2 Bacula® - The Network Backup Solution
4 Copyright (C) 2000-2010 Free Software Foundation Europe e.V.
6 The main author of Bacula is Kern Sibbald, with contributions from
7 many others, a complete list can be found in the file AUTHORS.
8 This program is Free Software; you can redistribute it and/or
9 modify it under the terms of version two of the GNU General Public
10 License as published by the Free Software Foundation and included
13 This program is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
23 Bacula® is a registered trademark of Kern Sibbald.
24 The licensor of Bacula is the Free Software Foundation Europe
25 (FSFE), Fiduciary Program, Sumatrastrasse 25, 8006 Zürich,
26 Switzerland, email:ftf@fsfeurope.org.
31 Smart Memory Allocator
33 Evolved over several years, starting with the initial
34 SMARTALLOC code for AutoSketch in 1986, guided by the Blind
35 Watchbreaker, John Walker. Isolated in this general-purpose
36 form in September of 1989. Updated with be more POSIX
37 compliant and to include Web-friendly HTML documentation in
38 October of 1998 by the same culprit. For additional
39 information and the current version visit the Web page:
41 http://www.fourmilab.ch/smartall/
45 #define _LOCKMGR_COMPLIANT
48 /* Use the real routines here */
54 /* We normally turn off debugging here.
55 * If you want it, simply #ifdef all the
64 #define Dmsg2(l,f,a1,a2)
65 #define Dmsg3(l,f,a1,a2,a3)
66 #define Dmsg4(l,f,a1,a2,a3,a4)
70 uint64_t sm_max_bytes = 0;
71 uint64_t sm_bytes = 0;
72 uint32_t sm_max_buffers = 0;
73 uint32_t sm_buffers = 0;
77 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
79 extern char my_name[]; /* daemon name */
81 #define EOS '\0' /* End of string sentinel */
82 #define sm_min(a, b) ((a) < (b) ? (a) : (b))
84 /* Queue data structures */
86 /* Memory allocation control structures and storage. */
89 struct b_queue abq; /* Links on allocated queue */
90 uint32_t ablen; /* Buffer length in bytes */
91 const char *abfname; /* File name pointer */
92 uint32_t ablineno; /* Line number of allocation */
93 bool abin_use; /* set when malloced and cleared when free */
96 static struct b_queue abqueue = { /* Allocated buffer queue */
101 static bool bufimode = false; /* Buffers not tracked when True */
103 #define HEAD_SIZE BALIGN(sizeof(struct abufhead))
106 /* SMALLOC -- Allocate buffer, enqueing on the orphaned buffer
109 static void *smalloc(const char *fname, int lineno, unsigned int nbytes)
113 /* Note: Unix MALLOC actually permits a zero length to be
114 passed and allocates a valid block with zero user bytes.
115 Such a block can later be expanded with realloc(). We
116 disallow this based on the belief that it's better to make
117 a special case and allocate one byte in the rare case this
118 is desired than to miss all the erroneous occurrences where
119 buffer length calculation code results in a zero. */
123 nbytes += HEAD_SIZE + 1;
124 if ((buf = (char *)malloc(nbytes)) != NULL) {
125 struct abufhead *head = (struct abufhead *)buf;
127 /* Enqueue buffer on allocated list */
128 qinsert(&abqueue, (struct b_queue *) buf);
129 head->ablen = nbytes;
130 head->abfname = bufimode ? NULL : fname;
131 head->ablineno = (uint32_t)lineno;
132 head->abin_use = true;
133 /* Emplace end-clobber detector at end of buffer */
134 buf[nbytes - 1] = (uint8_t)((((intptr_t) buf) & 0xFF) ^ 0xC5);
135 buf += HEAD_SIZE; /* Increment to user data start */
136 if (++sm_buffers > sm_max_buffers) {
137 sm_max_buffers = sm_buffers;
140 if (sm_bytes > sm_max_bytes) {
141 sm_max_bytes = sm_bytes;
145 Emsg0(M_ABORT, 0, _("Out of memory\n"));
147 Dmsg4(1150, "smalloc %d at %p from %s:%d\n", nbytes, buf, fname, lineno);
148 #if SMALLOC_SANITY_CHECK > 0
149 if (sm_bytes > SMALLOC_SANITY_CHECK) {
150 Emsg0(M_ABORT, 0, _("Too much memory used."));
156 /* SM_NEW_OWNER -- Update the File and line number for a buffer
157 This is to accomodate mem_pool. */
159 void sm_new_owner(const char *fname, int lineno, char *buf)
161 buf -= HEAD_SIZE; /* Decrement to header */
162 ((struct abufhead *)buf)->abfname = bufimode ? NULL : fname;
163 ((struct abufhead *)buf)->ablineno = (uint32_t) lineno;
164 ((struct abufhead *)buf)->abin_use = true;
168 /* SM_FREE -- Update free pool availability. FREE is never called
169 except through this interface or by actuallyfree().
