Taint: slow-mode checking only
[exim.git] / src / src / store.c
CommitLineData
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
f9ba5e22 5/* Copyright (c) University of Cambridge 1995 - 2018 */
f3ebb786 6/* Copyright (c) The Exim maintainers 2019 */
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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
10implementation there was a lot of mallocing and freeing of small bits of store.
11The 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
13need to do any garbage collection, but the stack concept allows quick resetting
14in places where this seems sensible.
15
16Obviously the long-running processes (the daemon, the queue runner, and eximon)
17must take care not to eat store.
18
19The 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.
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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
adc4ecf9 44 are implemented by duplicating the three pool types. Pool resets are requested
f3ebb786 45 against the nontainted sibling and apply to both siblings.
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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
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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.
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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
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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
69 the classic case).
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70*/
71
72
73#include "exim.h"
438257ba
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74/* keep config.h before memcheck.h, for NVALGRIND */
75#include "config.h"
76
f3ebb786 77#include <sys/mman.h>
7f36d675 78#include "memcheck.h"
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79
80
81/* We need to know how to align blocks of data for general use. I'm not sure
82how to get an alignment factor in general. In the current world, a value of 8
83is 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
85is a constant, the compiler should optimize it to a simple constant wherever it
86appears (I checked that gcc does do this). */
87
88#define alignment \
f3ebb786 89 (sizeof(void *) > sizeof(double) ? sizeof(void *) : sizeof(double))
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90
91/* store_reset() will not free the following block if the last used block has
92less than this much left in it. */
93
94#define STOREPOOL_MIN_SIZE 256
95
96/* Structure describing the beginning of each big block. */
97
98typedef struct storeblock {
99 struct storeblock *next;
100 size_t length;
101} storeblock;
102
103/* Just in case we find ourselves on a system where the structure above has a
104length that is not a multiple of the alignment, set up a macro for the padded
105length. */
106
107#define ALIGNED_SIZEOF_STOREBLOCK \
108 (((sizeof(storeblock) + alignment - 1) / alignment) * alignment)
109
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110/* Size of block to get from malloc to carve up into smaller ones. This
111must be a multiple of the alignment. We assume that 8192 is going to be
112suitably aligned. */
113
114#define STORE_BLOCK_SIZE (8192 - ALIGNED_SIZEOF_STOREBLOCK)
115
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116/* Variables holding data for the local pools of store. The current pool number
117is held in store_pool, which is global so that it can be changed from outside.
118Setting the initial length values to -1 forces a malloc for the first call,
119even if the length is zero (which is used for getting a point to reset to). */
120
f3ebb786 121int store_pool = POOL_MAIN;
059ec3d9 122
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123#define NPOOLS 6
124static storeblock *chainbase[NPOOLS];
125static storeblock *current_block[NPOOLS];
126static void *next_yield[NPOOLS];
127static int yield_length[NPOOLS] = { -1, -1, -1, -1, -1, -1 };
128
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129/* pool_malloc holds the amount of memory used by the store pools; this goes up
130and down as store is reset or released. nonpool_malloc is the total got by
131malloc from other calls; this doesn't go down because it is just freed by
132pointer. */
133
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134static int pool_malloc;
135static int nonpool_malloc;
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136
137/* This variable is set by store_get() to its yield, and by store_reset() to
138NULL. This enables string_cat() to optimize its store handling for very long
139strings. That's why the variable is global. */
140
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141void *store_last_get[NPOOLS];
142
143/* These are purely for stats-gathering */
144
145static int nbytes[NPOOLS]; /* current bytes allocated */
146static int maxbytes[NPOOLS]; /* max number reached */
147static int nblocks[NPOOLS]; /* current number of blocks allocated */
148static int maxblocks[NPOOLS];
149static int n_nonpool_blocks; /* current number of direct store_malloc() blocks */
150static int max_nonpool_blocks;
151static int max_pool_malloc; /* max value for pool_malloc */
152static int max_nonpool_malloc; /* max value for nonpool_malloc */
153
154
81a559c8 155#ifndef COMPILE_UTILITY
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156static const uschar * pooluse[NPOOLS] = {
157[POOL_MAIN] = US"main",
158[POOL_PERM] = US"perm",
159[POOL_SEARCH] = US"search",
160[POOL_TAINT_MAIN] = US"main",
161[POOL_TAINT_PERM] = US"perm",
162[POOL_TAINT_SEARCH] = US"search",
163};
164static const uschar * poolclass[NPOOLS] = {
165[POOL_MAIN] = US"untainted",
166[POOL_PERM] = US"untainted",
167[POOL_SEARCH] = US"untainted",
168[POOL_TAINT_MAIN] = US"tainted",
169[POOL_TAINT_PERM] = US"tainted",
170[POOL_TAINT_SEARCH] = US"tainted",
171};
81a559c8 172#endif
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173
174
175static void * store_mmap(int, const char *, int);
176static void * internal_store_malloc(int, const char *, int);
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177static void internal_untainted_free(void *, const char *, int linenumber);
178static void internal_tainted_free(storeblock *, const char *, int linenumber);
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179
180/******************************************************************************/
181
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182/* Test if a pointer refers to tainted memory.
