Commit | Line | Data |
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143dce84 | 1 | /* Opening CTF files with BFD. |
b3adc24a | 2 | Copyright (C) 2019-2020 Free Software Foundation, Inc. |
143dce84 NA |
3 | |
4 | This file is part of libctf. | |
5 | ||
6 | libctf 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 | This program is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
14 | See the GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program; see the file COPYING. If not see | |
18 | <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #include <ctf-impl.h> | |
21 | #include <stddef.h> | |
6d5944fc | 22 | #include <assert.h> |
143dce84 NA |
23 | #include <sys/types.h> |
24 | #include <sys/stat.h> | |
25 | #include <errno.h> | |
26 | #include <string.h> | |
27 | #include <fcntl.h> | |
28 | #include <elf.h> | |
29 | #include <bfd.h> | |
cf02c44d NA |
30 | #include "swap.h" |
31 | #include "ctf-endian.h" | |
143dce84 NA |
32 | |
33 | #include "elf-bfd.h" | |
34 | ||
35 | /* Make a new struct ctf_archive_internal wrapper for a ctf_archive or a | |
6d5944fc NA |
36 | ctf_file. Closes ARC and/or FP on error. Arrange to free the SYMSECT or |
37 | STRSECT, as needed, on close (though the STRSECT interior is bound to the bfd | |
38 | * and is not actually freed by this machinery). */ | |
143dce84 NA |
39 | |
40 | static struct ctf_archive_internal * | |
41 | ctf_new_archive_internal (int is_archive, struct ctf_archive *arc, | |
42 | ctf_file_t *fp, const ctf_sect_t *symsect, | |
43 | const ctf_sect_t *strsect, | |
44 | int *errp) | |
45 | { | |
46 | struct ctf_archive_internal *arci; | |
47 | ||
48 | if ((arci = calloc (1, sizeof (struct ctf_archive_internal))) == NULL) | |
49 | { | |
50 | if (is_archive) | |
51 | ctf_arc_close_internal (arc); | |
52 | else | |
53 | ctf_file_close (fp); | |
54 | return (ctf_set_open_errno (errp, errno)); | |
55 | } | |
56 | arci->ctfi_is_archive = is_archive; | |
57 | if (is_archive) | |
58 | arci->ctfi_archive = arc; | |
59 | else | |
60 | arci->ctfi_file = fp; | |
61 | if (symsect) | |
62 | memcpy (&arci->ctfi_symsect, symsect, sizeof (struct ctf_sect)); | |
63 | if (strsect) | |
64 | memcpy (&arci->ctfi_strsect, strsect, sizeof (struct ctf_sect)); | |
65 | ||
66 | return arci; | |
67 | } | |
68 | ||
f046147d | 69 | /* Free the BFD bits of a CTF file on ctf_arc_close(). */ |
143dce84 NA |
70 | |
71 | static void | |
72 | ctf_bfdclose (struct ctf_archive_internal *arci) | |
73 | { | |
74 | if (arci->ctfi_abfd != NULL) | |
75 | if (!bfd_close_all_done (arci->ctfi_abfd)) | |
76 | ctf_dprintf ("Cannot close BFD: %s\n", bfd_errmsg (bfd_get_error())); | |
77 | } | |
78 | ||
79 | /* Open a CTF file given the specified BFD. */ | |
80 | ||
81 | ctf_archive_t * | |
82 | ctf_bfdopen (struct bfd *abfd, int *errp) | |
83 | { | |
84 | ctf_archive_t *arc; | |
85 | asection *ctf_asect; | |
86 | bfd_byte *contents; | |
87 | ctf_sect_t ctfsect; | |
88 | ||
89 | libctf_init_debug(); | |
90 | ||
91 | if ((ctf_asect = bfd_get_section_by_name (abfd, _CTF_SECTION)) == NULL) | |
92 | { | |
93 | return (ctf_set_open_errno (errp, ECTF_NOCTFDATA)); | |
94 | } | |
95 | ||
96 | if (!bfd_malloc_and_get_section (abfd, ctf_asect, &contents)) | |
97 | { | |
98 | ctf_dprintf ("ctf_bfdopen(): cannot malloc CTF section: %s\n", | |
99 | bfd_errmsg (bfd_get_error())); | |
