1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 23 /* 24 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 25 * Use is subject to license terms. 26 */ 27 28 #pragma ident "%Z%%M% %I% %E% SMI" 29 30 #include <sys/sysmacros.h> 31 #include <ctf_impl.h> 32 33 /* 34 * Compare the given input string and length against a table of known C storage 35 * qualifier keywords. We just ignore these in ctf_lookup_by_name, below. To 36 * do this quickly, we use a pre-computed Perfect Hash Function similar to the 37 * technique originally described in the classic paper: 38 * 39 * R.J. Cichelli, "Minimal Perfect Hash Functions Made Simple", 40 * Communications of the ACM, Volume 23, Issue 1, January 1980, pp. 17-19. 41 * 42 * For an input string S of length N, we use hash H = S[N - 1] + N - 105, which 43 * for the current set of qualifiers yields a unique H in the range [0 .. 20]. 44 * The hash can be modified when the keyword set changes as necessary. We also 45 * store the length of each keyword and check it prior to the final strcmp(). 46 */ 47 static int 48 isqualifier(const char *s, size_t len) 49 { 50 static const struct qual { 51 const char *q_name; 52 size_t q_len; 53 } qhash[] = { 54 { "static", 6 }, { "", 0 }, { "", 0 }, { "", 0 }, 55 { "volatile", 8 }, { "", 0 }, { "", 0 }, { "", 0 }, { "", 0 }, 56 { "", 0 }, { "auto", 4 }, { "extern", 6 }, { "", 0 }, { "", 0 }, 57 { "", 0 }, { "", 0 }, { "const", 5 }, { "register", 8 }, 58 { "", 0 }, { "restrict", 8 }, { "_Restrict", 9 } 59 }; 60 61 int h = s[len - 1] + (int)len - 105; 62 const struct qual *qp; 63 64 if (h < 0 || h >= sizeof (qhash) / sizeof (qhash[0])) 65 return (0); 66 qp = &qhash[h]; 67 return (len == qp->q_len && strncmp(qp->q_name, s, qp->q_len) == 0); 68 } 69 70 /* 71 * Attempt to convert the given C type name into the corresponding CTF type ID. 72 * It is not possible to do complete and proper conversion of type names 73 * without implementing a more full-fledged parser, which is necessary to 74 * handle things like types that are function pointers to functions that 75 * have arguments that are function pointers, and fun stuff like that. 76 * Instead, this function implements a very simple conversion algorithm that 77 * finds the things that we actually care about: structs, unions, enums, 78 * integers, floats, typedefs, and pointers to any of these named types. 79 */ 80 ctf_id_t 81 ctf_lookup_by_name(ctf_file_t *fp, const char *name) 82 { 83 static const char delimiters[] = " \t\n\r\v\f*"; 84 85 const ctf_lookup_t *lp; 86 const ctf_helem_t *hp; 87 const char *p, *q, *end; 88 ctf_id_t type = 0; 89 ctf_id_t ntype, ptype; 90 91 if (name == NULL) 92 return (ctf_set_errno(fp, EINVAL)); 93 94 for (p = name, end = name + strlen(name); *p != '\0'; p = q) { 95 while (isspace(*p)) 96 p++; /* skip leading ws */ 97 98 if (p == end) 99 break; 100 101 if ((q = strpbrk(p + 1, delimiters)) == NULL) 102 q = end; /* compare until end */ 103 104 if (*p == '*') { 105 /* 106 * Find a pointer to type by looking in fp->ctf_ptrtab. 