| 1 | /* unexec() support for Cygwin; |
| 2 | complete rewrite of xemacs Cygwin unexec() code |
| 3 | |
| 4 | Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GNU Emacs. |
| 7 | |
| 8 | GNU Emacs is free software: you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation, either version 3 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | GNU Emacs is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
| 20 | |
| 21 | #include <config.h> |
| 22 | #include <setjmp.h> |
| 23 | #include <lisp.h> |
| 24 | #include <stdio.h> |
| 25 | #include <fcntl.h> |
| 26 | #include <a.out.h> |
| 27 | #include <unistd.h> |
| 28 | #include <assert.h> |
| 29 | |
| 30 | #define DOTEXE ".exe" |
| 31 | |
| 32 | extern int bss_sbrk_did_unexec; |
| 33 | |
| 34 | /* emacs symbols that indicate where bss and data end for emacs internals */ |
| 35 | extern char my_endbss[]; |
| 36 | extern char my_edata[]; |
| 37 | |
| 38 | /* |
| 39 | ** header for Windows executable files |
| 40 | */ |
| 41 | typedef struct |
| 42 | { |
| 43 | FILHDR file_header; |
| 44 | PEAOUTHDR file_optional_header; |
| 45 | SCNHDR section_header[32]; |
| 46 | } exe_header_t; |
| 47 | |
| 48 | int debug_unexcw = 0; |
| 49 | |
| 50 | /* |
| 51 | ** Read the header from the executable into memory so we can more easily access it. |
| 52 | */ |
| 53 | static exe_header_t * |
| 54 | read_exe_header (int fd, exe_header_t * exe_header_buffer) |
| 55 | { |
| 56 | int i; |
| 57 | int ret; |
| 58 | |
| 59 | assert (fd >= 0); |
| 60 | assert (exe_header_buffer != 0); |
| 61 | |
| 62 | ret = lseek (fd, 0L, SEEK_SET); |
| 63 | assert (ret != -1); |
| 64 | |
| 65 | ret = |
| 66 | read (fd, &exe_header_buffer->file_header, |
| 67 | sizeof (exe_header_buffer->file_header)); |
| 68 | assert (ret == sizeof (exe_header_buffer->file_header)); |
| 69 | |
| 70 | assert (exe_header_buffer->file_header.e_magic == 0x5a4d); |
| 71 | assert (exe_header_buffer->file_header.nt_signature == 0x4550); |
| 72 | assert (exe_header_buffer->file_header.f_magic == 0x014c); |
| 73 | assert (exe_header_buffer->file_header.f_nscns > 0); |
| 74 | assert (exe_header_buffer->file_header.f_nscns <= |
| 75 | sizeof (exe_header_buffer->section_header) / |
| 76 | sizeof (exe_header_buffer->section_header[0])); |
| 77 | assert (exe_header_buffer->file_header.f_opthdr > 0); |
| 78 | |
| 79 | ret = |
| 80 | read (fd, &exe_header_buffer->file_optional_header, |
| 81 | sizeof (exe_header_buffer->file_optional_header)); |
| 82 | assert (ret == sizeof (exe_header_buffer->file_optional_header)); |
| 83 | |
| 84 | assert (exe_header_buffer->file_optional_header.magic == 0x010b); |
| 85 | |
| 86 | for (i = 0; i < exe_header_buffer->file_header.f_nscns; ++i) |
| 87 | { |
| 88 | ret = |
| 89 | read (fd, &exe_header_buffer->section_header[i], |
| 90 | sizeof (exe_header_buffer->section_header[i])); |
| 91 | assert (ret == sizeof (exe_header_buffer->section_header[i])); |
| 92 | } |
| 93 | |
| 94 | return (exe_header_buffer); |
| 95 | } |
| 96 | |
| 97 | /* |
| 98 | ** Fix the dumped emacs executable: |
| 99 | ** |
| 100 | ** - copy .data section data of interest from running executable into |
| 101 | ** output .exe file |
| 102 | ** |
| 103 | ** - convert .bss section into an initialized data section (like |
| 104 | ** .data) and copy .bss section data of interest from running |
| 105 | ** executable into output .exe file |
| 106 | */ |
| 107 | static void |
