1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 * $FreeBSD$ 29 */ 30 31 /* 32 * Note this file is included by both link_elf.c and link_elf_obj.c. 33 * 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. 37 */ 38 #define CTF_HDR_SIZE 36 39 #define CTF_HDR_STRTAB_U32 7 40 #define CTF_HDR_STRLEN_U32 8 41 42 #ifdef DDB_CTF 43 #include <contrib/zlib/zlib.h> 44 #endif 45 46 static int 47 link_elf_ctf_get(linker_file_t lf, linker_ctf_t *lc) 48 { 49 #ifdef DDB_CTF 50 Elf_Ehdr *hdr = NULL; 51 Elf_Shdr *shdr = NULL; 52 caddr_t ctftab = NULL; 53 caddr_t raw = NULL; 54 caddr_t shstrtab = NULL; 55 elf_file_t ef = (elf_file_t) lf; 56 int flags; 57 int i; 58 int nbytes; 59 size_t sz; 60 struct nameidata nd; 61 struct thread *td = curthread; 62 uint8_t ctf_hdr[CTF_HDR_SIZE]; 63 #endif 64 int error = 0; 65 66 if (lf == NULL || lc == NULL) 67 return (EINVAL); 68 69 /* Set the defaults for no CTF present. That's not a crime! */ 70 bzero(lc, sizeof(*lc)); 71 72 #ifdef DDB_CTF 73 /* 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. 77 */ 78 if (ef->ctfcnt < 0) 79 return (EFTYPE); 80 81 /* Now check if we've already loaded the CTF data.. */ 82 if (ef->ctfcnt > 0) { 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; 93 return (0); 94 } 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, td); 104 flags = FREAD; 105 error = vn_open(&nd, &flags, 0, NULL); 106 if (error) 107 return (error); 108 NDFREE(&nd, NDF_ONLY_PNBUF); 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, ctf_hdr, sizeof(ctf_hdr), 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 #ifdef __LITTLE_ENDIAN__ 184 if (ctf_hdr[0] != 0xf1 || ctf_hdr[1] != 0xcf) { 185 #else 186 if (ctf_hdr[0] != 0xcf || ctf_hdr[1] != 0xf1) { 187 #endif 188 printf("%s(%d): module %s has invalid format\n", 189 __func__, __LINE__, lf->pathname); 190 error = EFTYPE; 191 goto out; 192 } 193 194 /* Check if version 2. */ 195 if (ctf_hdr[2] != 2) { 196 printf("%s(%d): module %s CTF format version is %d " 197 "(2 expected)\n", 198 __func__, __LINE__, lf->pathname, ctf_hdr[2]); 199 error = EFTYPE; 200 goto out; 201 } 202 203 /* Check if the data is compressed. */ 204 if ((ctf_hdr[3] & 0x1) != 0) { 205 uint32_t *u32 = (uint32_t *) ctf_hdr; 206 207 /* 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 212 * buffer required. 213 */ 214 sz = u32[CTF_HDR_STRTAB_U32] + u32[CTF_HDR_STRLEN_U32] + 215 sizeof(ctf_hdr); 216 217 /* 218 * Allocate memory for the compressed CTF data, including 219 * the header (which isn't compressed). 220 */ 221 raw = malloc(shdr[i].sh_size, M_LINKER, M_WAITOK); 222 } else { 223 /* 224 * The CTF data is not compressed, so the ELF section 225 * size is the same as the buffer size required. 226 */ 227 sz = shdr[i].sh_size; 228 } 229 230 /* 231 * Allocate memory to buffer the CTF data in its decompressed 232 * form. 233 */ 234 ctftab = malloc(sz, M_LINKER, M_WAITOK); 235 236 /* 237 * Read the CTF data into the raw buffer if compressed, or 238 * directly into the CTF buffer otherwise. 239 */ 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) 243 goto out; 244 245 /* Check if decompression is required. */ 246 if (raw != NULL) { 247 z_stream zs; 248 int ret; 249 250 /* 251 * The header isn't compressed, so copy that into the 252 * CTF buffer first. 253 */ 254 bcopy(ctf_hdr, ctftab, sizeof(ctf_hdr)); 255 256 /* Initialise the zlib structure. */ 257 bzero(&zs, sizeof(zs)); 258 259 if (inflateInit(&zs) != Z_OK) { 260 error = EIO; 261 goto out; 262 } 263 264 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); 269 inflateEnd(&zs); 270 if (ret != Z_STREAM_END) { 271 printf("%s(%d): zlib inflate returned %d\n", __func__, __LINE__, ret); 272 error = EIO; 273 goto out; 274 } 275 } 276 277 /* Got the CTF data! */ 278 ef->ctftab = ctftab; 279 ef->ctfcnt = shdr[i].sh_size; 280 281 /* We'll retain the memory allocated for the CTF data. */ 282 ctftab = NULL; 283 284 /* 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; 294 295 out: 296 VOP_UNLOCK(nd.ni_vp); 297 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 298 299 if (hdr != NULL) 300 free(hdr, M_LINKER); 301 if (shdr != NULL) 302 free(shdr, M_LINKER); 303 if (shstrtab != NULL) 304 free(shstrtab, M_LINKER); 305 if (ctftab != NULL) 306 free(ctftab, M_LINKER); 307 if (raw != NULL) 308 free(raw, M_LINKER); 309 #else 310 error = EOPNOTSUPP; 311 #endif 312 313 return (error); 314 } 315