1 /* unexec() support for Cygwin;
2 complete rewrite of xemacs Cygwin unexec() code
4 Copyright (C) 2004-2017 Free Software Foundation, Inc.
6 This file is part of GNU Emacs.
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 (at
11 your option) any later version.
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.
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/>. */
33 extern void report_sheap_usage (int);
35 extern int bss_sbrk_did_unexec
;
38 ** header for Windows executable files
43 PEAOUTHDR file_optional_header
;
44 SCNHDR section_header
[32];
50 ** Read the header from the executable into memory so we can more easily access it.
53 read_exe_header (int fd
, exe_header_t
* exe_header_buffer
)
59 assert (exe_header_buffer
!= 0);
61 ret
= lseek (fd
, 0L, SEEK_SET
);
65 read (fd
, &exe_header_buffer
->file_header
,
66 sizeof (exe_header_buffer
->file_header
));
67 assert (ret
== sizeof (exe_header_buffer
->file_header
));
69 assert (exe_header_buffer
->file_header
.e_magic
== 0x5a4d);
70 assert (exe_header_buffer
->file_header
.nt_signature
== 0x4550);
72 assert (exe_header_buffer
->file_header
.f_magic
== 0x8664);
74 assert (exe_header_buffer
->file_header
.f_magic
== 0x014c);
76 assert (exe_header_buffer
->file_header
.f_nscns
> 0);
77 assert (exe_header_buffer
->file_header
.f_nscns
<=
78 ARRAYELTS (exe_header_buffer
->section_header
));
79 assert (exe_header_buffer
->file_header
.f_opthdr
> 0);
82 read (fd
, &exe_header_buffer
->file_optional_header
,
83 sizeof (exe_header_buffer
->file_optional_header
));
84 assert (ret
== sizeof (exe_header_buffer
->file_optional_header
));
87 assert (exe_header_buffer
->file_optional_header
.magic
== 0x020b);
89 assert (exe_header_buffer
->file_optional_header
.magic
== 0x010b);
92 for (i
= 0; i
< exe_header_buffer
->file_header
.f_nscns
; ++i
)
95 read (fd
, &exe_header_buffer
->section_header
[i
],
96 sizeof (exe_header_buffer
->section_header
[i
]));
97 assert (ret
== sizeof (exe_header_buffer
->section_header
[i
]));
100 return (exe_header_buffer
);
104 ** Fix the dumped emacs executable:
106 ** - copy .data section data of interest from running executable into
109 ** - convert .bss section into an initialized data section (like
110 ** .data) and copy .bss section data of interest from running
111 ** executable into output .exe file
114 fixup_executable (int fd
)
116 exe_header_t exe_header_buffer
;
117 exe_header_t
*exe_header
;
123 exe_header
= read_exe_header (fd
, &exe_header_buffer
);
124 assert (exe_header
!= 0);
126 assert (exe_header
->file_header
.f_nscns
> 0);
127 for (i
= 0; i
< exe_header
->file_header
.f_nscns
; ++i
)
129 unsigned long start_address
=
130 exe_header
->section_header
[i
].s_vaddr
+
131 exe_header
->file_optional_header
.ImageBase
;
132 unsigned long end_address
=
133 exe_header
->section_header
[i
].s_vaddr
+
134 exe_header
->file_optional_header
.ImageBase
+
135 exe_header
->section_header
[i
].s_paddr
;
137 printf ("%8s start %#lx end %#lx\n",
138 exe_header
->section_header
[i
].s_name
,
139 start_address
, end_address
);
140 if (my_edata
>= (char *) start_address
141 && my_edata
< (char *) end_address
)
145 lseek (fd
, (long) (exe_header
->section_header
[i
].s_scnptr
),
149 write (fd
, (char *) start_address
,
150 my_edata
- (char *) start_address
);
151 assert (ret
== my_edata
- (char *) start_address
);
154 printf (" .data, mem start %#lx mem length %d\n",
155 start_address
, my_edata
- (char *) start_address
);
157 printf (" .data, file start %d file length %d\n",
158 (int) exe_header
->section_header
[i
].s_scnptr
,
