| File: | root/firefox-clang/security/nss/lib/base/tracker.c |
| Warning: | line 29, column 39 Subtraction of a probably non-null pointer and a null pointer may result in undefined behavior |
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| 1 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| 2 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| 3 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| 4 | |
| 5 | /* |
| 6 | * tracker.c |
| 7 | * |
| 8 | * This file contains the code used by the pointer-tracking calls used |
| 9 | * in the debug builds to catch bad pointers. The entire contents are |
| 10 | * only available in debug builds (both internal and external builds). |
| 11 | */ |
| 12 | |
| 13 | #ifndef BASE_H |
| 14 | #include "base.h" |
| 15 | #endif /* BASE_H */ |
| 16 | |
| 17 | #ifdef DEBUG1 |
| 18 | /* |
| 19 | * identity_hash |
| 20 | * |
| 21 | * This static callback is a PLHashFunction as defined in plhash.h |
| 22 | * It merely returns the value of the object pointer as its hash. |
| 23 | * There are no possible errors. |
| 24 | */ |
| 25 | |
| 26 | static PLHashNumber PR_CALLBACK |
| 27 | identity_hash(const void *key) |
| 28 | { |
| 29 | return (PLHashNumber)((char *)key - (char *)NULL((void*)0)); |
Subtraction of a probably non-null pointer and a null pointer may result in undefined behavior | |
| 30 | } |
| 31 | |
| 32 | /* |
| 33 | * trackerOnceFunc |
| 34 | * |
| 35 | * This function is called once, using the nssCallOnce function above. |
| 36 | * It creates a new pointer tracker object; initialising its hash |
| 37 | * table and protective lock. |
| 38 | */ |
| 39 | |
| 40 | static PRStatus |
| 41 | trackerOnceFunc(void *arg) |
| 42 | { |
| 43 | nssPointerTracker *tracker = (nssPointerTracker *)arg; |
| 44 | |
| 45 | tracker->lock = PZ_NewLock(nssILockOther)PR_NewLock(); |
| 46 | if ((PZLockPRLock *)NULL((void*)0) == tracker->lock) { |
| 47 | return PR_FAILURE; |
| 48 | } |
| 49 | |
| 50 | tracker->table = |
| 51 | PL_NewHashTable(0, identity_hash, PL_CompareValues, PL_CompareValues, |
| 52 | (PLHashAllocOps *)NULL((void*)0), (void *)NULL((void*)0)); |
| 53 | if ((PLHashTable *)NULL((void*)0) == tracker->table) { |
| 54 | PZ_DestroyLock(tracker->lock)PR_DestroyLock((tracker->lock)); |
| 55 | tracker->lock = (PZLockPRLock *)NULL((void*)0); |
| 56 | return PR_FAILURE; |
| 57 | } |
| 58 | |
| 59 | return PR_SUCCESS; |
| 60 | } |
| 61 | |
| 62 | /* |
| 63 | * nssPointerTracker_initialize |
| 64 | * |
| 65 | * This method is only present in debug builds. |
| 66 | * |
| 67 | * This routine initializes an nssPointerTracker object. Note that |
| 68 | * the object must have been declared *static* to guarantee that it |
| 69 | * is in a zeroed state initially. This routine is idempotent, and |
| 70 | * may even be safely called by multiple threads simultaneously with |
| 71 | * the same argument. This routine returns a PRStatus value; if |
| 72 | * successful, it will return PR_SUCCESS. On failure it will set an |
| 73 | * error on the error stack and return PR_FAILURE. |
| 74 | * |
| 75 | * The error may be one of the following values: |
| 76 | * NSS_ERROR_NO_MEMORY |
| 77 | * |
| 78 | * Return value: |
| 79 | * PR_SUCCESS |
| 80 | * PR_FAILURE |
| 81 | */ |
| 82 | |
| 83 | NSS_IMPLEMENT PRStatus |
| 84 | nssPointerTracker_initialize(nssPointerTracker *tracker) |
| 85 | { |
| 86 | PRStatus rv = PR_CallOnceWithArg(&tracker->once, trackerOnceFunc, tracker); |
| 87 | if (PR_SUCCESS != rv) { |
