1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* Copyright (c) The Exim maintainers 2019 - 2021 */
7 /* See the file NOTICE for conditions of use and distribution. */
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.
16 Obviously the long-running processes (the daemon, the queue runner, and eximon)
17 must take care not to eat store.
19 The following different types of store are recognized:
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.
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.
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.
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
40 - There is another pool (POOL_MESSAGE) used for medium-lifetime objects; within
41 a single message transaction but needed for longer than the use of the main
42 pool permits. Currently this means only receive-time DKIM information.
44 - There is a dedicated pool for configuration data read from the config file(s).
45 Once complete, it is made readonly.
47 . Orthogonal to the three pool types, there are two classes of memory: untainted
48 and tainted. The latter is used for values derived from untrusted input, and
49 the string-expansion mechanism refuses to operate on such values (obviously,
50 it can expand an untainted value to return a tainted result). The classes
51 are implemented by duplicating the four pool types. Pool resets are requested
52 against the nontainted sibling and apply to both siblings.
54 Only memory blocks requested for tainted use are regarded as tainted; anything
55 else (including stack auto variables) is untainted. Care is needed when coding
56 to not copy untrusted data into untainted memory, as downstream taint-checks
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. Intermediate-layer functions (eg. Ustrncpy) that modify
66 existing allocations fail if tainted data is written into an untainted area.
67 Users of functions that modify existing allocations should check if a tainted
68 source and an untainted destination is used, and fail instead (sprintf() being
74 /* keep config.h before memcheck.h, for NVALGRIND */
81 /* We need to know how to align blocks of data for general use. I'm not sure
82 how to get an alignment factor in general. In the current world, a value of 8
83 is probably right, and this is sizeof(double) on some systems and sizeof(void
84 *) on others, so take the larger of those. Since everything in this expression
85 is a constant, the compiler should optimize it to a simple constant wherever it
86 appears (I checked that gcc does do this). */
89 (sizeof(void *) > sizeof(double) ? sizeof(void *) : sizeof(double))
91 /* store_reset() will not free the following block if the last used block has
92 less than this much left in it. */
94 #define STOREPOOL_MIN_SIZE 256
96 /* Structure describing the beginning of each big block. */
98 typedef struct storeblock {
99 struct storeblock *next;
103 /* Just in case we find ourselves on a system where the structure above has a
104 length that is not a multiple of the alignment, set up a macro for the padded
107 #define ALIGNED_SIZEOF_STOREBLOCK \
108 (((sizeof(storeblock) + alignment - 1) / alignment) * alignment)
110 /* Size of block to get from malloc to carve up into smaller ones. This
111 must be a multiple of the alignment. We assume that 4096 is going to be
112 suitably aligned. Double the size per-pool for every malloc, to mitigate
113 certain denial-of-service attacks. Don't bother to decrease on block frees.
114 We waste average half the current alloc size per pool. This could be several
115 hundred kB now, vs. 4kB with a constant-size block size. But the search time
116 for is_tainted(), linear in the number of blocks for the pool, is O(n log n)
118 A test of 2000 RCPTs and just accept ACL had 370kB in 21 blocks before,
119 504kB in 6 blocks now, for the untainted-main (largest) pool.
120 Builds for restricted-memory system can disable the expansion by
121 defining RESTRICTED_MEMORY */
122 /*XXX should we allow any for malloc's own overhead? But how much? */
124 /* #define RESTRICTED_MEMORY */
125 #define STORE_BLOCK_SIZE(order) ((1U << (order)) - ALIGNED_SIZEOF_STOREBLOCK)
127 /* Variables holding data for the local pools of store. The current pool number
128 is held in store_pool, which is global so that it can be changed from outside.