183
184Slower version check, for use when platform intermixes malloc and mmap area
185addresses. Test against the current-block of all tainted pools first, then all
186blocks of all tainted pools.
187
188Return: TRUE iff tainted
189*/
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190
191BOOL
192is_tainted_fn(const void * p)
193{
194storeblock * b;
14ca5d2a 195
677481d4 196for (int pool = POOL_TAINT_BASE; pool < nelem(chainbase); pool++)
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197 if ((b = current_block[pool]))
198 {
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199 uschar * bc = US b + ALIGNED_SIZEOF_STOREBLOCK;
200 if (US p >= bc && US p <= bc + b->length) return TRUE;
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201 }
202
677481d4 203for (int pool = POOL_TAINT_BASE; pool < nelem(chainbase); pool++)
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204 for (b = chainbase[pool]; b; b = b->next)
205 {
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206 uschar * bc = US b + ALIGNED_SIZEOF_STOREBLOCK;
207 if (US p >= bc && US p <= bc + b->length) return TRUE;
14ca5d2a
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208 }
209return FALSE;
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210}
211
212
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213void
214die_tainted(const uschar * msg, const uschar * func, int line)
215{
216log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Taint mismatch, %s: %s %d\n",
217 msg, func, line);
218}
059ec3d9 219
677481d4 220
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221
222/*************************************************
223* Get a block from the current pool *
224*************************************************/
225
226/* Running out of store is a total disaster. This function is called via the
227macro store_get(). It passes back a block of store within the current big
228block, getting a new one if necessary. The address is saved in
229store_last_was_get.
230
231Arguments:
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232 size amount wanted, bytes
233 tainted class: set to true for untrusted data (eg. from smtp input)
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234 func function from which called
235 linenumber line number in source file
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236
237Returns: pointer to store (panic on malloc failure)
238*/
239
240void *
f3ebb786 241store_get_3(int size, BOOL tainted, const char *func, int linenumber)
059ec3d9 242{
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243int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool;
244
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245/* Round up the size to a multiple of the alignment. Although this looks a
246messy statement, because "alignment" is a constant expression, the compiler can
247do a reasonable job of optimizing, especially if the value of "alignment" is a
248power of two. I checked this with -O2, and gcc did very well, compiling it to 4
249instructions on a Sparc (alignment = 8). */
250
251if (size % alignment != 0) size += alignment - (size % alignment);
252
253/* If there isn't room in the current block, get a new one. The minimum
254size is STORE_BLOCK_SIZE, and we would expect this to be the norm, since
255these functions are mostly called for small amounts of store. */
256
f3ebb786 257if (size > yield_length[pool])
059ec3d9 258 {
f3ebb786 259 int length = size <= STORE_BLOCK_SIZE ? STORE_BLOCK_SIZE : size;
059ec3d9 260 int mlength = length + ALIGNED_SIZEOF_STOREBLOCK;
f3ebb786 261 storeblock * newblock;
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262
263 /* Sometimes store_reset() may leave a block for us; check if we can use it */
264
f3ebb786 265 if ( (newblock = current_block[pool])
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266 && (newblock = newblock->next)
267 && newblock->length < length
268 )
059ec3d9 269 {
64073d9c 270 /* Give up on this block, because it's too small */
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271 nblocks[pool]--;
272 if (pool < POOL_TAINT_BASE)
65766f1b 273 internal_untainted_free(newblock, func, linenumber);
f3ebb786 274 else
65766f1b 275 internal_tainted_free(newblock, func, linenumber);
