1 /* ELF string table handling. 2 Copyright (C) 2000, 2001, 2002 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 Written by Ulrich Drepper <drepper (at) redhat.com>, 2000. 5 6 Red Hat elfutils is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by the 8 Free Software Foundation; version 2 of the License. 9 10 Red Hat elfutils is distributed in the hope that it will be useful, but 11 WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 General Public License for more details. 14 15 You should have received a copy of the GNU General Public License along 16 with Red Hat elfutils; if not, write to the Free Software Foundation, 17 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 18 19 In addition, as a special exception, Red Hat, Inc. gives You the 20 additional right to link the code of Red Hat elfutils with code licensed 21 under any Open Source Initiative certified open source license 22 (http://www.opensource.org/licenses/index.php) which requires the 23 distribution of source code with any binary distribution and to 24 distribute linked combinations of the two. Non-GPL Code permitted under 25 this exception must only link to the code of Red Hat elfutils through 26 those well defined interfaces identified in the file named EXCEPTION 27 found in the source code files (the "Approved Interfaces"). The files 28 of Non-GPL Code may instantiate templates or use macros or inline 29 functions from the Approved Interfaces without causing the resulting 30 work to be covered by the GNU General Public License. Only Red Hat, 31 Inc. may make changes or additions to the list of Approved Interfaces. 32 Red Hat's grant of this exception is conditioned upon your not adding 33 any new exceptions. If you wish to add a new Approved Interface or 34 exception, please contact Red Hat. You must obey the GNU General Public 35 License in all respects for all of the Red Hat elfutils code and other 36 code used in conjunction with Red Hat elfutils except the Non-GPL Code 37 covered by this exception. If you modify this file, you may extend this 38 exception to your version of the file, but you are not obligated to do 39 so. If you do not wish to provide this exception without modification, 40 you must delete this exception statement from your version and license 41 this file solely under the GPL without exception. 42 43 Red Hat elfutils is an included package of the Open Invention Network. 44 An included package of the Open Invention Network is a package for which 45 Open Invention Network licensees cross-license their patents. No patent 46 license is granted, either expressly or impliedly, by designation as an 47 included package. Should you wish to participate in the Open Invention 48 Network licensing program, please visit www.openinventionnetwork.com 49 <http://www.openinventionnetwork.com>. */ 50 51 #ifdef HAVE_CONFIG_H 52 # include <config.h> 53 #endif 54 55 #include <assert.h> 56 #include <inttypes.h> 57 #include <libelf.h> 58 #include <stddef.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 #include <wchar.h> 63 #include <sys/param.h> 64 65 #include "libebl.h" 66 #include <system.h> 67 68 #ifndef MIN 69 # define MIN(a, b) ((a) < (b) ? (a) : (b)) 70 #endif 71 72 73 struct Ebl_WStrent 74 { 75 const wchar_t *string; 76 size_t len; 77 struct Ebl_WStrent *next; 78 struct Ebl_WStrent *left; 79 struct Ebl_WStrent *right; 80 size_t offset; 81 wchar_t reverse[0]; 82 }; 83 84 85 struct memoryblock 86 { 87 struct memoryblock *next; 88 char memory[0]; 89 }; 90 91 92 struct Ebl_WStrtab 93 { 94 struct Ebl_WStrent *root; 95 struct memoryblock *memory; 96 char *backp; 97 size_t left; 98 size_t total; 99 bool nullstr; 100 101 struct Ebl_WStrent null; 102 }; 103 