be placed in the .data segment;
  43    MSVC 5.0 otherwise places them in .bss, which breaks the dumping code.  */
  44 #pragma data_seg(".data")
  45
  46 /* Basically, our "initialized" flag.  */
  47 BOOL need_to_recreate_heap = FALSE;
  48
  49 /* So we can find our heap in the file to recreate it.  */
  50 unsigned long heap_index_in_executable = 0;
  51
  52 void open_input_file (file_data *p_file, char *name);
  53 void open_output_file (file_data *p_file, char *name, unsigned long size);
  54 void close_file_data (file_data *p_file);
  55
  56 void get_section_info (file_data *p_file);
  57 void copy_executable_and_dump_data_section (file_data *, file_data *);
  58 void dump_bss_and_heap (file_data *p_infile, file_data *p_outfile);
  59
  60 /* Cached info about the .data section in the executable.  */
  61 PUCHAR data_start_va = 0;
  62 DWORD  data_start_file = 0;
  63 DWORD  data_size = 0;
  64
  65 /* Cached info about the .bss section in the executable.  */
  66 PUCHAR bss_start = 0;
  67 DWORD  bss_size = 0;
  68
  69 #ifdef HAVE_NTGUI
  70 HINSTANCE hinst = NULL;
  71 HINSTANCE hprevinst = NULL;
  72 LPSTR lpCmdLine = "";
  73 int nCmdShow = 0;
  74 #endif /* HAVE_NTGUI */
  75
  76 /* Startup code for running on NT.  When we are running as the dumped
  77    version, we need to bootstrap our heap and .bss section into our
  78    address space before we can actually hand off control to the startup
  79    code supplied by NT (primarily because that code relies upon malloc ()).  */
  80 void
  81 _start (void)
  82 {
  83   extern void mainCRTStartup (void);
  84
  85   /* Cache system info, e.g., the NT page size.  */
  86   cache_system_info ();
  87
  88   /* If we're a dumped version of emacs then we need to recreate
  89      our heap and play tricks with our .bss section.  Do this before
  90      start up.  (WARNING:  Do not put any code before this section
  91      that relies upon malloc () and runs in the dumped version.  It
  92      won't work.)  */
  93   if (need_to_recreate_heap)
  94     {
  95       char executable_path[MAX_PATH];
  96
  97       if (GetModuleFileName (NULL, executable_path, MAX_PATH) == 0)
  98         {
  99           printf ("Failed to find path for executable.\n");
 100           exit (1);
 101         }
 102       recreate_heap (executable_path);
 103       need_to_recreate_heap = FALSE;
 104     }
 105
 106   /* The default behavior is to treat files as binary and patch up
 107      text files appropriately, in accordance with the MSDOS code.  */
 108   _fmode = O_BINARY;
 109
 110   /* This prevents ctrl-c's in shells running while we're suspended from
 111      having us exit.  */
 112   SetConsoleCtrlHandler ((PHANDLER_ROUTINE) ctrl_c_handler, TRUE);
 113
 114   /* Invoke the NT CRT startup routine now that our housecleaning
 115      is finished.  */
 116 #ifdef HAVE_NTGUI
 117   /* determine WinMain args like crt0.c does */
 118   hinst = GetModuleHandle(NULL);
 119   lpCmdLine = GetCommandLine();
 120   nCmdShow = SW_SHOWDEFAULT;
 121 #endif
 122   mainCRTStartup ();
 123 }
 124
 125 /* Dump out .data and .bss sections into a new executable.  */
 126 void
 127 unexec (char *new_name, char *old_name, void *start_data, void *start_bss,
 128         void *entry_address)
 129 {
 130   file_data in_file, out_file;
 131   char out_filename[MAX_PATH], in_filename[MAX_PATH];
 132   unsigned long size;
 133   char *ptr;
 134
 135   /* Make sure that the input and output filenames have the
 136      ".exe" extension...patch them up if they don't.  */
 137   strcpy (in_filename, old_name);
 138   ptr = in_filename + strlen (in_filename) - 4;
 139   if (strcmp (ptr, ".exe"))
 140     strcat (in_filename, ".exe");
 141
 142   strcpy (out_filename, new_name);
 143   ptr = out_filename + strlen (out_filename) - 4;