| 88 | nss_SetError(NSS_ERROR_NO_MEMORY); |
| 89 | } |
| 90 | |
| 91 | return rv; |
| 92 | } |
| 93 | |
| 94 | #ifdef DONT_DESTROY_EMPTY_TABLES |
| 95 | /* See same #ifdef below */ |
| 96 | /* |
| 97 | * count_entries |
| 98 | * |
| 99 | * This static routine is a PLHashEnumerator, as defined in plhash.h. |
| 100 | * It merely causes the enumeration function to count the number of |
| 101 | * entries. |
| 102 | */ |
| 103 | |
| 104 | static PRIntn PR_CALLBACK |
| 105 | count_entries(PLHashEntry *he, PRIntn index, void *arg) |
| 106 | { |
| 107 | return HT_ENUMERATE_NEXT0; |
| 108 | } |
| 109 | #endif /* DONT_DESTROY_EMPTY_TABLES */ |
| 110 | |
| 111 | /* |
| 112 | * zero_once |
| 113 | * |
| 114 | * This is a guaranteed zeroed once block. It's used to help clear |
| 115 | * the tracker. |
| 116 | */ |
| 117 | |
| 118 | static const PRCallOnceType zero_once; |
| 119 | |
| 120 | /* |
| 121 | * nssPointerTracker_finalize |
| 122 | * |
| 123 | * This method is only present in debug builds. |
| 124 | * |
| 125 | * This routine returns the nssPointerTracker object to the pre- |
| 126 | * initialized state, releasing all resources used by the object. |
| 127 | * It will *NOT* destroy the objects being tracked by the pointer |
| 128 | * (should any remain), and therefore cannot be used to "sweep up" |
| 129 | * remaining objects. This routine returns a PRStatus value; if |
| 130 | * successful, it will return PR_SUCCES. On failure it will set an |
| 131 | * error on the error stack and return PR_FAILURE. If any objects |
| 132 | * remain in the tracker when it is finalized, that will be treated |
| 133 | * as an error. |
| 134 | * |
| 135 | * The error may be one of the following values: |
| 136 | * NSS_ERROR_INVALID_POINTER |
| 137 | * NSS_ERROR_TRACKER_NOT_INITIALIZED |
| 138 | * NSS_ERROR_TRACKER_NOT_EMPTY |
| 139 | * |
| 140 | * Return value: |
| 141 | * PR_SUCCESS |
| 142 | * PR_FAILURE |
| 143 | */ |
| 144 | |
| 145 | NSS_IMPLEMENT PRStatus |
| 146 | nssPointerTracker_finalize(nssPointerTracker *tracker) |
| 147 | { |
| 148 | PZLockPRLock *lock; |
| 149 | |
| 150 | if ((nssPointerTracker *)NULL((void*)0) == tracker) { |
| 151 | nss_SetError(NSS_ERROR_INVALID_POINTER); |
| 152 | return PR_FAILURE; |
| 153 | } |
| 154 | |
| 155 | if ((PZLockPRLock *)NULL((void*)0) == tracker->lock) { |
| 156 | nss_SetError(NSS_ERROR_TRACKER_NOT_INITIALIZED); |
| 157 | return PR_FAILURE; |
| 158 | } |
| 159 | |
| 160 | lock = tracker->lock; |
| 161 | PZ_Lock(lock)PR_Lock((lock)); |
| 162 | |
| 163 | if ((PLHashTable *)NULL((void*)0) == tracker->table) { |
| 164 | PZ_Unlock(lock)PR_Unlock((lock)); |
| 165 | nss_SetError(NSS_ERROR_TRACKER_NOT_INITIALIZED); |
| 166 | return PR_FAILURE; |
| 167 | } |
| 168 | |
| 169 | #ifdef DONT_DESTROY_EMPTY_TABLES |
| 170 | /* |
| 171 | * I changed my mind; I think we don't want this after all. |
| 172 | * Comments? |
| 173 | */ |
| 174 | count = PL_HashTableEnumerateEntries(tracker->table, count_entries, |
| 175 | (void *)NULL((void*)0)); |
| 176 | |
| 177 | if (0 != count) { |
| 178 | PZ_Unlock(lock)PR_Unlock((lock)); |
| 179 | nss_SetError(NSS_ERROR_TRACKER_NOT_EMPTY); |
| 180 | return PR_FAILURE; |
| 181 | } |
| 182 | #endif /* DONT_DESTROY_EMPTY_TABLES */ |
| 183 | |
| 184 | PL_HashTableDestroy(tracker->table); |
| 185 | /* memset(tracker, 0, sizeof(nssPointerTracker)); */ |
| 186 | tracker->once = zero_once; |
| 187 | tracker->lock = (PZLockPRLock *)NULL((void*)0); |