104 105 /* Cache for the pagesize. We correct this value a bit so that `malloc' 106 is not allocating more than a page. */ 107 static size_t ps; 108 109 110 struct Ebl_WStrtab * 111 ebl_wstrtabinit (bool nullstr) 112 { 113 struct Ebl_WStrtab *ret; 114 115 if (ps == 0) 116 { 117 ps = sysconf (_SC_PAGESIZE) - 2 * sizeof (void *); 118 assert (sizeof (struct memoryblock) < ps); 119 } 120 121 ret = (struct Ebl_WStrtab *) calloc (1, sizeof (struct Ebl_WStrtab)); 122 if (ret != NULL) 123 { 124 ret->nullstr = nullstr; 125 if (nullstr) 126 { 127 ret->null.len = 1; 128 ret->null.string = L""; 129 } 130 } 131 return ret; 132 } 133 134 135 static int 136 morememory (struct Ebl_WStrtab *st, size_t len) 137 { 138 struct memoryblock *newmem; 139 140 if (len < ps) 141 len = ps; 142 newmem = (struct memoryblock *) malloc (len); 143 if (newmem == NULL) 144 return 1; 145 146 newmem->next = st->memory; 147 st->memory = newmem; 148 st->backp = newmem->memory; 149 st->left = len - offsetof (struct memoryblock, memory); 150 151 return 0; 152 } 153 154 155 void 156 ebl_wstrtabfree (struct Ebl_WStrtab *st) 157 { 158 struct memoryblock *mb = st->memory; 159 160 while (mb != NULL) 161 { 162 void *old = mb; 163 mb = mb->next; 164 free (old); 165 } 166 167 free (st); 168 } 169 170 171 static struct Ebl_WStrent * 172 newstring (struct Ebl_WStrtab *st, const wchar_t *str, size_t len) 173 { 174 struct Ebl_WStrent *newstr; 175 size_t align; 176 int i; 177 178 /* Compute the amount of padding needed to make the structure aligned. */ 179 align = ((__alignof__ (struct Ebl_WStrent) 180 - (((uintptr_t) st->backp) 181 & (__alignof__ (struct Ebl_WStrent) - 1))) 182 & (__alignof__ (struct Ebl_WStrent) - 1)); 183 184 /* Make sure there is enough room in the memory block. */ 185 if (st->left < align + sizeof (struct Ebl_WStrent) + len * sizeof (wchar_t)) 186 { 187 if (morememory (st, 188 sizeof (struct Ebl_WStrent) + len * sizeof (wchar_t))) 189 return NULL; 190 191 align = 0; 192 } 193 194 /* Create the reserved string. */ 195 newstr = (struct Ebl_WStrent *) (st->backp + align); 196 newstr->string = str; 197 newstr->len = len; 198 newstr->next = NULL; 199 newstr->left = NULL; 200 newstr->right = NULL; 201 newstr->offset = 0; 202 for (i = len - 2; i >= 0; --i) 203 newstr->reverse[i] = str[len - 2 - i]; 204 newstr->reverse[len - 1] = L'\0'; 205 st->backp += align + sizeof (struct Ebl_WStrent) + len * sizeof (wchar_t); 206 st->left -= align + sizeof (struct Ebl_WStrent) + len * sizeof (wchar_t); 207 208 return newstr; 209 } 210 211 212 /* XXX This function should definitely be rewritten to use a balancing 213 tree algorith (AVL, red-black trees). For now a simple, correct 214 implementation is enough. */ 215 static struct Ebl_WStrent ** 216 searchstring (struct Ebl_WStrent **sep, struct Ebl_WStrent *newstr) 217 { 218 int cmpres; 219 220 /* More strings? */ 221 if (*sep == NULL) 222 { 223 *sep = newstr; 224 return sep; 225 } 226 227 /* Compare the strings. */ 228 cmpres = wmemcmp ((*sep)->reverse, newstr->reverse, 229 MIN ((*sep)->len, newstr->len) - 1); 230 if (cmpres == 0) 231 /* We found a matching string. */ 232 return sep; 233 else if (cmpres > 0) 234 return searchstring (&(*sep)->left, newstr); 235 else 236 return searchstring (&(*sep)->right, newstr); 237 } 238 239 240 /* Add new string. The actual string is assumed to be permanent. */ 241 struct Ebl_WStrent * 242 ebl_wstrtabadd (struct Ebl_WStrtab *st, const wchar_t *str, size_t len) 243 { 244 struct Ebl_WStrent *newstr; 245 struct Ebl_WStrent **sep; 246 247 /* Compute the string length if the caller doesn't know it. */ 248 if (len == 0) 249 len = wcslen (str) + 1; 250 251 /* Make sure all "" strings get offset 0 but only if the table