| 1 | /************************************************* |
| 2 | * Exim - an Internet mail transport agent * |
| 3 | *************************************************/ |
| 4 | |
| 5 | /* Copyright (c) University of Cambridge 1995 - 2018 */ |
| 6 | /* Copyright (c) The Exim maintainers 2019 */ |
| 7 | /* See the file NOTICE for conditions of use and distribution. */ |
| 8 | |
| 9 | /* Exim gets and frees all its store through these functions. In the original |
| 10 | implementation there was a lot of mallocing and freeing of small bits of store. |
| 11 | The philosophy has now changed to a scheme which includes the concept of |
| 12 | "stacking pools" of store. For the short-lived processes, there isn't any real |
| 13 | need to do any garbage collection, but the stack concept allows quick resetting |
| 14 | in places where this seems sensible. |
| 15 | |
| 16 | Obviously the long-running processes (the daemon, the queue runner, and eximon) |
| 17 | must take care not to eat store. |
| 18 | |
| 19 | The following different types of store are recognized: |
| 20 | |
| 21 | . Long-lived, large blocks: This is implemented by retaining the original |
| 22 | malloc/free functions, and it used for permanent working buffers and for |
| 23 | getting blocks to cut up for the other types. |
| 24 | |
| 25 | . Long-lived, small blocks: This is used for blocks that have to survive until |
| 26 | the process exits. It is implemented as a stacking pool (POOL_PERM). This is |
| 27 | functionally the same as store_malloc(), except that the store can't be |
| 28 | freed, but I expect it to be more efficient for handling small blocks. |
| 29 | |
| 30 | . Short-lived, short blocks: Most of the dynamic store falls into this |
| 31 | category. It is implemented as a stacking pool (POOL_MAIN) which is reset |
| 32 | after accepting a message when multiple messages are received by a single |
| 33 | process. Resetting happens at some other times as well, usually fairly |
| 34 | locally after some specific processing that needs working store. |
| 35 | |
| 36 | . There is a separate pool (POOL_SEARCH) that is used only for lookup storage. |
| 37 | This means it can be freed when search_tidyup() is called to close down all |
| 38 | the lookup caching. |
| 39 | |
| 40 | . Orthogonal to the three pool types, there are two classes of memory: untainted |
| 41 | and tainted. The latter is used for values derived from untrusted input, and |
| 42 | the string-expansion mechanism refuses to operate on such values (obviously, |
| 43 | it can expand an untainted value to return a tainted result). The classes |
| 44 | are implemented by duplicating the three pool types. Pool resets are requested |
| 45 | against the nontainted sibling and apply to both siblings. |
| 46 | |
| 47 | Only memory blocks requested for tainted use are regarded as tainted; anything |
| 48 | else (including stack auto variables) is untainted. Care is needed when coding |
| 49 | to not copy untrusted data into untainted memory, as downstream taint-checks |
| 50 | would be avoided. |
| 51 | |
| 52 | Internally we currently use malloc for nontainted pools, and mmap for tainted |
| 53 | pools. The disparity is for speed of testing the taintedness of pointers; |
| 54 | because Linux appears to use distinct non-overlapping address allocations for |
| 55 | mmap vs. everything else, which means only two pointer-compares suffice for the |
| 56 | test. Other OS' cannot use that optimisation, and a more lengthy test against |
| 57 | the limits of tainted-pool allcations has to be done. |
| 58 | |
| 59 | Intermediate layers (eg. the string functions) can test for taint, and use this |
| 60 | for ensurinng that results have proper state. For example the |
| 61 | string_vformat_trc() routing supporting the string_sprintf() interface will |
| 62 | recopy a string being built into a tainted allocation if it meets a %s for a |
| 63 | tainted argument. Any intermediate-layer function that (can) return a new |
| 64 | allocation should behave this way; returning a tainted result if any tainted |
| 65 | content is used. Users of functions that modify existing allocations should |
| 66 | check if a tainted source and an untainted destination is used, and fail instead |
| 67 | (sprintf() being the classic case). |
| 68 | */ |
| 69 | |
| 70 | |
| 71 | #include "exim.h" |
| 72 | /* keep config.h before memcheck.h, for NVALGRIND */ |
| 73 | #include "config.h" |
| 74 | |
| 75 | #include <sys/mman.h> |
| 76 | #include "memcheck.h" |
| 77 | |
| 78 | |
| 79 | /* We need to know how to align blocks of data for general use. I'm not sure |