170 free(x) is defined to generate a call to this
173 void sm_free(const char *file, int line, void *fp)
175 char *cp = (char *) fp;
179 Emsg2(M_ABORT, 0, _("Attempt to free NULL called from %s:%d\n"), file, line);
183 qp = (struct b_queue *)cp;
184 struct abufhead *head = (struct abufhead *)cp;
187 Dmsg4(1150, "sm_free %d at %p from %s:%d\n",
189 head->abfname, head->ablineno);
191 if (!head->abin_use) {
193 Emsg2(M_ABORT, 0, _("double free from %s:%d\n"), file, line);
195 head->abin_use = false;
197 /* The following assertions will catch virtually every release
198 of an address which isn't an allocated buffer. */
199 if (qp->qnext->qprev != qp) {
201 Emsg2(M_ABORT, 0, _("qp->qnext->qprev != qp called from %s:%d\n"), file, line);
203 if (qp->qprev->qnext != qp) {
205 Emsg2(M_ABORT, 0, _("qp->qprev->qnext != qp called from %s:%d\n"), file, line);
208 /* The following assertion detects storing off the end of the
209 allocated space in the buffer by comparing the end of buffer
210 checksum with the address of the buffer. */
212 if (((unsigned char *)cp)[head->ablen - 1] != ((((intptr_t) cp) & 0xFF) ^ 0xC5)) {
214 Emsg2(M_ABORT, 0, _("Buffer overrun called from %s:%d\n"), file, line);
216 if (sm_buffers > 0) {
218 sm_bytes -= head->ablen;
224 /* Now we wipe the contents of the just-released buffer with
225 "designer garbage" (Duff Kurland's phrase) of alternating
226 bits. This is intended to ruin the day for any miscreant who
227 attempts to access data through a pointer into storage that's
228 been previously released.
230 Modified, kes May, 2007 to not zap the header. This allows us
231 to check the in_use bit and detect doubly freed buffers.
234 memset(cp+HEAD_SIZE, 0xAA, (int)(head->ablen - HEAD_SIZE));
239 /* SM_MALLOC -- Allocate buffer. NULL is returned if no memory
242 void *sm_malloc(const char *fname, int lineno, unsigned int nbytes)
246 if ((buf = smalloc(fname, lineno, nbytes)) != NULL) {
248 /* To catch sloppy code that assumes buffers obtained from
249 malloc() are zeroed, we preset the buffer contents to
250 "designer garbage" consisting of alternating bits. */
252 memset(buf, 0x55, (int) nbytes);
254 Emsg0(M_ABORT, 0, _("Out of memory\n"));
259 /* SM_CALLOC -- Allocate an array and clear it to zero. */
261 void *sm_calloc(const char *fname, int lineno,
262 unsigned int nelem, unsigned int elsize)
266 if ((buf = smalloc(fname, lineno, nelem * elsize)) != NULL) {
267 memset(buf, 0, (int) (nelem * elsize));
269 Emsg0(M_ABORT, 0, _("Out of memory\n"));
274 /* SM_REALLOC -- Adjust the size of a previously allocated buffer.
275 Note that the trick of "resurrecting" a previously
276 freed buffer with realloc() is NOT supported by this
277 function. Further, because of the need to maintain
278 our control storage, SM_REALLOC must always allocate
279 a new block and copy the data in the old block.
280 This may result in programs which make heavy use of
281 realloc() running much slower than normally. */
283 void *sm_realloc(const char *fname, int lineno, void *ptr, unsigned int size)
287 char *cp = (char *) ptr;
289 Dmsg4(1400, "sm_realloc %s:%d %p %d\n", fname, lineno, ptr, size);
291 e_msg(fname, lineno, M_ABORT, 0, _("sm_realloc size: %d\n"), size);
294 /* If the old block pointer is NULL, treat realloc() as a
295 malloc(). SVID is silent on this, but many C libraries
298 return sm_malloc(fname, lineno, size);
301 /* If the old and new sizes are the same, be a nice guy and just
302 return the buffer passed in. */
304 struct abufhead *head = (struct abufhead *)cp;
305 osize = head->ablen - (HEAD_SIZE + 1);
310 /* Sizes differ. Allocate a new buffer of the requested size.
