1 | /* AIX cross support for collect2. |
2 | Copyright (C) 2009-2024 Free Software Foundation, Inc. |
3 | |
4 | This file is part of GCC. |
5 | |
6 | GCC is free software; you can redistribute it and/or modify it under |
7 | the terms of the GNU General Public License as published by the Free |
8 | Software Foundation; either version 3, or (at your option) any later |
9 | version. |
10 | |
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
12 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
13 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
14 | for more details. |
15 | |
16 | You should have received a copy of the GNU General Public License |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #include "config.h" |
21 | #include "system.h" |
22 | #include "coretypes.h" |
23 | #include "tm.h" |
24 | #include "collect2-aix.h" |
25 | |
26 | #ifdef CROSS_AIX_SUPPORT |
27 | |
28 | /* Read SIZE bytes starting at DATA as a big-endian value. */ |
29 | |
30 | static inline bfd_vma |
31 | read_value (char *data, unsigned int size) |
32 | { |
33 | bfd_vma value; |
34 | unsigned int i; |
35 | |
36 | value = 0; |
37 | for (i = 0; i < size; i++) |
38 | { |
39 | value <<= 8; |
40 | value += (unsigned char) data[i]; |
41 | } |
42 | return value; |
43 | } |
44 | |
45 | /* FIELD is a char array. Read the contents as a big-endian integer. */ |
46 | #define READ_FIELD(FIELD) \ |
47 | read_value (FIELD, sizeof (FIELD)) |
48 | |
49 | /* OBJECT is a char pointer to an in-file object of type struct TYPE. |
50 | Return the address of field FIELD. */ |
51 | #define OBJECT_FIELD(OBJECT, TYPE, FIELD) \ |
52 | (OBJECT) + offsetof (struct TYPE, FIELD) |
53 | |
54 | /* Return the size of FIELD, which is a field of struct TYPE. */ |
55 | #define FIELD_SIZE(TYPE, FIELD) \ |
56 | sizeof (((struct TYPE *) (0))->FIELD) |
57 | |
58 | /* OBJECT is a char pointer to an in-file object of type struct TYPE. |
59 | Read the value of field FIELD as a big-endian integer. */ |
60 | #define READ_OBJECT(OBJECT, TYPE, FIELD) \ |
61 | read_value (OBJECT_FIELD (OBJECT, TYPE, FIELD), FIELD_SIZE (TYPE, FIELD)) |
62 | |
63 | /* Copy FIELD from an external structure of type TYPE at address FROM |
64 | to an internal structure pointed to by TO. */ |
65 | #define COPY_FIELD(TO, FROM, TYPE, FIELD) \ |
66 | ((TO)->FIELD = READ_OBJECT (FROM, TYPE, FIELD)) |
67 | |
68 | /* Return true if STRING is less than SIZE bytes long. EXTRA_TERMINATOR |
69 | is another character (besides '\0') that acts as a terminator, |
70 | or '\0' if none. */ |
71 | |
72 | static bool |
73 | string_within_bounds_p (const char *string, size_t size, char extra_terminator) |
74 | { |
75 | const char *p; |
76 | |
77 | for (p = string; p < string + size; p++) |
78 | if (*p == '\0' || *p == extra_terminator) |
79 | return true; |
80 | return false; |
81 | } |
82 | |
83 | /* STRING is a pointer to a char array. Try to read its value as an |
84 | ASCII-encoded integer. On success, return true and store the result |
85 | in TARGET. */ |
86 | #define PARSE_INTEGER(TARGET, STRING) \ |
87 | (string_within_bounds_p (&(STRING)[0], sizeof (STRING), ' ') \ |
88 | && ((TARGET) = strtoul (STRING, NULL, 0), true)) |
89 | |
90 | /* Check that LDFILE's current object has SIZE bytes starting at OFFSET. */ |
91 | |