107 * If we can't find a pointer to the given type, see if 108 * we can compute a pointer to the type resulting from 109 * resolving the type down to its base type and use 110 * that instead. This helps with cases where the CTF 111 * data includes "struct foo *" but not "foo_t *" and 112 * the user tries to access "foo_t *" in the debugger. 113 */ 114 ntype = fp->ctf_ptrtab[LCTF_TYPE_TO_INDEX(fp, type)]; 115 if (ntype == 0) { 116 ntype = ctf_type_resolve(fp, type); 117 if (ntype == CTF_ERR || (ntype = fp->ctf_ptrtab[ 118 LCTF_TYPE_TO_INDEX(fp, ntype)]) == 0) { 119 (void) ctf_set_errno(fp, ECTF_NOTYPE); 120 goto err; 121 } 122 } 123 124 type = LCTF_INDEX_TO_TYPE(fp, ntype, 125 (fp->ctf_flags & LCTF_CHILD)); 126 127 q = p + 1; 128 continue; 129 } 130 131 if (isqualifier(p, (size_t)(q - p))) 132 continue; /* skip qualifier keyword */ 133 134 for (lp = fp->ctf_lookups; lp->ctl_prefix != NULL; lp++) { 135 if (lp->ctl_prefix[0] == '\0' || 136 ((size_t)(q - p) >= lp->ctl_len && strncmp(p, 137 lp->ctl_prefix, (size_t)(q - p)) == 0)) { 138 for (p += lp->ctl_len; isspace(*p); p++) 139 continue; /* skip prefix and next ws */ 140 141 if ((q = strchr(p, '*')) == NULL) 142 q = end; /* compare until end */ 143 144 while (isspace(q[-1])) 145 q--; /* exclude trailing ws */ 146 147 if ((hp = ctf_hash_lookup(lp->ctl_hash, fp, p, 148 (size_t)(q - p))) == NULL) { 149 (void) ctf_set_errno(fp, ECTF_NOTYPE); 150 goto err; 151 } 152 153 type = hp->h_type; 154 break; 155 } 156 } 157 158 if (lp->ctl_prefix == NULL) { 159 (void) ctf_set_errno(fp, ECTF_NOTYPE); 160 goto err; 161 } 162 } 163 164 if (*p != '\0' || type == 0) 165 return (ctf_set_errno(fp, ECTF_SYNTAX)); 166 167 return (type); 168 169 err: 170 if (fp->ctf_parent != NULL && 171 (ptype = ctf_lookup_by_name(fp->ctf_parent, name)) != CTF_ERR) 172 return (ptype); 173 174 return (CTF_ERR); 175 } 176 177 /* 178 * Given a symbol table index, return the type of the data object described 179 * by the corresponding entry in the symbol table. 180 */ 181 ctf_id_t 182 ctf_lookup_by_symbol(ctf_file_t *fp, ulong_t symidx) 183 { 184 const ctf_sect_t *sp = &fp->ctf_symtab; 185 ctf_id_t type; 186 187 if (sp->cts_data == NULL) 188 return (ctf_set_errno(fp, ECTF_NOSYMTAB)); 189 190 if (symidx >= fp->ctf_nsyms) 191 return (ctf_set_errno(fp, EINVAL)); 192 193 if (sp->cts_entsize == sizeof (Elf32_Sym)) { 194 const Elf32_Sym *symp = (Elf32_Sym *)sp->cts_data + symidx; 195 if (ELF32_ST_TYPE(symp->st_info) != STT_OBJECT) 196 return (ctf_set_errno(fp, ECTF_NOTDATA)); 197 } else { 198 const Elf64_Sym *symp = (Elf64_Sym *)sp->cts_data + symidx; 199 if (ELF64_ST_TYPE(symp->st_info) != STT_OBJECT) 200 return (ctf_set_errno(fp, ECTF_NOTDATA)); 201 } 202 203 if (fp->ctf_sxlate[symidx] == -1u) 204 return (ctf_set_errno(fp, ECTF_NOTYPEDAT)); 205 206 type = *(uint_t *)((uintptr_t)fp->ctf_buf + fp->ctf_sxlate[symidx]); 207 if (type == 0) 208 return (ctf_set_errno(fp, ECTF_NOTYPEDAT)); 209 210 return (type); 211 } 212 213 /* 214 * Return the pointer to the internal CTF type data corresponding to the 215 * given type ID. If the ID is invalid, the function returns NULL. 216 * This function is not exported outside of the library. 