1 /* Opening CTF files with BFD.
2 Copyright (C) 2019 Free Software Foundation, Inc.
4 This file is part of libctf.
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
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.
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/>. */
22 #include <sys/types.h>
32 /* Make a new struct ctf_archive_internal wrapper for a ctf_archive or a
33 ctf_file. Closes ARC and/or FP on error. Arrange to free the SYMSECT and
34 STRSECT interior on close. */
36 static struct ctf_archive_internal *
37 ctf_new_archive_internal (int is_archive, struct ctf_archive *arc,
38 ctf_file_t *fp, const ctf_sect_t *symsect,
39 const ctf_sect_t *strsect,
42 struct ctf_archive_internal *arci;
44 if ((arci = calloc (1, sizeof (struct ctf_archive_internal))) == NULL)
47 ctf_arc_close_internal (arc);
50 return (ctf_set_open_errno (errp, errno));
52 arci->ctfi_is_archive = is_archive;
54 arci->ctfi_archive = arc;
58 memcpy (&arci->ctfi_symsect, symsect, sizeof (struct ctf_sect));
60 memcpy (&arci->ctfi_strsect, strsect, sizeof (struct ctf_sect));
65 /* Free the BFD bits of a CTF file on ctf_file_close(). */
68 ctf_bfdclose (struct ctf_archive_internal *arci)
70 if (arci->ctfi_abfd != NULL)
71 if (!bfd_close_all_done (arci->ctfi_abfd))
72 ctf_dprintf ("Cannot close BFD: %s\n", bfd_errmsg (bfd_get_error()));
75 /* Open a CTF file given the specified BFD. */
78 ctf_bfdopen (struct bfd *abfd, int *errp)
87 if ((ctf_asect = bfd_get_section_by_name (abfd, _CTF_SECTION)) == NULL)
89 return (ctf_set_open_errno (errp, ECTF_NOCTFDATA));
92 if (!bfd_malloc_and_get_section (abfd, ctf_asect, &contents))
94 ctf_dprintf ("ctf_bfdopen(): cannot malloc CTF section: %s\n",
95 bfd_errmsg (bfd_get_error()));
96 return (ctf_set_open_errno (errp, ECTF_FMT));
99 ctfsect.cts_name = _CTF_SECTION;
100 ctfsect.cts_type = SHT_PROGBITS;
101 ctfsect.cts_flags = 0;
102 ctfsect.cts_entsize = 1;
103 ctfsect.cts_offset = 0;
104 ctfsect.cts_size = bfd_section_size (abfd, ctf_asect);
105 ctfsect.cts_data = contents;
107 if ((arc = ctf_bfdopen_ctfsect (abfd, &ctfsect, errp)) != NULL)
109 arc->ctfi_data = (void *) ctfsect.cts_data;
114 return NULL; /* errno is set for us. */
117 /* Open a CTF file given the specified BFD and CTF section (which may contain a
118 CTF archive or a file). Takes ownership of the ctfsect, and frees it
122 ctf_bfdopen_ctfsect (struct bfd *abfd, const ctf_sect_t *ctfsect, int *errp)
124 struct ctf_archive *arc = NULL;
126 ctf_file_t *fp = NULL;
127 ctf_sect_t *symsectp = NULL;
128 ctf_sect_t *strsectp = NULL;
129 const char *bfderrstr = NULL;
133 ctf_sect_t symsect, strsect;
134 /* TODO: handle SYMTAB_SHNDX. */
136 if ((sym_asect = bfd_section_from_elf_index (abfd,
137 elf_onesymtab (abfd))) != NULL)
139 Elf_Internal_Shdr *symhdr = &elf_symtab_hdr (abfd);
140 asection *str_asect = NULL;
143 if (symhdr->sh_link != SHN_UNDEF &&
144 symhdr->sh_link <= elf_numsections (abfd))
145 str_asect = bfd_section_from_elf_index (abfd, symhdr->sh_link);
147 Elf_Internal_Shdr *strhdr = elf_elfsections (abfd)[symhdr->sh_link];
149 if (sym_asect && str_asect)
151 if (!bfd_malloc_and_get_section (abfd, str_asect, &contents))
153 bfderrstr = "Cannot malloc string table";
157 strsect.cts_data = contents;
158 strsect.cts_name = (char *) strsect.cts_data + strhdr->sh_name;
159 strsect.cts_type = strhdr->sh_type;
160 strsect.cts_flags = strhdr->sh_flags;
161 strsect.cts_entsize = strhdr->sh_size;
162 strsect.cts_offset = strhdr->sh_offset;
165 if (!bfd_malloc_and_get_section (abfd, sym_asect, &contents))
167 bfderrstr = "Cannot malloc symbol table";
172 symsect.cts_name = (char *) strsect.cts_data + symhdr->sh_name;
173 symsect.cts_type = symhdr->sh_type;
174 symsect.cts_flags = symhdr->sh_flags;
175 symsect.cts_entsize = symhdr->sh_size;
176 symsect.cts_data = contents;
177 symsect.cts_offset = symhdr->sh_offset;
182 if (ctfsect->cts_size > sizeof (uint64_t) &&
183 ((*(uint64_t *) ctfsect->cts_data) == CTFA_MAGIC))
186 if ((arc = ctf_arc_bufopen ((void *) ctfsect->cts_data,
187 ctfsect->cts_size, errp)) == NULL)
