1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2008 John Birrell <jb@freebsd.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 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. 15 * 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 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/ctf.h> 30 #include <sys/kdb.h> 31 #include <sys/linker.h> 32 33 #include <ddb/db_ctf.h> 34 35 /* 36 * Note this file is included by both link_elf.c and link_elf_obj.c. 37 */ 38 39 #ifdef DDB_CTF 40 #include <contrib/zlib/zlib.h> 41 #endif 42 43 static int 44 link_elf_ctf_get(linker_file_t lf, linker_ctf_t *lc) 45 { 46 #ifdef DDB_CTF 47 Elf_Ehdr *hdr = NULL; 48 Elf_Shdr *shdr = NULL; 49 caddr_t ctftab = NULL; 50 caddr_t raw = NULL; 51 caddr_t shstrtab = NULL; 52 elf_file_t ef = (elf_file_t) lf; 53 int flags; 54 int i; 55 int nbytes; 56 size_t sz; 57 struct nameidata nd; 58 struct thread *td = curthread; 59 struct ctf_header cth; 60 #endif 61 int error = 0; 62 63 if (lf == NULL || lc == NULL) 64 return (EINVAL); 65 66 /* Set the defaults for no CTF present. That's not a crime! */ 67 bzero(lc, sizeof(*lc)); 68 69 #ifdef DDB_CTF 70 /* 71 * First check if we've tried to load CTF data previously and the 72 * CTF ELF section wasn't found. We flag that condition by setting 73 * ctfcnt to -1. See below. 74 */ 75 if (ef->ctfcnt < 0) 76 return (EFTYPE); 77 78 /* Now check if we've already loaded the CTF data.. */ 79 if (ef->ctfcnt > 0) { 80 /* We only need to load once. */ 81 lc->ctftab = ef->ctftab; 82 lc->ctfcnt = ef->ctfcnt; 83 lc->symtab = ef->ddbsymtab; 84 lc->strtab = ef->ddbstrtab; 85 lc->strcnt = ef->ddbstrcnt; 86 lc->nsym = ef->ddbsymcnt; 87 lc->ctfoffp = (uint32_t **) &ef->ctfoff; 88 lc->typoffp = (uint32_t **) &ef->typoff; 89 lc->typlenp = &ef->typlen; 90 return (0); 91 } 92 93 if (panicstr != NULL || kdb_active) 94 return (ENXIO); 95 96 /* 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. 100 */ 101 ef->ctfcnt = -1; 102 103 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, lf->pathname); 104 flags = FREAD; 105 error = vn_open(&nd, &flags, 0, NULL); 106 if (error) 107 return (error); 108 NDFREE_PNBUF(&nd); 109 110 /* Allocate memory for the FLF header. */ 111 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 112 113 /* 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, 116 td)) != 0) 117 goto out; 118 119 /* Sanity check. */ 120 if (!IS_ELF(*hdr)) { 121 error = ENOEXEC; 122 goto out; 123 } 124 125 nbytes = hdr->e_shnum * hdr->e_shentsize; 126 if (nbytes == 0 || hdr->e_shoff == 0 || 127 hdr->e_shentsize != sizeof(Elf_Shdr)) { 128 error = ENOEXEC; 129 goto out; 130 } 131 132 /* Allocate memory for all the section headers */ 133 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 134 135 /* 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, 138 NULL, td)) != 0) 139 goto out; 140 141 /* 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. 145 */ 146 if (hdr->e_shstrndx == 0 || shdr[hdr->e_shstrndx].sh_type != SHT_STRTAB) { 147 if (bootverbose) { 148 printf( 149 "%s(%d): module %s e_shstrndx is %d, sh_type is %d\n", 150 __func__, __LINE__, lf->pathname, hdr->e_shstrndx, 151 shdr[hdr->e_shstrndx].sh_type); 152 } 153 error = EFTYPE; 154 goto out; 155 } 156 157 /* Allocate memory to buffer the section header strings. */ 158 shstrtab = malloc(shdr[hdr->e_shstrndx].sh_size, M_LINKER, M_WAITOK); 159 160 /* Read the section header strings. */ 161 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, shstrtab, 162 shdr[hdr->e_shstrndx].sh_size, shdr[hdr->e_shstrndx].sh_offset, 163 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, NULL, td)) != 0) 164 goto out; 165 166 /* Search for the section containing the CTF data. */ 167 for (i = 0; i < hdr->e_shnum; i++) 168 if (strcmp(".SUNW_ctf", shstrtab + shdr[i].sh_name) == 0) 169 break; 170 171 /* Check if the CTF section wasn't found. */ 172 if (i >= hdr->e_shnum) { 173 if (bootverbose) { 174 printf("%s(%d): module %s has no .SUNW_ctf section\n", 175 __func__, __LINE__, lf->pathname); 176 } 177 error = EFTYPE; 178 goto out; 179 } 180 181 /* Read the CTF header. */ 182 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, &cth, sizeof(cth), 183 shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 184 NOCRED, NULL, td)) != 0) 185 goto out; 186 187 /* Check the CTF magic number. */ 188 if (cth.cth_magic != CTF_MAGIC) { 189 if (bootverbose) { 190 printf("%s(%d): module %s has invalid format\n", 191 __func__, __LINE__, lf->pathname); 192 } 193 error = EFTYPE; 194 goto out; 195 } 196 197 if (cth.cth_version != CTF_VERSION_2 && 198 cth.cth_version != CTF_VERSION_3) { 199 if (bootverbose) { 200 printf( 201 "%s(%d): module %s CTF format has unsupported version %d\n", 202 __func__, __LINE__, lf->pathname, cth.cth_version); 203 } 204 error = EFTYPE; 205 goto out; 206 } 207 208 /* Check if the data is compressed. */ 209 if ((cth.cth_flags & CTF_F_COMPRESS) != 0) { 210 /* 211 * The last two fields in the CTF header are the offset 212 * from the end of the header to the start of the string 213 * data and the length of that string data. Use this 214 * information to determine the decompressed CTF data 215 * buffer required. 216 */ 217 sz = cth.cth_stroff + cth.cth_strlen + sizeof(cth); 218 219 /* 220 * Allocate memory for the compressed CTF data, including 221 * the header (which isn't compressed). 222 */ 223 raw = malloc(shdr[i].sh_size, M_LINKER, M_WAITOK); 224 } else { 225 /* 226 * The CTF data is not compressed, so the ELF section 227 * size is the same as the buffer size required. 228 */ 229 sz = shdr[i].sh_size; 230 } 231 232 /* 233 * Allocate memory to buffer the CTF data in its decompressed 234 * form. 235 */ 236 ctftab = malloc(sz, M_LINKER, M_WAITOK); 237 238 /* 239 * Read the CTF data into the raw buffer if compressed, or 240 * directly into the CTF buffer otherwise. 241 */ 242 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, raw == NULL ? ctftab : raw, 243 shdr[i].sh_size, shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, 244 td->td_ucred, NOCRED, NULL, td)) != 0) 245 goto out; 246 247 /* Check if decompression is required. */ 248 if (raw != NULL) { 249 uLongf destlen; 250 int ret; 251 252 /* 253 * The header isn't compressed, so copy that into the 254 * CTF buffer first. 255 */ 256 bcopy(&cth, ctftab, sizeof(cth)); 257 258 destlen = sz - sizeof(cth); 259 ret = uncompress(ctftab + sizeof(cth), &destlen, 260 raw + sizeof(cth), shdr[i].sh_size - sizeof(cth)); 261 if (ret != Z_OK) { 262 if (bootverbose) { 263 printf("%s(%d): zlib uncompress returned %d\n", 264 __func__, __LINE__, ret); 265 } 266 error = EIO; 267 goto out; 268 } 269 } 270 271 /* Got the CTF data! */ 272 ef->ctftab = ctftab; 273 ef->ctfcnt = shdr[i].sh_size; 274 275 /* We'll retain the memory allocated for the CTF data. */ 276 ctftab = NULL; 277 278 /* Let the caller use the CTF data read. */ 279 lc->ctftab = ef->ctftab; 280 lc->ctfcnt = ef->ctfcnt; 281 lc->symtab = ef->ddbsymtab; 282 lc->strtab = ef->ddbstrtab; 283 lc->strcnt = ef->ddbstrcnt; 284 lc->nsym = ef->ddbsymcnt; 285 lc->ctfoffp = (uint32_t **) &ef->ctfoff; 286 lc->typoffp = (uint32_t **) &ef->typoff; 287 lc->typlenp = &ef->typlen; 288 289 out: 290 VOP_UNLOCK(nd.ni_vp); 291 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 292 293 if (hdr != NULL) 294 free(hdr, M_LINKER); 295 if (shdr != NULL) 296 free(shdr, M_LINKER); 297 if (shstrtab != NULL) 298 free(shstrtab, M_LINKER); 299 if (ctftab != NULL) 300 free(ctftab, M_LINKER); 301 if (raw != NULL) 302 free(raw, M_LINKER); 303 #else 304 error = EOPNOTSUPP; 305 #endif 306 307 return (error); 308 } 309 310 static int 311 link_elf_ctf_get_ddb(linker_file_t lf, linker_ctf_t *lc) 312 { 313 elf_file_t ef = (elf_file_t)lf; 314 315 /* 316 * Check whether CTF data was loaded or if a 317 * previous loading attempt failed (ctfcnt == -1). 318 */ 319 if (ef->ctfcnt <= 0) { 320 return (ENOENT); 321 } 322 323 lc->ctftab = ef->ctftab; 324 lc->ctfcnt = ef->ctfcnt; 325 lc->symtab = ef->ddbsymtab; 326 lc->strtab = ef->ddbstrtab; 327 lc->strcnt = ef->ddbstrcnt; 328 lc->nsym = ef->ddbsymcnt; 329 330 return (0); 331 } 332 333 static int 334 link_elf_ctf_lookup_typename(linker_file_t lf, linker_ctf_t *lc, 335 const char *typename) 336 { 337 if (link_elf_ctf_get_ddb(lf, lc)) 338 return (ENOENT); 339 340 #ifdef DDB 341 return (db_ctf_lookup_typename(lc, typename) ? 0 : ENOENT); 342 #else 343 return (ENOENT); 344 #endif 345 } 346