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 static void * 44 z_alloc(void *nil, u_int items, u_int size) 45 { 46 void *ptr; 47 48 ptr = malloc(items * size, M_TEMP, M_NOWAIT); 49 return ptr; 50 } 51 52 static void 53 z_free(void *nil, void *ptr) 54 { 55 free(ptr, M_TEMP); 56 } 57 58 #endif 59 60 static int 61 link_elf_ctf_get(linker_file_t lf, linker_ctf_t *lc) 62 { 63 #ifdef DDB_CTF 64 Elf_Ehdr *hdr = NULL; 65 Elf_Shdr *shdr = NULL; 66 caddr_t ctftab = NULL; 67 caddr_t raw = NULL; 68 caddr_t shstrtab = NULL; 69 elf_file_t ef = (elf_file_t) lf; 70 int flags; 71 int i; 72 int nbytes; 73 size_t sz; 74 struct nameidata nd; 75 struct thread *td = curthread; 76 uint8_t ctf_hdr[CTF_HDR_SIZE]; 77 #endif 78 int error = 0; 79 80 if (lf == NULL || lc == NULL) 81 return (EINVAL); 82 83 /* Set the defaults for no CTF present. That's not a crime! */ 84 bzero(lc, sizeof(*lc)); 85 86 #ifdef DDB_CTF 87 /* 88 * First check if we've tried to load CTF data previously and the 89 * CTF ELF section wasn't found. We flag that condition by setting 90 * ctfcnt to -1. See below. 91 */ 92 if (ef->ctfcnt < 0) 93 return (EFTYPE); 94 95 /* Now check if we've already loaded the CTF data.. */ 96 if (ef->ctfcnt > 0) { 97 /* We only need to load once. */ 98 lc->ctftab = ef->ctftab; 99 lc->ctfcnt = ef->ctfcnt; 100 lc->symtab = ef->ddbsymtab; 101 lc->strtab = ef->ddbstrtab; 102 lc->strcnt = ef->ddbstrcnt; 103 lc->nsym = ef->ddbsymcnt; 104 lc->ctfoffp = (uint32_t **) &ef->ctfoff; 105 lc->typoffp = (uint32_t **) &ef->typoff; 106 lc->typlenp = &ef->typlen; 107 return (0); 108 } 109 110 /* 111 * We need to try reading the CTF data. Flag no CTF data present 112 * by default and if we actually succeed in reading it, we'll 113 * update ctfcnt to the number of bytes read. 114 */ 115 ef->ctfcnt = -1; 116 117 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, lf->pathname, td); 118 flags = FREAD; 119 error = vn_open(&nd, &flags, 0, NULL); 120 if (error) 121 return (error); 122 NDFREE(&nd, NDF_ONLY_PNBUF); 123 124 /* Allocate memory for the FLF header. */ 125 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK); 126 127 /* Read the ELF header. */ 128 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, hdr, sizeof(*hdr), 129 0, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, NULL, 130 td)) != 0) 131 goto out; 132 133 /* Sanity check. */ 134 if (!IS_ELF(*hdr)) { 135 error = ENOEXEC; 136 goto out; 137 } 138 139 nbytes = hdr->e_shnum * hdr->e_shentsize; 140 if (nbytes == 0 || hdr->e_shoff == 0 || 141 hdr->e_shentsize != sizeof(Elf_Shdr)) { 142 error = ENOEXEC; 143 goto out; 144 } 145 146 /* Allocate memory for all the section headers */ 147 shdr = malloc(nbytes, M_LINKER, M_WAITOK); 148 149 /* Read all the section headers */ 150 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, 151 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 152 NULL, td)) != 0) 153 goto out; 154 155 /* 156 * We need to search for the CTF section by name, so if the 157 * section names aren't present, then we can't locate the 158 * .SUNW_ctf section containing the CTF data. 159 */ 160 if (hdr->e_shstrndx == 0 || shdr[hdr->e_shstrndx].sh_type != SHT_STRTAB) { 161 printf("%s(%d): module %s e_shstrndx is %d, sh_type is %d\n", 162 __func__, __LINE__, lf->pathname, hdr->e_shstrndx, 163 shdr[hdr->e_shstrndx].sh_type); 164 error = EFTYPE; 165 goto out; 166 } 167 168 /* Allocate memory to buffer the section header strings. */ 169 shstrtab = malloc(shdr[hdr->e_shstrndx].sh_size, M_LINKER, M_WAITOK); 170 171 /* Read the section header strings. */ 172 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, shstrtab, 173 shdr[hdr->e_shstrndx].sh_size, shdr[hdr->e_shstrndx].sh_offset, 174 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, NULL, td)) != 0) 175 goto out; 176 177 /* Search for the section containing the CTF data. */ 178 for (i = 0; i < hdr->e_shnum; i++) 179 if (strcmp(".SUNW_ctf", shstrtab + shdr[i].sh_name) == 0) 180 break; 181 182 /* Check if the CTF section wasn't found. */ 