1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) The Exim maintainers 2019 - 2022 */
6 /* Copyright (c) University of Cambridge 1995 - 2018 */
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 - There are pools for each active combination of lookup-quoting, dynamically created.
49 . Orthogonal to the four main pool types, there are two classes of memory: untainted
50 and tainted. The latter is used for values derived from untrusted input, and
51 the string-expansion mechanism refuses to operate on such values (obviously,
52 it can expand an untainted value to return a tainted result). The classes
53 are implemented by duplicating the four pool types. Pool resets are requested
54 against the nontainted sibling and apply to both siblings.
56 Only memory blocks requested for tainted use are regarded as tainted; anything
57 else (including stack auto variables) is untainted. Care is needed when coding
58 to not copy untrusted data into untainted memory, as downstream taint-checks
61 Intermediate layers (eg. the string functions) can test for taint, and use this
62 for ensurinng that results have proper state. For example the
63 string_vformat_trc() routing supporting the string_sprintf() interface will
64 recopy a string being built into a tainted allocation if it meets a %s for a
65 tainted argument. Any intermediate-layer function that (can) return a new
66 allocation should behave this way; returning a tainted result if any tainted
67 content is used. Intermediate-layer functions (eg. Ustrncpy) that modify
68 existing allocations fail if tainted data is written into an untainted area.
69 Users of functions that modify existing allocations should check if a tainted
70 source and an untainted destination is used, and fail instead (sprintf() being
76 /* keep config.h before memcheck.h, for NVALGRIND */
83 /* We need to know how to align blocks of data for general use. I'm not sure
84 how to get an alignment factor in general. In the current world, a value of 8
85 is probably right, and this is sizeof(double) on some systems and sizeof(void
86 *) on others, so take the larger of those. Since everything in this expression
87 is a constant, the compiler should optimize it to a simple constant wherever it
88 appears (I checked that gcc does do this). */
91 (sizeof(void *) > sizeof(double) ? sizeof(void *) : sizeof(double))
93 /* store_reset() will not free the following block if the last used block has
94 less than this much left in it. */
96 #define STOREPOOL_MIN_SIZE 256
98 /* Structure describing the beginning of each big block. */
100 typedef struct storeblock {
101 struct storeblock *next;
105 /* Pool descriptor struct */
107 typedef struct pooldesc {
108 storeblock * chainbase; /* list of blocks in pool */
109 storeblock * current_block; /* top block, still with free space */
110 void * next_yield; /* next allocation point */
111 int yield_length; /* remaining space in current block */
112 unsigned store_block_order; /* log2(size) block allocation size */
114 /* This variable is set by store_get() to its yield, and by store_reset() to
115 NULL. This enables string_cat() to optimize its store handling for very long
116 strings. That's why the variable is global. */
118 void * store_last_get;
120 /* These are purely for stats-gathering */
129 /* Enhanced pool descriptor for quoted pools */
131 typedef struct quoted_pooldesc {
134 struct quoted_pooldesc * next;
137 /* Just in case we find ourselves on a system where the structure above has a
138 length that is not a multiple of the alignment, set up a macro for the padded
141 #define ALIGNED_SIZEOF_STOREBLOCK \
142 (((sizeof(storeblock) + alignment - 1) / alignment) * alignment)
144 /* Size of block to get from malloc to carve up into smaller ones. This
145 must be a multiple of the alignment. We assume that 4096 is going to be
146 suitably aligned. Double the size per-pool for every malloc, to mitigate
147 certain denial-of-service attacks. Don't bother to decrease on block frees.
148 We waste average half the current alloc size per pool. This could be several
149 hundred kB now, vs. 4kB with a constant-size block size. But the search time
150 for is_tainted(), linear in the number of blocks for the pool, is O(n log n)
152 A test of 2000 RCPTs and just accept ACL had 370kB in 21 blocks before,
153 504kB in 6 blocks now, for the untainted-main (largest) pool.
154 Builds for restricted-memory system can disable the expansion by
155 defining RESTRICTED_MEMORY */
156 /*XXX should we allow any for malloc's own overhead? But how much? */
158 /* #define RESTRICTED_MEMORY */
159 #define STORE_BLOCK_SIZE(order) ((1U << (order)) - ALIGNED_SIZEOF_STOREBLOCK)
161 /* Variables holding data for the local pools of store. The current pool number
162 is held in store_pool, which is global so that it can be changed from outside.
