1 /* unexec() support for Cygwin;
2 complete rewrite of xemacs Cygwin unexec() code
4 Copyright (C) 2004-2012 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
11 (at 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 int bss_sbrk_did_unexec
;
35 extern int __malloc_initialized
;
37 /* emacs symbols that indicate where bss and data end for emacs internals */
38 extern char my_endbss
[];
39 extern char my_edata
[];
42 ** header for Windows executable files
47 PEAOUTHDR file_optional_header
;
48 SCNHDR section_header
[32];
54 ** Read the header from the executable into memory so we can more easily access it.
57 read_exe_header (int fd
, exe_header_t
* exe_header_buffer
)
63 assert (exe_header_buffer
!= 0);
65 ret
= lseek (fd
, 0L, SEEK_SET
);
69 read (fd
, &exe_header_buffer
->file_header
,
70 sizeof (exe_header_buffer
->file_header
));
71 assert (ret
== sizeof (exe_header_buffer
->file_header
));
73 assert (exe_header_buffer
->file_header
.e_magic
== 0x5a4d);
74 assert (exe_header_buffer
->file_header
.nt_signature
== 0x4550);
75 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 sizeof (exe_header_buffer
->section_header
) /
79 sizeof (exe_header_buffer
->section_header
[0]));
80 assert (exe_header_buffer
->file_header
.f_opthdr
> 0);
83 read (fd
, &exe_header_buffer
->file_optional_header
,
84 sizeof (exe_header_buffer
->file_optional_header
));
85 assert (ret
== sizeof (exe_header_buffer
->file_optional_header
));
87 assert (exe_header_buffer
->file_optional_header
.magic
== 0x010b);
89 for (i
= 0; i
< exe_header_buffer
->file_header
.f_nscns
; ++i
)
92 read (fd
, &exe_header_buffer
->section_header
[i
],
93 sizeof (exe_header_buffer
->section_header
[i
]));
94 assert (ret
== sizeof (exe_header_buffer
->section_header
[i
]));
97 return (exe_header_buffer
);
101 ** Fix the dumped emacs executable:
103 ** - copy .data section data of interest from running executable into
106 ** - convert .bss section into an initialized data section (like
107 ** .data) and copy .bss section data of interest from running
108 ** executable into output .exe file
111 fixup_executable (int fd
)
113 exe_header_t exe_header_buffer
;
114 exe_header_t
*exe_header
;
120 exe_header
= read_exe_header (fd
, &exe_header_buffer
);
121 assert (exe_header
!= 0);
123 assert (exe_header
->file_header
.f_nscns
> 0);
124 for (i
= 0; i
< exe_header
->file_header
.f_nscns
; ++i
)
126 unsigned long start_address
=
127 exe_header
->section_header
[i
].s_vaddr
+
128 exe_header
->file_optional_header
.ImageBase
;
129 unsigned long end_address
=
130 exe_header
->section_header
[i
].s_vaddr
+
131 exe_header
->file_optional_header
.ImageBase
+
132 exe_header
->section_header
[i
].s_paddr
;
134 printf ("%8s start 0x%08x end 0x%08x\n",
135 exe_header
->section_header
[i
].s_name
,
136 start_address
, end_address
);
137 if (my_edata
>= (char *) start_address
138 && my_edata
< (char *) end_address
)
142 lseek (fd
, (long) (exe_header
->section_header
[i
].s_scnptr
),
146 write (fd
, (char *) start_address
,
147 my_edata
- (char *) start_address
);
148 assert (ret
== my_edata
- (char *) start_address
);
151 printf (" .data, mem start 0x%08x mem length %d\n",
152 start_address
, my_edata
- (char *) start_address
);
154 printf (" .data, file start %d file length %d\n",
155 (int) exe_header
->section_header
[i
].s_scnptr
,
156 (int) exe_header