64073d9c 276 newblock = NULL;
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277 }
278
279 /* If there was no free block, get a new one */
280
64073d9c 281 if (!newblock)
059ec3d9 282 {
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283 if ((nbytes[pool] += mlength) > maxbytes[pool])
284 maxbytes[pool] = nbytes[pool];
285 if ((pool_malloc += mlength) > max_pool_malloc) /* Used in pools */
286 max_pool_malloc = pool_malloc;
287 nonpool_malloc -= mlength; /* Exclude from overall total */
288 if (++nblocks[pool] > maxblocks[pool])
289 maxblocks[pool] = nblocks[pool];
290
291 newblock = tainted
292 ? store_mmap(mlength, func, linenumber)
293 : internal_store_malloc(mlength, func, linenumber);
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294 newblock->next = NULL;
295 newblock->length = length;
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296
297 if (!chainbase[pool])
298 chainbase[pool] = newblock;
64073d9c 299 else
f3ebb786 300 current_block[pool]->next = newblock;
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301 }
302
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303 current_block[pool] = newblock;
304 yield_length[pool] = newblock->length;
305 next_yield[pool] =
306 (void *)(CS current_block[pool] + ALIGNED_SIZEOF_STOREBLOCK);
307 (void) VALGRIND_MAKE_MEM_NOACCESS(next_yield[pool], yield_length[pool]);
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308 }
309
310/* There's (now) enough room in the current block; the yield is the next
311pointer. */
312
f3ebb786 313store_last_get[pool] = next_yield[pool];
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314
315/* Cut out the debugging stuff for utilities, but stop picky compilers from
316giving warnings. */
317
318#ifdef COMPILE_UTILITY
f3ebb786 319func = func;
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320linenumber = linenumber;
321#else
322DEBUG(D_memory)
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323 debug_printf("---%d Get %6p %5d %-14s %4d\n", pool,
324 store_last_get[pool], size, func, linenumber);
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325#endif /* COMPILE_UTILITY */
326
f3ebb786 327(void) VALGRIND_MAKE_MEM_UNDEFINED(store_last_get[pool], size);
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328/* Update next pointer and number of bytes left in the current block. */
329
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330next_yield[pool] = (void *)(CS next_yield[pool] + size);
331yield_length[pool] -= size;
332return store_last_get[pool];
059ec3d9
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333}
334
335
336
337/*************************************************
338* Get a block from the PERM pool *
339*************************************************/
340
341/* This is just a convenience function, useful when just a single block is to
342be obtained.
343
344Arguments:
345 size amount wanted
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346 func function from which called
347 linenumber line number in source file
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348
349Returns: pointer to store (panic on malloc failure)
350*/
351
352void *
f3ebb786 353store_get_perm_3(int size, BOOL tainted, const char *func, int linenumber)
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354{
355void *yield;
356int old_pool = store_pool;
357store_pool = POOL_PERM;
f3ebb786 358yield = store_get_3(size, tainted, func, linenumber);
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359store_pool = old_pool;
360return yield;
361}
362
363
364
365/*************************************************
366* Extend a block if it is at the top *
367*************************************************/
368
369/* While reading strings of unknown length, it is often the case that the
370string is being read into the block at the top of the stack. If it needs to be
f3ebb786 371extended, it is more efficient just to extend within the top block rather than
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372allocate a new block and then have to copy the data. This function is provided
373for the use of string_cat(), but of course can be used elsewhere too.
f3ebb786 374The block itself is not expanded; only the top allocation from it.