| 188 | tracker->table = (PLHashTable *)NULL((void*)0); |
| 189 | |
| 190 | PZ_Unlock(lock)PR_Unlock((lock)); |
| 191 | PZ_DestroyLock(lock)PR_DestroyLock((lock)); |
| 192 | |
| 193 | return PR_SUCCESS; |
| 194 | } |
| 195 | |
| 196 | /* |
| 197 | * nssPointerTracker_add |
| 198 | * |
| 199 | * This method is only present in debug builds. |
| 200 | * |
| 201 | * This routine adds the specified pointer to the nssPointerTracker |
| 202 | * object. It should be called in constructor objects to register |
| 203 | * new valid objects. The nssPointerTracker is threadsafe, but this |
| 204 | * call is not idempotent. This routine returns a PRStatus value; |
| 205 | * if successful it will return PR_SUCCESS. On failure it will set |
| 206 | * an error on the error stack and return PR_FAILURE. |
| 207 | * |
| 208 | * The error may be one of the following values: |
| 209 | * NSS_ERROR_INVALID_POINTER |
| 210 | * NSS_ERROR_NO_MEMORY |
| 211 | * NSS_ERROR_TRACKER_NOT_INITIALIZED |
| 212 | * NSS_ERROR_DUPLICATE_POINTER |
| 213 | * |
| 214 | * Return value: |
| 215 | * PR_SUCCESS |
| 216 | * PR_FAILURE |
| 217 | */ |
| 218 | |
| 219 | NSS_IMPLEMENT PRStatus |
| 220 | nssPointerTracker_add(nssPointerTracker *tracker, const void *pointer) |
| 221 | { |
| 222 | void *check; |
| 223 | PLHashEntry *entry; |
| 224 | |
| 225 | if ((nssPointerTracker *)NULL((void*)0) == tracker) { |
| 226 | nss_SetError(NSS_ERROR_INVALID_POINTER); |
| 227 | return PR_FAILURE; |
| 228 | } |
| 229 | |
| 230 | if ((PZLockPRLock *)NULL((void*)0) == tracker->lock) { |
| 231 | nss_SetError(NSS_ERROR_TRACKER_NOT_INITIALIZED); |
| 232 | return PR_FAILURE; |
| 233 | } |
| 234 | |
| 235 | PZ_Lock(tracker->lock)PR_Lock((tracker->lock)); |
| 236 | |
| 237 | if ((PLHashTable *)NULL((void*)0) == tracker->table) { |
| 238 | PZ_Unlock(tracker->lock)PR_Unlock((tracker->lock)); |
| 239 | nss_SetError(NSS_ERROR_TRACKER_NOT_INITIALIZED); |
| 240 | return PR_FAILURE; |
| 241 | } |
| 242 | |
| 243 | check = PL_HashTableLookup(tracker->table, pointer); |
| 244 | if ((void *)NULL((void*)0) != check) { |
| 245 | PZ_Unlock(tracker->lock)PR_Unlock((tracker->lock)); |
| 246 | nss_SetError(NSS_ERROR_DUPLICATE_POINTER); |
| 247 | return PR_FAILURE; |
| 248 | } |
| 249 | |
| 250 | entry = PL_HashTableAdd(tracker->table, pointer, (void *)pointer); |
| 251 | |
| 252 | PZ_Unlock(tracker->lock)PR_Unlock((tracker->lock)); |
| 253 | |
| 254 | if ((PLHashEntry *)NULL((void*)0) == entry) { |
| 255 | nss_SetError(NSS_ERROR_NO_MEMORY); |
| 256 | return PR_FAILURE; |
| 257 | } |
| 258 | |
| 259 | return PR_SUCCESS; |
| 260 | } |
| 261 | |
| 262 | /* |
| 263 | * nssPointerTracker_remove |
| 264 | * |
| 265 | * This method is only present in debug builds. |
| 266 | * |
| 267 | * This routine removes the specified pointer from the |
| 268 | * nssPointerTracker object. It does not call any destructor for the |
| 269 | * object; rather, this should be called from the object's destructor. |
| 270 | * The nssPointerTracker is threadsafe, but this call is not |
| 271 | * idempotent. This routine returns a PRStatus value; if successful |
| 272 | * it will return PR_SUCCESS. On failure it will set an error on the |
| 273 | * error stack and return PR_FAILURE. |
| 274 | * |
| 275 | * The error may be one of the following values: |
| 276 | * NSS_ERROR_INVALID_POINTER |
| 277 | * NSS_ERROR_TRACKER_NOT_INITIALIZED |
| 278 | * NSS_ERROR_POINTER_NOT_REGISTERED |
| 279 | * |
| 280 | * Return value: |
| 281 | * PR_SUCCESS |
| 282 | * PR_FAILURE |