129 Setting the initial length values to -1 forces a malloc for the first call,
130 even if the length is zero (which is used for getting a point to reset to). */
132 int store_pool = POOL_MAIN;
134 static storeblock *chainbase[NPOOLS];
135 static storeblock *current_block[NPOOLS];
136 static void *next_yield[NPOOLS];
137 static int yield_length[NPOOLS];
138 static unsigned store_block_order[NPOOLS];
140 /* pool_malloc holds the amount of memory used by the store pools; this goes up
141 and down as store is reset or released. nonpool_malloc is the total got by
142 malloc from other calls; this doesn't go down because it is just freed by
145 static int pool_malloc;
146 static int nonpool_malloc;
148 /* This variable is set by store_get() to its yield, and by store_reset() to
149 NULL. This enables string_cat() to optimize its store handling for very long
150 strings. That's why the variable is global. */
152 void *store_last_get[NPOOLS];
154 /* These are purely for stats-gathering */
156 static int nbytes[NPOOLS]; /* current bytes allocated */
157 static int maxbytes[NPOOLS]; /* max number reached */
158 static int nblocks[NPOOLS]; /* current number of blocks allocated */
159 static int maxblocks[NPOOLS];
160 static unsigned maxorder[NPOOLS];
161 static int n_nonpool_blocks; /* current number of direct store_malloc() blocks */
162 static int max_nonpool_blocks;
163 static int max_pool_malloc; /* max value for pool_malloc */
164 static int max_nonpool_malloc; /* max value for nonpool_malloc */
167 #ifndef COMPILE_UTILITY
168 static const uschar * pooluse[NPOOLS] = {
169 [POOL_MAIN] = US"main",
170 [POOL_PERM] = US"perm",
171 [POOL_CONFIG] = US"config",
172 [POOL_SEARCH] = US"search",
173 [POOL_MESSAGE] = US"message",
174 [POOL_TAINT_MAIN] = US"main",
175 [POOL_TAINT_PERM] = US"perm",
176 [POOL_TAINT_CONFIG] = US"config",
177 [POOL_TAINT_SEARCH] = US"search",
178 [POOL_TAINT_MESSAGE] = US"message",
180 static const uschar * poolclass[NPOOLS] = {
181 [POOL_MAIN] = US"untainted",
182 [POOL_PERM] = US"untainted",
183 [POOL_CONFIG] = US"untainted",
184 [POOL_SEARCH] = US"untainted",
185 [POOL_MESSAGE] = US"untainted",
186 [POOL_TAINT_MAIN] = US"tainted",
187 [POOL_TAINT_PERM] = US"tainted",
188 [POOL_TAINT_CONFIG] = US"tainted",
189 [POOL_TAINT_SEARCH] = US"tainted",
190 [POOL_TAINT_MESSAGE] = US"tainted",
195 static void * internal_store_malloc(size_t, const char *, int);
196 static void internal_store_free(void *, const char *, int linenumber);
198 /******************************************************************************/
199 /* Initialisation, for things fragile with parameter channges when using
200 static initialisers. */
205 for (int i = 0; i < NPOOLS; i++)
207 yield_length[i] = -1;
208 store_block_order[i] = 12; /* log2(allocation_size) ie. 4kB */
212 /******************************************************************************/
214 /* Test if a pointer refers to tainted memory.
216 Slower version check, for use when platform intermixes malloc and mmap area
217 addresses. Test against the current-block of all tainted pools first, then all
218 blocks of all tainted pools.
220 Return: TRUE iff tainted
224 is_tainted_fn(const void * p)
228 for (int pool = POOL_TAINT_BASE; pool < nelem(chainbase); pool++)
229 if ((b = current_block[pool]))
231 uschar * bc = US b + ALIGNED_SIZEOF_STOREBLOCK;
232 if (US p >= bc && US p < bc + b->length) return TRUE;
235 for (int pool = POOL_TAINT_BASE; pool < nelem(chainbase); pool++)
236 for (b = chainbase[pool]; b; b = b->next)
238 uschar * bc = US b + ALIGNED_SIZEOF_STOREBLOCK;
239 if (US p >= bc && US p < bc + b->length) return TRUE;
246 die_tainted(const uschar * msg, const uschar * func, int line)
248 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Taint mismatch, %s: %s %d\n",
254 /******************************************************************************/
256 store_writeprotect(int pool)
258 #if !defined(COMPILE_UTILITY) && !defined(MISSING_POSIX_MEMALIGN)
259 for (storeblock * b = chainbase[pool]; b; b = b->next)
260 if (mprotect(b, ALIGNED_SIZEOF_STOREBLOCK + b->length, PROT_READ) != 0)
261 DEBUG(D_any) debug_printf("config block mprotect: (%d) %s\n", errno, strerror(errno));
265 /******************************************************************************/
267 /*************************************************
268 * Get a block from the current pool *
269 *************************************************/
271 /* Running out of store is a total disaster. This function is called via the
272 macro store_get(). It passes back a block of store within the current big
273 block, getting a new one if necessary. The address is saved in
277 size amount wanted, bytes
278 tainted class: set to true for untrusted data (eg. from smtp input)
279 func function from which called
280 linenumber line number in source file
282 Returns: pointer to store (panic on malloc failure)
286 store_get_3(int size, BOOL tainted, const char * func, int linenumber)
288 int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool;
290 /* Ensure we've been asked to allocate memory.