183 if (i >= hdr->e_shnum) { 184 printf("%s(%d): module %s has no .SUNW_ctf section\n", 185 __func__, __LINE__, lf->pathname); 186 error = EFTYPE; 187 goto out; 188 } 189 190 /* Read the CTF header. */ 191 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, ctf_hdr, sizeof(ctf_hdr), 192 shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 193 NOCRED, NULL, td)) != 0) 194 goto out; 195 196 /* Check the CTF magic number. (XXX check for big endian!) */ 197 if (ctf_hdr[0] != 0xf1 || ctf_hdr[1] != 0xcf) { 198 printf("%s(%d): module %s has invalid format\n", 199 __func__, __LINE__, lf->pathname); 200 error = EFTYPE; 201 goto out; 202 } 203 204 /* Check if version 2. */ 205 if (ctf_hdr[2] != 2) { 206 printf("%s(%d): module %s CTF format version is %d " 207 "(2 expected)\n", 208 __func__, __LINE__, lf->pathname, ctf_hdr[2]); 209 error = EFTYPE; 210 goto out; 211 } 212 213 /* Check if the data is compressed. */ 214 if ((ctf_hdr[3] & 0x1) != 0) { 215 uint32_t *u32 = (uint32_t *) ctf_hdr; 216 217 /* 218 * The last two fields in the CTF header are the offset 219 * from the end of the header to the start of the string 220 * data and the length of that string data. se this 221 * information to determine the decompressed CTF data 222 * buffer required. 223 */ 224 sz = u32[CTF_HDR_STRTAB_U32] + u32[CTF_HDR_STRLEN_U32] + 225 sizeof(ctf_hdr); 226 227 /* 228 * Allocate memory for the compressed CTF data, including 229 * the header (which isn't compressed). 230 */ 231 raw = malloc(shdr[i].sh_size, M_LINKER, M_WAITOK); 232 } else { 233 /* 234 * The CTF data is not compressed, so the ELF section 235 * size is the same as the buffer size required. 236 */ 237 sz = shdr[i].sh_size; 238 } 239 240 /* 241 * Allocate memory to buffer the CTF data in its decompressed 242 * form. 243 */ 244 ctftab = malloc(sz, M_LINKER, M_WAITOK); 245 246 /* 247 * Read the CTF data into the raw buffer if compressed, or 248 * directly into the CTF buffer otherwise. 249 */ 250 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, raw == NULL ? ctftab : raw, 251 shdr[i].sh_size, shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, 252 td->td_ucred, NOCRED, NULL, td)) != 0) 253 goto out; 254 255 /* Check if decompression is required. */ 256 if (raw != NULL) { 257 z_stream zs; 258 int ret; 259 260 /* 261 * The header isn't compressed, so copy that into the 262 * CTF buffer first. 263 */ 264 bcopy(ctf_hdr, ctftab, sizeof(ctf_hdr)); 265 266 /* Initialise the zlib structure. */ 267 bzero(&zs, sizeof(zs)); 268 zs.zalloc = z_alloc; 269 zs.zfree = z_free; 270 271 if (inflateInit(&zs) != Z_OK) { 272 error = EIO; 273 goto out; 274 } 275 276 zs.avail_in = shdr[i].sh_size - sizeof(ctf_hdr); 277 zs.next_in = ((uint8_t *) raw) + sizeof(ctf_hdr); 278 zs.avail_out = sz - sizeof(ctf_hdr); 279 zs.next_out = ((uint8_t *) ctftab) + sizeof(ctf_hdr); 280 ret = inflate(&zs, Z_FINISH); 281 inflateEnd(&zs); 282 if (ret != Z_STREAM_END) { 283 printf("%s(%d): zlib inflate returned %d\n", __func__, __LINE__, ret); 284 error = EIO; 285 goto out; 286 } 287 } 288 289 /* Got the CTF data! */ 290 ef->ctftab = ctftab; 291 ef->ctfcnt = shdr[i].sh_size; 292 293 /* We'll retain the memory allocated for the CTF data. */ 294 ctftab = NULL; 295 296 /* Let the caller use the CTF data read. */ 297 lc->ctftab = ef->ctftab; 298 lc->ctfcnt = ef->ctfcnt; 299 lc->symtab = ef->ddbsymtab; 300 lc->strtab = ef->ddbstrtab; 301 lc->strcnt = ef->ddbstrcnt; 302 lc->nsym = ef->ddbsymcnt; 303 lc->ctfoffp = (uint32_t **) &ef->ctfoff; 304 lc->typoffp = (uint32_t **) &ef->typoff; 305 lc->typlenp = &ef->typlen; 306 307 out: 308 VOP_UNLOCK(nd.ni_vp, 0); 309 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 310 311 if (hdr != NULL) 312 free(hdr, M_LINKER); 313 if (shdr != NULL) 314 free(shdr, M_LINKER); 315 if (shstrtab != NULL) 316 free(shstrtab, M_LINKER); 317 if (ctftab != NULL) 318 free(ctftab, M_LINKER); 319 if (raw != NULL) 320 free(raw, M_LINKER); 321 #else 322 error = EOPNOTSUPP; 323 #endif 324 325 return (error); 326 } 327