| 80 | how to get an alignment factor in general. In the current world, a value of 8 |
| 81 | is probably right, and this is sizeof(double) on some systems and sizeof(void |
| 82 | *) on others, so take the larger of those. Since everything in this expression |
| 83 | is a constant, the compiler should optimize it to a simple constant wherever it |
| 84 | appears (I checked that gcc does do this). */ |
| 85 | |
| 86 | #define alignment \ |
| 87 | (sizeof(void *) > sizeof(double) ? sizeof(void *) : sizeof(double)) |
| 88 | |
| 89 | /* store_reset() will not free the following block if the last used block has |
| 90 | less than this much left in it. */ |
| 91 | |
| 92 | #define STOREPOOL_MIN_SIZE 256 |
| 93 | |
| 94 | /* Structure describing the beginning of each big block. */ |
| 95 | |
| 96 | typedef struct storeblock { |
| 97 | struct storeblock *next; |
| 98 | size_t length; |
| 99 | } storeblock; |
| 100 | |
| 101 | /* Just in case we find ourselves on a system where the structure above has a |
| 102 | length that is not a multiple of the alignment, set up a macro for the padded |
| 103 | length. */ |
| 104 | |
| 105 | #define ALIGNED_SIZEOF_STOREBLOCK \ |
| 106 | (((sizeof(storeblock) + alignment - 1) / alignment) * alignment) |
| 107 | |
| 108 | /* Size of block to get from malloc to carve up into smaller ones. This |
| 109 | must be a multiple of the alignment. We assume that 8192 is going to be |
| 110 | suitably aligned. */ |
| 111 | |
| 112 | #define STORE_BLOCK_SIZE (8192 - ALIGNED_SIZEOF_STOREBLOCK) |
| 113 | |
| 114 | /* Variables holding data for the local pools of store. The current pool number |
| 115 | is held in store_pool, which is global so that it can be changed from outside. |
| 116 | Setting the initial length values to -1 forces a malloc for the first call, |
| 117 | even if the length is zero (which is used for getting a point to reset to). */ |
| 118 | |
| 119 | int store_pool = POOL_MAIN; |
| 120 | |
| 121 | #define NPOOLS 6 |
| 122 | static storeblock *chainbase[NPOOLS]; |
| 123 | static storeblock *current_block[NPOOLS]; |
| 124 | static void *next_yield[NPOOLS]; |
| 125 | static int yield_length[NPOOLS] = { -1, -1, -1, -1, -1, -1 }; |
| 126 | |
| 127 | /* The limits of the tainted pools. Tracking these on new allocations enables |
| 128 | a fast is_tainted implementation. We assume the kernel only allocates mmaps using |
| 129 | one side or the other of data+heap, not both. */ |
| 130 | |
| 131 | void * tainted_base = (void *)-1; |
| 132 | void * tainted_top = (void *)0; |
| 133 | |
| 134 | /* pool_malloc holds the amount of memory used by the store pools; this goes up |
| 135 | and down as store is reset or released. nonpool_malloc is the total got by |
| 136 | malloc from other calls; this doesn't go down because it is just freed by |
| 137 | pointer. */ |
| 138 | |
| 139 | static int pool_malloc; |
| 140 | static int nonpool_malloc; |
| 141 | |
| 142 | /* This variable is set by store_get() to its yield, and by store_reset() to |
| 143 | NULL. This enables string_cat() to optimize its store handling for very long |
| 144 | strings. That's why the variable is global. */ |
| 145 | |
| 146 | void *store_last_get[NPOOLS]; |
| 147 | |
| 148 | /* These are purely for stats-gathering */ |
| 149 | |
| 150 | static int nbytes[NPOOLS]; /* current bytes allocated */ |
| 151 | static int maxbytes[NPOOLS]; /* max number reached */ |
| 152 | static int nblocks[NPOOLS]; /* current number of blocks allocated */ |
| 153 | static int maxblocks[NPOOLS]; |
| 154 | static int n_nonpool_blocks; /* current number of direct store_malloc() blocks */ |
| 155 | static int max_nonpool_blocks; |
| 156 | static int max_pool_malloc; /* max value for pool_malloc */ |
| 157 | static int max_nonpool_malloc; /* max value for nonpool_malloc */ |
| 158 | |
| 159 | |
| 160 | #ifndef COMPILE_UTILITY |
| 161 | static const uschar * pooluse[NPOOLS] = { |
| 162 | [POOL_MAIN] = US"main", |
| 163 | [POOL_PERM] = US"perm", |
| 164 | [POOL_SEARCH] = US"search", |
| 165 | [POOL_TAINT_MAIN] = US"main", |
| 166 | [POOL_TAINT_PERM] = US"perm", |
| 167 | [POOL_TAINT_SEARCH] = US"search", |
| 168 | }; |
| 169 | static const uschar * poolclass[NPOOLS] = { |
| 170 | [POOL_MAIN] = US"untainted", |
| 171 | [POOL_PERM] = US"untainted", |
| 172 | [POOL_SEARCH] = US"untainted", |
| 173 | [POOL_TAINT_MAIN] = US"tainted", |
| 174 | [POOL_TAINT_PERM] = US"tainted", |
| 175 | [POOL_TAINT_SEARCH] = US"tainted", |
| 176 | }; |
| 177 | #endif |
| 178 | |
| 179 | |
| 180 | static void * store_mmap(int, const char *, int); |
| 181 | static void * internal_store_malloc(int, const char *, int); |