291 A negative size is a sign of a security problem.
292 A zero size might be also suspect, but our internal usage deliberately
293 does this to return a current watermark value for a later release of
296 if (size < 0 || size >= INT_MAX/2)
297 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
298 "bad memory allocation requested (%d bytes) at %s %d",
299 size, func, linenumber);
301 /* Round up the size to a multiple of the alignment. Although this looks a
302 messy statement, because "alignment" is a constant expression, the compiler can
303 do a reasonable job of optimizing, especially if the value of "alignment" is a
304 power of two. I checked this with -O2, and gcc did very well, compiling it to 4
305 instructions on a Sparc (alignment = 8). */
307 if (size % alignment != 0) size += alignment - (size % alignment);
309 /* If there isn't room in the current block, get a new one. The minimum
310 size is STORE_BLOCK_SIZE, and we would expect this to be the norm, since
311 these functions are mostly called for small amounts of store. */
313 if (size > yield_length[pool])
316 STORE_BLOCK_SIZE(store_block_order[pool]) - ALIGNED_SIZEOF_STOREBLOCK,
318 int mlength = length + ALIGNED_SIZEOF_STOREBLOCK;
319 storeblock * newblock;
321 /* Sometimes store_reset() may leave a block for us; check if we can use it */
323 if ( (newblock = current_block[pool])
324 && (newblock = newblock->next)
325 && newblock->length < length
328 /* Give up on this block, because it's too small */
330 internal_store_free(newblock, func, linenumber);
334 /* If there was no free block, get a new one */
338 if ((nbytes[pool] += mlength) > maxbytes[pool])
339 maxbytes[pool] = nbytes[pool];
340 if ((pool_malloc += mlength) > max_pool_malloc) /* Used in pools */
341 max_pool_malloc = pool_malloc;
342 nonpool_malloc -= mlength; /* Exclude from overall total */
343 if (++nblocks[pool] > maxblocks[pool])
344 maxblocks[pool] = nblocks[pool];
346 #ifndef MISSING_POSIX_MEMALIGN
347 if (pool == POOL_CONFIG)
349 long pgsize = sysconf(_SC_PAGESIZE);
350 int err = posix_memalign((void **)&newblock,
351 pgsize, (mlength + pgsize - 1) & ~(pgsize - 1));
353 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
354 "failed to alloc (using posix_memalign) %d bytes of memory: '%s'"
355 "called from line %d in %s",
356 size, strerror(err), linenumber, func);
360 newblock = internal_store_malloc(mlength, func, linenumber);
361 newblock->next = NULL;
362 newblock->length = length;
363 #ifndef RESTRICTED_MEMORY
364 if (store_block_order[pool]++ > maxorder[pool])
365 maxorder[pool] = store_block_order[pool];
368 if (!chainbase[pool])
369 chainbase[pool] = newblock;
371 current_block[pool]->next = newblock;
374 current_block[pool] = newblock;
375 yield_length[pool] = newblock->length;
377 (void *)(CS current_block[pool] + ALIGNED_SIZEOF_STOREBLOCK);
378 (void) VALGRIND_MAKE_MEM_NOACCESS(next_yield[pool], yield_length[pool]);
381 /* There's (now) enough room in the current block; the yield is the next
384 store_last_get[pool] = next_yield[pool];
386 /* Cut out the debugging stuff for utilities, but stop picky compilers from
389 #ifndef COMPILE_UTILITY
391 debug_printf("---%d Get %6p %5d %-14s %4d\n", pool,
392 store_last_get[pool], size, func, linenumber);
393 #endif /* COMPILE_UTILITY */
395 (void) VALGRIND_MAKE_MEM_UNDEFINED(store_last_get[pool], size);
396 /* Update next pointer and number of bytes left in the current block. */