 144   if (strcmp (ptr, ".exe"))
 145     strcat (out_filename, ".exe");
 146
 147   printf ("Dumping from %s\n", in_filename);
 148   printf ("          to %s\n", out_filename);
 149
 150   /* We need to round off our heap to NT's allocation unit (64KB).  */
 151   round_heap (get_allocation_unit ());
 152
 153   /* Open the undumped executable file.  */
 154   open_input_file (&in_file, in_filename);
 155
 156   /* Get the interesting section info, like start and size of .bss...  */
 157   get_section_info (&in_file);
 158
 159   /* The size of the dumped executable is the size of the original
 160      executable plus the size of the heap and the size of the .bss section.  */
 161   heap_index_in_executable = (unsigned long)
 162     round_to_next ((unsigned char *) in_file.size, get_allocation_unit ());
 163   size = heap_index_in_executable + get_committed_heap_size () + bss_size;
 164   open_output_file (&out_file, out_filename, size);
 165
 166   /* Set the flag (before dumping).  */
 167   need_to_recreate_heap = TRUE;
 168
 169   copy_executable_and_dump_data_section (&in_file, &out_file);
 170   dump_bss_and_heap (&in_file, &out_file);
 171
 172   close_file_data (&in_file);
 173   close_file_data (&out_file);
 174 }
 175
 176
 177 /* File handling.  */
 178
 179
 180 void
 181 open_input_file (file_data *p_file, char *filename)
 182 {
 183   HANDLE file;
 184   HANDLE file_mapping;
 185   void  *file_base;
 186   unsigned long size, upper_size;
 187
 188   file = CreateFile (filename, GENERIC_READ, FILE_SHARE_READ, NULL,
 189                      OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
 190   if (file == INVALID_HANDLE_VALUE)
 191       {
 192         printf ("Failed to open %s (%d)...bailing.\n",
 193                filename, GetLastError ());
 194         exit (1);
 195       }
 196
 197   size = GetFileSize (file, &upper_size);
 198   file_mapping = CreateFileMapping (file, NULL, PAGE_READONLY,
 199                                     0, size, NULL);
 200   if (!file_mapping)
 201     {
 202       printf ("Failed to create file mapping of %s (%d)...bailing.\n",
 203              filename, GetLastError ());
 204       exit (1);
 205     }
 206
 207   file_base = MapViewOfFile (file_mapping, FILE_MAP_READ, 0, 0, size);
 208   if (file_base == 0)
 209     {
 210       printf ("Failed to map view of file of %s (%d)...bailing.\n",
 211              filename, GetLastError ());
 212       exit (1);
 213     }
 214
 215   p_file->name = filename;
 216   p_file->size = size;
 217   p_file->file = file;
 218   p_file->file_mapping = file_mapping;
 219   p_file->file_base = file_base;
 220 }
 221
 222 void
 223 open_output_file (file_data *p_file, char *filename, unsigned long size)
 224 {
 225   HANDLE file;
 226   HANDLE file_mapping;
 227   void  *file_base;
 228   int    i;
 229
 230   file = CreateFile (filename, GENERIC_READ | GENERIC_WRITE, 0, NULL,
 231                      CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
 232   if (file == INVALID_HANDLE_VALUE)
 233     {
 234       i = GetLastError ();
 235       printf ("open_output_file: Failed to open %s (%d).\n",
 236              filename, i);
 237       exit (1);
 238     }
 239
 240   file_mapping = CreateFileMapping (file, NULL, PAGE_READWRITE,
 241                                     0, size, NULL);
 242   if (!file_mapping)
 243     {
 244       i = GetLastError ();
 245       printf ("open_output_file: Failed to create file mapping of %s (%d).\n",
 246              filename, i);
 247       exit (1);
 248     }
 249
 250   file_base = MapViewOfFile (file_mapping, FILE_MAP_WRITE, 0, 0, size);
 251   if (file_base == 0)
 252     {
 253       i = GetLastError ();
 254       printf ("open_output_file: Failed to map view of file of %s (%d).\n",
 255              filename, i);