163 Setting the initial length values to -1 forces a malloc for the first call,
164 even if the length is zero (which is used for getting a point to reset to). */
166 int store_pool = POOL_MAIN;
168 pooldesc paired_pools[N_PAIRED_POOLS];
169 quoted_pooldesc * quoted_pools = NULL;
171 static int n_nonpool_blocks; /* current number of direct store_malloc() blocks */
172 static int max_nonpool_blocks;
173 static int max_pool_malloc; /* max value for pool_malloc */
174 static int max_nonpool_malloc; /* max value for nonpool_malloc */
176 /* pool_malloc holds the amount of memory used by the store pools; this goes up
177 and down as store is reset or released. nonpool_malloc is the total got by
178 malloc from other calls; this doesn't go down because it is just freed by
181 static int pool_malloc;
182 static int nonpool_malloc;
185 #ifndef COMPILE_UTILITY
186 static const uschar * pooluse[N_PAIRED_POOLS] = {
187 [POOL_MAIN] = US"main",
188 [POOL_PERM] = US"perm",
189 [POOL_CONFIG] = US"config",
190 [POOL_SEARCH] = US"search",
191 [POOL_MESSAGE] = US"message",
192 [POOL_TAINT_MAIN] = US"main",
193 [POOL_TAINT_PERM] = US"perm",
194 [POOL_TAINT_CONFIG] = US"config",
195 [POOL_TAINT_SEARCH] = US"search",
196 [POOL_TAINT_MESSAGE] = US"message",
198 static const uschar * poolclass[N_PAIRED_POOLS] = {
199 [POOL_MAIN] = US"untainted",
200 [POOL_PERM] = US"untainted",
201 [POOL_CONFIG] = US"untainted",
202 [POOL_SEARCH] = US"untainted",
203 [POOL_MESSAGE] = US"untainted",
204 [POOL_TAINT_MAIN] = US"tainted",
205 [POOL_TAINT_PERM] = US"tainted",
206 [POOL_TAINT_CONFIG] = US"tainted",
207 [POOL_TAINT_SEARCH] = US"tainted",
208 [POOL_TAINT_MESSAGE] = US"tainted",
213 static void * internal_store_malloc(size_t, const char *, int);
214 static void internal_store_free(void *, const char *, int linenumber);
216 /******************************************************************************/
219 pool_init(pooldesc * pp)
221 memset(pp, 0, sizeof(*pp));
222 pp->yield_length = -1;
223 pp->store_block_order = 12; /* log2(allocation_size) ie. 4kB */
226 /* Initialisation, for things fragile with parameter channges when using
227 static initialisers. */
232 for (pooldesc * pp = paired_pools; pp < paired_pools + N_PAIRED_POOLS; pp++)
236 /******************************************************************************/
237 /* Locating elements given memory pointer */
240 is_pointer_in_block(const storeblock * b, const void * p)
242 uschar * bc = US b + ALIGNED_SIZEOF_STOREBLOCK;
243 return US p >= bc && US p < bc + b->length;
247 pool_current_for_pointer(const void * p)
251 for (quoted_pooldesc * qp = quoted_pools; qp; qp = qp->next)
252 if ((b = qp->pool.current_block) && is_pointer_in_block(b, p))
255 for (pooldesc * pp = paired_pools; pp < paired_pools + N_PAIRED_POOLS; pp++)
256 if ((b = pp->current_block) && is_pointer_in_block(b, p))
262 pool_for_pointer(const void * p, const char * func, int linenumber)
267 if ((pp = pool_current_for_pointer(p))) return pp;
269 for (quoted_pooldesc * qp = quoted_pools; qp; qp = qp->next)
270 for (b = qp->pool.chainbase; b; b = b->next)
271 if (is_pointer_in_block(b, p)) return &qp->pool;
273 for (pp = paired_pools; pp < paired_pools + N_PAIRED_POOLS; pp++)
274 for (b = pp->chainbase; b; b = b->next)
275 if (is_pointer_in_block(b, p)) return pp;
277 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
278 "bad memory reference; pool not found, at %s %d", func, linenumber);
282 /******************************************************************************/
283 /* Test if a pointer refers to tainted memory.
285 Slower version check, for use when platform intermixes malloc and mmap area
286 addresses. Test against the current-block of all tainted pools first, then all
287 blocks of all tainted pools.