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375
376Arguments:
377 ptr pointer to store block
378 oldsize current size of the block, as requested by user
379 newsize new size required
f3ebb786 380 func function from which called
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381 linenumber line number in source file
382
383Returns: TRUE if the block is at the top of the stack and has been
384 extended; FALSE if it isn't at the top of the stack, or cannot
385 be extended
386*/
387
388BOOL
f3ebb786
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389store_extend_3(void *ptr, BOOL tainted, int oldsize, int newsize,
390 const char *func, int linenumber)
059ec3d9 391{
f3ebb786 392int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool;
059ec3d9
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393int inc = newsize - oldsize;
394int rounded_oldsize = oldsize;
395
f3ebb786
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396/* Check that the block being extended was already of the required taint status;
397refuse to extend if not. */
398
399if (is_tainted(ptr) != tainted)
400 return FALSE;
401
059ec3d9
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402if (rounded_oldsize % alignment != 0)
403 rounded_oldsize += alignment - (rounded_oldsize % alignment);
404
f3ebb786
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405if (CS ptr + rounded_oldsize != CS (next_yield[pool]) ||
406 inc > yield_length[pool] + rounded_oldsize - oldsize)
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407 return FALSE;
408
409/* Cut out the debugging stuff for utilities, but stop picky compilers from
410giving warnings. */
411
412#ifdef COMPILE_UTILITY
f3ebb786 413func = func;
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414linenumber = linenumber;
415#else
416DEBUG(D_memory)
f3ebb786
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417 debug_printf("---%d Ext %6p %5d %-14s %4d\n", pool, ptr, newsize,
418 func, linenumber);
059ec3d9
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419#endif /* COMPILE_UTILITY */
420
421if (newsize % alignment != 0) newsize += alignment - (newsize % alignment);
f3ebb786
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422next_yield[pool] = CS ptr + newsize;
423yield_length[pool] -= newsize - rounded_oldsize;
4d8bb202 424(void) VALGRIND_MAKE_MEM_UNDEFINED(ptr + oldsize, inc);
059ec3d9
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425return TRUE;
426}
427
428
429
430
431/*************************************************
432* Back up to a previous point on the stack *
433*************************************************/
434
435/* This function resets the next pointer, freeing any subsequent whole blocks
f3ebb786
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436that are now unused. Call with a cookie obtained from store_mark() only; do
437not call with a pointer returned by store_get(). Both the untainted and tainted
438pools corresposding to store_pool are reset.
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439
440Arguments:
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441 r place to back up to
442 func function from which called
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443 linenumber line number in source file
444
445Returns: nothing
446*/
447
f3ebb786
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448static void
449internal_store_reset(void * ptr, int pool, const char *func, int linenumber)
059ec3d9 450{
cf0812d5 451storeblock * bb;
f3ebb786 452storeblock * b = current_block[pool];
cf0812d5 453char * bc = CS b + ALIGNED_SIZEOF_STOREBLOCK;
f3ebb786
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454int newlength, count;
455#ifndef COMPILE_UTILITY
456int oldmalloc = pool_malloc;
457#endif
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458
459/* Last store operation was not a get */
460
f3ebb786 461store_last_get[pool] = NULL;
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462
463/* See if the place is in the current block - as it often will be. Otherwise,
464search for the block in which it lies. */