->section_header
[i
].s_paddr
);
158 else if (my_endbss
>= (char *) start_address
159 && my_endbss
< (char *) end_address
)
163 if (exe_header
->section_header
[i
].s_flags
& 0x00000080)
165 /* convert uninitialized data section to initialized data section */
167 ret
= fstat (fd
, &statbuf
);
170 exe_header
->section_header
[i
].s_flags
&= ~0x00000080;
171 exe_header
->section_header
[i
].s_flags
|= 0x00000040;
173 exe_header
->section_header
[i
].s_scnptr
=
175 exe_header
->file_optional_header
.FileAlignment
) /
176 exe_header
->file_optional_header
.FileAlignment
*
177 exe_header
->file_optional_header
.FileAlignment
;
179 exe_header
->section_header
[i
].s_size
=
180 (exe_header
->section_header
[i
].s_paddr
+
181 exe_header
->file_optional_header
.FileAlignment
) /
182 exe_header
->file_optional_header
.FileAlignment
*
183 exe_header
->file_optional_header
.FileAlignment
;
187 (long) (exe_header
->section_header
[i
].s_scnptr
+
188 exe_header
->section_header
[i
].s_size
- 1),
191 ret
= write (fd
, "", 1);
196 (long) ((char *) &exe_header
->section_header
[i
] -
197 (char *) exe_header
), SEEK_SET
);
200 write (fd
, &exe_header
->section_header
[i
],
201 sizeof (exe_header
->section_header
[i
]));
202 assert (ret
== sizeof (exe_header
->section_header
[i
]));
204 printf (" seek to %ld, write %d\n",
205 (long) ((char *) &exe_header
->section_header
[i
] -
206 (char *) exe_header
),
207 sizeof (exe_header
->section_header
[i
]));
209 /* write initialized data section */
211 lseek (fd
, (long) (exe_header
->section_header
[i
].s_scnptr
),
214 /* force the dumped emacs to reinitialize malloc */
215 __malloc_initialized
= 0;
217 write (fd
, (char *) start_address
,
218 my_endbss
- (char *) start_address
);
219 __malloc_initialized
= 1;
220 assert (ret
== (my_endbss
- (char *) start_address
));
222 printf (" .bss, mem start 0x%08x mem length %d\n",
223 start_address
, my_endbss
- (char *) start_address
);
225 printf (" .bss, file start %d file length %d\n",
226 (int) exe_header
->section_header
[i
].s_scnptr
,
227 (int) exe_header
->section_header
[i
].s_paddr
);
230 assert (found_bss
== 1);
231 assert (found_data
== 1);
235 ** Windows likes .exe suffixes on executables.
238 add_exe_suffix_if_necessary (const char *name
, char *modified
)
240 int i
= strlen (name
);
241 if (i
<= (sizeof (DOTEXE
) - 1))
243 sprintf (modified
, "%s%s", name
, DOTEXE
);
245 else if (!strcasecmp (name
+ i
- (sizeof (DOTEXE
) - 1), DOTEXE
))
247 strcpy (modified
, name
);
251 sprintf (modified
, "%s%s", name
, DOTEXE
);
257 unexec (const char *outfile
, const char *infile
)
259 char infile_buffer
[FILENAME_MAX
];
260 char outfile_buffer
[FILENAME_MAX
];
266 if (bss_sbrk_did_unexec
)
268 /* can only dump once */
269 printf ("You can only dump Emacs once on this platform.\n");
273 report_sheap_usage (1);
275 infile
= add_exe_suffix_if_necessary (infile
, infile_buffer
);
276 outfile
= add_exe_suffix_if_necessary (outfile
, outfile_buffer
);
278 fd_in
= open (infile
, O_RDONLY
| O_BINARY
);
280 fd_out
= open (outfile
, O_RDWR
| O_TRUNC
| O_CREAT
| O_BINARY
, 0755);
281 assert (fd_out
>= 0);
285 ret
= read (fd_in
, buffer
, sizeof (buffer
));
293 ret2
= write (fd_out
, buffer
, ret
);
294 assert (ret2
== ret
);
299 bss_sbrk_did_unexec
= 1;
300 fixup_executable (fd_out
);
301 bss_sbrk_did_unexec
= 0;
303 ret
= close (fd_out
);