100 | return (ctf_set_open_errno (errp, ECTF_FMT)); | |
101 | } | |
102 | ||
103 | ctfsect.cts_name = _CTF_SECTION; | |
143dce84 | 104 | ctfsect.cts_entsize = 1; |
fd361982 | 105 | ctfsect.cts_size = bfd_section_size (ctf_asect); |
143dce84 NA |
106 | ctfsect.cts_data = contents; |
107 | ||
108 | if ((arc = ctf_bfdopen_ctfsect (abfd, &ctfsect, errp)) != NULL) | |
109 | { | |
110 | arc->ctfi_data = (void *) ctfsect.cts_data; | |
111 | return arc; | |
112 | } | |
113 | ||
114 | free (contents); | |
115 | return NULL; /* errno is set for us. */ | |
116 | } | |
117 | ||
118 | /* Open a CTF file given the specified BFD and CTF section (which may contain a | |
119 | CTF archive or a file). Takes ownership of the ctfsect, and frees it | |
120 | later. */ | |
121 | ||
122 | ctf_archive_t * | |
9698cf9b NA |
123 | ctf_bfdopen_ctfsect (struct bfd *abfd _libctf_unused_, |
124 | const ctf_sect_t *ctfsect, int *errp) | |
143dce84 NA |
125 | { |
126 | struct ctf_archive *arc = NULL; | |
127 | ctf_archive_t *arci; | |
128 | ctf_file_t *fp = NULL; | |
129 | ctf_sect_t *symsectp = NULL; | |
130 | ctf_sect_t *strsectp = NULL; | |
131 | const char *bfderrstr = NULL; | |
132 | int is_archive; | |
133 | ||
9698cf9b | 134 | #ifdef HAVE_BFD_ELF |
143dce84 | 135 | ctf_sect_t symsect, strsect; |
6d5944fc NA |
136 | Elf_Internal_Shdr *strhdr; |
137 | Elf_Internal_Shdr *symhdr = &elf_symtab_hdr (abfd); | |
138 | size_t symcount = symhdr->sh_size / symhdr->sh_entsize; | |
139 | Elf_Internal_Sym *isymbuf; | |
140 | bfd_byte *symtab; | |
141 | const char *strtab = NULL; | |
143dce84 NA |
142 | /* TODO: handle SYMTAB_SHNDX. */ |
143 | ||
6d5944fc | 144 | if ((symtab = malloc (symhdr->sh_size)) == NULL) |
143dce84 | 145 | { |
6d5944fc NA |
146 | bfderrstr = "Cannot malloc symbol table"; |
147 | goto err; | |
148 | } | |
143dce84 | 149 | |
6d5944fc NA |
150 | isymbuf = bfd_elf_get_elf_syms (abfd, symhdr, symcount, 0, |
151 | NULL, symtab, NULL); | |
152 | free (isymbuf); | |
153 | if (isymbuf == NULL) | |
154 | { | |
155 | bfderrstr = "Cannot read symbol table"; | |
156 | goto err_free_sym; | |
157 | } | |
143dce84 | 158 | |
6d5944fc NA |
159 | if (elf_elfsections (abfd) != NULL |
160 | && symhdr->sh_link < elf_numsections (abfd)) | |
161 | { | |
162 | strhdr = elf_elfsections (abfd)[symhdr->sh_link]; | |
163 | if (strhdr->contents == NULL) | |
143dce84 | 164 | { |
6d5944fc | 165 | if ((strtab = bfd_elf_get_str_section (abfd, symhdr->sh_link)) == NULL) |
143dce84 | 166 | { |
6d5944fc NA |
167 | bfderrstr = "Cannot read string table"; |
168 | goto err_free_sym; | |
143dce84 | 169 | } |
143dce84 | 170 | } |
6d5944fc NA |
171 | else |
172 | strtab = (const char *) strhdr->contents; | |
173 | } | |
174 | ||
175 | if (strtab) | |
176 | { | |
177 | /* The names here are more or less arbitrary, but there is no point | |
178 | thrashing around digging the name out of the shstrtab given that we don't | |
179 | use it for anything but debugging. */ | |
180 | ||
181 | strsect.cts_data = strtab; | |
182 | strsect.cts_name = ".strtab"; | |
183 | strsect.cts_size = strhdr->sh_size; | |
184 | strsectp = &strsect; | |
185 | ||
186 | assert (symhdr->sh_entsize == get_elf_backend_data (abfd)->s->sizeof_sym); | |
187 | symsect.cts_name = ".symtab"; | |
188 | symsect.cts_entsize = symhdr->sh_entsize; | |
189 | symsect.cts_size = symhdr->sh_size; | |