289 Return: TRUE iff tainted
293 is_tainted_fn(const void * p)
297 if (p == GET_UNTAINTED) return FALSE;
298 if (p == GET_TAINTED) return TRUE;
300 for (pooldesc * pp = paired_pools + POOL_TAINT_BASE;
301 pp < paired_pools + N_PAIRED_POOLS; pp++)
302 if ((b = pp->current_block))
303 if (is_pointer_in_block(b, p)) return TRUE;
305 for (quoted_pooldesc * qp = quoted_pools; qp; qp = qp->next)
306 if (b = qp->pool.current_block)
307 if (is_pointer_in_block(b, p)) return TRUE;
309 for (pooldesc * pp = paired_pools + POOL_TAINT_BASE;
310 pp < paired_pools + N_PAIRED_POOLS; pp++)
311 for (b = pp->chainbase; b; b = b->next)
312 if (is_pointer_in_block(b, p)) return TRUE;
314 for (quoted_pooldesc * qp = quoted_pools; qp; qp = qp->next)
315 for (b = qp->pool.chainbase; b; b = b->next)
316 if (is_pointer_in_block(b, p)) return TRUE;
323 die_tainted(const uschar * msg, const uschar * func, int line)
325 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Taint mismatch, %s: %s %d\n",
330 #ifndef COMPILE_UTILITY
331 /* Return the pool for the given quoter, or null */
334 pool_for_quoter(unsigned quoter)
336 for (quoted_pooldesc * qp = quoted_pools; qp; qp = qp->next)
337 if (qp->quoter == quoter)
342 /* Allocate/init a new quoted-pool and return the pool */
345 quoted_pool_new(unsigned quoter)
347 // debug_printf("allocating quoted-pool\n");
348 quoted_pooldesc * qp = store_get_perm(sizeof(quoted_pooldesc), GET_UNTAINTED);
350 pool_init(&qp->pool);
352 qp->next = quoted_pools;
359 /******************************************************************************/
361 store_writeprotect(int pool)
363 #if !defined(COMPILE_UTILITY) && !defined(MISSING_POSIX_MEMALIGN)
364 for (storeblock * b = paired_pools[pool].chainbase; b; b = b->next)
365 if (mprotect(b, ALIGNED_SIZEOF_STOREBLOCK + b->length, PROT_READ) != 0)
366 DEBUG(D_any) debug_printf("config block mprotect: (%d) %s\n", errno, strerror(errno));
370 /******************************************************************************/
373 pool_get(pooldesc * pp, int size, BOOL align_mem, const char * func, int linenumber)
375 /* Ensure we've been asked to allocate memory.
376 A negative size is a sign of a security problem.
377 A zero size might be also suspect, but our internal usage deliberately
378 does this to return a current watermark value for a later release of
381 if (size < 0 || size >= INT_MAX/2)
382 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
383 "bad memory allocation requested (%d bytes) at %s %d",
384 size, func, linenumber);
386 /* Round up the size to a multiple of the alignment. Although this looks a
387 messy statement, because "alignment" is a constant expression, the compiler can
388 do a reasonable job of optimizing, especially if the value of "alignment" is a
389 power of two. I checked this with -O2, and gcc did very well, compiling it to 4
390 instructions on a Sparc (alignment = 8). */
392 if (size % alignment != 0) size += alignment - (size % alignment);
394 /* If there isn't room in the current block, get a new one. The minimum
395 size is STORE_BLOCK_SIZE, and we would expect this to be the norm, since
396 these functions are mostly called for small amounts of store. */
398 if (size > pp->yield_length)
401 STORE_BLOCK_SIZE(pp->store_block_order) - ALIGNED_SIZEOF_STOREBLOCK,
403 int mlength = length + ALIGNED_SIZEOF_STOREBLOCK;
404 storeblock * newblock;
406 /* Sometimes store_reset() may leave a block for us; check if we can use it */
408 if ( (newblock = pp->current_block)
409 && (newblock = newblock->next)
410 && newblock->length < length
413 /* Give up on this block, because it's too small */
415 internal_store_free(newblock, func, linenumber);
419 /* If there was no free block, get a new one */
423 if ((pp->nbytes += mlength) > pp->maxbytes)
424 pp->maxbytes = pp->nbytes;
425 if ((pool_malloc += mlength) > max_pool_malloc) /* Used in pools */
426 max_pool_malloc = pool_malloc;
427 nonpool_malloc -= mlength; /* Exclude from overall total */
428 if (++pp->nblocks > pp->maxblocks)
429 pp->maxblocks = pp->nblocks;
431 #ifndef MISSING_POSIX_MEMALIGN
434 long pgsize = sysconf(_SC_PAGESIZE);
435 int err = posix_memalign((void **)&newblock,
436 pgsize, (mlength + pgsize - 1) & ~(pgsize - 1));
438 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
439 "failed to alloc (using posix_memalign) %d bytes of memory: '%s'"
440 "called from line %d in %s",
441 size, strerror(err), linenumber, func);
445 newblock = internal_store_malloc(mlength, func, linenumber);
446 newblock->next = NULL;
447 newblock->length = length;
448 #ifndef RESTRICTED_MEMORY
449 if (pp->store_block_order++ > pp->maxorder)
450 pp->maxorder = pp->store_block_order;
454 pp->chainbase = newblock;
456 pp->current_block->next = newblock;
459 pp->current_block = newblock;
460 pp->yield_length = newblock->length;
462 (void *)(CS pp->current_block + ALIGNED_SIZEOF_STOREBLOCK);
463 (void) VALGRIND_MAKE_MEM_NOACCESS(pp->next_yield, pp->yield_length);
466 /* There's (now) enough room in the current block; the yield is the next
469 pp->store_last_get = pp->next_yield;
471 (void) VALGRIND_MAKE_MEM_UNDEFINED(pp->store_last_get, size);
472 /* Update next pointer and number of bytes left in the current block. */
474 pp->next_yield = (void *)(CS pp->next_yield + size);
475 pp->yield_length -= size;
476 return pp->store_last_get;
479 /*************************************************
480 * Get a block from the current pool *
481 *************************************************/
483 /* Running out of store is a total disaster. This function is called via the
484 macro store_get(). The current store_pool is used, adjusting for taint.