398 next_yield[pool] = (void *)(CS next_yield[pool] + size);
399 yield_length[pool] -= size;
400 return store_last_get[pool];
405 /*************************************************
406 * Get a block from the PERM pool *
407 *************************************************/
409 /* This is just a convenience function, useful when just a single block is to
414 func function from which called
415 linenumber line number in source file
417 Returns: pointer to store (panic on malloc failure)
421 store_get_perm_3(int size, BOOL tainted, const char *func, int linenumber)
424 int old_pool = store_pool;
425 store_pool = POOL_PERM;
426 yield = store_get_3(size, tainted, func, linenumber);
427 store_pool = old_pool;
433 /*************************************************
434 * Extend a block if it is at the top *
435 *************************************************/
437 /* While reading strings of unknown length, it is often the case that the
438 string is being read into the block at the top of the stack. If it needs to be
439 extended, it is more efficient just to extend within the top block rather than
440 allocate a new block and then have to copy the data. This function is provided
441 for the use of string_cat(), but of course can be used elsewhere too.
442 The block itself is not expanded; only the top allocation from it.
445 ptr pointer to store block
446 oldsize current size of the block, as requested by user
447 newsize new size required
448 func function from which called
449 linenumber line number in source file
451 Returns: TRUE if the block is at the top of the stack and has been
452 extended; FALSE if it isn't at the top of the stack, or cannot
457 store_extend_3(void *ptr, BOOL tainted, int oldsize, int newsize,
458 const char *func, int linenumber)
460 int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool;
461 int inc = newsize - oldsize;
462 int rounded_oldsize = oldsize;
464 if (oldsize < 0 || newsize < oldsize || newsize >= INT_MAX/2)
465 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
466 "bad memory extension requested (%d -> %d bytes) at %s %d",
467 oldsize, newsize, func, linenumber);
469 /* Check that the block being extended was already of the required taint status;
470 refuse to extend if not. */
472 if (is_tainted(ptr) != tainted)
475 if (rounded_oldsize % alignment != 0)
476 rounded_oldsize += alignment - (rounded_oldsize % alignment);
478 if (CS ptr + rounded_oldsize != CS (next_yield[pool]) ||
479 inc > yield_length[pool] + rounded_oldsize - oldsize)
482 /* Cut out the debugging stuff for utilities, but stop picky compilers from
485 #ifndef COMPILE_UTILITY
487 debug_printf("---%d Ext %6p %5d %-14s %4d\n", pool, ptr, newsize,
489 #endif /* COMPILE_UTILITY */
491 if (newsize % alignment != 0) newsize += alignment - (newsize % alignment);
492 next_yield[pool] = CS ptr + newsize;
493 yield_length[pool] -= newsize - rounded_oldsize;
494 (void) VALGRIND_MAKE_MEM_UNDEFINED(ptr + oldsize, inc);
502 is_pwr2_size(int len)
505 return (x & (x - 1)) == 0;
509 /*************************************************
510 * Back up to a previous point on the stack *
511 *************************************************/
513 /* This function resets the next pointer, freeing any subsequent whole blocks
514 that are now unused. Call with a cookie obtained from store_mark() only; do
515 not call with a pointer returned by store_get(). Both the untainted and tainted
516 pools corresposding to store_pool are reset.