92 | static inline bool |
93 | within_object_p (LDFILE *ldfile, size_t offset, size_t size) |
94 | { |
95 | return offset <= ldfile->object_size && offset + size <= ldfile->object_size; |
96 | } |
97 | |
98 | /* Try to read the file header for an XCOFF object at OFFSET bytes into |
99 | LDFILE. The object is expected to be OBJECT_SIZE bytes in size. |
100 | If the object is a member of an archive, NEXT_MEMBER is the offset |
101 | of the next member, otherwise it is -1. |
102 | |
103 | Return true on success, recording the object information in LDFILE. */ |
104 | |
105 | static bool |
106 | read_xcoff_object (LDFILE *ldfile, size_t offset, size_t object_size, |
107 | off_t next_member) |
108 | { |
109 | struct internal_filehdr *internal; |
110 | char *external; |
111 | void *map; |
112 | size_t page_size; |
113 | |
114 | /* First try to map the file into memory. */ |
115 | page_size = getpagesize (); |
116 | ldfile->page_offset = offset & (page_size - 1); |
117 | map = mmap (NULL, object_size + ldfile->page_offset, PROT_READ, |
118 | MAP_SHARED, ldfile->fd, offset - ldfile->page_offset); |
119 | if (map == MAP_FAILED) |
120 | return false; |
121 | |
122 | /* Record the success. */ |
123 | ldfile->object = (char *) map + ldfile->page_offset; |
124 | ldfile->object_size = object_size; |
125 | ldfile->next_member = next_member; |
126 | |
127 | /* Read the magic value to determine the type of file. */ |
128 | if (!within_object_p (ldfile, 0, F_MAGIC_SIZE)) |
129 | return false; |
130 | |
131 | internal = &ldfile->filehdr; |
132 | external = ldfile->object; |
133 | internal->f_magic = read_value (external, F_MAGIC_SIZE); |
134 | if (internal->f_magic == U802TOCMAGIC) |
135 | { |
136 | if (!within_object_p (ldfile, 0, sizeof (struct external_filehdr_32))) |
137 | return false; |
138 | |
139 | COPY_FIELD (internal, external, external_filehdr_32, f_nscns); |
140 | COPY_FIELD (internal, external, external_filehdr_32, f_timdat); |
141 | COPY_FIELD (internal, external, external_filehdr_32, f_symptr); |
142 | COPY_FIELD (internal, external, external_filehdr_32, f_nsyms); |
143 | COPY_FIELD (internal, external, external_filehdr_32, f_opthdr); |
144 | COPY_FIELD (internal, external, external_filehdr_32, f_flags); |
145 | return true; |
146 | } |
147 | else if (internal->f_magic == U803XTOCMAGIC |
148 | || internal->f_magic == U64_TOCMAGIC) |
149 | { |
150 | if (!within_object_p (ldfile, 0, sizeof (struct external_filehdr_64))) |
151 | return false; |
152 | |
153 | COPY_FIELD (internal, external, external_filehdr_64, f_nscns); |
154 | COPY_FIELD (internal, external, external_filehdr_64, f_timdat); |
155 | COPY_FIELD (internal, external, external_filehdr_64, f_symptr); |
156 | COPY_FIELD (internal, external, external_filehdr_64, f_nsyms); |
157 | COPY_FIELD (internal, external, external_filehdr_64, f_opthdr); |
158 | COPY_FIELD (internal, external, external_filehdr_64, f_flags); |
159 | return true; |
160 | } |
161 | return false; |
162 | } |
163 | |
164 | /* Try to read an archive member at OFFSET bytes into LDFILE. |
165 | Return true on success, recording the member and object |
166 | information in LDFILE. */ |
167 | |
168 | static bool |
169 | read_archive_member (LDFILE *ldfile, size_t offset) |
170 | { |
171 | struct external_big_ar_member member; |