485 If the protoype is quoted, use a quoted-pool.
486 Return a block of store within the current big block of the pool, getting a new
487 one if necessary. The address is saved in store_last_get for the pool.
490 size amount wanted, bytes
491 proto_mem class: get store conformant to this
492 Special values: 0 forces untainted, 1 forces tainted
493 func function from which called
494 linenumber line number in source file
496 Returns: pointer to store (panic on malloc failure)
500 store_get_3(int size, const void * proto_mem, const char * func, int linenumber)
502 #ifndef COMPILE_UTILITY
503 int quoter = quoter_for_address(proto_mem);
508 #ifndef COMPILE_UTILITY
509 if (!is_real_quoter(quoter))
512 BOOL tainted = is_tainted(proto_mem);
513 int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool;
514 pp = paired_pools + pool;
515 yield = pool_get(pp, size, (pool == POOL_CONFIG), func, linenumber);
517 /* Cut out the debugging stuff for utilities, but stop picky compilers from
520 #ifndef COMPILE_UTILITY
522 debug_printf("---%d Get %6p %5d %-14s %4d\n", pool,
523 pp->store_last_get, size, func, linenumber);
526 #ifndef COMPILE_UTILITY
530 debug_printf("allocating quoted-block for quoter %u (from %s %d)\n",
531 quoter, func, linenumber);
532 if (!(pp = pool_for_quoter(quoter))) pp = quoted_pool_new(quoter);
533 yield = pool_get(pp, size, FALSE, func, linenumber);
535 debug_printf("---QQ Get %6p %5d %-14s %4d\n",
536 pp->store_last_get, size, func, linenumber);
544 /*************************************************
545 * Get a block from the PERM pool *
546 *************************************************/
548 /* This is just a convenience function, useful when just a single block is to
553 proto_mem class: get store conformant to this
554 func function from which called
555 linenumber line number in source file
557 Returns: pointer to store (panic on malloc failure)
561 store_get_perm_3(int size, const void * proto_mem, const char * func, int linenumber)
564 int old_pool = store_pool;
565 store_pool = POOL_PERM;
566 yield = store_get_3(size, proto_mem, func, linenumber);
567 store_pool = old_pool;
572 #ifndef COMPILE_UTILITY
573 /*************************************************
574 * Get a block annotated as being lookup-quoted *
575 *************************************************/
577 /* Allocate from pool a pool consistent with the proto_mem augmented by the
578 requested quoter type.
580 XXX currently not handling mark/release
582 Args: size number of bytes to allocate
583 quoter id for the quoting type
584 func caller, for debug
585 linenumber caller, for debug
587 Return: allocated memory block
591 store_force_get_quoted(int size, unsigned quoter,
592 const char * func, int linenumber)
594 pooldesc * pp = pool_for_quoter(quoter);
598 debug_printf("allocating quoted-block for quoter %u (from %s %d)\n", quoter, func, linenumber);
600 if (!pp) pp = quoted_pool_new(quoter);
601 yield = pool_get(pp, size, FALSE, func, linenumber);
604 debug_printf("---QQ Get %6p %5d %-14s %4d\n",
605 pp->store_last_get, size, func, linenumber);
610 /* Maybe get memory for the specified quoter, but only if the
611 prototype memory is tainted. Otherwise, get plain memory.
614 store_get_quoted_3(int size, const void * proto_mem, unsigned quoter,
615 const char * func, int linenumber)
617 // debug_printf("store_get_quoted_3: quoter %u\n", quoter);
618 return is_tainted(proto_mem)
619 ? store_force_get_quoted(size, quoter, func, linenumber)
620 : store_get_3(size, proto_mem, func, linenumber);
623 /* Return quoter for given address, or -1 if not in a quoted-pool. */
625 quoter_for_address(const void * p)
627 for (quoted_pooldesc * qp = quoted_pools; qp; qp = qp->next)
629 pooldesc * pp = &qp->pool;
632 if (b = pp->current_block)
633 if (is_pointer_in_block(b, p))
636 for (b = pp->chainbase; b; b = b->next)
637 if (is_pointer_in_block(b, p))
643 /* Return TRUE iff the given address is quoted for the given type.
