2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2008 John Birrell <jb@freebsd.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * Note this file is included by both link_elf.c and link_elf_obj.c.
34 * The CTF header structure definition can't be used here because it's
35 * (annoyingly) covered by the CDDL. We will just use a few bytes from
36 * it as an integer array where we 'know' what they mean.
38 #define CTF_HDR_SIZE 36
39 #define CTF_HDR_STRTAB_U32 7
40 #define CTF_HDR_STRLEN_U32 8
43 #include <contrib/zlib/zlib.h>
47 link_elf_ctf_get(linker_file_t lf, linker_ctf_t *lc)
51 Elf_Shdr *shdr = NULL;
52 caddr_t ctftab = NULL;
54 caddr_t shstrtab = NULL;
55 elf_file_t ef = (elf_file_t) lf;
61 struct thread *td = curthread;
62 uint8_t ctf_hdr[CTF_HDR_SIZE];
66 if (lf == NULL || lc == NULL)
69 /* Set the defaults for no CTF present. That's not a crime! */
70 bzero(lc, sizeof(*lc));
74 * First check if we've tried to load CTF data previously and the
75 * CTF ELF section wasn't found. We flag that condition by setting
76 * ctfcnt to -1. See below.
81 /* Now check if we've already loaded the CTF data.. */
83 /* We only need to load once. */
84 lc->ctftab = ef->ctftab;
85 lc->ctfcnt = ef->ctfcnt;
86 lc->symtab = ef->ddbsymtab;
87 lc->strtab = ef->ddbstrtab;
88 lc->strcnt = ef->ddbstrcnt;
89 lc->nsym = ef->ddbsymcnt;
90 lc->ctfoffp = (uint32_t **) &ef->ctfoff;
91 lc->typoffp = (uint32_t **) &ef->typoff;
92 lc->typlenp = &ef->typlen;
97 * We need to try reading the CTF data. Flag no CTF data present
98 * by default and if we actually succeed in reading it, we'll
99 * update ctfcnt to the number of bytes read.
103 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, lf->pathname, td);
105 error = vn_open(&nd, &flags, 0, NULL);
108 NDFREE(&nd, NDF_ONLY_PNBUF);
110 /* Allocate memory for the FLF header. */
111 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
113 /* Read the ELF header. */
114 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, hdr, sizeof(*hdr),
115 0, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, NULL,
125 nbytes = hdr->e_shnum * hdr->e_shentsize;
126 if (nbytes == 0 || hdr->e_shoff == 0 ||
127 hdr->e_shentsize != sizeof(Elf_Shdr)) {
132 /* Allocate memory for all the section headers */
133 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
135 /* Read all the section headers */
136 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes,
137 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
142 * We need to search for the CTF section by name, so if the
143 * section names aren't present, then we can't locate the
144 * .SUNW_ctf section containing the CTF data.
