xref: /openbmc/u-boot/common/dlmalloc.c (revision a26cd049)
1 #include <common.h>
2 
3 #ifdef CONFIG_SANDBOX
4 #define DEBUG
5 #endif
6 
7 #if 0	/* Moved to malloc.h */
8 /* ---------- To make a malloc.h, start cutting here ------------ */
9 
10 /*
11   A version of malloc/free/realloc written by Doug Lea and released to the
12   public domain.  Send questions/comments/complaints/performance data
13   to dl@cs.oswego.edu
14 
15 * VERSION 2.6.6  Sun Mar  5 19:10:03 2000  Doug Lea  (dl at gee)
16 
17    Note: There may be an updated version of this malloc obtainable at
18 	   ftp://g.oswego.edu/pub/misc/malloc.c
19 	 Check before installing!
20 
21 * Why use this malloc?
22 
23   This is not the fastest, most space-conserving, most portable, or
24   most tunable malloc ever written. However it is among the fastest
25   while also being among the most space-conserving, portable and tunable.
26   Consistent balance across these factors results in a good general-purpose
27   allocator. For a high-level description, see
28      http://g.oswego.edu/dl/html/malloc.html
29 
30 * Synopsis of public routines
31 
32   (Much fuller descriptions are contained in the program documentation below.)
33 
34   malloc(size_t n);
35      Return a pointer to a newly allocated chunk of at least n bytes, or null
36      if no space is available.
37   free(Void_t* p);
38      Release the chunk of memory pointed to by p, or no effect if p is null.
39   realloc(Void_t* p, size_t n);
40      Return a pointer to a chunk of size n that contains the same data
41      as does chunk p up to the minimum of (n, p's size) bytes, or null
42      if no space is available. The returned pointer may or may not be
43      the same as p. If p is null, equivalent to malloc.  Unless the
44      #define REALLOC_ZERO_BYTES_FREES below is set, realloc with a
45      size argument of zero (re)allocates a minimum-sized chunk.
46   memalign(size_t alignment, size_t n);
47      Return a pointer to a newly allocated chunk of n bytes, aligned
48      in accord with the alignment argument, which must be a power of
49      two.
50   valloc(size_t n);
51      Equivalent to memalign(pagesize, n), where pagesize is the page
52      size of the system (or as near to this as can be figured out from
53      all the includes/defines below.)
54   pvalloc(size_t n);
55      Equivalent to valloc(minimum-page-that-holds(n)), that is,
56      round up n to nearest pagesize.
57   calloc(size_t unit, size_t quantity);
58      Returns a pointer to quantity * unit bytes, with all locations
59      set to zero.
60   cfree(Void_t* p);
61      Equivalent to free(p).
62   malloc_trim(size_t pad);
63      Release all but pad bytes of freed top-most memory back
64      to the system. Return 1 if successful, else 0.
65   malloc_usable_size(Void_t* p);
66      Report the number usable allocated bytes associated with allocated
67      chunk p. This may or may not report more bytes than were requested,
68      due to alignment and minimum size constraints.
69   malloc_stats();
70      Prints brief summary statistics.
71   mallinfo()
72      Returns (by copy) a struct containing various summary statistics.
73   mallopt(int parameter_number, int parameter_value)
74      Changes one of the tunable parameters described below. Returns
75      1 if successful in changing the parameter, else 0.
76 
77 * Vital statistics:
78 
79   Alignment:                            8-byte
80        8 byte alignment is currently hardwired into the design.  This
81        seems to suffice for all current machines and C compilers.
82 
83   Assumed pointer representation:       4 or 8 bytes
84        Code for 8-byte pointers is untested by me but has worked
85        reliably by Wolfram Gloger, who contributed most of the
86        changes supporting this.
87 
88   Assumed size_t  representation:       4 or 8 bytes
89        Note that size_t is allowed to be 4 bytes even if pointers are 8.
90 
91   Minimum overhead per allocated chunk: 4 or 8 bytes
92        Each malloced chunk has a hidden overhead of 4 bytes holding size
93        and status information.