193 if ((fp = ctf_bufopen (ctfsect, symsectp, strsectp, errp)) == NULL)
195 ctf_dprintf ("ctf_internal_open(): cannot open CTF: %s\n",
200 arci = ctf_new_archive_internal (is_archive, arc, fp, symsectp, strsectp,
206 free ((void *) symsect.cts_data);
208 free ((void *) strsect.cts_data);
209 err: _libctf_unused_;
212 ctf_dprintf ("ctf_bfdopen(): %s: %s\n", bfderrstr,
213 bfd_errmsg (bfd_get_error()));
214 ctf_set_open_errno (errp, ECTF_FMT);
219 /* Open the specified file descriptor and return a pointer to a CTF archive that
220 contains one or more CTF containers. The file can be an ELF file, a raw CTF
221 file, or a CTF archive. The caller is responsible for closing the file
222 descriptor when it is no longer needed. If this is an ELF file, TARGET, if
223 non-NULL, should be the name of a suitable BFD target. */
226 ctf_fdopen (int fd, const char *filename, const char *target, int *errp)
235 ctf_preamble_t ctfhdr;
238 memset (&ctfhdr, 0, sizeof (ctfhdr));
242 if (fstat (fd, &st) == -1)
243 return (ctf_set_open_errno (errp, errno));
245 if ((nbytes = ctf_pread (fd, &ctfhdr, sizeof (ctfhdr), 0)) <= 0)
246 return (ctf_set_open_errno (errp, nbytes < 0 ? errno : ECTF_FMT));
248 /* If we have read enough bytes to form a CTF header and the magic
249 string matches, attempt to interpret the file as raw CTF. */
251 if ((size_t) nbytes >= sizeof (ctf_preamble_t) &&
252 ctfhdr.ctp_magic == CTF_MAGIC)
254 ctf_file_t *fp = NULL;
257 if (ctfhdr.ctp_version > CTF_VERSION)
258 return (ctf_set_open_errno (errp, ECTF_CTFVERS));
260 if ((data = ctf_mmap (st.st_size, 0, fd)) == NULL)
261 return (ctf_set_open_errno (errp, errno));
263 if ((fp = ctf_simple_open (data, (size_t) st.st_size, NULL, 0, 0,
264 NULL, 0, errp)) == NULL)
265 ctf_munmap (data, (size_t) st.st_size);
266 fp->ctf_data_mmapped = data;
267 fp->ctf_data_mmapped_len = (size_t) st.st_size;
269 return ctf_new_archive_internal (0, NULL, fp, NULL, NULL, errp);
272 if ((nbytes = ctf_pread (fd, &arc_magic, sizeof (arc_magic), 0)) <= 0)
273 return (ctf_set_open_errno (errp, nbytes < 0 ? errno : ECTF_FMT));
275 if ((size_t) nbytes >= sizeof (uint64_t) && arc_magic == CTFA_MAGIC)
277 struct ctf_archive *arc;
279 if ((arc = ctf_arc_open_internal (filename, errp)) == NULL)
280 return NULL; /* errno is set for us. */
282 return ctf_new_archive_internal (1, arc, NULL, NULL, NULL, errp);
285 /* Attempt to open the file with BFD. We must dup the fd first, since bfd
286 takes ownership of the passed fd. */
288 if ((nfd = dup (fd)) < 0)
289 return (ctf_set_open_errno (errp, errno));
291 if ((abfd = bfd_fdopenr (filename, target, nfd)) == NULL)
293 ctf_dprintf ("Cannot open BFD from %s: %s\n",
294 filename ? filename : "(unknown file)",
295 bfd_errmsg (bfd_get_error()));
296 return (ctf_set_open_errno (errp, ECTF_FMT));
299 if (!bfd_check_format (abfd, bfd_object))
301 ctf_dprintf ("BFD format problem in %s: %s\n",
302 filename ? filename : "(unknown file)",
303 bfd_errmsg (bfd_get_error()));
304 if (bfd_get_error() == bfd_error_file_ambiguously_recognized)
305 return (ctf_set_open_errno (errp, ECTF_BFD_AMBIGUOUS));
307 return (ctf_set_open_errno (errp, ECTF_FMT));
310 if ((arci = ctf_bfdopen (abfd, errp)) == NULL)
312 if (!bfd_close_all_done (abfd))
313 ctf_dprintf ("Cannot close BFD: %s\n", bfd_errmsg (bfd_get_error()));
314 return NULL; /* errno is set for us. */
316 arci->ctfi_bfd_close = ctf_bfdclose;
317 arci->ctfi_abfd = abfd;
322 /* Open the specified file and return a pointer to a CTF container. The file
323 can be either an ELF file or raw CTF file. This is just a convenient
324 wrapper around ctf_fdopen() for callers. */
327 ctf_open (const char *filename, const char *target, int *errp)
332 if ((fd = open (filename, O_RDONLY)) == -1)
339 arc = ctf_fdopen (fd, filename, target, errp);
344 /* Public entry point: open a CTF archive, or CTF file. Returns the archive, or
345 NULL and an error in *err. Despite the fact that this uses CTF archives, it
346 must be in this file to avoid dragging in BFD into non-BFD-using programs. */
348 ctf_arc_open (const char *filename, int *errp)
350 return ctf_open (filename, NULL, errp);