| 182 | static void internal_untainted_free(void *, const char *, int linenumber); |
| 183 | static void internal_tainted_free(storeblock *, const char *, int linenumber); |
| 184 | |
| 185 | /******************************************************************************/ |
| 186 | |
| 187 | #ifndef TAINT_CHECK_FAST |
| 188 | /* Test if a pointer refers to tainted memory. |
| 189 | |
| 190 | Slower version check, for use when platform intermixes malloc and mmap area |
| 191 | addresses. Test against the current-block of all tainted pools first, then all |
| 192 | blocks of all tainted pools. |
| 193 | |
| 194 | Return: TRUE iff tainted |
| 195 | */ |
| 196 | |
| 197 | BOOL |
| 198 | is_tainted_fn(const void * p) |
| 199 | { |
| 200 | storeblock * b; |
| 201 | int pool; |
| 202 | |
| 203 | for (pool = POOL_TAINT_BASE; pool < nelem(chainbase); pool++) |
| 204 | if ((b = current_block[pool])) |
| 205 | { |
| 206 | char * bc = CS b + ALIGNED_SIZEOF_STOREBLOCK; |
| 207 | if (CS p >= bc && CS p <= bc + b->length) return TRUE; |
| 208 | } |
| 209 | |
| 210 | for (pool = POOL_TAINT_BASE; pool < nelem(chainbase); pool++) |
| 211 | for (b = chainbase[pool]; b; b = b->next) |
| 212 | { |
| 213 | char * bc = CS b + ALIGNED_SIZEOF_STOREBLOCK; |
| 214 | if (CS p >= bc && CS p <= bc + b->length) return TRUE; |
| 215 | } |
| 216 | return FALSE; |
| 217 | } |
| 218 | #endif |
| 219 | |
| 220 | |
| 221 | void |
| 222 | die_tainted(const uschar * msg, const uschar * func, int line) |
| 223 | { |
| 224 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Taint mismatch, %s: %s %d\n", |
| 225 | msg, func, line); |
| 226 | } |
| 227 | |
| 228 | |
| 229 | /************************************************* |
| 230 | * Get a block from the current pool * |
| 231 | *************************************************/ |
| 232 | |
| 233 | /* Running out of store is a total disaster. This function is called via the |
| 234 | macro store_get(). It passes back a block of store within the current big |
| 235 | block, getting a new one if necessary. The address is saved in |
| 236 | store_last_was_get. |
| 237 | |
| 238 | Arguments: |
| 239 | size amount wanted, bytes |
| 240 | tainted class: set to true for untrusted data (eg. from smtp input) |
| 241 | func function from which called |
| 242 | linenumber line number in source file |
| 243 | |
| 244 | Returns: pointer to store (panic on malloc failure) |
| 245 | */ |
| 246 | |
| 247 | void * |
| 248 | store_get_3(int size, BOOL tainted, const char *func, int linenumber) |
| 249 | { |
| 250 | int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool; |
| 251 | |
| 252 | /* Round up the size to a multiple of the alignment. Although this looks a |
| 253 | messy statement, because "alignment" is a constant expression, the compiler can |
| 254 | do a reasonable job of optimizing, especially if the value of "alignment" is a |
| 255 | power of two. I checked this with -O2, and gcc did very well, compiling it to 4 |
| 256 | instructions on a Sparc (alignment = 8). */ |
| 257 | |
| 258 | if (size % alignment != 0) size += alignment - (size % alignment); |
| 259 | |
| 260 | /* If there isn't room in the current block, get a new one. The minimum |
| 261 | size is STORE_BLOCK_SIZE, and we would expect this to be the norm, since |
| 262 | these functions are mostly called for small amounts of store. */ |
| 263 | |
| 264 | if (size > yield_length[pool]) |
| 265 | { |
| 266 | int length = size <= STORE_BLOCK_SIZE ? STORE_BLOCK_SIZE : size; |
| 267 | int mlength = length + ALIGNED_SIZEOF_STOREBLOCK; |
| 268 | storeblock * newblock; |
| 269 | |
| 270 | /* Sometimes store_reset() may leave a block for us; check if we can use it */ |
| 271 | |
| 272 | if ( (newblock = current_block[pool]) |
| 273 | && (newblock = newblock->next) |
| 274 | && newblock->length < length |
| 275 | ) |
| 276 | { |
| 277 | /* Give up on this block, because it's too small */ |
| 278 | nblocks[pool]--; |
| 279 | if (pool < POOL_TAINT_BASE) |
| 280 | internal_untainted_free(newblock, func, linenumber); |
| 281 | else |
| 282 | internal_tainted_free(newblock, func, linenumber); |
| 283 | newblock = NULL; |
| 284 | } |
| 285 | |
| 286 | /* If there was no free block, get a new one */ |
| 287 | |
| 288 | if (!newblock) |
| 289 | { |
| 290 | if ((nbytes[pool] += mlength) > maxbytes[pool]) |
| 291 | maxbytes[pool] = nbytes[pool]; |
| 292 | if ((pool_malloc += mlength) > max_pool_malloc) /* Used in pools */ |
| 293 | max_pool_malloc = pool_malloc; |
| 294 | nonpool_malloc -= mlength; /* Exclude from overall total */ |
| 295 | if (++nblocks[pool] > maxblocks[pool]) |