644 There is extra complexity to handle lookup providers with multiple
645 find variants but shared quote functions. */
647 is_quoted_like(const void * p, unsigned quoter)
649 int pq = quoter_for_address(p);
651 is_real_quoter(pq) && lookup_list[pq]->quote == lookup_list[quoter]->quote;
652 /* debug_printf("is_quoted(%p, %u): %c\n", p, quoter, y?'T':'F'); */
656 /* Return TRUE if the quoter value indicates an actual quoter */
658 is_real_quoter(int quoter)
663 /* Return TRUE if the "new" data requires that the "old" data
664 be recopied to new-class memory. We order the classes as
666 2: tainted, not quoted
667 1: quoted (which is also tainted)
670 If the "new" is higher-order than the "old", they are not compatible
671 and a copy is needed. If both are quoted, but the quoters differ,
672 not compatible. Otherwise they are compatible.
675 is_incompatible_fn(const void * old, const void * new)
680 ni = is_real_quoter(nq = quoter_for_address(new)) ? 1 : is_tainted(new) ? 2 : 0;
681 oi = is_real_quoter(oq = quoter_for_address(old)) ? 1 : is_tainted(old) ? 2 : 0;
682 return ni > oi || ni == oi && nq != oq;
685 #endif /*!COMPILE_UTILITY*/
687 /*************************************************
688 * Extend a block if it is at the top *
689 *************************************************/
691 /* While reading strings of unknown length, it is often the case that the
692 string is being read into the block at the top of the stack. If it needs to be
693 extended, it is more efficient just to extend within the top block rather than
694 allocate a new block and then have to copy the data. This function is provided
695 for the use of string_cat(), but of course can be used elsewhere too.
696 The block itself is not expanded; only the top allocation from it.
699 ptr pointer to store block
700 oldsize current size of the block, as requested by user
701 newsize new size required
702 func function from which called
703 linenumber line number in source file
705 Returns: TRUE if the block is at the top of the stack and has been
706 extended; FALSE if it isn't at the top of the stack, or cannot
709 XXX needs extension for quoted-tracking. This assumes that the global store_pool
710 is the one to alloc from, which breaks with separated pools.
714 store_extend_3(void * ptr, int oldsize, int newsize,
715 const char * func, int linenumber)
717 pooldesc * pp = pool_for_pointer(ptr, func, linenumber);
718 int inc = newsize - oldsize;
719 int rounded_oldsize = oldsize;
721 if (oldsize < 0 || newsize < oldsize || newsize >= INT_MAX/2)
722 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
723 "bad memory extension requested (%d -> %d bytes) at %s %d",
724 oldsize, newsize, func, linenumber);
726 if (rounded_oldsize % alignment != 0)
727 rounded_oldsize += alignment - (rounded_oldsize % alignment);
729 if (CS ptr + rounded_oldsize != CS (pp->next_yield) ||
730 inc > pp->yield_length + rounded_oldsize - oldsize)
733 /* Cut out the debugging stuff for utilities, but stop picky compilers from
736 #ifndef COMPILE_UTILITY
739 quoted_pooldesc * qp;
740 for (qp = quoted_pools; qp; qp = qp->next)
743 debug_printf("---Q%d Ext %6p %5d %-14s %4d\n",
744 (int)(qp - quoted_pools),
745 ptr, newsize, func, linenumber);
749 debug_printf("---%d Ext %6p %5d %-14s %4d\n",
750 (int)(pp - paired_pools),
751 ptr, newsize, func, linenumber);
753 #endif /* COMPILE_UTILITY */
755 if (newsize % alignment != 0) newsize += alignment - (newsize % alignment);
756 pp->next_yield = CS ptr + newsize;
757 pp->yield_length -= newsize - rounded_oldsize;
758 (void) VALGRIND_MAKE_MEM_UNDEFINED(ptr + oldsize, inc);
766 is_pwr2_size(int len)
769 return (x & (x - 1)) == 0;
773 /*************************************************
774 * Back up to a previous point on the stack *
775 *************************************************/
777 /* This function resets the next pointer, freeing any subsequent whole blocks
778 that are now unused. Call with a cookie obtained from store_mark() only; do
779 not call with a pointer returned by store_get(). Both the untainted and tainted
780 pools corresposding to store_pool are reset.