190 | symsect.cts_data = symtab; | |
191 | symsectp = &symsect; | |
143dce84 | 192 | } |
9698cf9b | 193 | #endif |
143dce84 NA |
194 | |
195 | if (ctfsect->cts_size > sizeof (uint64_t) && | |
196 | ((*(uint64_t *) ctfsect->cts_data) == CTFA_MAGIC)) | |
197 | { | |
198 | is_archive = 1; | |
199 | if ((arc = ctf_arc_bufopen ((void *) ctfsect->cts_data, | |
200 | ctfsect->cts_size, errp)) == NULL) | |
6d5944fc | 201 | goto err_free_str; |
143dce84 NA |
202 | } |
203 | else | |
204 | { | |
205 | is_archive = 0; | |
206 | if ((fp = ctf_bufopen (ctfsect, symsectp, strsectp, errp)) == NULL) | |
207 | { | |
208 | ctf_dprintf ("ctf_internal_open(): cannot open CTF: %s\n", | |
209 | ctf_errmsg (*errp)); | |
6d5944fc | 210 | goto err_free_str; |
143dce84 NA |
211 | } |
212 | } | |
213 | arci = ctf_new_archive_internal (is_archive, arc, fp, symsectp, strsectp, | |
214 | errp); | |
215 | ||
216 | if (arci) | |
217 | return arci; | |
6d5944fc | 218 | err_free_str: ; |
9698cf9b | 219 | #ifdef HAVE_BFD_ELF |
6d5944fc NA |
220 | err_free_sym: |
221 | free (symtab); | |
9698cf9b | 222 | #endif |
143dce84 NA |
223 | err: _libctf_unused_; |
224 | if (bfderrstr) | |
225 | { | |
226 | ctf_dprintf ("ctf_bfdopen(): %s: %s\n", bfderrstr, | |
227 | bfd_errmsg (bfd_get_error())); | |
228 | ctf_set_open_errno (errp, ECTF_FMT); | |
229 | } | |
230 | return NULL; | |
231 | } | |
232 | ||
233 | /* Open the specified file descriptor and return a pointer to a CTF archive that | |
234 | contains one or more CTF containers. The file can be an ELF file, a raw CTF | |
235 | file, or a CTF archive. The caller is responsible for closing the file | |
236 | descriptor when it is no longer needed. If this is an ELF file, TARGET, if | |
237 | non-NULL, should be the name of a suitable BFD target. */ | |
238 | ||
239 | ctf_archive_t * | |
240 | ctf_fdopen (int fd, const char *filename, const char *target, int *errp) | |
241 | { | |
242 | ctf_archive_t *arci; | |
243 | bfd *abfd; | |
244 | int nfd; | |
245 | ||
246 | struct stat st; | |
247 | ssize_t nbytes; | |
248 | ||
249 | ctf_preamble_t ctfhdr; | |
250 | uint64_t arc_magic; | |
251 | ||
252 | memset (&ctfhdr, 0, sizeof (ctfhdr)); | |
253 | ||
254 | libctf_init_debug(); | |
255 | ||
256 | if (fstat (fd, &st) == -1) | |
257 | return (ctf_set_open_errno (errp, errno)); | |
258 | ||
259 | if ((nbytes = ctf_pread (fd, &ctfhdr, sizeof (ctfhdr), 0)) <= 0) | |
260 | return (ctf_set_open_errno (errp, nbytes < 0 ? errno : ECTF_FMT)); | |
261 | ||
cf02c44d NA |
262 | /* If we have read enough bytes to form a CTF header and the magic string |
263 | matches, in either endianness, attempt to interpret the file as raw | |
264 | CTF. */ | |
143dce84 | 265 | |
cf02c44d NA |
266 | if ((size_t) nbytes >= sizeof (ctf_preamble_t) |
267 | && (ctfhdr.ctp_magic == CTF_MAGIC | |
268 | || ctfhdr.ctp_magic == bswap_16 (CTF_MAGIC))) | |
143dce84 NA |
269 | { |
270 | ctf_file_t *fp = NULL; | |
271 | void *data; | |
272 | ||
143dce84 NA |
273 | if ((data = ctf_mmap (st.st_size, 0, fd)) == NULL) |
274 | return (ctf_set_open_errno (errp, errno)); | |
275 | ||
276 | if ((fp = ctf_simple_open (data, (size_t) st.st_size, NULL, 0, 0, | |
277 | NULL, 0, errp)) == NULL) | |
cf02c44d NA |
278 | { |
279 | ctf_munmap (data, (size_t) st.st_size); | |
280 | return NULL; /* errno is set for us. */ | |