465
cf0812d5 466if (CS ptr < bc || CS ptr > bc + b->length)
059ec3d9 467 {
f3ebb786 468 for (b = chainbase[pool]; b; b = b->next)
059ec3d9 469 {
cf0812d5
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470 bc = CS b + ALIGNED_SIZEOF_STOREBLOCK;
471 if (CS ptr >= bc && CS ptr <= bc + b->length) break;
059ec3d9 472 }
cf0812d5 473 if (!b)
438257ba 474 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "internal error: store_reset(%p) "
f3ebb786 475 "failed: pool=%d %-14s %4d", ptr, pool, func, linenumber);
059ec3d9
PH
476 }
477
478/* Back up, rounding to the alignment if necessary. When testing, flatten
479the released memory. */
480
cf0812d5 481newlength = bc + b->length - CS ptr;
059ec3d9 482#ifndef COMPILE_UTILITY
65a32f85 483if (debug_store)
2c9f7ff8 484 {
f3ebb786 485 assert_no_variables(ptr, newlength, func, linenumber);
8768d548 486 if (f.running_in_test_harness)
64073d9c
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487 {
488 (void) VALGRIND_MAKE_MEM_DEFINED(ptr, newlength);
489 memset(ptr, 0xF0, newlength);
490 }
2c9f7ff8 491 }
059ec3d9 492#endif
4d8bb202 493(void) VALGRIND_MAKE_MEM_NOACCESS(ptr, newlength);
f3ebb786
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494next_yield[pool] = CS ptr + (newlength % alignment);
495count = yield_length[pool];
496count = (yield_length[pool] = newlength - (newlength % alignment)) - count;
497current_block[pool] = b;
498
499/* Free any subsequent block. Do NOT free the first
500successor, if our current block has less than 256 bytes left. This should
501prevent us from flapping memory. However, keep this block only when it has
502the default size. */
503
504if ( yield_length[pool] < STOREPOOL_MIN_SIZE
505 && b->next
506 && b->next->length == STORE_BLOCK_SIZE)
7f36d675 507 {
059ec3d9 508 b = b->next;
cf0812d5 509#ifndef COMPILE_UTILITY
65a32f85 510 if (debug_store)
cf0812d5 511 assert_no_variables(b, b->length + ALIGNED_SIZEOF_STOREBLOCK,
f3ebb786 512 func, linenumber);
cf0812d5
JH
513#endif
514 (void) VALGRIND_MAKE_MEM_NOACCESS(CS b + ALIGNED_SIZEOF_STOREBLOCK,
4d8bb202 515 b->length - ALIGNED_SIZEOF_STOREBLOCK);
7f36d675 516 }
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517
518bb = b->next;
519b->next = NULL;
520
cf0812d5 521while ((b = bb))
059ec3d9 522 {
f3ebb786 523 int siz = b->length + ALIGNED_SIZEOF_STOREBLOCK;
cf0812d5 524#ifndef COMPILE_UTILITY
65a32f85 525 if (debug_store)
cf0812d5 526 assert_no_variables(b, b->length + ALIGNED_SIZEOF_STOREBLOCK,
f3ebb786 527 func, linenumber);
cf0812d5 528#endif
059ec3d9 529 bb = bb->next;
f3ebb786
JH
530 nbytes[pool] -= siz;
531 pool_malloc -= siz;
532 nblocks[pool]--;
533 if (pool < POOL_TAINT_BASE)
65766f1b 534 internal_untainted_free(b, func, linenumber);
f3ebb786 535 else
65766f1b 536 internal_tainted_free(b, func, linenumber);
059ec3d9
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537 }
538
539/* Cut out the debugging stuff for utilities, but stop picky compilers from
540giving warnings. */
541
542#ifdef COMPILE_UTILITY
f3ebb786 543func = func;
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544linenumber = linenumber;
545#else
546DEBUG(D_memory)
f3ebb786
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547 debug_printf("---%d Rst %6p %5d %-14s %4d %d\n", pool, ptr,
548 count + oldmalloc - pool_malloc,
549 func, linenumber, pool_malloc);
550#endif /* COMPILE_UTILITY */
551}
552
553
554rmark
555store_reset_3(rmark r, int pool, const char *func, int linenumber)
556{
557void ** ptr = r;
558
559if (pool >= POOL_TAINT_BASE)
560 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
561 "store_reset called for pool %d: %s %d\n", pool, func, linenumber);
562if (!r)
563 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
564 "store_reset called with bad mark: %s %d\n", func, linenumber);
565
566internal_store_reset(*ptr, pool + POOL_TAINT_BASE, func, linenumber);
567internal_store_reset(ptr, pool, func, linenumber);
568return NULL;
569}
570
571
572
573/* Free tail-end unused allocation. This lets us allocate a big chunk
574early, for cases when we only discover later how much was really needed.