| 296 | maxblocks[pool] = nblocks[pool]; |
| 297 | |
| 298 | newblock = tainted |
| 299 | ? store_mmap(mlength, func, linenumber) |
| 300 | : internal_store_malloc(mlength, func, linenumber); |
| 301 | newblock->next = NULL; |
| 302 | newblock->length = length; |
| 303 | |
| 304 | if (!chainbase[pool]) |
| 305 | chainbase[pool] = newblock; |
| 306 | else |
| 307 | current_block[pool]->next = newblock; |
| 308 | } |
| 309 | |
| 310 | current_block[pool] = newblock; |
| 311 | yield_length[pool] = newblock->length; |
| 312 | next_yield[pool] = |
| 313 | (void *)(CS current_block[pool] + ALIGNED_SIZEOF_STOREBLOCK); |
| 314 | (void) VALGRIND_MAKE_MEM_NOACCESS(next_yield[pool], yield_length[pool]); |
| 315 | } |
| 316 | |
| 317 | /* There's (now) enough room in the current block; the yield is the next |
| 318 | pointer. */ |
| 319 | |
| 320 | store_last_get[pool] = next_yield[pool]; |
| 321 | |
| 322 | /* Cut out the debugging stuff for utilities, but stop picky compilers from |
| 323 | giving warnings. */ |
| 324 | |
| 325 | #ifdef COMPILE_UTILITY |
| 326 | func = func; |
| 327 | linenumber = linenumber; |
| 328 | #else |
| 329 | DEBUG(D_memory) |
| 330 | debug_printf("---%d Get %6p %5d %-14s %4d\n", pool, |
| 331 | store_last_get[pool], size, func, linenumber); |
| 332 | #endif /* COMPILE_UTILITY */ |
| 333 | |
| 334 | (void) VALGRIND_MAKE_MEM_UNDEFINED(store_last_get[pool], size); |
| 335 | /* Update next pointer and number of bytes left in the current block. */ |
| 336 | |
| 337 | next_yield[pool] = (void *)(CS next_yield[pool] + size); |
| 338 | yield_length[pool] -= size; |
| 339 | return store_last_get[pool]; |
| 340 | } |
| 341 | |
| 342 | |
| 343 | |
| 344 | /************************************************* |
| 345 | * Get a block from the PERM pool * |
| 346 | *************************************************/ |
| 347 | |
| 348 | /* This is just a convenience function, useful when just a single block is to |
| 349 | be obtained. |
| 350 | |
| 351 | Arguments: |
| 352 | size amount wanted |
| 353 | func function from which called |
| 354 | linenumber line number in source file |
| 355 | |
| 356 | Returns: pointer to store (panic on malloc failure) |
| 357 | */ |
| 358 | |
| 359 | void * |
| 360 | store_get_perm_3(int size, BOOL tainted, const char *func, int linenumber) |
| 361 | { |
| 362 | void *yield; |
| 363 | int old_pool = store_pool; |
| 364 | store_pool = POOL_PERM; |
| 365 | yield = store_get_3(size, tainted, func, linenumber); |
| 366 | store_pool = old_pool; |
| 367 | return yield; |
| 368 | } |
| 369 | |
| 370 | |
| 371 | |
| 372 | /************************************************* |
| 373 | * Extend a block if it is at the top * |
| 374 | *************************************************/ |
| 375 | |
| 376 | /* While reading strings of unknown length, it is often the case that the |
| 377 | string is being read into the block at the top of the stack. If it needs to be |
| 378 | extended, it is more efficient just to extend within the top block rather than |
| 379 | allocate a new block and then have to copy the data. This function is provided |
| 380 | for the use of string_cat(), but of course can be used elsewhere too. |
| 381 | The block itself is not expanded; only the top allocation from it. |
| 382 | |
| 383 | Arguments: |
| 384 | ptr pointer to store block |
| 385 | oldsize current size of the block, as requested by user |
| 386 | newsize new size required |
| 387 | func function from which called |
| 388 | linenumber line number in source file |
| 389 | |
| 390 | Returns: TRUE if the block is at the top of the stack and has been |
| 391 | extended; FALSE if it isn't at the top of the stack, or cannot |
| 392 | be extended |
| 393 | */ |
| 394 | |
| 395 | BOOL |
| 396 | store_extend_3(void *ptr, BOOL tainted, int oldsize, int newsize, |
| 397 | const char *func, int linenumber) |
| 398 | { |
| 399 | int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool; |
| 400 | int inc = newsize - oldsize; |
| 401 | int rounded_oldsize = oldsize; |
| 402 | |
| 403 | /* Check that the block being extended was already of the required taint status; |
| 404 | refuse to extend if not. */ |
| 405 | |
| 406 | if (is_tainted(ptr) != tainted) |
| 407 | return FALSE; |
| 408 | |
| 409 | if (rounded_oldsize % alignment != 0) |
| 410 | rounded_oldsize += alignment - (rounded_oldsize % alignment); |
| 411 | |
| 412 | if (CS ptr + rounded_oldsize != CS (next_yield[pool]) || |
| 413 | inc > yield_length[pool] + rounded_oldsize - oldsize) |
| 414 | return FALSE; |
| 415 | |
| 416 | /* Cut out the debugging stuff for utilities, but stop picky compilers from |