782 Quoted pools are not handled.
785 ptr place to back up to
786 pool pool holding the pointer
787 func function from which called
788 linenumber line number in source file
794 internal_store_reset(void * ptr, int pool, const char *func, int linenumber)
797 pooldesc * pp = paired_pools + pool;
798 storeblock * b = pp->current_block;
799 char * bc = CS b + ALIGNED_SIZEOF_STOREBLOCK;
800 int newlength, count;
801 #ifndef COMPILE_UTILITY
802 int oldmalloc = pool_malloc;
805 if (!b) return; /* exim_dumpdb gets this, becuse it has never used tainted mem */
807 /* Last store operation was not a get */
809 pp->store_last_get = NULL;
811 /* See if the place is in the current block - as it often will be. Otherwise,
812 search for the block in which it lies. */
814 if (CS ptr < bc || CS ptr > bc + b->length)
816 for (b = pp->chainbase; b; b = b->next)
818 bc = CS b + ALIGNED_SIZEOF_STOREBLOCK;
819 if (CS ptr >= bc && CS ptr <= bc + b->length) break;
822 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal error: store_reset(%p) "
823 "failed: pool=%d %-14s %4d", ptr, pool, func, linenumber);
826 /* Back up, rounding to the alignment if necessary. When testing, flatten
827 the released memory. */
829 newlength = bc + b->length - CS ptr;
830 #ifndef COMPILE_UTILITY
833 assert_no_variables(ptr, newlength, func, linenumber);
834 if (f.running_in_test_harness)
836 (void) VALGRIND_MAKE_MEM_DEFINED(ptr, newlength);
837 memset(ptr, 0xF0, newlength);
841 (void) VALGRIND_MAKE_MEM_NOACCESS(ptr, newlength);
842 pp->next_yield = CS ptr + (newlength % alignment);
843 count = pp->yield_length;
844 count = (pp->yield_length = newlength - (newlength % alignment)) - count;
845 pp->current_block = b;
847 /* Free any subsequent block. Do NOT free the first
848 successor, if our current block has less than 256 bytes left. This should
849 prevent us from flapping memory. However, keep this block only when it has
850 a power-of-two size so probably is not a custom inflated one. */
852 if ( pp->yield_length < STOREPOOL_MIN_SIZE
854 && is_pwr2_size(b->next->length + ALIGNED_SIZEOF_STOREBLOCK))
857 #ifndef COMPILE_UTILITY
859 assert_no_variables(b, b->length + ALIGNED_SIZEOF_STOREBLOCK,
862 (void) VALGRIND_MAKE_MEM_NOACCESS(CS b + ALIGNED_SIZEOF_STOREBLOCK,
863 b->length - ALIGNED_SIZEOF_STOREBLOCK);
867 if (pool != POOL_CONFIG)
872 int siz = b->length + ALIGNED_SIZEOF_STOREBLOCK;
874 #ifndef COMPILE_UTILITY
876 assert_no_variables(b, b->length + ALIGNED_SIZEOF_STOREBLOCK,
883 if (pool != POOL_CONFIG)
884 internal_store_free(b, func, linenumber);
886 #ifndef RESTRICTED_MEMORY
887 if (pp->store_block_order > 13) pp->store_block_order--;
891 /* Cut out the debugging stuff for utilities, but stop picky compilers from
894 #ifndef COMPILE_UTILITY
896 debug_printf("---%d Rst %6p %5d %-14s %4d\tpool %d\n", pool, ptr,
897 count + oldmalloc - pool_malloc,
898 func, linenumber, pool_malloc);
899 #endif /* COMPILE_UTILITY */
903 /* Back up the pool pair, untainted and tainted, of the store_pool setting.
904 Quoted pools are not handled.
908 store_reset_3(rmark r, const char * func, int linenumber)
912 if (store_pool >= POOL_TAINT_BASE)
913 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
914 "store_reset called for pool %d: %s %d\n", store_pool, func, linenumber);
916 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
917 "store_reset called with bad mark: %s %d\n", func, linenumber);
919 internal_store_reset(*ptr, store_pool + POOL_TAINT_BASE, func, linenumber);
920 internal_store_reset(ptr, store_pool, func, linenumber);
927 /* Free tail-end unused allocation. This lets us allocate a big chunk
928 early, for cases when we only discover later how much was really needed.
930 Can be called with a value from store_get(), or an offset after such. Only
931 the tainted or untainted pool that serviced the store_get() will be affected.
