1 /*- 2 * Copyright (c) 2008 John Birrell <jb@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 /* 30 * Note this file is included by both link_elf.c and link_elf_obj.c. 31 * 32 * The CTF header structure definition can't be used here because it's 33 * (annoyingly) covered by the CDDL. We will just use a few bytes from 34 * it as an integer array where we 'know' what they mean. 35 */ 36 #define CTF_HDR_SIZE 36 37 #define CTF_HDR_STRTAB_U32 7 38 #define CTF_HDR_STRLEN_U32 8 39 40 #ifdef DDB_CTF 41 static void * 42 z_alloc(void *nil, u_int items, u_int size) 43 { 44 void *ptr; 45 46 ptr = malloc(items * size, M_TEMP, M_NOWAIT); 47 return ptr; 48 } 49 50 static void 51 z_free(void *nil, void *ptr) 52 { 53 free(ptr, M_TEMP); 54 } 55 56 #endif 57 58 static int 59 link_elf_ctf_get(linker_file_t lf, linker_ctf_t *lc) 60 { 61 #ifdef DDB_CTF 62 Elf_Ehdr *hdr = NULL; 63 Elf_Shdr *shdr = NULL; 64 caddr_t ctftab = NULL; 65 caddr_t raw = NULL; 66 caddr_t shstrtab = NULL; 67 elf_file_t ef = (elf_file_t) lf; 68 int flags; 69 int i; 70 int nbytes; 71 ssize_t resid; 72 size_t sz; 73 struct nameidata nd; 74 struct thread *td = curthread; 75 uint8_t ctf_hdr[CTF_HDR_SIZE]; 76 #endif 77 int error = 0; 78 79 if (lf == NULL || lc == NULL) 80 return (EINVAL); 81 82 /* Set the defaults for no CTF present. That's not a crime! */ 83 bzero(lc, sizeof(*lc)); 84 85 #ifdef DDB_CTF 86 /* 87 * First check if we've tried to load CTF data previously and the 88 * CTF ELF section wasn't found. We flag that condition by setting 89 * ctfcnt to -1. See below. 90 */ 91 if (ef->ctfcnt < 0) 92 return (EFTYPE); 93 94 /* Now check if we've already loaded the CTF data.. */ 95 if (ef->ctfcnt > 0) { 96 /* We only need to load once. */ 97 lc->ctftab = ef->ctftab; 98 lc->ctfcnt = ef->ctfcnt; 99 lc->symtab = ef->ddbsymtab; 100 lc->strtab = ef->ddbstrtab; 101 lc->strcnt = ef->ddbstrcnt; 102 lc->nsym = ef->ddbsymcnt; 103 lc->ctfoffp = (uint32_t **) &ef->ctfoff; 104 lc->typoffp = (uint32_t **) &ef->typoff; 105 lc->typlenp = &ef->typlen; 106 return (0); 107 } 108 109 /* 110 * We need to try reading the CTF data. Flag no CTF data present 111 * by default and if we actually succeed in reading it, we'll 112 * update ctfcnt to the number of bytes read. 113 */ 114 ef->ctfcnt = -1; 115 116 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, lf->pathname, td); 117 flags = FREAD; 118 error = vn_open(&nd, &flags, 0, NULL); 119 if (error) 120 return (error); 121 NDFREE(&nd, NDF_ONLY_PNBUF); 122 123 /* Allocate memory for the FLF header. */ 124 if ((hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK)) == NULL) { 125 error = ENOMEM; 126 goto out; 127 } 128 129 /* Read the ELF header. */ 130 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, hdr, sizeof(*hdr), 131 0, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, 132 td)) != 0) 133 goto out; 134 135 /* Sanity check. */ 136 if (!IS_ELF(*hdr)) { 137 error = ENOEXEC; 138 goto out; 139 } 140 141 nbytes = hdr->e_shnum * hdr->e_shentsize; 142 if (nbytes == 0 || hdr->e_shoff == 0 || 143 hdr->e_shentsize != sizeof(Elf_Shdr)) { 144 error = ENOEXEC; 145 goto out; 146 } 147 148 /* Allocate memory for all the section headers */ 149 if ((shdr = malloc(nbytes, M_LINKER, M_WAITOK)) == NULL) { 150 error = ENOMEM; 151 goto out; 152 } 153 154 /* Read all the section headers */ 155 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, 156 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, 157 &resid, td)) != 0) 158 goto out; 159 160 /* 161 * We need to search for the CTF section by name, so if the 162 * section names aren't present, then we can't locate the 163 * .SUNW_ctf section containing the CTF data. 164 */ 165 if (hdr->e_shstrndx == 0 || shdr[hdr->e_shstrndx].sh_type != SHT_STRTAB) { 166 printf("%s(%d): module %s e_shstrndx is %d, sh_type is %d\n", 167 __func__, __LINE__, lf->pathname, hdr->e_shstrndx, 168 shdr[hdr->e_shstrndx].sh_type); 169 error = EFTYPE; 170 goto out; 171 } 172 173 /* Allocate memory to buffer the section header strings. */ 174 if ((shstrtab = malloc(shdr[hdr->e_shstrndx].sh_size, M_LINKER, 175 M_WAITOK)) == NULL) { 176 error = ENOMEM; 177 goto out; 178 } 179 180 /* Read the section header strings. */ 181 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, shstrtab, 182 shdr[hdr->e_shstrndx].sh_size, shdr[hdr->e_shstrndx].sh_offset, 183 