575
576Can be called with a value from store_get(), or an offset after such. Only
577the tainted or untainted pool that serviced the store_get() will be affected.
578
579This is mostly a cut-down version of internal_store_reset().
580XXX needs rationalising
581*/
582
583void
584store_release_above_3(void *ptr, const char *func, int linenumber)
585{
586/* Search all pools' "current" blocks. If it isn't one of those,
587ignore it (it usually will be). */
588
589for (int pool = 0; pool < nelem(current_block); pool++)
059ec3d9 590 {
f3ebb786
JH
591 storeblock * b = current_block[pool];
592 char * bc;
593 int count, newlength;
594
595 if (!b)
596 continue;
597
598 bc = CS b + ALIGNED_SIZEOF_STOREBLOCK;
599 if (CS ptr < bc || CS ptr > bc + b->length)
600 continue;
601
602 /* Last store operation was not a get */
603
604 store_last_get[pool] = NULL;
605
606 /* Back up, rounding to the alignment if necessary. When testing, flatten
607 the released memory. */
608
609 newlength = bc + b->length - CS ptr;
610#ifndef COMPILE_UTILITY
611 if (debug_store)
612 {
613 assert_no_variables(ptr, newlength, func, linenumber);
614 if (f.running_in_test_harness)
615 {
616 (void) VALGRIND_MAKE_MEM_DEFINED(ptr, newlength);
617 memset(ptr, 0xF0, newlength);
618 }
619 }
620#endif
621 (void) VALGRIND_MAKE_MEM_NOACCESS(ptr, newlength);
622 next_yield[pool] = CS ptr + (newlength % alignment);
623 count = yield_length[pool];
624 count = (yield_length[pool] = newlength - (newlength % alignment)) - count;
625
626 /* Cut out the debugging stuff for utilities, but stop picky compilers from
627 giving warnings. */
628
629#ifdef COMPILE_UTILITY
630 func = func;
631 linenumber = linenumber;
632#else
633 DEBUG(D_memory)
634 debug_printf("---%d Rel %6p %5d %-14s %4d %d\n", pool, ptr, count,
635 func, linenumber, pool_malloc);
636#endif
637 return;
059ec3d9 638 }
f3ebb786
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639#ifndef COMPILE_UTILITY
640DEBUG(D_memory)
641 debug_printf("non-last memory release try: %s %d\n", func, linenumber);
642#endif
059ec3d9
PH
643}
644
645
646
f3ebb786
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647rmark
648store_mark_3(const char *func, int linenumber)
649{
650void ** p;
651
652if (store_pool >= POOL_TAINT_BASE)
653 log_write(0, LOG_MAIN|LOG_PANIC_DIE,
654 "store_mark called for pool %d: %s %d\n", store_pool, func, linenumber);
655
656/* Stash a mark for the tainted-twin release, in the untainted twin. Return
657a cookie (actually the address in the untainted pool) to the caller.
658Reset uses the cookie to recover the t-mark, winds back the tainted pool with it
659and winds back the untainted pool with the cookie. */
660
661p = store_get_3(sizeof(void *), FALSE, func, linenumber);
662*p = store_get_3(0, TRUE, func, linenumber);
663return p;
664}
665
666
059ec3d9
PH
667
668
669/************************************************
670* Release store *
671************************************************/
672
459fca58
JH
673/* This function checks that the pointer it is given is the first thing in a
674block, and if so, releases that block.