281 | } | |
282 | ||
143dce84 NA |
283 | fp->ctf_data_mmapped = data; |
284 | fp->ctf_data_mmapped_len = (size_t) st.st_size; | |
285 | ||
286 | return ctf_new_archive_internal (0, NULL, fp, NULL, NULL, errp); | |
287 | } | |
288 | ||
289 | if ((nbytes = ctf_pread (fd, &arc_magic, sizeof (arc_magic), 0)) <= 0) | |
290 | return (ctf_set_open_errno (errp, nbytes < 0 ? errno : ECTF_FMT)); | |
291 | ||
cf02c44d | 292 | if ((size_t) nbytes >= sizeof (uint64_t) && le64toh (arc_magic) == CTFA_MAGIC) |
143dce84 NA |
293 | { |
294 | struct ctf_archive *arc; | |
295 | ||
296 | if ((arc = ctf_arc_open_internal (filename, errp)) == NULL) | |
297 | return NULL; /* errno is set for us. */ | |
298 | ||
299 | return ctf_new_archive_internal (1, arc, NULL, NULL, NULL, errp); | |
300 | } | |
301 | ||
302 | /* Attempt to open the file with BFD. We must dup the fd first, since bfd | |
303 | takes ownership of the passed fd. */ | |
304 | ||
305 | if ((nfd = dup (fd)) < 0) | |
306 | return (ctf_set_open_errno (errp, errno)); | |
307 | ||
308 | if ((abfd = bfd_fdopenr (filename, target, nfd)) == NULL) | |
309 | { | |
310 | ctf_dprintf ("Cannot open BFD from %s: %s\n", | |
311 | filename ? filename : "(unknown file)", | |
312 | bfd_errmsg (bfd_get_error())); | |
313 | return (ctf_set_open_errno (errp, ECTF_FMT)); | |
314 | } | |
edc8bbe9 | 315 | bfd_set_cacheable (abfd, 1); |
143dce84 NA |
316 | |
317 | if (!bfd_check_format (abfd, bfd_object)) | |
318 | { | |
319 | ctf_dprintf ("BFD format problem in %s: %s\n", | |
320 | filename ? filename : "(unknown file)", | |
321 | bfd_errmsg (bfd_get_error())); | |
322 | if (bfd_get_error() == bfd_error_file_ambiguously_recognized) | |
323 | return (ctf_set_open_errno (errp, ECTF_BFD_AMBIGUOUS)); | |
324 | else | |
325 | return (ctf_set_open_errno (errp, ECTF_FMT)); | |
326 | } | |
327 | ||
328 | if ((arci = ctf_bfdopen (abfd, errp)) == NULL) | |
329 | { | |
330 | if (!bfd_close_all_done (abfd)) | |
331 | ctf_dprintf ("Cannot close BFD: %s\n", bfd_errmsg (bfd_get_error())); | |
332 | return NULL; /* errno is set for us. */ | |
333 | } | |
334 | arci->ctfi_bfd_close = ctf_bfdclose; | |
335 | arci->ctfi_abfd = abfd; | |
336 | ||
337 | return arci; | |
338 | } | |
339 | ||
340 | /* Open the specified file and return a pointer to a CTF container. The file | |
341 | can be either an ELF file or raw CTF file. This is just a convenient | |
342 | wrapper around ctf_fdopen() for callers. */ | |
343 | ||
344 | ctf_archive_t * | |
345 | ctf_open (const char *filename, const char *target, int *errp) | |
346 | { | |
347 | ctf_archive_t *arc; | |
348 | int fd; | |
349 | ||
350 | if ((fd = open (filename, O_RDONLY)) == -1) | |
351 | { | |
352 | if (errp != NULL) | |
353 | *errp = errno; | |
354 | return NULL; | |
355 | } | |
356 | ||
357 | arc = ctf_fdopen (fd, filename, target, errp); | |
358 | (void) close (fd); | |
359 | return arc; | |
360 | } | |
361 | ||
362 | /* Public entry point: open a CTF archive, or CTF file. Returns the archive, or | |
363 | NULL and an error in *err. Despite the fact that this uses CTF archives, it | |
364 | must be in this file to avoid dragging in BFD into non-BFD-using programs. */ | |
365 | ctf_archive_t * | |
366 | ctf_arc_open (const char *filename, int *errp) | |
367 | { | |
368 | return ctf_open (filename, NULL, errp); | |
369 | } |