311 If we can't obtain such a buffer, act as defined in SVID:
312 return NULL from realloc() and leave the buffer in PTR
316 // sm_bytes -= head->ablen;
318 if ((buf = smalloc(fname, lineno, size)) != NULL) {
319 memcpy(buf, ptr, (int)sm_min(size, osize));
320 /* If the new buffer is larger than the old, fill the balance
321 of it with "designer garbage". */
323 memset(((char *) buf) + osize, 0x55, (int) (size - osize));
326 /* All done. Free and dechain the original buffer. */
327 sm_free(fname, lineno, ptr);
329 Dmsg4(4150, _("sm_realloc %d at %p from %s:%d\n"), size, buf, fname, lineno);
333 /* ACTUALLYMALLOC -- Call the system malloc() function to obtain
334 storage which will eventually be released
335 by system or library routines not compiled
338 void *actuallymalloc(unsigned int size)
343 /* ACTUALLYCALLOC -- Call the system calloc() function to obtain
344 storage which will eventually be released
345 by system or library routines not compiled
348 void *actuallycalloc(unsigned int nelem, unsigned int elsize)
350 return calloc(nelem, elsize);
353 /* ACTUALLYREALLOC -- Call the system realloc() function to obtain
354 storage which will eventually be released
355 by system or library routines not compiled
358 void *actuallyrealloc(void *ptr, unsigned int size)
360 Dmsg2(1400, "Actuallyrealloc %p %d\n", ptr, size);
361 return realloc(ptr, size);
364 /* ACTUALLYFREE -- Interface to system free() function to release
365 buffers allocated by low-level routines. */
367 void actuallyfree(void *cp)
372 /* SM_DUMP -- Print orphaned buffers (and dump them if BUFDUMP is
375 void sm_dump(bool bufdump, bool in_use)
381 ap = (struct abufhead *)abqueue.qnext;
383 while (ap != (struct abufhead *) &abqueue) {
386 (ap->abq.qnext->qprev != (struct b_queue *) ap) ||
387 (ap->abq.qprev->qnext != (struct b_queue *) ap)) {
389 "\nOrphaned buffers exist. Dump terminated following\n"
390 " discovery of bad links in chain of orphaned buffers.\n"
391 " Buffer address with bad links: %p\n"), ap);
395 if (ap->abfname != NULL) {
396 uint32_t memsize = ap->ablen - (HEAD_SIZE + 1);
398 char *cp = ((char *)ap) + HEAD_SIZE;
400 bsnprintf(errmsg, sizeof(errmsg),
401 _("%s buffer: %s %6u bytes buf=%p allocated at %s:%d\n"),
402 in_use?"In use":"Orphaned",
403 my_name, memsize, cp, ap->abfname, ap->ablineno
405 Pmsg1(0, "%s", errmsg);
413 bstrncat(errmsg, "\n", sizeof(errmsg));
415 Pmsg1(0, "%s", errmsg);
418 bsnprintf(buf, sizeof(buf), " %02X",
420 bstrncat(errmsg, buf, sizeof(errmsg));
424 Pmsg1(0, "%s\n", errmsg);
427 ap = (struct abufhead *) ap->abq.qnext;
433 /* SM_CHECK -- Check the buffers and dump if any damage exists. */
434 void sm_check(const char *fname, int lineno, bool bufdump)
436 if (!sm_check_rtn(fname, lineno, bufdump)) {
437 Emsg2(M_ABORT, 0, _("Damaged buffer found. Called from %s:%d\n"),
443 /* SM_CHECK_RTN -- Check the buffers and return 1 if OK otherwise 0 */
444 int sm_check_rtn(const char *fname, int lineno, bool bufdump)
450 ap = (struct abufhead *) abqueue.qnext;
451 while (ap != (struct abufhead *)&abqueue) {
454 if (ap->abq.qnext->qprev != (struct b_queue *)ap) {
457 if (ap->abq.qprev->qnext != (struct b_queue *)ap) {
460 if (((unsigned char *) ap)[((struct abufhead *)ap)->ablen - 1] !=
461 ((((intptr_t) ap) & 0xFF) ^ 0xC5)) {
470 _("\nDamaged buffers found at %s:%d\n"), fname, lineno);
473 Pmsg0(0, _(" discovery of bad prev link.\n"));
476 Pmsg0(0, _(" discovery of bad next link.\n"));
479 Pmsg0(0, _(" discovery of data overrun.\n"));
482 Pmsg0(0, _(" NULL pointer.\n"));
488 Pmsg1(0, _(" Buffer address: %p\n"), ap);
490 if (ap->abfname != NULL) {
491 unsigned memsize = ap->ablen - (HEAD_SIZE + 1);
495 _("Damaged buffer: %6u bytes allocated at line %d of %s %s\n"),
496 memsize, ap->ablineno, my_name, ap->abfname
500 char *cp = ((char *) ap) + HEAD_SIZE;
505 strcat(errmsg, "\n");
507 Pmsg1(0, "%s", errmsg);
511 sprintf(errmsg + strlen(errmsg), " %02X",
514 sprintf(errmsg + strlen(errmsg), " %c ",
520 Pmsg1(0, "%s\n", errmsg);
524 ap = (struct abufhead *)ap->abq.qnext;
528 return badbuf ? 0 : 1;
532 /* SM_STATIC -- Orphaned buffer detection can be disabled (for such
533 items as buffers allocated during initialisation) by
534 calling sm_static(1). Normal orphaned buffer
535 detection can be re-enabled with sm_static(0). Note
536 that all the other safeguards still apply to buffers
537 allocated when sm_static(1) mode is in effect. */
539 void sm_static(bool mode)
545 * Here we overload C++'s global new and delete operators
546 * so that the memory is allocated through smartalloc.
550 void * operator new(size_t size)
552 // Dmsg1(000, "new called %d\n", size);
553 return sm_malloc(__FILE__, __LINE__, size);
556 void operator delete(void *buf)
558 // Dmsg1(000, "free called %p\n", buf);
559 sm_free(__FILE__, __LINE__, buf);