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 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); 150 error = EFTYPE; 151 goto out; 152 } 153 154 /* Allocate memory to buffer the section header strings. */ 155 shstrtab = malloc(shdr[hdr->e_shstrndx].sh_size, M_LINKER, M_WAITOK); 156 157 /* 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) 161 goto out; 162 163 /* 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) 166 break; 167 168 /* 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); 172 error = EFTYPE; 173 goto out; 174 } 175 176 /* Read the CTF header. */ 177 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, &cth, sizeof(cth), 178 shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 179 NOCRED, NULL, td)) != 0) 180 goto out; 181 182 /* Check the CTF magic number. */ 183 if (cth.cth_magic != CTF_MAGIC) { 184 printf("%s(%d): module %s has invalid format\n", 185 __func__, __LINE__, lf->pathname); 186 error = EFTYPE; 187 goto out; 188 } 189 190 if (cth.cth_version != CTF_VERSION_2 && 191 cth.cth_version != CTF_VERSION_3) { 192 printf( 193 "%s(%d): module %s CTF format has unsupported version %d\n", 194 __func__, __LINE__, lf->pathname, cth.cth_version); 195 error = EFTYPE; 196 goto out; 197 } 198 199 /* Check if the data is compressed. */ 200 if ((cth.cth_flags & CTF_F_COMPRESS) != 0) { 201 /* 202 * The last two fields in the CTF header are the offset 203 * from the end of the header to the start of the string 204 * data and the length of that string data. Use this 205 * information to determine the decompressed CTF data 206 * buffer required. 207 */ 208 sz = cth.cth_stroff + cth.cth_strlen + sizeof(cth); 209 210 /* 211 * Allocate memory for the compressed CTF data, including 212 * the header (which isn't compressed). 213 */ 214 raw = malloc(shdr[i].sh_size, M_LINKER, M_WAITOK); 215 } else { 216 /* 217 * The CTF data is not compressed, so the ELF section 218 * size is the same as the buffer size required. 219 */ 220 sz = shdr[i].sh_size; 221 } 222 223 /* 224 * Allocate memory to buffer the CTF data in its decompressed 225 * form. 226 */ 227 ctftab = malloc(sz, M_LINKER, M_WAITOK); 228 229 /* 230 * Read the CTF data into the raw buffer if compressed, or 231 * directly into the CTF buffer otherwise. 232 */ 233 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, raw == NULL ? ctftab : raw, 234 shdr[i].sh_size, shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, 235 td->td_ucred, NOCRED, NULL, td)) != 0) 236 goto out; 237 238 /* Check if decompression is required. */ 239 if (raw != NULL) { 240 uLongf destlen; 241 int ret; 242 243 /* 244 * The header isn't compressed, so copy that into the 245 * CTF buffer first. 246 */ 247 bcopy(&cth, ctftab, sizeof(cth)); 248 249 destlen = sz - sizeof(cth); 250 ret = uncompress(ctftab + sizeof(cth), &destlen, 251 raw + sizeof(cth), shdr[i].sh_size - sizeof(cth)); 252 if (ret != Z_OK) { 253 printf("%s(%d): zlib uncompress returned %d\n", 254 __func__, __LINE__, ret); 255 error = EIO; 256 goto out; 257 } 258 } 259 260 /* Got the CTF data! */ 261 ef->ctftab = ctftab; 262 ef->ctfcnt = shdr[i].sh_size; 263 264 /* We'll retain the memory allocated for the CTF data. */ 265 ctftab = NULL; 266 267 /* Let the caller use the CTF data read. */ 268 lc->ctftab = ef->ctftab; 269 lc->ctfcnt = ef->ctfcnt; 270 lc->symtab = ef->ddbsymtab; 271 lc->strtab = ef->ddbstrtab; 272 lc->strcnt = ef->ddbstrcnt; 273 lc->nsym = ef->ddbsymcnt; 274 lc->ctfoffp = (uint32_t **) &ef->ctfoff; 275 lc->typoffp = (uint32_t **) &ef->typoff; 276 lc->typlenp = &ef->typlen; 277 278 out: 279 VOP_UNLOCK(nd.ni_vp); 280 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 281 282 if (hdr != NULL) 283 free(hdr, M_LINKER); 284 if (shdr != NULL) 285 free(shdr, M_LINKER); 286 if (shstrtab != NULL) 287 free(shstrtab, M_LINKER); 288 if (ctftab != NULL) 289 free(ctftab, M_LINKER); 290 if (raw != NULL) 291 free(raw, M_LINKER); 292 #else 293 error = EOPNOTSUPP; 294 #endif 295 296 return (error); 297 } 298 299 static int 300 link_elf_ctf_get_ddb(linker_file_t lf, linker_ctf_t *lc) 301 { 302 elf_file_t ef = (elf_file_t)lf; 303 304 /* 305 * Check whether CTF data was loaded or if a 306 * previous loading attempt failed (ctfcnt == -1). 307 */ 308 if (ef->ctfcnt <= 0) { 309 return (ENOENT); 310 } 311 312 lc->ctftab = ef->ctftab; 313 lc->ctfcnt = ef->ctfcnt; 314 lc->symtab = ef->ddbsymtab; 315 lc->strtab = ef->ddbstrtab; 316 lc->strcnt = ef->ddbstrcnt; 317 lc->nsym = ef->ddbsymcnt; 318 319 return (0); 320 } 321 322 static int 323 link_elf_ctf_lookup_typename(linker_file_t lf, linker_ctf_t *lc, 324 const char *typename) 325 { 326 if (link_elf_ctf_get_ddb(lf, lc)) 327 return (ENOENT); 328 329 #ifdef DDB 330 return (db_ctf_lookup_typename(lc, typename) ? 0 : ENOENT); 331 #else 332 return (ENOENT); 333 #endif 334 } 335