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, 184 td)) != 0) 185 goto out; 186 187 /* Search for the section containing the CTF data. */ 188 for (i = 0; i < hdr->e_shnum; i++) 189 if (strcmp(".SUNW_ctf", shstrtab + shdr[i].sh_name) == 0) 190 break; 191 192 /* Check if the CTF section wasn't found. */ 193 if (i >= hdr->e_shnum) { 194 printf("%s(%d): module %s has no .SUNW_ctf section\n", 195 __func__, __LINE__, lf->pathname); 196 error = EFTYPE; 197 goto out; 198 } 199 200 /* Read the CTF header. */ 201 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, ctf_hdr, sizeof(ctf_hdr), 202 shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, 203 NOCRED, &resid, td)) != 0) 204 goto out; 205 206 /* Check the CTF magic number. (XXX check for big endian!) */ 207 if (ctf_hdr[0] != 0xf1 || ctf_hdr[1] != 0xcf) { 208 printf("%s(%d): module %s has invalid format\n", 209 __func__, __LINE__, lf->pathname); 210 error = EFTYPE; 211 goto out; 212 } 213 214 /* Check if version 2. */ 215 if (ctf_hdr[2] != 2) { 216 printf("%s(%d): module %s CTF format version is %d " 217 "(2 expected)\n", 218 __func__, __LINE__, lf->pathname, ctf_hdr[2]); 219 error = EFTYPE; 220 goto out; 221 } 222 223 /* Check if the data is compressed. */ 224 if ((ctf_hdr[3] & 0x1) != 0) { 225 uint32_t *u32 = (uint32_t *) ctf_hdr; 226 227 /* 228 * The last two fields in the CTF header are the offset 229 * from the end of the header to the start of the string 230 * data and the length of that string data. se this 231 * information to determine the decompressed CTF data 232 * buffer required. 233 */ 234 sz = u32[CTF_HDR_STRTAB_U32] + u32[CTF_HDR_STRLEN_U32] + 235 sizeof(ctf_hdr); 236 237 /* 238 * Allocate memory for the compressed CTF data, including 239 * the header (which isn't compressed). 240 */ 241 if ((raw = malloc(shdr[i].sh_size, M_LINKER, M_WAITOK)) == NULL) { 242 error = ENOMEM; 243 goto out; 244 } 245 } else { 246 /* 247 * The CTF data is not compressed, so the ELF section 248 * size is the same as the buffer size required. 249 */ 250 sz = shdr[i].sh_size; 251 } 252 253 /* 254 * Allocate memory to buffer the CTF data in it's decompressed 255 * form. 256 */ 257 if ((ctftab = malloc(sz, M_LINKER, M_WAITOK)) == NULL) { 258 error = ENOMEM; 259 goto out; 260 } 261 262 /* 263 * Read the CTF data into the raw buffer if compressed, or 264 * directly into the CTF buffer otherwise. 265 */ 266 if ((error = vn_rdwr(UIO_READ, nd.ni_vp, raw == NULL ? ctftab : raw, 267 shdr[i].sh_size, shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, 268 td->td_ucred, NOCRED, &resid, td)) != 0) 269 goto out; 270 271 /* Check if decompression is required. */ 272 if (raw != NULL) { 273 z_stream zs; 274 int ret; 275 276 /* 277 * The header isn't compressed, so copy that into the 278 * CTF buffer first. 279 */ 280 bcopy(ctf_hdr, ctftab, sizeof(ctf_hdr)); 281 282 /* Initialise the zlib structure. */ 283 bzero(&zs, sizeof(zs)); 284 zs.zalloc = z_alloc; 285 zs.zfree = z_free; 286 287 if (inflateInit(&zs) != Z_OK) { 288 error = EIO; 289 goto out; 290 } 291 292 zs.avail_in = shdr[i].sh_size - sizeof(ctf_hdr); 293 zs.next_in = ((uint8_t *) raw) + sizeof(ctf_hdr); 294 zs.avail_out = sz - sizeof(ctf_hdr); 295 zs.next_out = ((uint8_t *) ctftab) + sizeof(ctf_hdr); 296 if ((ret = inflate(&zs, Z_FINISH)) != Z_STREAM_END) { 297 printf("%s(%d): zlib inflate returned %d\n", __func__, __LINE__, ret); 298 error = EIO; 299 goto out; 300 } 301 } 302 303 /* Got the CTF data! */ 304 ef->ctftab = ctftab; 305 ef->ctfcnt = shdr[i].sh_size; 306 307 /* We'll retain the memory allocated for the CTF data. */ 308 ctftab = NULL; 309 310 /* Let the caller use the CTF data read. */ 311 lc->ctftab = ef->ctftab; 312 lc->ctfcnt = ef->ctfcnt; 313 lc->symtab = ef->ddbsymtab; 314 lc->strtab = ef->ddbstrtab; 315 lc->strcnt = ef->ddbstrcnt; 316 lc->nsym = ef->ddbsymcnt; 317 lc->ctfoffp = (uint32_t **) &ef->ctfoff; 318 lc->typoffp = (uint32_t **) &ef->typoff; 319 lc->typlenp = &ef->typlen; 320 321 out: 322 VOP_UNLOCK(nd.ni_vp, 0); 323 vn_close(nd.ni_vp, FREAD, td->td_ucred, td); 324 325 if (hdr != NULL) 326 free(hdr, M_LINKER); 327 if (shdr != NULL) 328 free(shdr, M_LINKER); 329 if (shstrtab != NULL) 330 free(shstrtab, M_LINKER); 331 if (ctftab != NULL) 332 free(ctftab, M_LINKER); 333 if (raw != NULL) 334 free(raw, M_LINKER); 335 #else 336 error = EOPNOTSUPP; 337 #endif 338 339 return (error); 340 } 341