 256       exit (1);
 257     }
 258
 259   p_file->name = filename;
 260   p_file->size = size;
 261   p_file->file = file;
 262   p_file->file_mapping = file_mapping;
 263   p_file->file_base = file_base;
 264 }
 265
 266 /* Close the system structures associated with the given file.  */
 267 static void
 268 close_file_data (file_data *p_file)
 269 {
 270     UnmapViewOfFile (p_file->file_base);
 271     CloseHandle (p_file->file_mapping);
 272     CloseHandle (p_file->file);
 273 }
 274
 275
 276 /* Routines to manipulate NT executable file sections.  */
 277
 278 static void
 279 get_bss_info_from_map_file (file_data *p_infile, PUCHAR *p_bss_start,
 280                             DWORD *p_bss_size)
 281 {
 282   int n, start, len;
 283   char map_filename[MAX_PATH];
 284   char buffer[256];
 285   FILE *map;
 286
 287   /* Overwrite the .exe extension on the executable file name with
 288      the .map extension.  */
 289   strcpy (map_filename, p_infile->name);
 290   n = strlen (map_filename) - 3;
 291   strcpy (&map_filename[n], "map");
 292
 293   map = fopen (map_filename, "r");
 294   if (!map)
 295     {
 296       printf ("Failed to open map file %s, error %d...bailing out.\n",
 297               map_filename, GetLastError ());
 298       exit (-1);
 299     }
 300
 301   while (fgets (buffer, sizeof (buffer), map))
 302     {
 303       if (!(strstr (buffer, ".bss") && strstr (buffer, "DATA")))
 304         continue;
 305       n = sscanf (buffer, " %*d:%x %x", &start, &len);
 306       if (n != 2)
 307         {
 308           printf ("Failed to scan the .bss section line:\n%s", buffer);
 309           exit (-1);
 310         }
 311       break;
 312     }
 313   *p_bss_start = (PUCHAR) start;
 314   *p_bss_size = (DWORD) len;
 315 }
 316
 317 static unsigned long
 318 get_section_size (PIMAGE_SECTION_HEADER p_section)
 319 {
 320   /* The section size is in different locations in the different versions.  */
 321   switch (get_w32_minor_version ())
 322     {
 323     case 10:
 324       return p_section->SizeOfRawData;
 325     default:
 326       return p_section->Misc.VirtualSize;
 327     }
 328 }
 329
 330 /* Flip through the executable and cache the info necessary for dumping.  */
 331 static void
 332 get_section_info (file_data *p_infile)
 333 {
 334   PIMAGE_DOS_HEADER dos_header;
 335   PIMAGE_NT_HEADERS nt_header;
 336   PIMAGE_SECTION_HEADER section, data_section;
 337   unsigned char *ptr;
 338   int i;
 339
 340   dos_header = (PIMAGE_DOS_HEADER) p_infile->file_base;
 341   if (dos_header->e_magic != IMAGE_DOS_SIGNATURE)
 342     {
 343       printf ("Unknown EXE header in %s...bailing.\n", p_infile->name);
 344       exit (1);
 345     }
 346   nt_header = (PIMAGE_NT_HEADERS) (((unsigned long) dos_header) +
 347                                    dos_header->e_lfanew);
 348   if (nt_header == NULL)
 349     {
 350       printf ("Failed to find IMAGE_NT_HEADER in %s...bailing.\n",
 351              p_infile->name);
 352       exit (1);
 353     }
 354
 355   /* Check the NT header signature ...  */
 356   if (nt_header->Signature != IMAGE_NT_SIGNATURE)
 357     {
 358       printf ("Invalid IMAGE_NT_SIGNATURE 0x%x in %s...bailing.\n",
 359               nt_header->Signature, p_infile->name);
 360     }
 361
 362   /* Flip through the sections for .data and .bss ...  */
 363   section = (PIMAGE_SECTION_HEADER) IMAGE_FIRST_SECTION (nt_header);
 364   for (i = 0; i < nt_header->FileHeader.NumberOfSections; i++)
 365     {
 366       if (!strcmp (section->Name, ".bss"))
 367         {
 368           /* The .bss section.  */
 369           ptr = (char *) nt_header->OptionalHeader.ImageBase +
 370             section->VirtualAddress;
 371           bss_start = ptr;
 372           bss_size = get_section_size (section);