was 252 created with a special null entry in mind. */ 253 if (len == 1 && st->null.string != NULL) 254 return &st->null; 255 256 /* Allocate memory for the new string and its associated information. */ 257 newstr = newstring (st, str, len); 258 if (newstr == NULL) 259 return NULL; 260 261 /* Search in the array for the place to insert the string. If there 262 is no string with matching prefix and no string with matching 263 leading substring, create a new entry. */ 264 sep = searchstring (&st->root, newstr); 265 if (*sep != newstr) 266 { 267 /* This is not the same entry. This means we have a prefix match. */ 268 if ((*sep)->len > newstr->len) 269 { 270 struct Ebl_WStrent *subs; 271 272 /* Check whether we already know this string. */ 273 for (subs = (*sep)->next; subs != NULL; subs = subs->next) 274 if (subs->len == newstr->len) 275 { 276 /* We have an exact match with a substring. Free the memory 277 we allocated. */ 278 st->left += st->backp - (char *) newstr; 279 st->backp = (char *) newstr; 280 281 return subs; 282 } 283 284 /* We have a new substring. This means we don't need the reverse 285 string of this entry anymore. */ 286 st->backp -= newstr->len; 287 st->left += newstr->len; 288 289 newstr->next = (*sep)->next; 290 (*sep)->next = newstr; 291 } 292 else if ((*sep)->len != newstr->len) 293 { 294 /* When we get here it means that the string we are about to 295 add has a common prefix with a string we already have but 296 it is longer. In this case we have to put it first. */ 297 st->total += newstr->len - (*sep)->len; 298 newstr->next = *sep; 299 newstr->left = (*sep)->left; 300 newstr->right = (*sep)->right; 301 *sep = newstr; 302 } 303 else 304 { 305 /* We have an exact match. Free the memory we allocated. */ 306 st->left += st->backp - (char *) newstr; 307 st->backp = (char *) newstr; 308 309 newstr = *sep; 310 } 311 } 312 else 313 st->total += newstr->len; 314 315 return newstr; 316 } 317 318 319 static void 320 copystrings (struct Ebl_WStrent *nodep, wchar_t **freep, size_t *offsetp) 321 { 322 struct Ebl_WStrent *subs; 323 324 if (nodep->left != NULL) 325 copystrings (nodep->left, freep, offsetp); 326 327 /* Process the current node. */ 328 nodep->offset = *offsetp; 329 *freep = wmempcpy (*freep, nodep->string, nodep->len); 330 *offsetp += nodep->len * sizeof (wchar_t); 331 332 for (subs = nodep->next; subs != NULL; subs = subs->next) 333 { 334 assert (subs->len < nodep->len); 335 subs->offset = nodep->offset + nodep->len - subs->len; 336 assert (subs->offset != 0 || subs->string[0] == '\0'); 337 } 338 339 if (nodep->right != NULL) 340 copystrings (nodep->right, freep, offsetp); 341 } 342 343 344 void 345 ebl_wstrtabfinalize (struct Ebl_WStrtab *st, Elf_Data *data) 346 { 347 size_t copylen; 348 wchar_t *endp; 349 size_t nulllen = st->nullstr ? 1 : 0; 350 351 /* Fill in the information. */ 352 data->d_buf = malloc ((st->total + nulllen) * sizeof (wchar_t)); 353 if (data->d_buf == NULL) 354 abort (); 355 356 /* The first byte must always be zero if we created the table with a 357 null string. */ 358 if (st->nullstr) 359 *((wchar_t *) data->d_buf) = L'\0'; 360 361 data->d_type = ELF_T_BYTE; 362 data->d_size = st->total + nulllen; 363 data->d_off = 0; 364 data->d_align = 1; 365 data->d_version = EV_CURRENT; 366 367 /* Now run through the tree and add all the string while also updating 368 the offset members of the elfstrent records. */ 369 endp = (wchar_t *) data->d_buf + nulllen; 370 copylen = sizeof (wchar_t) * nulllen; 371 copystrings (st->root, &endp, ©len); 372 assert (copylen == (st->total + nulllen) * sizeof (wchar_t)); 373 } 374 375 376 size_t 377 ebl_wstrtaboffset (struct Ebl_WStrent *se) 378 { 379 return se->offset; 380 } 381
