| 1 | /* Miscellaneous utilities. |
| 2 | Copyright (C) 2019-2021 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of libctf. |
| 5 | |
| 6 | libctf is free software; you can redistribute it and/or modify it under |
| 7 | the terms of the GNU General Public License as published by the Free |
| 8 | Software Foundation; either version 3, or (at your option) any later |
| 9 | version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, but |
| 12 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 14 | See the GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; see the file COPYING. If not see |
| 18 | <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include <ctf-impl.h> |
| 21 | #include <string.h> |
| 22 | #include "ctf-endian.h" |
| 23 | |
| 24 | /* Simple doubly-linked list append routine. This implementation assumes that |
| 25 | each list element contains an embedded ctf_list_t as the first member. |
| 26 | An additional ctf_list_t is used to store the head (l_next) and tail |
| 27 | (l_prev) pointers. The current head and tail list elements have their |
| 28 | previous and next pointers set to NULL, respectively. */ |
| 29 | |
| 30 | void |
| 31 | ctf_list_append (ctf_list_t *lp, void *newp) |
| 32 | { |
| 33 | ctf_list_t *p = lp->l_prev; /* p = tail list element. */ |
| 34 | ctf_list_t *q = newp; /* q = new list element. */ |
| 35 | |
| 36 | lp->l_prev = q; |
| 37 | q->l_prev = p; |
| 38 | q->l_next = NULL; |
| 39 | |
| 40 | if (p != NULL) |
| 41 | p->l_next = q; |
| 42 | else |
| 43 | lp->l_next = q; |
| 44 | } |
| 45 | |
| 46 | /* Prepend the specified existing element to the given ctf_list_t. The |
| 47 | existing pointer should be pointing at a struct with embedded ctf_list_t. */ |
| 48 | |
| 49 | void |
| 50 | ctf_list_prepend (ctf_list_t * lp, void *newp) |
| 51 | { |
| 52 | ctf_list_t *p = newp; /* p = new list element. */ |
| 53 | ctf_list_t *q = lp->l_next; /* q = head list element. */ |
| 54 | |
| 55 | lp->l_next = p; |
| 56 | p->l_prev = NULL; |
| 57 | p->l_next = q; |
| 58 | |
| 59 | if (q != NULL) |
| 60 | q->l_prev = p; |
| 61 | else |
| 62 | lp->l_prev = p; |
| 63 | } |
| 64 | |
| 65 | /* Delete the specified existing element from the given ctf_list_t. The |
| 66 | existing pointer should be pointing at a struct with embedded ctf_list_t. */ |
| 67 | |
| 68 | void |
| 69 | ctf_list_delete (ctf_list_t *lp, void *existing) |
| 70 | { |
| 71 | ctf_list_t *p = existing; |
| 72 | |
| 73 | if (p->l_prev != NULL) |
| 74 | p->l_prev->l_next = p->l_next; |
| 75 | else |
| 76 | lp->l_next = p->l_next; |
| 77 | |
| 78 | if (p->l_next != NULL) |
| 79 | p->l_next->l_prev = p->l_prev; |
| 80 | else |
| 81 | lp->l_prev = p->l_prev; |
| 82 | } |
| 83 | |
| 84 | /* Return 1 if the list is empty. */ |
| 85 | |
| 86 | int |
| 87 | ctf_list_empty_p (ctf_list_t *lp) |
| 88 | { |
| 89 | return (lp->l_next == NULL && lp->l_prev == NULL); |
| 90 | } |
| 91 | |
| 92 | /* Splice one entire list onto the end of another one. The existing list is |
| 93 | emptied. */ |
| 94 | |
| 95 | void |
| 96 | ctf_list_splice (ctf_list_t *lp, ctf_list_t *append) |
| 97 | { |
| 98 | if (ctf_list_empty_p (append)) |
| 99 | return; |
| 100 | |
| 101 | if (lp->l_prev != NULL) |
| 102 | lp->l_prev->l_next = append->l_next; |
| 103 | else |