 373         }
 374       if (!strcmp (section->Name, ".data"))
 375         {
 376           /* From lastfile.c  */
 377           extern char my_edata[];
 378
 379           /* The .data section.  */
 380           data_section = section;
 381           ptr = (char *) nt_header->OptionalHeader.ImageBase +
 382             section->VirtualAddress;
 383           data_start_va = ptr;
 384           data_start_file = section->PointerToRawData;
 385
 386           /* We want to only write Emacs data back to the executable,
 387              not any of the library data (if library data is included,
 388              then a dumped Emacs won't run on system versions other
 389              than the one Emacs was dumped on).  */
 390           data_size = my_edata - data_start_va;
 391         }
 392       section++;
 393     }
 394
 395   if (!bss_start && !bss_size)
 396     {
 397       /* Starting with MSVC 4.0, the .bss section has been eliminated
 398          and appended virtually to the end of the .data section.  Our
 399          only hint about where the .bss section starts in the address
 400          comes from the SizeOfRawData field in the .data section
 401          header.  Unfortunately, this field is only approximate, as it
 402          is a rounded number and is typically rounded just beyond the
 403          start of the .bss section.  To find the start and size of the
 404          .bss section exactly, we have to peek into the map file.  */
 405       get_bss_info_from_map_file (p_infile, &ptr, &bss_size);
 406       bss_start = ptr + nt_header->OptionalHeader.ImageBase
 407         + data_section->VirtualAddress;
 408     }
 409 }
 410
 411
 412 /* The dump routines.  */
 413
 414 static void
 415 copy_executable_and_dump_data_section (file_data *p_infile,
 416                                        file_data *p_outfile)
 417 {
 418   unsigned char *data_file, *data_va;
 419   unsigned long size, index;
 420
 421   /* Get a pointer to where the raw data should go in the executable file.  */
 422   data_file = (char *) p_outfile->file_base + data_start_file;
 423
 424   /* Get a pointer to the raw data in our address space.  */
 425   data_va = data_start_va;
 426
 427   size = (DWORD) data_file - (DWORD) p_outfile->file_base;
 428   printf ("Copying executable up to data section...\n");
 429   printf ("\t0x%08x Offset in input file.\n", 0);
 430   printf ("\t0x%08x Offset in output file.\n", 0);
 431   printf ("\t0x%08x Size in bytes.\n", size);
 432   memcpy (p_outfile->file_base, p_infile->file_base, size);
 433
 434   size = data_size;
 435   printf ("Dumping .data section...\n");
 436   printf ("\t0x%08x Address in process.\n", data_va);
 437   printf ("\t0x%08x Offset in output file.\n",
 438           data_file - p_outfile->file_base);
 439   printf ("\t0x%08x Size in bytes.\n", size);
 440   memcpy (data_file, data_va, size);
 441
 442   index = (DWORD) data_file + size - (DWORD) p_outfile->file_base;
 443   size = p_infile->size - index;
 444   printf ("Copying rest of executable...\n");
 445   printf ("\t0x%08x Offset in input file.\n", index);
 446   printf ("\t0x%08x Offset in output file.\n", index);
 447   printf ("\t0x%08x Size in bytes.\n", size);
 448   memcpy ((char *) p_outfile->file_base + index,
 449           (char *) p_infile->file_base + index, size);
 450 }
 451
 452 static void
 453 dump_bss_and_heap (file_data *p_infile, file_data *p_outfile)
 454 {
 455     unsigned char *heap_data, *bss_data;
 456     unsigned long size, index;
 457
 458     printf ("Dumping heap into executable...\n");
 459
 460     index = heap_index_in_executable;
 461     size = get_committed_heap_size ();
 462     heap_data = get_heap_start ();
 463
 464     printf ("\t0x%08x Heap start in process.\n", heap_data);