159 (int) exe_header
->section_header
[i
].s_paddr
);
161 else if (my_endbss
>= (char *) start_address
162 && my_endbss
< (char *) end_address
)
166 if (exe_header
->section_header
[i
].s_flags
& 0x00000080)
168 /* convert uninitialized data section to initialized data section */
170 ret
= fstat (fd
, &statbuf
);
173 exe_header
->section_header
[i
].s_flags
&= ~0x00000080;
174 exe_header
->section_header
[i
].s_flags
|= 0x00000040;
176 exe_header
->section_header
[i
].s_scnptr
=
178 exe_header
->file_optional_header
.FileAlignment
) /
179 exe_header
->file_optional_header
.FileAlignment
*
180 exe_header
->file_optional_header
.FileAlignment
;
182 exe_header
->section_header
[i
].s_size
=
183 (exe_header
->section_header
[i
].s_paddr
+
184 exe_header
->file_optional_header
.FileAlignment
) /
185 exe_header
->file_optional_header
.FileAlignment
*
186 exe_header
->file_optional_header
.FileAlignment
;
188 /* Make sure the generated bootstrap binary isn't
189 * sparse. NT doesn't use a file cache for sparse
190 * executables, so if we bootstrap Emacs using a sparse
191 * bootstrap-emacs.exe, bootstrap takes about twenty
192 * times longer than it would otherwise. */
194 ret
= posix_fallocate (fd
,
195 ( exe_header
->section_header
[i
].s_scnptr
+
196 exe_header
->section_header
[i
].s_size
),
203 (long) (exe_header
->section_header
[i
].s_scnptr
+
204 exe_header
->section_header
[i
].s_size
- 1),
207 ret
= write (fd
, "", 1);
212 (long) ((char *) &exe_header
->section_header
[i
] -
213 (char *) exe_header
), SEEK_SET
);
216 write (fd
, &exe_header
->section_header
[i
],
217 sizeof (exe_header
->section_header
[i
]));
218 assert (ret
== sizeof (exe_header
->section_header
[i
]));
220 printf (" seek to %ld, write %d\n",
221 (long) ((char *) &exe_header
->section_header
[i
] -
222 (char *) exe_header
),
223 sizeof (exe_header
->section_header
[i
]));
225 /* write initialized data section */
227 lseek (fd
, (long) (exe_header
->section_header
[i
].s_scnptr
),
231 write (fd
, (char *) start_address
,
232 my_endbss
- (char *) start_address
);
233 assert (ret
== (my_endbss
- (char *) start_address
));
235 printf (" .bss, mem start %#lx mem length %d\n",
236 start_address
, my_endbss
- (char *) start_address
);
238 printf (" .bss, file start %d file length %d\n",
239 (int) exe_header
->section_header
[i
].s_scnptr
,
240 (int) exe_header
->section_header
[i
].s_paddr
);
243 assert (found_bss
== 1);
244 assert (found_data
== 1);
248 ** Windows likes .exe suffixes on executables.
251 add_exe_suffix_if_necessary (const char *name
, char *modified
)
253 int i
= strlen (name
);
254 if (i
<= (sizeof (DOTEXE
) - 1))
256 sprintf (modified
, "%s%s", name
, DOTEXE
);
258 else if (!strcasecmp (name
+ i
- (sizeof (DOTEXE
) - 1), DOTEXE
))
260 strcpy (modified
, name
);
264 sprintf (modified
, "%s%s", name
, DOTEXE
);
270 unexec (const char *outfile
, const char *infile
)
272 char infile_buffer
[FILENAME_MAX
];
273 char outfile_buffer
[FILENAME_MAX
];
279 report_sheap_usage (1);
281 infile
= add_exe_suffix_if_necessary (infile
, infile_buffer
);
282 outfile
= add_exe_suffix_if_necessary (outfile
, outfile_buffer
);
284 fd_in
= emacs_open (infile
, O_RDONLY
| O_BINARY
, 0);
286 fd_out
= emacs_open (outfile
, O_RDWR
| O_TRUNC
| O_CREAT
| O_BINARY
, 0755);
287 assert (fd_out
>= 0);
291 ret
= read (fd_in
, buffer
, sizeof (buffer
));
299 ret2
= write (fd_out
, buffer
, ret
);
300 assert (ret2
== ret
);
302 ret
= emacs_close (fd_in
);
305 bss_sbrk_did_unexec
= 1;
306 fixup_executable (fd_out
);
307 bss_sbrk_did_unexec
= 0;
309 ret
= emacs_close (fd_out
);