059ec3d9
PH
675
676Arguments:
677 block block of store to consider
f3ebb786 678 func function from which called
059ec3d9
PH
679 linenumber line number in source file
680
681Returns: nothing
682*/
683
459fca58 684static void
f3ebb786 685store_release_3(void * block, int pool, const char * func, int linenumber)
059ec3d9 686{
059ec3d9
PH
687/* It will never be the first block, so no need to check that. */
688
f3ebb786 689for (storeblock * b = chainbase[pool]; b; b = b->next)
059ec3d9 690 {
459fca58
JH
691 storeblock * bb = b->next;
692 if (bb && CS block == CS bb + ALIGNED_SIZEOF_STOREBLOCK)
059ec3d9 693 {
f3ebb786 694 int siz = bb->length + ALIGNED_SIZEOF_STOREBLOCK;
059ec3d9 695 b->next = bb->next;
f3ebb786
JH
696 nbytes[pool] -= siz;
697 pool_malloc -= siz;
698 nblocks[pool]--;
059ec3d9
PH
699
700 /* Cut out the debugging stuff for utilities, but stop picky compilers
701 from giving warnings. */
702
459fca58 703#ifdef COMPILE_UTILITY
f3ebb786 704 func = func;
059ec3d9 705 linenumber = linenumber;
459fca58 706#else
059ec3d9 707 DEBUG(D_memory)
f3ebb786
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708 debug_printf("-Release %6p %-20s %4d %d\n", (void *)bb, func,
709 linenumber, pool_malloc);
459fca58 710
8768d548 711 if (f.running_in_test_harness)
059ec3d9 712 memset(bb, 0xF0, bb->length+ALIGNED_SIZEOF_STOREBLOCK);
459fca58 713#endif /* COMPILE_UTILITY */
059ec3d9
PH
714
715 free(bb);
716 return;
717 }
718 }
719}
720
721
459fca58
JH
722/************************************************
723* Move store *
724************************************************/
725
726/* Allocate a new block big enough to expend to the given size and
727copy the current data into it. Free the old one if possible.
728
729This function is specifically provided for use when reading very
730long strings, e.g. header lines. When the string gets longer than a
731complete block, it gets copied to a new block. It is helpful to free
732the old block iff the previous copy of the string is at its start,
733and therefore the only thing in it. Otherwise, for very long strings,
734dead store can pile up somewhat disastrously. This function checks that
735the pointer it is given is the first thing in a block, and that nothing
736has been allocated since. If so, releases that block.
737
738Arguments:
739 block
740 newsize
741 len
742
743Returns: new location of data
744*/
745
746void *
f3ebb786
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747store_newblock_3(void * block, BOOL tainted, int newsize, int len,
748 const char * func, int linenumber)
459fca58 749{
f3ebb786
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750int pool = tainted ? store_pool + POOL_TAINT_BASE : store_pool;
751BOOL release_ok = !tainted && store_last_get[pool] == block;
752uschar * newtext;
753
677481d4 754#if !defined(MACRO_PREDEF) && !defined(COMPILE_UTILITY)
f3ebb786
JH
755if (is_tainted(block) != tainted)
756 die_tainted(US"store_newblock", CUS func, linenumber);
aaabfafe 757#endif
459fca58 758
f3ebb786 759newtext = store_get(newsize, tainted);
459fca58 760memcpy(newtext, block, len);
f3ebb786 761if (release_ok) store_release_3(block, pool, func, linenumber);
459fca58
JH
762return (void *)newtext;
763}
764
765
059ec3d9
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766
767
f3ebb786
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768/******************************************************************************/
769static void *
770store_alloc_tail(void * yield, int size, const char * func, int line,
771 const uschar * type)
772{
773if ((nonpool_malloc += size) > max_nonpool_malloc)
774 max_nonpool_malloc = nonpool_malloc;
775
776/* Cut out the debugging stuff for utilities, but stop picky compilers from
777giving warnings. */
778
779#ifdef COMPILE_UTILITY
780func = func; line = line; type = type;
781#else
782
783/* If running in test harness, spend time making sure all the new store
784is not filled with zeros so as to catch problems. */
785
786if (f.running_in_test_harness)
787 memset(yield, 0xF0, (size_t)size);
788DEBUG(D_memory) debug_printf("--%6s %6p %5d bytes\t%-14s %4d\tpool %5d nonpool %5d\n",
789 type, yield, size, func, line, pool_malloc, nonpool_malloc);
790#endif /* COMPILE_UTILITY */
791
792return yield;
793}
794
795/*************************************************
796* Mmap store *
797*************************************************/
798
799static void *
800store_mmap(int size, const char * func, int line)
801{
802void * yield, * top;
803
804if (size < 16) size = 16;
805
806if (!(yield = mmap(NULL, (size_t)size,
807 PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)))
808 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to mmap %d bytes of memory: "
809 "called from line %d of %s", size, line, func);
810
f3ebb786
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811return store_alloc_tail(yield, size, func, line, US"Mmap");
812}
813
059ec3d9
PH
814/*************************************************
815* Malloc store *
816*************************************************/
817
818/* Running out of store is a total disaster for exim. Some malloc functions
819do not run happily on very small sizes, nor do they document this fact. This
820function is called via the macro store_malloc().