933 This is mostly a cut-down version of internal_store_reset().
934 XXX needs rationalising
938 store_release_above_3(void * ptr, const char * func, int linenumber)
942 /* Search all pools' "current" blocks. If it isn't one of those,
943 ignore it (it usually will be). */
945 if ((pp = pool_current_for_pointer(ptr)))
947 storeblock * b = pp->current_block;
948 int count, newlength;
950 /* Last store operation was not a get */
952 pp->store_last_get = NULL;
954 /* Back up, rounding to the alignment if necessary. When testing, flatten
955 the released memory. */
957 newlength = (CS b + ALIGNED_SIZEOF_STOREBLOCK) + b->length - CS ptr;
958 #ifndef COMPILE_UTILITY
961 assert_no_variables(ptr, newlength, func, linenumber);
962 if (f.running_in_test_harness)
964 (void) VALGRIND_MAKE_MEM_DEFINED(ptr, newlength);
965 memset(ptr, 0xF0, newlength);
969 (void) VALGRIND_MAKE_MEM_NOACCESS(ptr, newlength);
970 pp->next_yield = CS ptr + (newlength % alignment);
971 count = pp->yield_length;
972 count = (pp->yield_length = newlength - (newlength % alignment)) - count;
974 /* Cut out the debugging stuff for utilities, but stop picky compilers from
977 #ifndef COMPILE_UTILITY
980 quoted_pooldesc * qp;
981 for (qp = quoted_pools; qp; qp = qp->next)
983 debug_printf("---Q%d Rel %6p %5d %-14s %4d\tpool %d\n",
984 (int)(qp - quoted_pools),
985 ptr, count, func, linenumber, pool_malloc);
987 debug_printf("---%d Rel %6p %5d %-14s %4d\tpool %d\n",
988 (int)(pp - paired_pools), ptr, count,
989 func, linenumber, pool_malloc);
994 #ifndef COMPILE_UTILITY
996 debug_printf("non-last memory release try: %s %d\n", func, linenumber);
1003 store_mark_3(const char * func, int linenumber)
1007 #ifndef COMPILE_UTILITY
1009 debug_printf("---%d Mrk %-14s %4d\tpool %d\n",
1010 store_pool, func, linenumber, pool_malloc);
1011 #endif /* COMPILE_UTILITY */
1013 if (store_pool >= POOL_TAINT_BASE)
1014 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
1015 "store_mark called for pool %d: %s %d\n", store_pool, func, linenumber);
1017 /* Stash a mark for the tainted-twin release, in the untainted twin. Return
1018 a cookie (actually the address in the untainted pool) to the caller.
1019 Reset uses the cookie to recover the t-mark, winds back the tainted pool with it
1020 and winds back the untainted pool with the cookie. */
1022 p = store_get_3(sizeof(void *), GET_UNTAINTED, func, linenumber);
1023 *p = store_get_3(0, GET_TAINTED, func, linenumber);
1030 /************************************************
1032 ************************************************/
1034 /* This function checks that the pointer it is given is the first thing in a
1035 block, and if so, releases that block.
1038 block block of store to consider
1039 pp pool containing the block
1040 func function from which called
1041 linenumber line number in source file
1047 store_release_3(void * block, pooldesc * pp, const char * func, int linenumber)
1049 /* It will never be the first block, so no need to check that. */
1051 for (storeblock * b = pp->chainbase; b; b = b->next)
1053 storeblock * bb = b->next;
1054 if (bb && CS block == CS bb + ALIGNED_SIZEOF_STOREBLOCK)
1056 int siz = bb->length + ALIGNED_SIZEOF_STOREBLOCK;
1062 /* Cut out the debugging stuff for utilities, but stop picky compilers
1063 from giving warnings. */
1065 #ifndef COMPILE_UTILITY
1067 debug_printf("-Release %6p %-20s %4d %d\n", (void *)bb, func,
1068 linenumber, pool_malloc);
1070 if (f.running_in_test_harness)
1071 memset(bb, 0xF0, bb->length+ALIGNED_SIZEOF_STOREBLOCK);
1072 #endif /* COMPILE_UTILITY */
1074 internal_store_free(bb, func, linenumber);
1081 /************************************************
1083 ************************************************/
1085 /* Allocate a new block big enough to expend to the given size and
1086 copy the current data into it. Free the old one if possible.
1088 This function is specifically provided for use when reading very
1089 long strings, e.g. header lines. When the string gets longer than a
1090 complete block, it gets copied to a new block. It is helpful to free
1091 the old block iff the previous copy of the string is at its start,
1092 and therefore the only thing in it. Otherwise, for very long strings,
1093 dead store can pile up somewhat disastrously. This function checks that
1094 the pointer it is given is the first thing in a block, and that nothing
1095 has been allocated since. If so, releases that block.
1099 newsize requested size
1102 Returns: new location of data
1106 store_newblock_3(void * oldblock, int newsize, int len,
1107 const char * func, int linenumber)
1109 pooldesc * pp = pool_for_pointer(oldblock, func, linenumber);
1110 BOOL release_ok = !is_tainted(oldblock) && pp->store_last_get == oldblock; /*XXX why tainted not handled? */
1113 if (len < 0 || len > newsize)
1114 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
1115 "bad memory extension requested (%d -> %d bytes) at %s %d",
1116 len, newsize, func, linenumber);
1118 newblock = store_get(newsize, oldblock);
1119 memcpy(newblock, oldblock, len);
1120 if (release_ok) store_release_3(oldblock, pp, func, linenumber);
1121 return (void *)newblock;
1127 /*************************************************
1129 *************************************************/
1131 /* Running out of store is a total disaster for exim. Some malloc functions
1132 do not run happily on very small sizes, nor do they document this fact. This
1133 function is called via the macro store_malloc().
