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3e62da95 SM |
1 | /* unexec() support for Cygwin; |
2 | complete rewrite of xemacs Cygwin unexec() code | |
3 | ||
ab422c4d | 4 | Copyright (C) 2004-2013 Free Software Foundation, Inc. |
3e62da95 SM |
5 | |
6 | This file is part of GNU Emacs. | |
7 | ||
9ec0b715 | 8 | GNU Emacs is free software: you can redistribute it and/or modify |
3e62da95 | 9 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
10 | the Free Software Foundation, either version 3 of the License, or |
11 | (at your option) any later version. | |
3e62da95 SM |
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 | |
9ec0b715 | 19 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
3e62da95 SM |
20 | |
21 | #include <config.h> | |
ce701a33 | 22 | #include "unexec.h" |
501199a3 | 23 | #include "w32common.h" |
ce701a33 | 24 | |
3e62da95 SM |
25 | #include <lisp.h> |
26 | #include <stdio.h> | |
27 | #include <fcntl.h> | |
28 | #include <a.out.h> | |
29 | #include <unistd.h> | |
30 | #include <assert.h> | |
31 | ||
32 | #define DOTEXE ".exe" | |
33 | ||
34 | extern int bss_sbrk_did_unexec; | |
35 | ||
a4579d33 KB |
36 | extern int __malloc_initialized; |
37 | ||
3e62da95 SM |
38 | /* emacs symbols that indicate where bss and data end for emacs internals */ |
39 | extern char my_endbss[]; | |
40 | extern char my_edata[]; | |
41 | ||
42 | /* | |
43 | ** header for Windows executable files | |
44 | */ | |
45 | typedef struct | |
46 | { | |
47 | FILHDR file_header; | |
48 | PEAOUTHDR file_optional_header; | |
49 | SCNHDR section_header[32]; | |
50 | } exe_header_t; | |
51 | ||
52 | int debug_unexcw = 0; | |
53 | ||
54 | /* | |
55 | ** Read the header from the executable into memory so we can more easily access it. | |
56 | */ | |
57 | static exe_header_t * | |
58 | read_exe_header (int fd, exe_header_t * exe_header_buffer) | |
59 | { | |
60 | int i; | |
61 | int ret; | |
62 | ||
63 | assert (fd >= 0); | |
64 | assert (exe_header_buffer != 0); | |
65 | ||
66 | ret = lseek (fd, 0L, SEEK_SET); | |
67 | assert (ret != -1); | |
68 | ||
69 | ret = | |
70 | read (fd, &exe_header_buffer->file_header, | |
71 | sizeof (exe_header_buffer->file_header)); | |
72 | assert (ret == sizeof (exe_header_buffer->file_header)); | |
73 | ||
74 | assert (exe_header_buffer->file_header.e_magic == 0x5a4d); | |
75 | assert (exe_header_buffer->file_header.nt_signature == 0x4550); | |
76 | assert (exe_header_buffer->file_header.f_magic == 0x014c); | |
77 | assert (exe_header_buffer->file_header.f_nscns > 0); | |
78 | assert (exe_header_buffer->file_header.f_nscns <= | |
79 | sizeof (exe_header_buffer->section_header) / | |
80 | sizeof (exe_header_buffer->section_header[0])); | |
81 | assert (exe_header_buffer->file_header.f_opthdr > 0); | |
82 | ||
83 | ret = | |
84 | read (fd, &exe_header_buffer->file_optional_header, | |
85 | sizeof (exe_header_buffer->file_optional_header)); | |
86 | assert (ret == sizeof (exe_header_buffer->file_optional_header)); | |
87 | ||
88 | assert (exe_header_buffer->file_optional_header.magic == 0x010b); | |
89 | ||
90 | for (i = 0; i < exe_header_buffer->file_header.f_nscns; ++i) | |
91 | { | |
92 | ret = | |
93 | read (fd, &exe_header_buffer->section_header[i], | |
94 | sizeof (exe_header_buffer->section_header[i])); | |
95 | assert (ret == sizeof (exe_header_buffer->section_header[i])); | |
96 | } | |
97 | ||
98 | return (exe_header_buffer); | |
99 | } | |
100 | ||
101 | /* | |
102 | ** Fix the dumped emacs executable: | |
103 | ** | |
104 | ** - copy .data section data of interest from running executable into | |
105 | ** output .exe file | |
106 | ** | |
107 | ** - convert .bss section into an initialized data section (like | |
108 | ** .data) and copy .bss section data of interest from running | |