821
822Arguments:
823 size amount of store wanted
f3ebb786 824 func function from which called
059ec3d9
PH
825 linenumber line number in source file
826
827Returns: pointer to gotten store (panic on failure)
828*/
829
f3ebb786
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830static void *
831internal_store_malloc(int size, const char *func, int linenumber)
059ec3d9 832{
f3ebb786 833void * yield;
059ec3d9
PH
834
835if (size < 16) size = 16;
059ec3d9 836
40c90bca 837if (!(yield = malloc((size_t)size)))
059ec3d9 838 log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to malloc %d bytes of memory: "
f3ebb786 839 "called from line %d in %s", size, linenumber, func);
059ec3d9 840
f3ebb786
JH
841return store_alloc_tail(yield, size, func, linenumber, US"Malloc");
842}
059ec3d9 843
f3ebb786
JH
844void *
845store_malloc_3(int size, const char *func, int linenumber)
846{
847if (n_nonpool_blocks++ > max_nonpool_blocks)
848 max_nonpool_blocks = n_nonpool_blocks;
849return internal_store_malloc(size, func, linenumber);
059ec3d9
PH
850}
851
852
853/************************************************
854* Free store *
855************************************************/
856
857/* This function is called by the macro store_free().
858
859Arguments:
860 block block of store to free
f3ebb786 861 func function from which called
059ec3d9
PH
862 linenumber line number in source file
863
864Returns: nothing
865*/
866
f3ebb786 867static void
65766f1b 868internal_untainted_free(void * block, const char * func, int linenumber)
059ec3d9
PH
869{
870#ifdef COMPILE_UTILITY
f3ebb786 871func = func;
059ec3d9
PH
872linenumber = linenumber;
873#else
874DEBUG(D_memory)
f3ebb786 875 debug_printf("----Free %6p %-20s %4d\n", block, func, linenumber);
059ec3d9
PH
876#endif /* COMPILE_UTILITY */
877free(block);
878}
879
f3ebb786 880void
65766f1b 881store_free_3(void * block, const char * func, int linenumber)
f3ebb786
JH
882{
883n_nonpool_blocks--;
65766f1b
JH
884internal_untainted_free(block, func, linenumber);
885}
886
887/******************************************************************************/
888static void
889internal_tainted_free(storeblock * block, const char * func, int linenumber)
890{
891#ifdef COMPILE_UTILITY
892func = func;
893linenumber = linenumber;
894#else
895DEBUG(D_memory)
896 debug_printf("---Unmap %6p %-20s %4d\n", block, func, linenumber);
897#endif
898munmap((void *)block, block->length + ALIGNED_SIZEOF_STOREBLOCK);
f3ebb786
JH
899}
900
901/******************************************************************************/
902/* Stats output on process exit */
903void
904store_exit(void)
905{
906#ifndef COMPILE_UTILITY
907DEBUG(D_memory)
908 {
909 debug_printf("----Exit nonpool max: %3d kB in %d blocks\n",
910 (max_nonpool_malloc+1023)/1024, max_nonpool_blocks);
911 debug_printf("----Exit npools max: %3d kB\n", max_pool_malloc/1024);
912 for (int i = 0; i < NPOOLS; i++)
913 debug_printf("----Exit pool %d max: %3d kB in %d blocks\t%s %s\n",
914 i, maxbytes[i]/1024, maxblocks[i], poolclass[i], pooluse[i]);
915 }
916#endif
917}
918
059ec3d9 919/* End of store.c */