519 ptr place to back up to
520 pool pool holding the pointer
521 func function from which called
522 linenumber line number in source file
528 internal_store_reset(void * ptr, int pool, const char *func, int linenumber)
531 storeblock * b = current_block[pool];
532 char * bc = CS b + ALIGNED_SIZEOF_STOREBLOCK;
533 int newlength, count;
534 #ifndef COMPILE_UTILITY
535 int oldmalloc = pool_malloc;
538 /* Last store operation was not a get */
540 store_last_get[pool] = NULL;
542 /* See if the place is in the current block - as it often will be. Otherwise,
543 search for the block in which it lies. */
545 if (CS ptr < bc || CS ptr > bc + b->length)
547 for (b = chainbase[pool]; b; b = b->next)
549 bc = CS b + ALIGNED_SIZEOF_STOREBLOCK;
550 if (CS ptr >= bc && CS ptr <= bc + b->length) break;
553 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal error: store_reset(%p) "
554 "failed: pool=%d %-14s %4d", ptr, pool, func, linenumber);
557 /* Back up, rounding to the alignment if necessary. When testing, flatten
558 the released memory. */
560 newlength = bc + b->length - CS ptr;
561 #ifndef COMPILE_UTILITY
564 assert_no_variables(ptr, newlength, func, linenumber);
565 if (f.running_in_test_harness)
567 (void) VALGRIND_MAKE_MEM_DEFINED(ptr, newlength);
568 memset(ptr, 0xF0, newlength);
572 (void) VALGRIND_MAKE_MEM_NOACCESS(ptr, newlength);
573 next_yield[pool] = CS ptr + (newlength % alignment);
574 count = yield_length[pool];
575 count = (yield_length[pool] = newlength - (newlength % alignment)) - count;
576 current_block[pool] = b;
578 /* Free any subsequent block. Do NOT free the first
579 successor, if our current block has less than 256 bytes left. This should
580 prevent us from flapping memory. However, keep this block only when it has
581 a power-of-two size so probably is not a custom inflated one. */
583 if ( yield_length[pool] < STOREPOOL_MIN_SIZE
585 && is_pwr2_size(b->next->length + ALIGNED_SIZEOF_STOREBLOCK))
588 #ifndef COMPILE_UTILITY
590 assert_no_variables(b, b->length + ALIGNED_SIZEOF_STOREBLOCK,
593 (void) VALGRIND_MAKE_MEM_NOACCESS(CS b + ALIGNED_SIZEOF_STOREBLOCK,
594 b->length - ALIGNED_SIZEOF_STOREBLOCK);
598 if (pool != POOL_CONFIG)
603 int siz = b->length + ALIGNED_SIZEOF_STOREBLOCK;
605 #ifndef COMPILE_UTILITY
607 assert_no_variables(b, b->length + ALIGNED_SIZEOF_STOREBLOCK,
614 if (pool != POOL_CONFIG)
615 internal_store_free(b, func, linenumber);
617 #ifndef RESTRICTED_MEMORY
618 if (store_block_order[pool] > 13) store_block_order[pool]--;
622 /* Cut out the debugging stuff for utilities, but stop picky compilers from
625 #ifndef COMPILE_UTILITY
627 debug_printf("---%d Rst %6p %5d %-14s %4d\tpool %d\n", pool, ptr,
628 count + oldmalloc - pool_malloc,
629 func, linenumber, pool_malloc);
630 #endif /* COMPILE_UTILITY */
635 store_reset_3(rmark r, const char *func, int linenumber)
639 if (store_pool >= POOL_TAINT_BASE)
640 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
641 "store_reset called for pool %d: %s %d\n", store_pool, func, linenumber);
643 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
644 "store_reset called with bad mark: %s %d\n", func, linenumber);
646 internal_store_reset(*ptr, store_pool + POOL_TAINT_BASE, func, linenumber);
647 internal_store_reset(ptr, store_pool, func, linenumber);
653 /* Free tail-end unused allocation. This lets us allocate a big chunk
654 early, for cases when we only discover later how much was really needed.
656 Can be called with a value from store_get(), or an offset after such. Only
657 the tainted or untainted pool that serviced the store_get() will be affected.