| 108 | fixup_executable (int fd) |
| 109 | { |
| 110 | exe_header_t exe_header_buffer; |
| 111 | exe_header_t *exe_header; |
| 112 | int i; |
| 113 | int ret; |
| 114 | int found_data = 0; |
| 115 | int found_bss = 0; |
| 116 | |
| 117 | exe_header = read_exe_header (fd, &exe_header_buffer); |
| 118 | assert (exe_header != 0); |
| 119 | |
| 120 | assert (exe_header->file_header.f_nscns > 0); |
| 121 | for (i = 0; i < exe_header->file_header.f_nscns; ++i) |
| 122 | { |
| 123 | unsigned long start_address = |
| 124 | exe_header->section_header[i].s_vaddr + |
| 125 | exe_header->file_optional_header.ImageBase; |
| 126 | unsigned long end_address = |
| 127 | exe_header->section_header[i].s_vaddr + |
| 128 | exe_header->file_optional_header.ImageBase + |
| 129 | exe_header->section_header[i].s_paddr; |
| 130 | if (debug_unexcw) |
| 131 | printf ("%8s start 0x%08x end 0x%08x\n", |
| 132 | exe_header->section_header[i].s_name, |
| 133 | start_address, end_address); |
| 134 | if (my_edata >= (char *) start_address |
| 135 | && my_edata < (char *) end_address) |
| 136 | { |
| 137 | /* data section */ |
| 138 | ret = |
| 139 | lseek (fd, (long) (exe_header->section_header[i].s_scnptr), |
| 140 | SEEK_SET); |
| 141 | assert (ret != -1); |
| 142 | ret = |
| 143 | write (fd, (char *) start_address, |
| 144 | my_edata - (char *) start_address); |
| 145 | assert (ret == my_edata - (char *) start_address); |
| 146 | ++found_data; |
| 147 | if (debug_unexcw) |
| 148 | printf (" .data, mem start 0x%08x mem length %d\n", |
| 149 | start_address, my_edata - (char *) start_address); |
| 150 | if (debug_unexcw) |
| 151 | printf (" .data, file start %d file length %d\n", |
| 152 | (int) exe_header->section_header[i].s_scnptr, |
| 153 | (int) exe_header->section_header[i].s_paddr); |
| 154 | } |
| 155 | else if (my_endbss >= (char *) start_address |
| 156 | && my_endbss < (char *) end_address) |
| 157 | { |
| 158 | /* bss section */ |
| 159 | ++found_bss; |
| 160 | if (exe_header->section_header[i].s_flags & 0x00000080) |
| 161 | { |
| 162 | /* convert uninitialized data section to initialized data section */ |
| 163 | struct stat statbuf; |
| 164 | ret = fstat (fd, &statbuf); |
| 165 | assert (ret != -1); |
| 166 | |
| 167 | exe_header->section_header[i].s_flags &= ~0x00000080; |
| 168 | exe_header->section_header[i].s_flags |= 0x00000040; |
| 169 | |
| 170 | exe_header->section_header[i].s_scnptr = |
| 171 | (statbuf.st_size + |
| 172 | exe_header->file_optional_header.FileAlignment) / |
| 173 | exe_header->file_optional_header.FileAlignment * |
| 174 | exe_header->file_optional_header.FileAlignment; |
| 175 | |
| 176 | exe_header->section_header[i].s_size = |
| 177 | (exe_header->section_header[i].s_paddr + |
| 178 | exe_header->file_optional_header.FileAlignment) / |
| 179 | exe_header->file_optional_header.FileAlignment * |
| 180 | exe_header->file_optional_header.FileAlignment; |
| 181 | |
| 182 | ret = |
| 183 | lseek (fd, |
| 184 | (long) (exe_header->section_header[i].s_scnptr + |
| 185 | exe_header->section_header[i].s_size - 1), |
| 186 | SEEK_SET); |
| 187 | assert (ret != -1); |
| 188 | ret = write (fd, "", 1); |
| 189 | assert (ret == 1); |
| 190 | |
| 191 | ret = |
| 192 | lseek (fd, |
| 193 | (long) ((char *) &exe_header->section_header[i] - |
| 194 | (char *) exe_header), SEEK_SET); |
| 195 | assert (ret != -1); |
| 196 | ret = |
| 197 | write (fd, &exe_header->section_header[i], |
