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> | |
c1401ecc | 28 | #include <unistd.h> |
143dce84 NA |
29 | #include <elf.h> |
30 | #include <bfd.h> | |
cf02c44d NA |
31 | #include "swap.h" |
32 | #include "ctf-endian.h" | |
143dce84 NA |
33 | |
34 | #include "elf-bfd.h" | |
35 | ||
f046147d | 36 | /* Free the BFD bits of a CTF file on ctf_arc_close(). */ |
143dce84 NA |
37 | |
38 | static void | |
39 | ctf_bfdclose (struct ctf_archive_internal *arci) | |
40 | { | |
41 | if (arci->ctfi_abfd != NULL) | |
42 | if (!bfd_close_all_done (arci->ctfi_abfd)) | |
43 | ctf_dprintf ("Cannot close BFD: %s\n", bfd_errmsg (bfd_get_error())); | |
44 | } | |
45 | ||
46 | /* Open a CTF file given the specified BFD. */ | |
47 | ||
48 | ctf_archive_t * | |
49 | ctf_bfdopen (struct bfd *abfd, int *errp) | |
50 | { | |
51 | ctf_archive_t *arc; | |
52 | asection *ctf_asect; | |
53 | bfd_byte *contents; | |
54 | ctf_sect_t ctfsect; | |
55 | ||
56 | libctf_init_debug(); | |
57 | ||
58 | if ((ctf_asect = bfd_get_section_by_name (abfd, _CTF_SECTION)) == NULL) | |
59 | { | |
60 | return (ctf_set_open_errno (errp, ECTF_NOCTFDATA)); | |
61 | } | |
62 | ||
63 | if (!bfd_malloc_and_get_section (abfd, ctf_asect, &contents)) | |
64 | { | |
65 | ctf_dprintf ("ctf_bfdopen(): cannot malloc CTF section: %s\n", | |
66 | bfd_errmsg (bfd_get_error())); | |
67 | return (ctf_set_open_errno (errp, ECTF_FMT)); | |
68 | } | |
69 | ||
70 | ctfsect.cts_name = _CTF_SECTION; | |
143dce84 | 71 | ctfsect.cts_entsize = 1; |
fd361982 | 72 | ctfsect.cts_size = bfd_section_size (ctf_asect); |
143dce84 NA |
73 | ctfsect.cts_data = contents; |
74 | ||
75 | if ((arc = ctf_bfdopen_ctfsect (abfd, &ctfsect, errp)) != NULL) | |
76 | { | |
2f6ecaed | 77 | /* This frees the cts_data later. */ |
143dce84 NA |
78 | arc->ctfi_data = (void *) ctfsect.cts_data; |
79 | return arc; | |
80 | } | |
81 | ||
82 | free (contents); | |
83 | return NULL; /* errno is set for us. */ | |
84 | } | |
85 | ||
86 | /* Open a CTF file given the specified BFD and CTF section (which may contain a | |
2f6ecaed | 87 | CTF archive or a file). */ |
143dce84 NA |
88 | |
89 | ctf_archive_t * | |
9698cf9b NA |
90 | ctf_bfdopen_ctfsect (struct bfd *abfd _libctf_unused_, |
91 | const ctf_sect_t *ctfsect, int *errp) | |
143dce84 | 92 | { |
143dce84 | 93 | ctf_archive_t *arci; |
143dce84 NA |
94 | ctf_sect_t *symsectp = NULL; |
95 | ctf_sect_t *strsectp = NULL; | |
96 | const char *bfderrstr = NULL; | |
d50c0802 | 97 | char *strtab_alloc = NULL; |
143dce84 | 98 | |
9698cf9b | 99 | #ifdef HAVE_BFD_ELF |
143dce84 | 100 | ctf_sect_t symsect, strsect; |
6d5944fc | 101 | Elf_Internal_Shdr *symhdr = &elf_symtab_hdr (abfd); |
d50c0802 | 102 | size_t symcount; |
6d5944fc | 103 | Elf_Internal_Sym *isymbuf; |
d50c0802 | 104 | bfd_byte *symtab = NULL; |
6d5944fc | 105 | const char *strtab = NULL; |
d50c0802 | 106 | size_t strsize; |
143dce84 NA |
107 | /* TODO: handle SYMTAB_SHNDX. */ |
108 | ||
d50c0802 NA |