| 417 | giving warnings. */ |
| 418 | |
| 419 | #ifdef COMPILE_UTILITY |
| 420 | func = func; |
| 421 | linenumber = linenumber; |
| 422 | #else |
| 423 | DEBUG(D_memory) |
| 424 | debug_printf("---%d Ext %6p %5d %-14s %4d\n", pool, ptr, newsize, |
| 425 | func, linenumber); |
| 426 | #endif /* COMPILE_UTILITY */ |
| 427 | |
| 428 | if (newsize % alignment != 0) newsize += alignment - (newsize % alignment); |
| 429 | next_yield[pool] = CS ptr + newsize; |
| 430 | yield_length[pool] -= newsize - rounded_oldsize; |
| 431 | (void) VALGRIND_MAKE_MEM_UNDEFINED(ptr + oldsize, inc); |
| 432 | return TRUE; |
| 433 | } |
| 434 | |
| 435 | |
| 436 | |
| 437 | |
| 438 | /************************************************* |
| 439 | * Back up to a previous point on the stack * |
| 440 | *************************************************/ |
| 441 | |
| 442 | /* This function resets the next pointer, freeing any subsequent whole blocks |
| 443 | that are now unused. Call with a cookie obtained from store_mark() only; do |
| 444 | not call with a pointer returned by store_get(). Both the untainted and tainted |
| 445 | pools corresposding to store_pool are reset. |
| 446 | |
| 447 | Arguments: |
| 448 | r place to back up to |
| 449 | func function from which called |
| 450 | linenumber line number in source file |
| 451 | |
| 452 | Returns: nothing |
| 453 | */ |
| 454 | |
| 455 | static void |
| 456 | internal_store_reset(void * ptr, int pool, const char *func, int linenumber) |
| 457 | { |
| 458 | storeblock * bb; |
| 459 | storeblock * b = current_block[pool]; |
| 460 | char * bc = CS b + ALIGNED_SIZEOF_STOREBLOCK; |
| 461 | int newlength, count; |
| 462 | #ifndef COMPILE_UTILITY |
| 463 | int oldmalloc = pool_malloc; |
| 464 | #endif |
| 465 | |
| 466 | /* Last store operation was not a get */ |
| 467 | |
| 468 | store_last_get[pool] = NULL; |
| 469 | |
| 470 | /* See if the place is in the current block - as it often will be. Otherwise, |
| 471 | search for the block in which it lies. */ |
| 472 | |
| 473 | if (CS ptr < bc || CS ptr > bc + b->length) |
| 474 | { |
| 475 | for (b = chainbase[pool]; b; b = b->next) |
| 476 | { |
| 477 | bc = CS b + ALIGNED_SIZEOF_STOREBLOCK; |
| 478 | if (CS ptr >= bc && CS ptr <= bc + b->length) break; |
| 479 | } |
| 480 | if (!b) |
| 481 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal error: store_reset(%p) " |
| 482 | "failed: pool=%d %-14s %4d", ptr, pool, func, linenumber); |
| 483 | } |
| 484 | |
| 485 | /* Back up, rounding to the alignment if necessary. When testing, flatten |
| 486 | the released memory. */ |
| 487 | |
| 488 | newlength = bc + b->length - CS ptr; |
| 489 | #ifndef COMPILE_UTILITY |
| 490 | if (debug_store) |
| 491 | { |
| 492 | assert_no_variables(ptr, newlength, func, linenumber); |
| 493 | if (f.running_in_test_harness) |
| 494 | { |
| 495 | (void) VALGRIND_MAKE_MEM_DEFINED(ptr, newlength); |
| 496 | memset(ptr, 0xF0, newlength); |
| 497 | } |
| 498 | } |
| 499 | #endif |
| 500 | (void) VALGRIND_MAKE_MEM_NOACCESS(ptr, newlength); |
| 501 | next_yield[pool] = CS ptr + (newlength % alignment); |
| 502 | count = yield_length[pool]; |
| 503 | count = (yield_length[pool] = newlength - (newlength % alignment)) - count; |
| 504 | current_block[pool] = b; |
| 505 | |
| 506 | /* Free any subsequent block. Do NOT free the first |
| 507 | successor, if our current block has less than 256 bytes left. This should |
| 508 | prevent us from flapping memory. However, keep this block only when it has |
| 509 | the default size. */ |
| 510 | |
| 511 | if ( yield_length[pool] < STOREPOOL_MIN_SIZE |
| 512 | && b->next |
| 513 | && b->next->length == STORE_BLOCK_SIZE) |
| 514 | { |
| 515 | b = b->next; |
| 516 | #ifndef COMPILE_UTILITY |
| 517 | if (debug_store) |
| 518 | assert_no_variables(b, b->length + ALIGNED_SIZEOF_STOREBLOCK, |
| 519 | func, linenumber); |
| 520 | #endif |
| 521 | (void) VALGRIND_MAKE_MEM_NOACCESS(CS b + ALIGNED_SIZEOF_STOREBLOCK, |
| 522 | b->length - ALIGNED_SIZEOF_STOREBLOCK); |
| 523 | } |
| 524 | |
| 525 | bb = b->next; |
| 526 | b->next = NULL; |
| 527 | |
| 528 | while ((b = bb)) |
| 529 | { |
| 530 | int siz = b->length + ALIGNED_SIZEOF_STOREBLOCK; |
| 531 | #ifndef COMPILE_UTILITY |
| 532 | if (debug_store) |
| 533 | assert_no_variables(b, b->length + ALIGNED_SIZEOF_STOREBLOCK, |
| 534 | func, linenumber); |
| 535 | #endif |
| 536 | bb = bb->next; |
| 537 | nbytes[pool] -= siz; |
| 538 | pool_malloc -= siz; |
| 539 | nblocks[pool]--; |
| 540 | if (pool < POOL_TAINT_BASE) |
| 541 | internal_untainted_free(b, func, linenumber); |
| 542 | else |
| 543 | internal_tainted_free(b, func, linenumber); |