109 | ** executable into output .exe file | |
110 | */ | |
111 | static void | |
112 | fixup_executable (int fd) | |
113 | { | |
114 | exe_header_t exe_header_buffer; | |
115 | exe_header_t *exe_header; | |
116 | int i; | |
117 | int ret; | |
118 | int found_data = 0; | |
119 | int found_bss = 0; | |
120 | ||
121 | exe_header = read_exe_header (fd, &exe_header_buffer); | |
122 | assert (exe_header != 0); | |
123 | ||
124 | assert (exe_header->file_header.f_nscns > 0); | |
125 | for (i = 0; i < exe_header->file_header.f_nscns; ++i) | |
126 | { | |
127 | unsigned long start_address = | |
128 | exe_header->section_header[i].s_vaddr + | |
129 | exe_header->file_optional_header.ImageBase; | |
130 | unsigned long end_address = | |
131 | exe_header->section_header[i].s_vaddr + | |
132 | exe_header->file_optional_header.ImageBase + | |
133 | exe_header->section_header[i].s_paddr; | |
134 | if (debug_unexcw) | |
135 | printf ("%8s start 0x%08x end 0x%08x\n", | |
136 | exe_header->section_header[i].s_name, | |
137 | start_address, end_address); | |
138 | if (my_edata >= (char *) start_address | |
139 | && my_edata < (char *) end_address) | |
140 | { | |
141 | /* data section */ | |
142 | ret = | |
143 | lseek (fd, (long) (exe_header->section_header[i].s_scnptr), | |
144 | SEEK_SET); | |
145 | assert (ret != -1); | |
146 | ret = | |
147 | write (fd, (char *) start_address, | |
148 | my_edata - (char *) start_address); | |
149 | assert (ret == my_edata - (char *) start_address); | |
150 | ++found_data; | |
151 | if (debug_unexcw) | |
152 | printf (" .data, mem start 0x%08x mem length %d\n", | |
153 | start_address, my_edata - (char *) start_address); | |
154 | if (debug_unexcw) | |
155 | printf (" .data, file start %d file length %d\n", | |
156 | (int) exe_header->section_header[i].s_scnptr, | |
157 | (int) exe_header->section_header[i].s_paddr); | |
158 | } | |
159 | else if (my_endbss >= (char *) start_address | |
160 | && my_endbss < (char *) end_address) | |
161 | { | |
162 | /* bss section */ | |
163 | ++found_bss; | |
164 | if (exe_header->section_header[i].s_flags & 0x00000080) | |
165 | { | |
166 | /* convert uninitialized data section to initialized data section */ | |
167 | struct stat statbuf; | |
168 | ret = fstat (fd, &statbuf); | |
169 | assert (ret != -1); | |
170 | ||
171 | exe_header->section_header[i].s_flags &= ~0x00000080; | |
172 | exe_header->section_header[i].s_flags |= 0x00000040; | |
173 | ||
174 | exe_header->section_header[i].s_scnptr = | |
175 | (statbuf.st_size + | |
176 | exe_header->file_optional_header.FileAlignment) / | |
177 | exe_header->file_optional_header.FileAlignment * | |
178 | exe_header->file_optional_header.FileAlignment; | |
179 | ||
180 | exe_header->section_header[i].s_size = | |
181 | (exe_header->section_header[i].s_paddr + | |
182 | exe_header->file_optional_header.FileAlignment) / | |
183 | exe_header->file_optional_header.FileAlignment * | |
184 | exe_header->file_optional_header.FileAlignment; | |
185 | ||
cc98b684 DC |
186 | /* Make sure the generated bootstrap binary isn't |
187 | * sparse. NT doesn't use a file cache for sparse | |
188 | * executables, so if we bootstrap Emacs using a sparse | |
189 | * bootstrap-emacs.exe, bootstrap takes about twenty | |
190 | * times longer than it would otherwise. */ | |
191 | ||
192 | ret = posix_fallocate (fd, | |
193 | ( exe_header->section_header[i].s_scnptr + | |
194 | exe_header->section_header[i].s_size ), | |
195 | 1); | |
196 | ||
197 | assert (ret != -1); | |
198 | ||
3e62da95 SM |
199 | ret = |
200 | lseek (fd, | |
201 | (long) (exe_header->section_header[i].s_scnptr + | |
202 | exe_header->section_header[i].s_size - 1), | |
203 | SEEK_SET); | |
204 | assert (ret != -1); | |
205 | ret = write (fd, "", 1); | |