109 | /* Get the symtab, and the strtab associated with it. */ |
110 | if (elf_tdata (abfd) && symhdr && symhdr->sh_size && symhdr->sh_entsize) | |
143dce84 | 111 | { |
d50c0802 NA |
112 | symcount = symhdr->sh_size / symhdr->sh_entsize; |
113 | if ((symtab = malloc (symhdr->sh_size)) == NULL) | |
114 | { | |
115 | bfderrstr = "Cannot malloc symbol table"; | |
116 | goto err; | |
117 | } | |
143dce84 | 118 | |
d50c0802 NA |
119 | isymbuf = bfd_elf_get_elf_syms (abfd, symhdr, symcount, 0, |
120 | NULL, symtab, NULL); | |
121 | free (isymbuf); | |
122 | if (isymbuf == NULL) | |
123 | { | |
124 | bfderrstr = "Cannot read symbol table"; | |
125 | goto err_free_sym; | |
126 | } | |
127 | ||
128 | if (elf_elfsections (abfd) != NULL | |
129 | && symhdr->sh_link < elf_numsections (abfd)) | |
130 | { | |
131 | Elf_Internal_Shdr *strhdr = elf_elfsections (abfd)[symhdr->sh_link]; | |
143dce84 | 132 | |
d50c0802 NA |
133 | strsize = strhdr->sh_size; |
134 | if (strhdr->contents == NULL) | |
135 | { | |
136 | if ((strtab = bfd_elf_get_str_section (abfd, symhdr->sh_link)) == NULL) | |
137 | { | |
138 | bfderrstr = "Cannot read string table"; | |
139 | goto err_free_sym; | |
140 | } | |
141 | } | |
142 | else | |
143 | strtab = (const char *) strhdr->contents; | |
144 | } | |
145 | } | |
146 | else /* No symtab: just try getting .strtab by name. */ | |
6d5944fc | 147 | { |
d50c0802 NA |
148 | bfd_byte *str_bcontents; |
149 | asection *str_asect; | |
150 | ||
151 | if ((str_asect = bfd_get_section_by_name (abfd, ".strtab")) != NULL) | |
143dce84 | 152 | { |
d50c0802 | 153 | if (bfd_malloc_and_get_section (abfd, str_asect, &str_bcontents)) |
143dce84 | 154 | { |
d50c0802 NA |
155 | strtab = (const char *) str_bcontents; |
156 | strtab_alloc = (char *) str_bcontents; | |
157 | strsize = str_asect->size; | |
143dce84 | 158 | } |
143dce84 | 159 | } |
6d5944fc NA |
160 | } |
161 | ||
162 | if (strtab) | |
163 | { | |
164 | /* The names here are more or less arbitrary, but there is no point | |
165 | thrashing around digging the name out of the shstrtab given that we don't | |
166 | use it for anything but debugging. */ | |
167 | ||
168 | strsect.cts_data = strtab; | |
169 | strsect.cts_name = ".strtab"; | |
d50c0802 | 170 | strsect.cts_size = strsize; |
6d5944fc | 171 | strsectp = &strsect; |
d50c0802 | 172 | } |
6d5944fc | 173 | |
d50c0802 NA |
174 | if (symtab) |
175 | { | |
6d5944fc NA |
176 | assert (symhdr->sh_entsize == get_elf_backend_data (abfd)->s->sizeof_sym); |
177 | symsect.cts_name = ".symtab"; | |
178 | symsect.cts_entsize = symhdr->sh_entsize; | |
179 | symsect.cts_size = symhdr->sh_size; | |
180 | symsect.cts_data = symtab; | |
181 | symsectp = &symsect; | |
143dce84 | 182 | } |
9698cf9b | 183 | #endif |
143dce84 | 184 | |
2f6ecaed NA |
185 | arci = ctf_arc_bufopen (ctfsect, symsectp, strsectp, errp); |
186 | if (arci) | |
143dce84 | 187 | { |
d50c0802 | 188 | /* Request freeing of the symsect and possibly the strsect. */ |