172 | size_t namlen; |
173 | size_t size; |
174 | off_t next_member; |
175 | |
176 | if (lseek (ldfile->fd, offset, SEEK_SET) >= 0 |
177 | && read (ldfile->fd, &member, sizeof (member)) == sizeof (member) |
178 | && PARSE_INTEGER (namlen, member.ar_namlen) |
179 | /* Stop once we reach the member table entry, which has a name |
180 | of length 0. */ |
181 | && namlen > 0 |
182 | && PARSE_INTEGER (size, member.ar_size) |
183 | && PARSE_INTEGER (next_member, member.ar_nextoff)) |
184 | { |
185 | /* The archive is followed by an even-padded name, then by |
186 | a magic string of length SXCOFFARFMAG. The object itself |
187 | starts after that. */ |
188 | offset += sizeof (member) + namlen + SXCOFFARFMAG; |
189 | offset += offset & 1; |
190 | return read_xcoff_object (ldfile, offset, size, next_member); |
191 | } |
192 | return false; |
193 | } |
194 | |
195 | /* Try to treat LDFILE as a non-empty big archive. Return true |
196 | on success, storing the member and object information for |
197 | the first member in LDFILE. */ |
198 | |
199 | static bool |
200 | read_big_archive (LDFILE *ldfile) |
201 | { |
202 | struct external_big_ar_filehdr filehdr; |
203 | size_t offset; |
204 | |
205 | return (lseek (ldfile->fd, 0L, SEEK_SET) == 0 |
206 | && read (ldfile->fd, &filehdr, sizeof (filehdr)) == sizeof (filehdr) |
207 | && memcmp (filehdr.fl_magic, FL_MAGIC_BIG_AR, FL_MAGIC_SIZE) == 0 |
208 | && PARSE_INTEGER (offset, filehdr.fl_firstmemoff) |
209 | && read_archive_member (ldfile, offset)); |
210 | } |
211 | |
212 | /* LDFILE is a zero-initialized structure. Try to open FILENAME, |
213 | returning true on success. */ |
214 | |
215 | static bool |
216 | open_file (LDFILE *ldfile, const char *filename) |
217 | { |
218 | struct stat st; |
219 | |
220 | ldfile->fd = open (filename, O_RDONLY); |
221 | if (ldfile->fd < 0) |
222 | return false; |
223 | |
224 | if (read_big_archive (ldfile)) |
225 | return true; |
226 | |
227 | if (fstat (ldfile->fd, &st) < 0) |
228 | return false; |
229 | |
230 | return read_xcoff_object (ldfile, 0, st.st_size, -1); |
231 | } |
232 | |
233 | /* Release the memory associated with the current object, if one has |
234 | been mapped. */ |
235 | |
236 | static void |
237 | free_object (LDFILE *ldfile) |
238 | { |
239 | if (ldfile->object) |
240 | munmap (ldfile->object - ldfile->page_offset, |
241 | ldfile->object_size + ldfile->page_offset); |
242 | } |
243 | |
244 | /* Free LDFILE and all resources associated with it. */ |
245 | |
246 | static void |
247 | free_ldfile (LDFILE *ldfile) |
248 | { |
249 | if (ldfile->fd >= 0) |
250 | close (ldfile->fd); |
251 | XDELETE (ldfile); |
252 | } |
253 | |
254 | /* Implement the API-defined ldopen function. */ |
255 | |
256 | LDFILE * |
257 | ldopen (char *filename, LDFILE *ldfile) |
258 | { |
259 | if (ldfile == NULL) |
260 | { |
261 | ldfile = XCNEW (LDFILE); |
262 | if (!open_file (ldfile, filename)) |
263 | { |
264 | free_object (ldfile); |
265 | free_ldfile (ldfile); |
266 | return NULL; |
267 | } |
268 | } |
269 | return ldfile; |
270 | } |
271 | |
272 | /* Implement the API-defined ldtbread function. */ |
273 | |
274 | int |
275 | ldtbread (LDFILE *ldfile, long index, SYMENT *internal) |
276 | { |
277 | size_t offset, name_length; |
278 | char *external; |