206 | assert (ret == 1); | |
207 | ||
208 | ret = | |
209 | lseek (fd, | |
210 | (long) ((char *) &exe_header->section_header[i] - | |
211 | (char *) exe_header), SEEK_SET); | |
212 | assert (ret != -1); | |
213 | ret = | |
214 | write (fd, &exe_header->section_header[i], | |
215 | sizeof (exe_header->section_header[i])); | |
216 | assert (ret == sizeof (exe_header->section_header[i])); | |
217 | if (debug_unexcw) | |
218 | printf (" seek to %ld, write %d\n", | |
219 | (long) ((char *) &exe_header->section_header[i] - | |
220 | (char *) exe_header), | |
221 | sizeof (exe_header->section_header[i])); | |
222 | } | |
223 | /* write initialized data section */ | |
224 | ret = | |
225 | lseek (fd, (long) (exe_header->section_header[i].s_scnptr), | |
226 | SEEK_SET); | |
227 | assert (ret != -1); | |
a4579d33 KB |
228 | /* force the dumped emacs to reinitialize malloc */ |
229 | __malloc_initialized = 0; | |
3e62da95 SM |
230 | ret = |
231 | write (fd, (char *) start_address, | |
232 | my_endbss - (char *) start_address); | |
a4579d33 | 233 | __malloc_initialized = 1; |
3e62da95 SM |
234 | assert (ret == (my_endbss - (char *) start_address)); |
235 | if (debug_unexcw) | |
236 | printf (" .bss, mem start 0x%08x mem length %d\n", | |
237 | start_address, my_endbss - (char *) start_address); | |
238 | if (debug_unexcw) | |
239 | printf (" .bss, file start %d file length %d\n", | |
240 | (int) exe_header->section_header[i].s_scnptr, | |
241 | (int) exe_header->section_header[i].s_paddr); | |
242 | } | |
243 | } | |
244 | assert (found_bss == 1); | |
245 | assert (found_data == 1); | |
246 | } | |
247 | ||
248 | /* | |
249 | ** Windows likes .exe suffixes on executables. | |
250 | */ | |
251 | static char * | |
252 | add_exe_suffix_if_necessary (const char *name, char *modified) | |
253 | { | |
254 | int i = strlen (name); | |
255 | if (i <= (sizeof (DOTEXE) - 1)) | |
256 | { | |
257 | sprintf (modified, "%s%s", name, DOTEXE); | |
258 | } | |
259 | else if (!strcasecmp (name + i - (sizeof (DOTEXE) - 1), DOTEXE)) | |
260 | { | |
261 | strcpy (modified, name); | |
262 | } | |
263 | else | |
264 | { | |
265 | sprintf (modified, "%s%s", name, DOTEXE); | |
266 | } | |
267 | return (modified); | |
268 | } | |
269 | ||
381259ef | 270 | void |
dd5ecd6b | 271 | unexec (const char *outfile, const char *infile) |
3e62da95 SM |
272 | { |
273 | char infile_buffer[FILENAME_MAX]; | |
274 | char outfile_buffer[FILENAME_MAX]; | |
275 | int fd_in; | |
276 | int fd_out; | |
277 | int ret; | |
278 | int ret2; | |
279 | ||
280 | if (bss_sbrk_did_unexec) | |
281 | { | |
282 | /* can only dump once */ | |
60a294e2 | 283 | printf ("You can only dump Emacs once on this platform.\n"); |
fffe2e14 | 284 | return; |
3e62da95 SM |
285 | } |
286 | ||
287 | report_sheap_usage (1); | |
288 | ||
289 | infile = add_exe_suffix_if_necessary (infile, infile_buffer); | |
290 | outfile = add_exe_suffix_if_necessary (outfile, outfile_buffer); | |
291 | ||
292 | fd_in = open (infile, O_RDONLY | O_BINARY); | |
293 | assert (fd_in >= 0); | |
294 | fd_out = open (outfile, O_RDWR | O_TRUNC | O_CREAT | O_BINARY, 0755); | |
295 | assert (fd_out >= 0); | |
296 | for (;;) | |
297 | { | |
298 | char buffer[4096]; | |
299 | ret = read (fd_in, buffer, sizeof (buffer)); | |
300 | if (ret == 0) | |
301 | { | |
302 | /* eof */ | |
303 | break; | |
304 | } | |
305 | assert (ret > 0); | |
306 | /* data */ | |
307 | ret2 = write (fd_out, buffer, ret); | |
308 | assert (ret2 == ret); | |
309 | } | |
310 | ret = close (fd_in); | |
311 | assert (ret == 0); | |
312 | ||
313 | bss_sbrk_did_unexec = 1; | |
314 | fixup_executable (fd_out); | |
315 | bss_sbrk_did_unexec = 0; | |
316 | ||
317 | ret = close (fd_out); | |
318 | assert (ret == 0); | |
3e62da95 | 319 | } |