2f6ecaed | 189 | arci->ctfi_free_symsect = 1; |
d50c0802 NA |
190 | if (strtab_alloc) |
191 | arci->ctfi_free_strsect = 1; | |
2f6ecaed | 192 | return arci; |
143dce84 | 193 | } |
9698cf9b | 194 | #ifdef HAVE_BFD_ELF |
6d5944fc NA |
195 | err_free_sym: |
196 | free (symtab); | |
d50c0802 | 197 | free (strtab_alloc); |
9698cf9b | 198 | #endif |
143dce84 NA |
199 | err: _libctf_unused_; |
200 | if (bfderrstr) | |
201 | { | |
202 | ctf_dprintf ("ctf_bfdopen(): %s: %s\n", bfderrstr, | |
203 | bfd_errmsg (bfd_get_error())); | |
204 | ctf_set_open_errno (errp, ECTF_FMT); | |
205 | } | |
206 | return NULL; | |
207 | } | |
208 | ||
209 | /* Open the specified file descriptor and return a pointer to a CTF archive that | |
210 | contains one or more CTF containers. The file can be an ELF file, a raw CTF | |
211 | file, or a CTF archive. The caller is responsible for closing the file | |
212 | descriptor when it is no longer needed. If this is an ELF file, TARGET, if | |
213 | non-NULL, should be the name of a suitable BFD target. */ | |
214 | ||
215 | ctf_archive_t * | |
216 | ctf_fdopen (int fd, const char *filename, const char *target, int *errp) | |
217 | { | |
218 | ctf_archive_t *arci; | |
219 | bfd *abfd; | |
220 | int nfd; | |
221 | ||
222 | struct stat st; | |
223 | ssize_t nbytes; | |
224 | ||
225 | ctf_preamble_t ctfhdr; | |
226 | uint64_t arc_magic; | |
227 | ||
228 | memset (&ctfhdr, 0, sizeof (ctfhdr)); | |
229 | ||
230 | libctf_init_debug(); | |
231 | ||
232 | if (fstat (fd, &st) == -1) | |
233 | return (ctf_set_open_errno (errp, errno)); | |
234 | ||
235 | if ((nbytes = ctf_pread (fd, &ctfhdr, sizeof (ctfhdr), 0)) <= 0) | |
236 | return (ctf_set_open_errno (errp, nbytes < 0 ? errno : ECTF_FMT)); | |
237 | ||
cf02c44d NA |
238 | /* If we have read enough bytes to form a CTF header and the magic string |
239 | matches, in either endianness, attempt to interpret the file as raw | |
240 | CTF. */ | |
143dce84 | 241 | |
cf02c44d NA |
242 | if ((size_t) nbytes >= sizeof (ctf_preamble_t) |
243 | && (ctfhdr.ctp_magic == CTF_MAGIC | |
244 | || ctfhdr.ctp_magic == bswap_16 (CTF_MAGIC))) | |
143dce84 NA |
245 | { |
246 | ctf_file_t *fp = NULL; | |
247 | void *data; | |
248 | ||
143dce84 NA |
249 | if ((data = ctf_mmap (st.st_size, 0, fd)) == NULL) |
250 | return (ctf_set_open_errno (errp, errno)); | |
251 | ||
252 | if ((fp = ctf_simple_open (data, (size_t) st.st_size, NULL, 0, 0, | |
253 | NULL, 0, errp)) == NULL) | |
cf02c44d NA |
254 | { |
255 | ctf_munmap (data, (size_t) st.st_size); | |
256 | return NULL; /* errno is set for us. */ | |
257 | } | |
258 | ||
143dce84 NA |
259 | fp->ctf_data_mmapped = data; |
260 | fp->ctf_data_mmapped_len = (size_t) st.st_size; | |
261 | ||
601e455b | 262 | return ctf_new_archive_internal (0, 1, NULL, fp, NULL, NULL, errp); |
143dce84 NA |
263 | } |
264 | ||
265 | if ((nbytes = ctf_pread (fd, &arc_magic, sizeof (arc_magic), 0)) <= 0) | |
266 | return (ctf_set_open_errno (errp, nbytes < 0 ? errno : ECTF_FMT)); | |