| 104 | lp->l_next = append->l_next; |
| 105 | |
| 106 | append->l_next->l_prev = lp->l_prev; |
| 107 | lp->l_prev = append->l_prev; |
| 108 | append->l_next = NULL; |
| 109 | append->l_prev = NULL; |
| 110 | } |
| 111 | |
| 112 | /* Convert a 32-bit ELF symbol to a ctf_link_sym_t. */ |
| 113 | |
| 114 | ctf_link_sym_t * |
| 115 | ctf_elf32_to_link_sym (ctf_dict_t *fp, ctf_link_sym_t *dst, const Elf32_Sym *src, |
| 116 | uint32_t symidx) |
| 117 | { |
| 118 | Elf32_Sym tmp; |
| 119 | int needs_flipping = 0; |
| 120 | |
| 121 | #ifdef WORDS_BIGENDIAN |
| 122 | if (fp->ctf_symsect_little_endian) |
| 123 | needs_flipping = 1; |
| 124 | #else |
| 125 | if (!fp->ctf_symsect_little_endian) |
| 126 | needs_flipping = 1; |
| 127 | #endif |
| 128 | |
| 129 | memcpy (&tmp, src, sizeof (Elf32_Sym)); |
| 130 | if (needs_flipping) |
| 131 | { |
| 132 | swap_thing (tmp.st_name); |
| 133 | swap_thing (tmp.st_size); |
| 134 | swap_thing (tmp.st_shndx); |
| 135 | swap_thing (tmp.st_value); |
| 136 | } |
| 137 | /* The name must be in the external string table. */ |
| 138 | if (tmp.st_name < fp->ctf_str[CTF_STRTAB_1].cts_len) |
| 139 | dst->st_name = (const char *) fp->ctf_str[CTF_STRTAB_1].cts_strs + tmp.st_name; |
| 140 | else |
| 141 | dst->st_name = _CTF_NULLSTR; |
| 142 | dst->st_nameidx_set = 0; |
| 143 | dst->st_symidx = symidx; |
| 144 | dst->st_shndx = tmp.st_shndx; |
| 145 | dst->st_type = ELF32_ST_TYPE (tmp.st_info); |
| 146 | dst->st_value = tmp.st_value; |
| 147 | |
| 148 | return dst; |
| 149 | } |
| 150 | |
| 151 | /* Convert a 64-bit ELF symbol to a ctf_link_sym_t. */ |
| 152 | |
| 153 | ctf_link_sym_t * |
| 154 | ctf_elf64_to_link_sym (ctf_dict_t *fp, ctf_link_sym_t *dst, const Elf64_Sym *src, |
| 155 | uint32_t symidx) |
| 156 | { |
| 157 | Elf64_Sym tmp; |
| 158 | int needs_flipping = 0; |
| 159 | |
| 160 | #ifdef WORDS_BIGENDIAN |
| 161 | if (fp->ctf_symsect_little_endian) |
| 162 | needs_flipping = 1; |
| 163 | #else |
| 164 | if (!fp->ctf_symsect_little_endian) |
| 165 | needs_flipping = 1; |
| 166 | #endif |
| 167 | |
| 168 | memcpy (&tmp, src, sizeof (Elf64_Sym)); |
| 169 | if (needs_flipping) |
| 170 | { |
| 171 | swap_thing (tmp.st_name); |
| 172 | swap_thing (tmp.st_size); |
| 173 | swap_thing (tmp.st_shndx); |
| 174 | swap_thing (tmp.st_value); |
| 175 | } |
| 176 | |
| 177 | /* The name must be in the external string table. */ |
| 178 | if (tmp.st_name < fp->ctf_str[CTF_STRTAB_1].cts_len) |
| 179 | dst->st_name = (const char *) fp->ctf_str[CTF_STRTAB_1].cts_strs + tmp.st_name; |
| 180 | else |
| 181 | dst->st_name = _CTF_NULLSTR; |
| 182 | dst->st_nameidx_set = 0; |
| 183 | dst->st_symidx = symidx; |
| 184 | dst->st_shndx = tmp.st_shndx; |
| 185 | dst->st_type = ELF32_ST_TYPE (tmp.st_info); |
| 186 | |
| 187 | /* We only care if the value is zero, so avoid nonzeroes turning into |
| 188 | zeroes. */ |
| 189 | if (_libctf_unlikely_ (tmp.st_value != 0 && ((uint32_t) tmp.st_value == 0))) |
| 190 | dst->st_value = 1; |
| 191 | else |
| 192 | dst->st_value = (uint32_t) tmp.st_value; |
| 193 | |
| 194 | return dst; |
| 195 | } |
| 196 | |
| 197 | /* A string appender working on dynamic strings. Returns NULL on OOM. */ |
| 198 | |
| 199 | char * |
| 200 | ctf_str_append (char *s, const char *append) |
| 201 | { |