279 | |
280 | /* Make sure that the symbol index is valid. */ |
281 | if (index < 0 || index >= HEADER (ldfile).f_nsyms) |
282 | return FAILURE; |
283 | |
284 | /* Work out the offset of the symbol table entry. */ |
285 | offset = HEADER (ldfile).f_symptr + index * sizeof (struct external_syment); |
286 | if (!within_object_p (ldfile, offset, sizeof (struct external_syment))) |
287 | return FAILURE; |
288 | |
289 | /* Read all the fields. The format differs between 32-bit and |
290 | 64-bit files. */ |
291 | external = ldfile->object + offset; |
292 | if (HEADER (ldfile).f_magic == U802TOCMAGIC) |
293 | { |
294 | /* Copy the n_zeroes/n_offset interpretation. */ |
295 | internal->n_zeroes = READ_OBJECT (external, external_syment, |
296 | u.xcoff32.u.u.n_zeroes); |
297 | internal->n_offset = READ_OBJECT (external, external_syment, |
298 | u.xcoff32.u.u.n_offset); |
299 | |
300 | /* Copy the n_name interpretation. The internal version has room |
301 | for a null terminator. */ |
302 | name_length = FIELD_SIZE (external_syment, u.xcoff32.u.n_name); |
303 | memcpy (internal->n_name, |
304 | external + offsetof (struct external_syment, u.xcoff32.u.n_name), |
305 | name_length); |
306 | internal->n_name[name_length] = 0; |
307 | |
308 | internal->n_value = READ_OBJECT (external, external_syment, |
309 | u.xcoff32.n_value); |
310 | } |
311 | else |
312 | { |
313 | internal->n_zeroes = 0; |
314 | internal->n_offset = READ_OBJECT (external, external_syment, |
315 | u.xcoff64.n_offset); |
316 | internal->n_value = READ_OBJECT (external, external_syment, |
317 | u.xcoff64.n_value); |
318 | } |
319 | COPY_FIELD (internal, external, external_syment, n_scnum); |
320 | COPY_FIELD (internal, external, external_syment, n_type); |
321 | COPY_FIELD (internal, external, external_syment, n_sclass); |
322 | COPY_FIELD (internal, external, external_syment, n_numaux); |
323 | return SUCCESS; |
324 | } |
325 | |
326 | /* Implement the API-defined ldgetname function. */ |
327 | |
328 | char * |
329 | ldgetname (LDFILE *ldfile, SYMENT *symbol) |
330 | { |
331 | char *name; |
332 | size_t offset; |
333 | |
334 | /* If the zeroes field is nonzero, the name is in the symbol table |
335 | entry itself. */ |
336 | if (symbol->n_zeroes != 0) |
337 | return symbol->n_name; |
338 | |
339 | /* Otherwise, the symbol table entry contains an offset into the |
340 | string table, which starts after the end of the symbol table. */ |
341 | offset = (HEADER (ldfile).f_symptr |
342 | + HEADER (ldfile).f_nsyms * sizeof (struct external_syment) |
343 | + symbol->n_offset); |
344 | if (offset >= ldfile->object_size) |
345 | return NULL; |
346 | |
347 | /* Make sure that the name is entirely contained within the object. */ |
348 | name = ldfile->object + offset; |
349 | if (!string_within_bounds_p (name, ldfile->object_size - offset, '\0')) |
350 | return NULL; |
351 | |
352 | return name; |
353 | } |
354 | |
355 | /* Implement the API-defined ldclose function. */ |
356 | |
357 | int |
358 | ldclose (LDFILE *ldfile) |
359 | { |
360 | free_object (ldfile); |
361 | if (ldfile->next_member >= 0 |
362 | && read_archive_member (ldfile, ldfile->next_member)) |
363 | return FAILURE; |
364 | |
365 | free_ldfile (ldfile); |
366 | return SUCCESS; |
367 | } |
368 | |
369 | #endif |
370 | |