267 | ||
cf02c44d | 268 | if ((size_t) nbytes >= sizeof (uint64_t) && le64toh (arc_magic) == CTFA_MAGIC) |
143dce84 NA |
269 | { |
270 | struct ctf_archive *arc; | |
271 | ||
272 | if ((arc = ctf_arc_open_internal (filename, errp)) == NULL) | |
273 | return NULL; /* errno is set for us. */ | |
274 | ||
601e455b | 275 | return ctf_new_archive_internal (1, 1, arc, NULL, NULL, NULL, errp); |
143dce84 NA |
276 | } |
277 | ||
278 | /* Attempt to open the file with BFD. We must dup the fd first, since bfd | |
279 | takes ownership of the passed fd. */ | |
280 | ||
281 | if ((nfd = dup (fd)) < 0) | |
282 | return (ctf_set_open_errno (errp, errno)); | |
283 | ||
284 | if ((abfd = bfd_fdopenr (filename, target, nfd)) == NULL) | |
285 | { | |
286 | ctf_dprintf ("Cannot open BFD from %s: %s\n", | |
287 | filename ? filename : "(unknown file)", | |
288 | bfd_errmsg (bfd_get_error())); | |
289 | return (ctf_set_open_errno (errp, ECTF_FMT)); | |
290 | } | |
edc8bbe9 | 291 | bfd_set_cacheable (abfd, 1); |
143dce84 NA |
292 | |
293 | if (!bfd_check_format (abfd, bfd_object)) | |
294 | { | |
295 | ctf_dprintf ("BFD format problem in %s: %s\n", | |
296 | filename ? filename : "(unknown file)", | |
297 | bfd_errmsg (bfd_get_error())); | |
298 | if (bfd_get_error() == bfd_error_file_ambiguously_recognized) | |
299 | return (ctf_set_open_errno (errp, ECTF_BFD_AMBIGUOUS)); | |
300 | else | |
301 | return (ctf_set_open_errno (errp, ECTF_FMT)); | |
302 | } | |
303 | ||
304 | if ((arci = ctf_bfdopen (abfd, errp)) == NULL) | |
305 | { | |
306 | if (!bfd_close_all_done (abfd)) | |
307 | ctf_dprintf ("Cannot close BFD: %s\n", bfd_errmsg (bfd_get_error())); | |
308 | return NULL; /* errno is set for us. */ | |
309 | } | |
310 | arci->ctfi_bfd_close = ctf_bfdclose; | |
311 | arci->ctfi_abfd = abfd; | |
312 | ||
313 | return arci; | |
314 | } | |
315 | ||
316 | /* Open the specified file and return a pointer to a CTF container. The file | |
317 | can be either an ELF file or raw CTF file. This is just a convenient | |
318 | wrapper around ctf_fdopen() for callers. */ | |
319 | ||
320 | ctf_archive_t * | |
321 | ctf_open (const char *filename, const char *target, int *errp) | |
322 | { | |
323 | ctf_archive_t *arc; | |
324 | int fd; | |
325 | ||
326 | if ((fd = open (filename, O_RDONLY)) == -1) | |
327 | { | |
328 | if (errp != NULL) | |
329 | *errp = errno; | |
330 | return NULL; | |
331 | } | |
332 | ||
333 | arc = ctf_fdopen (fd, filename, target, errp); | |
334 | (void) close (fd); | |
335 | return arc; | |
336 | } | |
337 | ||
338 | /* Public entry point: open a CTF archive, or CTF file. Returns the archive, or | |
339 | NULL and an error in *err. Despite the fact that this uses CTF archives, it | |
340 | must be in this file to avoid dragging in BFD into non-BFD-using programs. */ | |
341 | ctf_archive_t * | |
342 | ctf_arc_open (const char *filename, int *errp) | |
343 | { | |
344 | return ctf_open (filename, NULL, errp); | |
345 | } |