1136 size amount of store wanted
1137 func function from which called
1138 line line number in source file
1140 Returns: pointer to gotten store (panic on failure)
1144 internal_store_malloc(size_t size, const char *func, int line)
1148 /* Check specifically for a possibly result of conversion from
1149 a negative int, to the (unsigned, wider) size_t */
1151 if (size >= INT_MAX/2)
1152 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
1153 "bad memory allocation requested (" SIZE_T_FMT " bytes) at %s %d",
1156 size += sizeof(size_t); /* space to store the size, used under debug */
1157 if (size < 16) size = 16;
1159 if (!(yield = malloc(size)))
1160 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to malloc " SIZE_T_FMT " bytes of memory: "
1161 "called from line %d in %s", size, line, func);
1163 #ifndef COMPILE_UTILITY
1164 DEBUG(D_any) *(size_t *)yield = size;
1166 yield = US yield + sizeof(size_t);
1168 if ((nonpool_malloc += size) > max_nonpool_malloc)
1169 max_nonpool_malloc = nonpool_malloc;
1171 /* Cut out the debugging stuff for utilities, but stop picky compilers from
1174 #ifndef COMPILE_UTILITY
1175 /* If running in test harness, spend time making sure all the new store
1176 is not filled with zeros so as to catch problems. */
1178 if (f.running_in_test_harness)
1179 memset(yield, 0xF0, size - sizeof(size_t));
1180 DEBUG(D_memory) debug_printf("--Malloc %6p %5lu bytes\t%-20s %4d\tpool %5d nonpool %5d\n",
1181 yield, size, func, line, pool_malloc, nonpool_malloc);
1182 #endif /* COMPILE_UTILITY */
1188 store_malloc_3(size_t size, const char *func, int linenumber)
1190 if (n_nonpool_blocks++ > max_nonpool_blocks)
1191 max_nonpool_blocks = n_nonpool_blocks;
1192 return internal_store_malloc(size, func, linenumber);
1196 /************************************************
1198 ************************************************/
1200 /* This function is called by the macro store_free().
1203 block block of store to free
1204 func function from which called
1205 linenumber line number in source file
1211 internal_store_free(void * block, const char * func, int linenumber)
1213 uschar * p = US block - sizeof(size_t);
1214 #ifndef COMPILE_UTILITY
1215 DEBUG(D_any) nonpool_malloc -= *(size_t *)p;
1216 DEBUG(D_memory) debug_printf("----Free %6p %5ld bytes\t%-20s %4d\n",
1217 block, *(size_t *)p, func, linenumber);
1223 store_free_3(void * block, const char * func, int linenumber)
1226 internal_store_free(block, func, linenumber);
1229 /******************************************************************************/
1230 /* Stats output on process exit */
1234 #ifndef COMPILE_UTILITY
1238 debug_printf("----Exit nonpool max: %3d kB in %d blocks\n",
1239 (max_nonpool_malloc+1023)/1024, max_nonpool_blocks);
1240 debug_printf("----Exit npools max: %3d kB\n", max_pool_malloc/1024);
1242 for (i = 0; i < N_PAIRED_POOLS; i++)
1244 pooldesc * pp = paired_pools + i;
1245 debug_printf("----Exit pool %2d max: %3d kB in %d blocks at order %u\t%s %s\n",
1246 i, (pp->maxbytes+1023)/1024, pp->maxblocks, pp->maxorder,
1247 poolclass[i], pooluse[i]);
1250 for (quoted_pooldesc * qp = quoted_pools; qp; i++, qp = qp->next)
1252 pooldesc * pp = &qp->pool;
1253 debug_printf("----Exit pool Q%d max: %3d kB in %d blocks at order %u\ttainted quoted:%s\n",
1254 i, (pp->maxbytes+1023)/1024, pp->maxblocks, pp->maxorder, lookup_list[qp->quoter]->name);
1261 /******************************************************************************/
1262 /* Per-message pool management */
1264 static rmark message_reset_point = NULL;
1269 int oldpool = store_pool;
1270 store_pool = POOL_MESSAGE;
1271 if (!message_reset_point) message_reset_point = store_mark();
1272 store_pool = oldpool;
1276 message_tidyup(void)
1279 if (!message_reset_point) return;
1280 oldpool = store_pool;
1281 store_pool = POOL_MESSAGE;
1282 message_reset_point = store_reset(message_reset_point);
1283 store_pool = oldpool;
1286 /******************************************************************************/
1287 /* Debug analysis of address */
1289 #ifndef COMPILE_UTILITY
1291 debug_print_taint(const void * p)
1293 int q = quoter_for_address(p);
1294 if (!is_tainted(p)) return;
1295 debug_printf("(tainted");
1296 if (is_real_quoter(q)) debug_printf(", quoted:%s", lookup_list[q]->name);
1297 debug_printf(")\n");
1301 /* End of store.c */