659 This is mostly a cut-down version of internal_store_reset().
660 XXX needs rationalising
664 store_release_above_3(void *ptr, const char *func, int linenumber)
666 /* Search all pools' "current" blocks. If it isn't one of those,
667 ignore it (it usually will be). */
669 for (int pool = 0; pool < nelem(current_block); pool++)
671 storeblock * b = current_block[pool];
673 int count, newlength;
678 bc = CS b + ALIGNED_SIZEOF_STOREBLOCK;
679 if (CS ptr < bc || CS ptr > bc + b->length)
682 /* Last store operation was not a get */
684 store_last_get[pool] = NULL;
686 /* Back up, rounding to the alignment if necessary. When testing, flatten
687 the released memory. */
689 newlength = bc + b->length - CS ptr;
690 #ifndef COMPILE_UTILITY
693 assert_no_variables(ptr, newlength, func, linenumber);
694 if (f.running_in_test_harness)
696 (void) VALGRIND_MAKE_MEM_DEFINED(ptr, newlength);
697 memset(ptr, 0xF0, newlength);
701 (void) VALGRIND_MAKE_MEM_NOACCESS(ptr, newlength);
702 next_yield[pool] = CS ptr + (newlength % alignment);
703 count = yield_length[pool];
704 count = (yield_length[pool] = newlength - (newlength % alignment)) - count;
706 /* Cut out the debugging stuff for utilities, but stop picky compilers from
709 #ifndef COMPILE_UTILITY
711 debug_printf("---%d Rel %6p %5d %-14s %4d\tpool %d\n", pool, ptr, count,
712 func, linenumber, pool_malloc);
716 #ifndef COMPILE_UTILITY
718 debug_printf("non-last memory release try: %s %d\n", func, linenumber);
725 store_mark_3(const char *func, int linenumber)
729 #ifndef COMPILE_UTILITY
731 debug_printf("---%d Mrk %-14s %4d\tpool %d\n",
732 store_pool, func, linenumber, pool_malloc);
733 #endif /* COMPILE_UTILITY */
735 if (store_pool >= POOL_TAINT_BASE)
736 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
737 "store_mark called for pool %d: %s %d\n", store_pool, func, linenumber);
739 /* Stash a mark for the tainted-twin release, in the untainted twin. Return
740 a cookie (actually the address in the untainted pool) to the caller.
741 Reset uses the cookie to recover the t-mark, winds back the tainted pool with it
742 and winds back the untainted pool with the cookie. */
744 p = store_get_3(sizeof(void *), FALSE, func, linenumber);
745 *p = store_get_3(0, TRUE, func, linenumber);
752 /************************************************
754 ************************************************/
756 /* This function checks that the pointer it is given is the first thing in a
757 block, and if so, releases that block.
760 block block of store to consider
761 func function from which called
762 linenumber line number in source file
768 store_release_3(void * block, int pool, const char * func, int linenumber)
770 /* It will never be the first block, so no need to check that. */
772 for (storeblock * b = chainbase[pool]; b; b = b->next)
774 storeblock * bb = b->next;
775 if (bb && CS block == CS bb + ALIGNED_SIZEOF_STOREBLOCK)
777 int siz = bb->length + ALIGNED_SIZEOF_STOREBLOCK;
783 /* Cut out the debugging stuff for utilities, but stop picky compilers
784 from giving warnings. */
786 #ifndef COMPILE_UTILITY
788 debug_printf("-Release %6p %-20s %4d %d\n", (void *)bb, func,
789 linenumber, pool_malloc);
791 if (f.running_in_test_harness)
792 memset(bb, 0xF0, bb->length+ALIGNED_SIZEOF_STOREBLOCK);
793 #endif /* COMPILE_UTILITY */
795 internal_store_free(bb, func, linenumber);
802 /************************************************
804 ************************************************/
806 /* Allocate a new block big enough to expend to the given size and
807 copy the current data into it. Free the old one if possible.
809 This function is specifically provided for use when reading very
810 long strings, e.g. header lines. When the string gets longer than a
811 complete block, it gets copied to a new block. It is helpful to free
812 the old block iff the previous copy of the string is at its start,
813 and therefore the only thing in it. Otherwise, for very long strings,
814 dead store can pile up somewhat disastrously. This function checks that
815 the pointer it is given is the first thing in a block, and that nothing
816 has been allocated since. If so, releases that block.
823 Returns: new location of data
827 store_newblock_3(void * block, BOOL tainted, int newsize, int len,
828 const char * func, int linenumber)
830 int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool;
831 BOOL release_ok = !tainted && store_last_get[pool] == block;
834 #if !defined(MACRO_PREDEF) && !defined(COMPILE_UTILITY)
835 if (is_tainted(block) != tainted)
836 die_tainted(US"store_newblock", CUS func, linenumber);
839 if (len < 0 || len > newsize)
840 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
841 "bad memory extension requested (%d -> %d bytes) at %s %d",
842 len, newsize, func, linenumber);
844 newtext = store_get(newsize, tainted);
845 memcpy(newtext, block, len);
846 if (release_ok) store_release_3(block, pool, func, linenumber);
847 return (void *)newtext;
853 /*************************************************
855 *************************************************/
857 /* Running out of store is a total disaster for exim. Some malloc functions
858 do not run happily on very small sizes, nor do they document this fact. This
859 function is called via the macro store_malloc().