217 */ 218 const void * 219 ctf_lookup_by_id(ctf_file_t **fpp, ctf_id_t type) 220 { 221 ctf_file_t *fp = *fpp; /* caller passes in starting CTF container */ 222 223 if ((fp->ctf_flags & LCTF_CHILD) && LCTF_TYPE_ISPARENT(fp, type)) { 224 if (fp->ctf_parent == NULL) { 225 (void) ctf_set_errno(*fpp, ECTF_NOPARENT); 226 return (NULL); 227 } 228 229 /* The parent may be using a different CTF version. */ 230 type = LCTF_TYPE_TO_INDEX(fp, type); 231 fp = fp->ctf_parent; 232 } else { 233 type = LCTF_TYPE_TO_INDEX(fp, type); 234 } 235 236 if (type > 0 && type <= fp->ctf_typemax) { 237 *fpp = fp; /* function returns ending CTF container */ 238 return (LCTF_INDEX_TO_TYPEPTR(fp, type)); 239 } 240 241 (void) ctf_set_errno(fp, ECTF_BADID); 242 return (NULL); 243 } 244 245 /* 246 * Given a symbol table index, return the info for the function described 247 * by the corresponding entry in the symbol table. 248 */ 249 int 250 ctf_func_info(ctf_file_t *fp, ulong_t symidx, ctf_funcinfo_t *fip) 251 { 252 const ctf_sect_t *sp = &fp->ctf_symtab; 253 const uint_t *dp; 254 uint_t info, kind, n; 255 256 if (sp->cts_data == NULL) 257 return (ctf_set_errno(fp, ECTF_NOSYMTAB)); 258 259 if (symidx >= fp->ctf_nsyms) 260 return (ctf_set_errno(fp, EINVAL)); 261 262 if (sp->cts_entsize == sizeof (Elf32_Sym)) { 263 const Elf32_Sym *symp = (Elf32_Sym *)sp->cts_data + symidx; 264 if (ELF32_ST_TYPE(symp->st_info) != STT_FUNC) 265 return (ctf_set_errno(fp, ECTF_NOTFUNC)); 266 } else { 267 const Elf64_Sym *symp = (Elf64_Sym *)sp->cts_data + symidx; 268 if (ELF64_ST_TYPE(symp->st_info) != STT_FUNC) 269 return (ctf_set_errno(fp, ECTF_NOTFUNC)); 270 } 271 272 if (fp->ctf_sxlate[symidx] == -1u) 273 return (ctf_set_errno(fp, ECTF_NOFUNCDAT)); 274 275 dp = (uint_t *)((uintptr_t)fp->ctf_buf + fp->ctf_sxlate[symidx]); 276 277 info = *dp++; 278 kind = LCTF_INFO_KIND(fp, info); 279 n = LCTF_INFO_VLEN(fp, info); 280 281 if (kind == CTF_K_UNKNOWN && n == 0) 282 return (ctf_set_errno(fp, ECTF_NOFUNCDAT)); 283 284 if (kind != CTF_K_FUNCTION) 285 return (ctf_set_errno(fp, ECTF_CORRUPT)); 286 287 fip->ctc_return = *dp++; 288 fip->ctc_argc = n; 289 fip->ctc_flags = 0; 290 291 if (n != 0 && dp[n - 1] == 0) { 292 fip->ctc_flags |= CTF_FUNC_VARARG; 293 fip->ctc_argc--; 294 } 295 296 return (0); 297 } 298 299 /* 300 * Given a symbol table index, return the arguments for the function described 301 * by the corresponding entry in the symbol table. 302 */ 303 int 304 ctf_func_args(ctf_file_t *fp, ulong_t symidx, uint_t argc, ctf_id_t *argv) 305 { 306 const uint_t *dp; 307 ctf_funcinfo_t f; 308 309 if (ctf_func_info(fp, symidx, &f) == CTF_ERR) 310 return (CTF_ERR); /* errno is set for us */ 311 312 /* 313 * The argument data is two uint_t's past the translation table 314 * offset: one for the function info, and one for the return type. 315 */ 316 dp = (uint_t *)((uintptr_t)fp->ctf_buf + fp->ctf_sxlate[symidx]) + 2; 317 318 for (argc = MIN(argc, f.ctc_argc); argc != 0; argc--) 319 *argv++ = *dp++; 320 321 return (0); 322 } 323