| 544 | } |
| 545 | |
| 546 | /* Cut out the debugging stuff for utilities, but stop picky compilers from |
| 547 | giving warnings. */ |
| 548 | |
| 549 | #ifdef COMPILE_UTILITY |
| 550 | func = func; |
| 551 | linenumber = linenumber; |
| 552 | #else |
| 553 | DEBUG(D_memory) |
| 554 | debug_printf("---%d Rst %6p %5d %-14s %4d %d\n", pool, ptr, |
| 555 | count + oldmalloc - pool_malloc, |
| 556 | func, linenumber, pool_malloc); |
| 557 | #endif /* COMPILE_UTILITY */ |
| 558 | } |
| 559 | |
| 560 | |
| 561 | rmark |
| 562 | store_reset_3(rmark r, int pool, const char *func, int linenumber) |
| 563 | { |
| 564 | void ** ptr = r; |
| 565 | |
| 566 | if (pool >= POOL_TAINT_BASE) |
| 567 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
| 568 | "store_reset called for pool %d: %s %d\n", pool, func, linenumber); |
| 569 | if (!r) |
| 570 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
| 571 | "store_reset called with bad mark: %s %d\n", func, linenumber); |
| 572 | |
| 573 | internal_store_reset(*ptr, pool + POOL_TAINT_BASE, func, linenumber); |
| 574 | internal_store_reset(ptr, pool, func, linenumber); |
| 575 | return NULL; |
| 576 | } |
| 577 | |
| 578 | |
| 579 | |
| 580 | /* Free tail-end unused allocation. This lets us allocate a big chunk |
| 581 | early, for cases when we only discover later how much was really needed. |
| 582 | |
| 583 | Can be called with a value from store_get(), or an offset after such. Only |
| 584 | the tainted or untainted pool that serviced the store_get() will be affected. |
| 585 | |
| 586 | This is mostly a cut-down version of internal_store_reset(). |
| 587 | XXX needs rationalising |
| 588 | */ |
| 589 | |
| 590 | void |
| 591 | store_release_above_3(void *ptr, const char *func, int linenumber) |
| 592 | { |
| 593 | /* Search all pools' "current" blocks. If it isn't one of those, |
| 594 | ignore it (it usually will be). */ |
| 595 | |
| 596 | for (int pool = 0; pool < nelem(current_block); pool++) |
| 597 | { |
| 598 | storeblock * b = current_block[pool]; |
| 599 | char * bc; |
| 600 | int count, newlength; |
| 601 | |
| 602 | if (!b) |
| 603 | continue; |
| 604 | |
| 605 | bc = CS b + ALIGNED_SIZEOF_STOREBLOCK; |
| 606 | if (CS ptr < bc || CS ptr > bc + b->length) |
| 607 | continue; |
| 608 | |
| 609 | /* Last store operation was not a get */ |
| 610 | |
| 611 | store_last_get[pool] = NULL; |
| 612 | |
| 613 | /* Back up, rounding to the alignment if necessary. When testing, flatten |
| 614 | the released memory. */ |
| 615 | |
| 616 | newlength = bc + b->length - CS ptr; |
| 617 | #ifndef COMPILE_UTILITY |
| 618 | if (debug_store) |
| 619 | { |
| 620 | assert_no_variables(ptr, newlength, func, linenumber); |
| 621 | if (f.running_in_test_harness) |
| 622 | { |
| 623 | (void) VALGRIND_MAKE_MEM_DEFINED(ptr, newlength); |
| 624 | memset(ptr, 0xF0, newlength); |
| 625 | } |
| 626 | } |
| 627 | #endif |
| 628 | (void) VALGRIND_MAKE_MEM_NOACCESS(ptr, newlength); |
| 629 | next_yield[pool] = CS ptr + (newlength % alignment); |
| 630 | count = yield_length[pool]; |
| 631 | count = (yield_length[pool] = newlength - (newlength % alignment)) - count; |
| 632 | |
| 633 | /* Cut out the debugging stuff for utilities, but stop picky compilers from |
| 634 | giving warnings. */ |
| 635 | |
| 636 | #ifdef COMPILE_UTILITY |
| 637 | func = func; |
| 638 | linenumber = linenumber; |
| 639 | #else |
| 640 | DEBUG(D_memory) |
| 641 | debug_printf("---%d Rel %6p %5d %-14s %4d %d\n", pool, ptr, count, |
| 642 | func, linenumber, pool_malloc); |
| 643 | #endif |
| 644 | return; |
| 645 | } |
| 646 | #ifndef COMPILE_UTILITY |
| 647 | DEBUG(D_memory) |
| 648 | debug_printf("non-last memory release try: %s %d\n", func, linenumber); |
| 649 | #endif |
| 650 | } |
| 651 | |
| 652 | |
| 653 | |
| 654 | rmark |
| 655 | store_mark_3(const char *func, int linenumber) |
| 656 | { |
| 657 | void ** p; |
| 658 | |
| 659 | if (store_pool >= POOL_TAINT_BASE) |
| 660 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
| 661 | "store_mark called for pool %d: %s %d\n", store_pool, func, linenumber); |
| 662 | |
| 663 | /* Stash a mark for the tainted-twin release, in the untainted twin. Return |
| 664 | a cookie (actually the address in the untainted pool) to the caller. |
| 665 | Reset uses the cookie to recover the t-mark, winds back the tainted pool with it |
| 666 | and winds back the untainted pool with the cookie. */ |
| 667 | |
| 668 | p = store_get_3(sizeof(void *), FALSE, func, linenumber); |
| 669 | *p = store_get_3(0, TRUE, func, linenumber); |
| 670 | return p; |
| 671 | } |
| 672 | |
| 673 | |
| 674 | |
| 675 | |