146 if (hdr->e_shstrndx == 0 || shdr[hdr->e_shstrndx].sh_type != SHT_STRTAB) {
147 printf("%s(%d): module %s e_shstrndx is %d, sh_type is %d\n",
148 __func__, __LINE__, lf->pathname, hdr->e_shstrndx,
149 shdr[hdr->e_shstrndx].sh_type);
154 /* Allocate memory to buffer the section header strings. */
155 shstrtab = malloc(shdr[hdr->e_shstrndx].sh_size, M_LINKER, M_WAITOK);
157 /* Read the section header strings. */
158 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, shstrtab,
159 shdr[hdr->e_shstrndx].sh_size, shdr[hdr->e_shstrndx].sh_offset,
160 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, NULL, td)) != 0)
163 /* Search for the section containing the CTF data. */
164 for (i = 0; i < hdr->e_shnum; i++)
165 if (strcmp(".SUNW_ctf", shstrtab + shdr[i].sh_name) == 0)
168 /* Check if the CTF section wasn't found. */
169 if (i >= hdr->e_shnum) {
170 printf("%s(%d): module %s has no .SUNW_ctf section\n",
171 __func__, __LINE__, lf->pathname);
176 /* Read the CTF header. */
177 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, ctf_hdr, sizeof(ctf_hdr),
178 shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
179 NOCRED, NULL, td)) != 0)
182 /* Check the CTF magic number. */
183 #ifdef __LITTLE_ENDIAN__
184 if (ctf_hdr[0] != 0xf1 || ctf_hdr[1] != 0xcf) {
186 if (ctf_hdr[0] != 0xcf || ctf_hdr[1] != 0xf1) {
188 printf("%s(%d): module %s has invalid format\n",
189 __func__, __LINE__, lf->pathname);
194 /* Check if version 2. */
195 if (ctf_hdr[2] != 2) {
196 printf("%s(%d): module %s CTF format version is %d "
198 __func__, __LINE__, lf->pathname, ctf_hdr[2]);
203 /* Check if the data is compressed. */
204 if ((ctf_hdr[3] & 0x1) != 0) {
205 uint32_t *u32 = (uint32_t *) ctf_hdr;
208 * The last two fields in the CTF header are the offset
209 * from the end of the header to the start of the string
210 * data and the length of that string data. se this
211 * information to determine the decompressed CTF data
214 sz = u32[CTF_HDR_STRTAB_U32] + u32[CTF_HDR_STRLEN_U32] +
218 * Allocate memory for the compressed CTF data, including
219 * the header (which isn't compressed).
221 raw = malloc(shdr[i].sh_size, M_LINKER, M_WAITOK);
224 * The CTF data is not compressed, so the ELF section
225 * size is the same as the buffer size required.
227 sz = shdr[i].sh_size;
231 * Allocate memory to buffer the CTF data in its decompressed
234 ctftab = malloc(sz, M_LINKER, M_WAITOK);
237 * Read the CTF data into the raw buffer if compressed, or
238 * directly into the CTF buffer otherwise.
240 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, raw == NULL ? ctftab : raw,
241 shdr[i].sh_size, shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED,
242 td->td_ucred, NOCRED, NULL, td)) != 0)
245 /* Check if decompression is required. */
251 * The header isn't compressed, so copy that into the
254 bcopy(ctf_hdr, ctftab, sizeof(ctf_hdr));
256 /* Initialise the zlib structure. */
257 bzero(&zs, sizeof(zs));
259 if (inflateInit(&zs) != Z_OK) {
264 zs.avail_in = shdr[i].sh_size - sizeof(ctf_hdr);
265 zs.next_in = ((uint8_t *) raw) + sizeof(ctf_hdr);
266 zs.avail_out = sz - sizeof(ctf_hdr);
267 zs.next_out = ((uint8_t *) ctftab) + sizeof(ctf_hdr);
268 ret = inflate(&zs, Z_FINISH);
270 if (ret != Z_STREAM_END) {
271 printf("%s(%d): zlib inflate returned %d\n", __func__, __LINE__, ret);
277 /* Got the CTF data! */
279 ef->ctfcnt = shdr[i].sh_size;
281 /* We'll retain the memory allocated for the CTF data. */
284 /* Let the caller use the CTF data read. */
285 lc->ctftab = ef->ctftab;
286 lc->ctfcnt = ef->ctfcnt;
287 lc->symtab = ef->ddbsymtab;
288 lc->strtab = ef->ddbstrtab;
289 lc->strcnt = ef->ddbstrcnt;
290 lc->nsym = ef->ddbsymcnt;
291 lc->ctfoffp = (uint32_t **) &ef->ctfoff;
292 lc->typoffp = (uint32_t **) &ef->typoff;
293 lc->typlenp = &ef->typlen;
296 VOP_UNLOCK(nd.ni_vp);
297 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
302 free(shdr, M_LINKER);
303 if (shstrtab != NULL)
304 free(shstrtab, M_LINKER);
306 free(ctftab, M_LINKER);