| 202 | size_t s_len = 0; |
| 203 | |
| 204 | if (append == NULL) |
| 205 | return s; |
| 206 | |
| 207 | if (s != NULL) |
| 208 | s_len = strlen (s); |
| 209 | |
| 210 | size_t append_len = strlen (append); |
| 211 | |
| 212 | if ((s = realloc (s, s_len + append_len + 1)) == NULL) |
| 213 | return NULL; |
| 214 | |
| 215 | memcpy (s + s_len, append, append_len); |
| 216 | s[s_len + append_len] = '\0'; |
| 217 | |
| 218 | return s; |
| 219 | } |
| 220 | |
| 221 | /* A version of ctf_str_append that returns the old string on OOM. */ |
| 222 | |
| 223 | char * |
| 224 | ctf_str_append_noerr (char *s, const char *append) |
| 225 | { |
| 226 | char *new_s; |
| 227 | |
| 228 | new_s = ctf_str_append (s, append); |
| 229 | if (!new_s) |
| 230 | return s; |
| 231 | return new_s; |
| 232 | } |
| 233 | |
| 234 | /* A realloc() that fails noisily if called with any ctf_str_num_users. */ |
| 235 | void * |
| 236 | ctf_realloc (ctf_dict_t *fp, void *ptr, size_t size) |
| 237 | { |
| 238 | if (fp->ctf_str_num_refs > 0) |
| 239 | { |
| 240 | ctf_dprintf ("%p: attempt to realloc() string table with %lu active refs\n", |
| 241 | (void *) fp, (unsigned long) fp->ctf_str_num_refs); |
| 242 | return NULL; |
| 243 | } |
| 244 | return realloc (ptr, size); |
| 245 | } |
| 246 | |
| 247 | /* Store the specified error code into errp if it is non-NULL, and then |
| 248 | return NULL for the benefit of the caller. */ |
| 249 | |
| 250 | void * |
| 251 | ctf_set_open_errno (int *errp, int error) |
| 252 | { |
| 253 | if (errp != NULL) |
| 254 | *errp = error; |
| 255 | return NULL; |
| 256 | } |
| 257 | |
| 258 | /* Store the specified error code into the CTF dict, and then return CTF_ERR / |
| 259 | -1 for the benefit of the caller. */ |
| 260 | |
| 261 | unsigned long |
| 262 | ctf_set_errno (ctf_dict_t *fp, int err) |
| 263 | { |
| 264 | fp->ctf_errno = err; |
| 265 | return CTF_ERR; |
| 266 | } |
| 267 | |
| 268 | /* Create a ctf_next_t. */ |
| 269 | |
| 270 | ctf_next_t * |
| 271 | ctf_next_create (void) |
| 272 | { |
| 273 | return calloc (1, sizeof (struct ctf_next)); |
| 274 | } |
| 275 | |
| 276 | /* Destroy a ctf_next_t, for early exit from iterators. */ |
| 277 | |
| 278 | void |
| 279 | ctf_next_destroy (ctf_next_t *i) |
| 280 | { |
| 281 | if (i == NULL) |
| 282 | return; |
| 283 | |
| 284 | if (i->ctn_iter_fun == (void (*) (void)) ctf_dynhash_next_sorted) |
| 285 | free (i->u.ctn_sorted_hkv); |
| 286 | if (i->ctn_next) |
| 287 | ctf_next_destroy (i->ctn_next); |
| 288 | free (i); |
| 289 | } |
| 290 | |
| 291 | /* Copy a ctf_next_t. */ |
| 292 | |
| 293 | ctf_next_t * |
| 294 | ctf_next_copy (ctf_next_t *i) |
| 295 | { |
| 296 | ctf_next_t *i2; |
| 297 | |
| 298 | if ((i2 = ctf_next_create()) == NULL) |
| 299 | return NULL; |
| 300 | memcpy (i2, i, sizeof (struct ctf_next)); |
| 301 | |
| 302 | if (i2->ctn_iter_fun == (void (*) (void)) ctf_dynhash_next_sorted) |
| 303 | { |
| 304 | size_t els = ctf_dynhash_elements ((ctf_dynhash_t *) i->cu.ctn_h); |
| 305 | if ((i2->u.ctn_sorted_hkv = calloc (els, sizeof (ctf_next_hkv_t))) == NULL) |
| 306 | { |
| 307 | free (i2); |
| 308 | return NULL; |
| 309 | } |
| 310 | memcpy (i2->u.ctn_sorted_hkv, i->u.ctn_sorted_hkv, |
| 311 | els * sizeof (ctf_next_hkv_t)); |
| 312 | } |
| 313 | return i2; |
| 314 | } |