 465     printf ("\t0x%08x Heap offset in executable.\n", index);
 466     printf ("\t0x%08x Heap size in bytes.\n", size);
 467
 468     memcpy ((PUCHAR) p_outfile->file_base + index, heap_data, size);
 469
 470     printf ("Dumping .bss into executable...\n");
 471
 472     index += size;
 473     size = bss_size;
 474     bss_data = bss_start;
 475
 476     printf ("\t0x%08x BSS start in process.\n", bss_data);
 477     printf ("\t0x%08x BSS offset in executable.\n", index);
 478     printf ("\t0x%08x BSS size in bytes.\n", size);
 479     memcpy ((char *) p_outfile->file_base + index, bss_data, size);
 480 }
 481
 482
 483 /* Reload and remap routines.  */
 484
 485
 486 /* Load the dumped .bss section into the .bss area of our address space.  */
 487 void
 488 read_in_bss (char *filename)
 489 {
 490   HANDLE file;
 491   unsigned long size, index, n_read, total_read;
 492   char   buffer[512], *bss;
 493   int    i;
 494
 495   file = CreateFile (filename, GENERIC_READ, FILE_SHARE_READ, NULL,
 496                      OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
 497   if (file == INVALID_HANDLE_VALUE)
 498     {
 499       i = GetLastError ();
 500       exit (1);
 501     }
 502
 503   /* Seek to where the .bss section is tucked away after the heap...  */
 504   index = heap_index_in_executable + get_committed_heap_size ();
 505   if (SetFilePointer (file, index, NULL, FILE_BEGIN) == 0xFFFFFFFF)
 506     {
 507       i = GetLastError ();
 508       exit (1);
 509     }
 510
 511
 512   /* Ok, read in the saved .bss section and initialize all
 513      uninitialized variables.  */
 514   if (!ReadFile (file, bss_start, bss_size, &n_read, NULL))
 515     {
 516       i = GetLastError ();
 517       exit (1);
 518     }
 519
 520   CloseHandle (file);
 521 }
 522
 523 /* Map the heap dumped into the executable file into our address space.  */
 524 void
 525 map_in_heap (char *filename)
 526 {
 527   HANDLE file;
 528   HANDLE file_mapping;
 529   void  *file_base;
 530   unsigned long size, upper_size, n_read;
 531   int    i;
 532
 533   file = CreateFile (filename, GENERIC_READ, FILE_SHARE_READ, NULL,
 534                      OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
 535   if (file == INVALID_HANDLE_VALUE)
 536     {
 537       i = GetLastError ();
 538       exit (1);
 539     }
 540
 541   size = GetFileSize (file, &upper_size);
 542   file_mapping = CreateFileMapping (file, NULL, PAGE_WRITECOPY,
 543                                     0, size, NULL);
 544   if (!file_mapping)
 545     {
 546       i = GetLastError ();
 547       exit (1);
 548     }
 549
 550   size = get_committed_heap_size ();
 551   file_base = MapViewOfFileEx (file_mapping, FILE_MAP_COPY, 0,
 552                                heap_index_in_executable, size,
 553                                get_heap_start ());
 554   if (file_base != 0)
 555     {
 556       return;
 557     }
 558
 559   /* If we don't succeed with the mapping, then copy from the
 560      data into the heap.  */
 561
 562   CloseHandle (file_mapping);
 563
 564   if (VirtualAlloc (get_heap_start (), get_committed_heap_size (),
 565                     MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE) == NULL)
 566     {
 567       i = GetLastError ();
 568       exit (1);
 569     }
 570
 571   /* Seek to the location of the heap data in the executable.  */
 572   i = heap_index_in_executable;
 573   if (SetFilePointer (file, i, NULL, FILE_BEGIN) == 0xFFFFFFFF)
 574     {
 575       i = GetLastError ();
 576       exit (1);
 577     }
 578
 579   /* Read in the data.  */
 580   if (!ReadFile (file, get_heap_start (),
 581                  get_committed_heap_size (), &n_read, NULL))
 582     {
 583       i = GetLastError ();
 584       exit (1);
 585     }
 586
 587   CloseHandle (file);
 588 }