| 283 | */ |
| 284 | |
| 285 | NSS_IMPLEMENT PRStatus |
| 286 | nssPointerTracker_remove(nssPointerTracker *tracker, const void *pointer) |
| 287 | { |
| 288 | PRBool registered; |
| 289 | |
| 290 | if ((nssPointerTracker *)NULL((void*)0) == tracker) { |
| 291 | nss_SetError(NSS_ERROR_INVALID_POINTER); |
| 292 | return PR_FAILURE; |
| 293 | } |
| 294 | |
| 295 | if ((PZLockPRLock *)NULL((void*)0) == tracker->lock) { |
| 296 | nss_SetError(NSS_ERROR_TRACKER_NOT_INITIALIZED); |
| 297 | return PR_FAILURE; |
| 298 | } |
| 299 | |
| 300 | PZ_Lock(tracker->lock)PR_Lock((tracker->lock)); |
| 301 | |
| 302 | if ((PLHashTable *)NULL((void*)0) == tracker->table) { |
| 303 | PZ_Unlock(tracker->lock)PR_Unlock((tracker->lock)); |
| 304 | nss_SetError(NSS_ERROR_TRACKER_NOT_INITIALIZED); |
| 305 | return PR_FAILURE; |
| 306 | } |
| 307 | |
| 308 | registered = PL_HashTableRemove(tracker->table, pointer); |
| 309 | PZ_Unlock(tracker->lock)PR_Unlock((tracker->lock)); |
| 310 | |
| 311 | if (!registered) { |
| 312 | nss_SetError(NSS_ERROR_POINTER_NOT_REGISTERED); |
| 313 | return PR_FAILURE; |
| 314 | } |
| 315 | |
| 316 | return PR_SUCCESS; |
| 317 | } |
| 318 | |
| 319 | /* |
| 320 | * nssPointerTracker_verify |
| 321 | * |
| 322 | * This method is only present in debug builds. |
| 323 | * |
| 324 | * This routine verifies that the specified pointer has been registered |
| 325 | * with the nssPointerTracker object. The nssPointerTracker object is |
| 326 | * threadsafe, and this call may be safely called from multiple threads |
| 327 | * simultaneously with the same arguments. This routine returns a |
| 328 | * PRStatus value; if the pointer is registered this will return |
| 329 | * PR_SUCCESS. Otherwise it will set an error on the error stack and |
| 330 | * return PR_FAILURE. Although the error is suitable for leaving on |
| 331 | * the stack, callers may wish to augment the information available by |
| 332 | * placing a more type-specific error on the stack. |
| 333 | * |
| 334 | * The error may be one of the following values: |
| 335 | * NSS_ERROR_INVALID_POINTER |
| 336 | * NSS_ERROR_TRACKER_NOT_INITIALIZED |
| 337 | * NSS_ERROR_POINTER_NOT_REGISTERED |
| 338 | * |
| 339 | * Return value: |
| 340 | * PR_SUCCESS |
| 341 | * PR_FAILRUE |
| 342 | */ |
| 343 | |
| 344 | NSS_IMPLEMENT PRStatus |
| 345 | nssPointerTracker_verify(nssPointerTracker *tracker, const void *pointer) |
| 346 | { |
| 347 | void *check; |
| 348 | |
| 349 | if ((nssPointerTracker *)NULL((void*)0) == tracker) { |
| 350 | nss_SetError(NSS_ERROR_INVALID_POINTER); |
| 351 | return PR_FAILURE; |
| 352 | } |
| 353 | |
| 354 | if ((PZLockPRLock *)NULL((void*)0) == tracker->lock) { |
| 355 | nss_SetError(NSS_ERROR_TRACKER_NOT_INITIALIZED); |
| 356 | return PR_FAILURE; |
| 357 | } |
| 358 | |
| 359 | PZ_Lock(tracker->lock)PR_Lock((tracker->lock)); |
| 360 | |
| 361 | if ((PLHashTable *)NULL((void*)0) == tracker->table) { |
| 362 | PZ_Unlock(tracker->lock)PR_Unlock((tracker->lock)); |
| 363 | nss_SetError(NSS_ERROR_TRACKER_NOT_INITIALIZED); |
| 364 | return PR_FAILURE; |
| 365 | } |
| 366 | |
| 367 | check = PL_HashTableLookup(tracker->table, pointer); |
| 368 | PZ_Unlock(tracker->lock)PR_Unlock((tracker->lock)); |
| 369 | |
| 370 | if ((void *)NULL((void*)0) == check) { |
| 371 | nss_SetError(NSS_ERROR_POINTER_NOT_REGISTERED); |
| 372 | return PR_FAILURE; |
| 373 | } |
| 374 | |
| 375 | return PR_SUCCESS; |
| 376 | } |
| 377 | |
| 378 | #endif /* DEBUG */ |