862 size amount of store wanted
863 func function from which called
864 line line number in source file
866 Returns: pointer to gotten store (panic on failure)
870 internal_store_malloc(size_t size, const char *func, int line)
874 /* Check specifically for a possibly result of conversion from
875 a negative int, to the (unsigned, wider) size_t */
877 if (size >= INT_MAX/2)
878 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
879 "bad memory allocation requested (%lld bytes) at %s %d",
880 (unsigned long long)size, func, line);
882 size += sizeof(size_t); /* space to store the size, used under debug */
883 if (size < 16) size = 16;
885 if (!(yield = malloc(size)))
886 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to malloc %d bytes of memory: "
887 "called from line %d in %s", size, line, func);
889 #ifndef COMPILE_UTILITY
890 DEBUG(D_any) *(size_t *)yield = size;
892 yield = US yield + sizeof(size_t);
894 if ((nonpool_malloc += size) > max_nonpool_malloc)
895 max_nonpool_malloc = nonpool_malloc;
897 /* Cut out the debugging stuff for utilities, but stop picky compilers from
900 #ifndef COMPILE_UTILITY
901 /* If running in test harness, spend time making sure all the new store
902 is not filled with zeros so as to catch problems. */
904 if (f.running_in_test_harness)
905 memset(yield, 0xF0, size - sizeof(size_t));
906 DEBUG(D_memory) debug_printf("--Malloc %6p %5lld bytes\t%-20s %4d\tpool %5d nonpool %5d\n",
907 yield, size, func, line, pool_malloc, nonpool_malloc);
908 #endif /* COMPILE_UTILITY */
914 store_malloc_3(size_t size, const char *func, int linenumber)
916 if (n_nonpool_blocks++ > max_nonpool_blocks)
917 max_nonpool_blocks = n_nonpool_blocks;
918 return internal_store_malloc(size, func, linenumber);
922 /************************************************
924 ************************************************/
926 /* This function is called by the macro store_free().
929 block block of store to free
930 func function from which called
931 linenumber line number in source file
937 internal_store_free(void * block, const char * func, int linenumber)
939 uschar * p = US block - sizeof(size_t);
940 #ifndef COMPILE_UTILITY
941 DEBUG(D_any) nonpool_malloc -= *(size_t *)p;
942 DEBUG(D_memory) debug_printf("----Free %6p %5lld bytes\t%-20s %4d\n",
943 block, (unsigned long long) *(size_t *)p, func, linenumber);
949 store_free_3(void * block, const char * func, int linenumber)
952 internal_store_free(block, func, linenumber);
955 /******************************************************************************/
956 /* Stats output on process exit */
960 #ifndef COMPILE_UTILITY
963 debug_printf("----Exit nonpool max: %3d kB in %d blocks\n",
964 (max_nonpool_malloc+1023)/1024, max_nonpool_blocks);
965 debug_printf("----Exit npools max: %3d kB\n", max_pool_malloc/1024);
966 for (int i = 0; i < NPOOLS; i++)
967 debug_printf("----Exit pool %d max: %3d kB in %d blocks at order %u\t%s %s\n",
968 i, (maxbytes[i]+1023)/1024, maxblocks[i], maxorder[i],
969 poolclass[i], pooluse[i]);
975 /******************************************************************************/
976 /* Per-message pool management */
978 static rmark message_reset_point = NULL;
983 int oldpool = store_pool;
984 store_pool = POOL_MESSAGE;
985 if (!message_reset_point) message_reset_point = store_mark();
986 store_pool = oldpool;
989 void message_tidyup(void)
992 if (!message_reset_point) return;
993 oldpool = store_pool;
994 store_pool = POOL_MESSAGE;
995 message_reset_point = store_reset(message_reset_point);
996 store_pool = oldpool;