| 198 | sizeof (exe_header->section_header[i])); |
| 199 | assert (ret == sizeof (exe_header->section_header[i])); |
| 200 | if (debug_unexcw) |
| 201 | printf (" seek to %ld, write %d\n", |
| 202 | (long) ((char *) &exe_header->section_header[i] - |
| 203 | (char *) exe_header), |
| 204 | sizeof (exe_header->section_header[i])); |
| 205 | } |
| 206 | /* write initialized data section */ |
| 207 | ret = |
| 208 | lseek (fd, (long) (exe_header->section_header[i].s_scnptr), |
| 209 | SEEK_SET); |
| 210 | assert (ret != -1); |
| 211 | ret = |
| 212 | write (fd, (char *) start_address, |
| 213 | my_endbss - (char *) start_address); |
| 214 | assert (ret == (my_endbss - (char *) start_address)); |
| 215 | if (debug_unexcw) |
| 216 | printf (" .bss, mem start 0x%08x mem length %d\n", |
| 217 | start_address, my_endbss - (char *) start_address); |
| 218 | if (debug_unexcw) |
| 219 | printf (" .bss, file start %d file length %d\n", |
| 220 | (int) exe_header->section_header[i].s_scnptr, |
| 221 | (int) exe_header->section_header[i].s_paddr); |
| 222 | } |
| 223 | } |
| 224 | assert (found_bss == 1); |
| 225 | assert (found_data == 1); |
| 226 | } |
| 227 | |
| 228 | /* |
| 229 | ** Windows likes .exe suffixes on executables. |
| 230 | */ |
| 231 | static char * |
| 232 | add_exe_suffix_if_necessary (const char *name, char *modified) |
| 233 | { |
| 234 | int i = strlen (name); |
| 235 | if (i <= (sizeof (DOTEXE) - 1)) |
| 236 | { |
| 237 | sprintf (modified, "%s%s", name, DOTEXE); |
| 238 | } |
| 239 | else if (!strcasecmp (name + i - (sizeof (DOTEXE) - 1), DOTEXE)) |
| 240 | { |
| 241 | strcpy (modified, name); |
| 242 | } |
| 243 | else |
| 244 | { |
| 245 | sprintf (modified, "%s%s", name, DOTEXE); |
| 246 | } |
| 247 | return (modified); |
| 248 | } |
| 249 | |
| 250 | int |
| 251 | unexec (char *outfile, char *infile, unsigned start_data, unsigned d1, |
| 252 | unsigned d2) |
| 253 | { |
| 254 | char infile_buffer[FILENAME_MAX]; |
| 255 | char outfile_buffer[FILENAME_MAX]; |
| 256 | int fd_in; |
| 257 | int fd_out; |
| 258 | int ret; |
| 259 | int ret2; |
| 260 | |
| 261 | if (bss_sbrk_did_unexec) |
| 262 | { |
| 263 | /* can only dump once */ |
| 264 | printf ("You can only dump Emacs once on this platform.\n"); |
| 265 | return (1); |
| 266 | } |
| 267 | |
| 268 | report_sheap_usage (1); |
| 269 | |
| 270 | infile = add_exe_suffix_if_necessary (infile, infile_buffer); |
| 271 | outfile = add_exe_suffix_if_necessary (outfile, outfile_buffer); |
| 272 | |
| 273 | fd_in = open (infile, O_RDONLY | O_BINARY); |
| 274 | assert (fd_in >= 0); |
| 275 | fd_out = open (outfile, O_RDWR | O_TRUNC | O_CREAT | O_BINARY, 0755); |
| 276 | assert (fd_out >= 0); |
| 277 | for (;;) |
| 278 | { |
| 279 | char buffer[4096]; |
| 280 | ret = read (fd_in, buffer, sizeof (buffer)); |
| 281 | if (ret == 0) |
| 282 | { |
| 283 | /* eof */ |
| 284 | break; |
| 285 | } |
| 286 | assert (ret > 0); |
| 287 | /* data */ |
| 288 | ret2 = write (fd_out, buffer, ret); |
| 289 | assert (ret2 == ret); |
| 290 | } |
| 291 | ret = close (fd_in); |
| 292 | assert (ret == 0); |
| 293 | |
| 294 | bss_sbrk_did_unexec = 1; |
| 295 | fixup_executable (fd_out); |
| 296 | bss_sbrk_did_unexec = 0; |
| 297 | |
| 298 | ret = close (fd_out); |
| 299 | assert (ret == 0); |
| 300 | |
| 301 | return (0); |
| 302 | } |
| 303 | |
| 304 | /* arch-tag: fc44f6c3-ca0a-45e0-a5a2-58b6101b1e65 |
| 305 | (do not change this comment) */ |