| 676 | /************************************************ |
| 677 | * Release store * |
| 678 | ************************************************/ |
| 679 | |
| 680 | /* This function checks that the pointer it is given is the first thing in a |
| 681 | block, and if so, releases that block. |
| 682 | |
| 683 | Arguments: |
| 684 | block block of store to consider |
| 685 | func function from which called |
| 686 | linenumber line number in source file |
| 687 | |
| 688 | Returns: nothing |
| 689 | */ |
| 690 | |
| 691 | static void |
| 692 | store_release_3(void * block, int pool, const char * func, int linenumber) |
| 693 | { |
| 694 | /* It will never be the first block, so no need to check that. */ |
| 695 | |
| 696 | for (storeblock * b = chainbase[pool]; b; b = b->next) |
| 697 | { |
| 698 | storeblock * bb = b->next; |
| 699 | if (bb && CS block == CS bb + ALIGNED_SIZEOF_STOREBLOCK) |
| 700 | { |
| 701 | int siz = bb->length + ALIGNED_SIZEOF_STOREBLOCK; |
| 702 | b->next = bb->next; |
| 703 | nbytes[pool] -= siz; |
| 704 | pool_malloc -= siz; |
| 705 | nblocks[pool]--; |
| 706 | |
| 707 | /* Cut out the debugging stuff for utilities, but stop picky compilers |
| 708 | from giving warnings. */ |
| 709 | |
| 710 | #ifdef COMPILE_UTILITY |
| 711 | func = func; |
| 712 | linenumber = linenumber; |
| 713 | #else |
| 714 | DEBUG(D_memory) |
| 715 | debug_printf("-Release %6p %-20s %4d %d\n", (void *)bb, func, |
| 716 | linenumber, pool_malloc); |
| 717 | |
| 718 | if (f.running_in_test_harness) |
| 719 | memset(bb, 0xF0, bb->length+ALIGNED_SIZEOF_STOREBLOCK); |
| 720 | #endif /* COMPILE_UTILITY */ |
| 721 | |
| 722 | free(bb); |
| 723 | return; |
| 724 | } |
| 725 | } |
| 726 | } |
| 727 | |
| 728 | |
| 729 | /************************************************ |
| 730 | * Move store * |
| 731 | ************************************************/ |
| 732 | |
| 733 | /* Allocate a new block big enough to expend to the given size and |
| 734 | copy the current data into it. Free the old one if possible. |
| 735 | |
| 736 | This function is specifically provided for use when reading very |
| 737 | long strings, e.g. header lines. When the string gets longer than a |
| 738 | complete block, it gets copied to a new block. It is helpful to free |
| 739 | the old block iff the previous copy of the string is at its start, |
| 740 | and therefore the only thing in it. Otherwise, for very long strings, |
| 741 | dead store can pile up somewhat disastrously. This function checks that |
| 742 | the pointer it is given is the first thing in a block, and that nothing |
| 743 | has been allocated since. If so, releases that block. |
| 744 | |
| 745 | Arguments: |
| 746 | block |
| 747 | newsize |
| 748 | len |
| 749 | |
| 750 | Returns: new location of data |
| 751 | */ |
| 752 | |
| 753 | void * |
| 754 | store_newblock_3(void * block, BOOL tainted, int newsize, int len, |
| 755 | const char * func, int linenumber) |
| 756 | { |
| 757 | int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool; |
| 758 | BOOL release_ok = !tainted && store_last_get[pool] == block; |
| 759 | uschar * newtext; |
| 760 | |
| 761 | #ifndef MACRO_PREDEF |
| 762 | if (is_tainted(block) != tainted) |
| 763 | die_tainted(US"store_newblock", CUS func, linenumber); |
| 764 | #endif |
| 765 | |
| 766 | newtext = store_get(newsize, tainted); |
| 767 | memcpy(newtext, block, len); |
| 768 | if (release_ok) store_release_3(block, pool, func, linenumber); |
| 769 | return (void *)newtext; |
| 770 | } |
| 771 | |
| 772 | |
| 773 | |
| 774 | |
| 775 | /******************************************************************************/ |
| 776 | static void * |
| 777 | store_alloc_tail(void * yield, int size, const char * func, int line, |
| 778 | const uschar * type) |
| 779 | { |
| 780 | if ((nonpool_malloc += size) > max_nonpool_malloc) |
| 781 | max_nonpool_malloc = nonpool_malloc; |
| 782 | |
| 783 | /* Cut out the debugging stuff for utilities, but stop picky compilers from |
| 784 | giving warnings. */ |
| 785 | |
| 786 | #ifdef COMPILE_UTILITY |
| 787 | func = func; line = line; type = type; |
| 788 | #else |
| 789 | |
| 790 | /* If running in test harness, spend time making sure all the new store |
| 791 | is not filled with zeros so as to catch problems. */ |
| 792 | |
| 793 | if (f.running_in_test_harness) |
| 794 | memset(yield, 0xF0, (size_t)size); |
| 795 | DEBUG(D_memory) debug_printf("--%6s %6p %5d bytes\t%-14s %4d\tpool %5d nonpool %5d\n", |
| 796 | type, yield, size, func, line, pool_malloc, nonpool_malloc); |
| 797 | #endif /* COMPILE_UTILITY */ |
| 798 | |
| 799 | return yield; |
| 800 | } |
| 801 | |
| 802 | /************************************************* |
| 803 | * Mmap store * |
| 804 | *************************************************/ |
| 805 | |
| 806 | static void * |
| 807 | store_mmap(int size, const char * func, int line) |
| 808 | { |
| 809 | void * yield, * top; |
| 810 | |
| 811 | if (size < 16) size = 16; |
| 812 | |
| 813 | if (!(yield = mmap(NULL, (size_t)size, |
| 814 | PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0))) |
| 815 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to mmap %d bytes of memory: " |
| 816 | "called from line %d of %s", size, line, func); |
| 817 | |
| 818 | if (yield < tainted_base) tainted_base = yield; |
| 819 | if ((top = US yield + size) > tainted_top) tainted_top = top; |
| 820 | |
| 821 | return store_alloc_tail(yield, size, func, line, US"Mmap"); |
| 822 | } |
| 823 | |
| 824 | /************************************************* |
| 825 | * Malloc store * |
| 826 | *************************************************/ |
| 827 | |
| 828 | /* Running out of store is a total disaster for exim. Some malloc functions |
| 829 | do not run happily on very small sizes, nor do they document this fact. This |
| 830 | function is called via the macro store_malloc(). |
| 831 | |
| 832 | Arguments: |
| 833 | size amount of store wanted |
| 834 | func function from which called |
| 835 | linenumber line number in source file |
| 836 | |
| 837 | Returns: pointer to gotten store (panic on failure) |
| 838 | */ |
| 839 | |
| 840 | static void * |
| 841 | internal_store_malloc(int size, const char *func, int linenumber) |
| 842 | { |
| 843 | void * yield; |
| 844 | |
| 845 | if (size < 16) size = 16; |
| 846 | |
| 847 | if (!(yield = malloc((size_t)size))) |
| 848 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to malloc %d bytes of memory: " |
| 849 | "called from line %d in %s", size, linenumber, func); |
| 850 | |
| 851 | return store_alloc_tail(yield, size, func, linenumber, US"Malloc"); |
| 852 | } |
| 853 | |
| 854 | void * |
| 855 | store_malloc_3(int size, const char *func, int linenumber) |
| 856 | { |
| 857 | if (n_nonpool_blocks++ > max_nonpool_blocks) |
| 858 | max_nonpool_blocks = n_nonpool_blocks; |
| 859 | return internal_store_malloc(size, func, linenumber); |
| 860 | } |
| 861 | |
| 862 | |
| 863 | /************************************************ |
| 864 | * Free store * |
| 865 | ************************************************/ |
| 866 | |
| 867 | /* This function is called by the macro store_free(). |
| 868 | |
| 869 | Arguments: |
| 870 | block block of store to free |
| 871 | func function from which called |
| 872 | linenumber line number in source file |
| 873 | |
| 874 | Returns: nothing |
| 875 | */ |
| 876 | |
| 877 | static void |
| 878 | internal_untainted_free(void * block, const char * func, int linenumber) |
| 879 | { |
| 880 | #ifdef COMPILE_UTILITY |
| 881 | func = func; |
| 882 | linenumber = linenumber; |
| 883 | #else |
| 884 | DEBUG(D_memory) |
| 885 | debug_printf("----Free %6p %-20s %4d\n", block, func, linenumber); |
| 886 | #endif /* COMPILE_UTILITY */ |
| 887 | free(block); |
| 888 | } |
| 889 | |
| 890 | void |
| 891 | store_free_3(void * block, const char * func, int linenumber) |
| 892 | { |
| 893 | n_nonpool_blocks--; |
| 894 | internal_untainted_free(block, func, linenumber); |
| 895 | } |
| 896 | |
| 897 | /******************************************************************************/ |
| 898 | static void |
| 899 | internal_tainted_free(storeblock * block, const char * func, int linenumber) |
| 900 | { |
| 901 | #ifdef COMPILE_UTILITY |
| 902 | func = func; |
| 903 | linenumber = linenumber; |
| 904 | #else |
| 905 | DEBUG(D_memory) |
| 906 | debug_printf("---Unmap %6p %-20s %4d\n", block, func, linenumber); |
| 907 | #endif |
| 908 | munmap((void *)block, block->length + ALIGNED_SIZEOF_STOREBLOCK); |
| 909 | } |
| 910 | |
| 911 | /******************************************************************************/ |
| 912 | /* Stats output on process exit */ |
| 913 | void |
| 914 | store_exit(void) |
| 915 | { |
| 916 | #ifndef COMPILE_UTILITY |
| 917 | DEBUG(D_memory) |
| 918 | { |
| 919 | debug_printf("----Exit nonpool max: %3d kB in %d blocks\n", |
| 920 | (max_nonpool_malloc+1023)/1024, max_nonpool_blocks); |
| 921 | debug_printf("----Exit npools max: %3d kB\n", max_pool_malloc/1024); |
| 922 | for (int i = 0; i < NPOOLS; i++) |
| 923 | debug_printf("----Exit pool %d max: %3d kB in %d blocks\t%s %s\n", |
| 924 | i, maxbytes[i]/1024, maxblocks[i], poolclass[i], pooluse[i]); |
| 925 | } |
| 926 | #endif |
| 927 | } |
| 928 | |
| 929 | /* End of store.c */ |