94 
95   Minimum allocated size: 4-byte ptrs:  16 bytes    (including 4 overhead)
96 			  8-byte ptrs:  24/32 bytes (including, 4/8 overhead)
97 
98        When a chunk is freed, 12 (for 4byte ptrs) or 20 (for 8 byte
99        ptrs but 4 byte size) or 24 (for 8/8) additional bytes are
100        needed; 4 (8) for a trailing size field
101        and 8 (16) bytes for free list pointers. Thus, the minimum
102        allocatable size is 16/24/32 bytes.
103 
104        Even a request for zero bytes (i.e., malloc(0)) returns a
105        pointer to something of the minimum allocatable size.
106 
107   Maximum allocated size: 4-byte size_t: 2^31 -  8 bytes
108 			  8-byte size_t: 2^63 - 16 bytes
109 
110        It is assumed that (possibly signed) size_t bit values suffice to
111        represent chunk sizes. `Possibly signed' is due to the fact
112        that `size_t' may be defined on a system as either a signed or
113        an unsigned type. To be conservative, values that would appear
114        as negative numbers are avoided.
115        Requests for sizes with a negative sign bit when the request
116        size is treaded as a long will return null.
117 
118   Maximum overhead wastage per allocated chunk: normally 15 bytes
119 
120        Alignnment demands, plus the minimum allocatable size restriction
121        make the normal worst-case wastage 15 bytes (i.e., up to 15
122        more bytes will be allocated than were requested in malloc), with
123        two exceptions:
124 	 1. Because requests for zero bytes allocate non-zero space,
125 	    the worst case wastage for a request of zero bytes is 24 bytes.
126 	 2. For requests >= mmap_threshold that are serviced via
127 	    mmap(), the worst case wastage is 8 bytes plus the remainder
128 	    from a system page (the minimal mmap unit); typically 4096 bytes.
129 
130 * Limitations
131 
132     Here are some features that are NOT currently supported
133 
134     * No user-definable hooks for callbacks and the like.
135     * No automated mechanism for fully checking that all accesses
136       to malloced memory stay within their bounds.
137     * No support for compaction.
138 
139 * Synopsis of compile-time options:
140 
141     People have reported using previous versions of this malloc on all
142     versions of Unix, sometimes by tweaking some of the defines
143     below. It has been tested most extensively on Solaris and
144     Linux. It is also reported to work on WIN32 platforms.
145     People have also reported adapting this malloc for use in
146     stand-alone embedded systems.
147 
148     The implementation is in straight, hand-tuned ANSI C.  Among other
149     consequences, it uses a lot of macros.  Because of this, to be at
150     all usable, this code should be compiled using an optimizing compiler
151     (for example gcc -O2) that can simplify expressions and control
152     paths.
153 
154   __STD_C                  (default: derived from C compiler defines)
155      Nonzero if using ANSI-standard C compiler, a C++ compiler, or
156      a C compiler sufficiently close to ANSI to get away with it.
157   DEBUG                    (default: NOT defined)
158      Define to enable debugging. Adds fairly extensive assertion-based
159      checking to help track down memory errors, but noticeably slows down
160      execution.
161   REALLOC_ZERO_BYTES_FREES (default: NOT defined)
162      Define this if you think that realloc(p, 0) should be equivalent
163      to free(p). Otherwise, since malloc returns a unique pointer for
164      malloc(0), so does realloc(p, 0).
165   HAVE_MEMCPY               (default: defined)
166      Define if you are not otherwise using ANSI STD C, but still
167      have memcpy and memset in your C library and want to use them.
168      Otherwise, simple internal versions are supplied.
169   USE_MEMCPY               (default: 1 if HAVE_MEMCPY is defined, 0 otherwise)
170      Define as 1 if you want the C library versions of memset and
171      memcpy called in realloc and calloc (otherwise macro versions are used).
172      At least on some platforms, the simple macro versions usually
173      outperform libc versions.
174   HAVE_MMAP                 (default: defined as 1)
175      Define to non-zero to optionally make malloc() use mmap() to
176      allocate very large blocks.
177   HAVE_MREMAP                 (default: defined as 0 unless Linux libc set)
178      Define to non-zero to optionally make realloc() use mremap() to
179      reallocate very large blocks.
180   malloc_getpagesize        (default: derived from system #includes)
181      Either a constant or routine call returning the system page size.
182   HAVE_USR_INCLUDE_MALLOC_H (default: NOT defined)
183      Optionally define if you are on a system with a /usr/include/malloc.h
184      that declares struct mallinfo. It is not at all necessary to
185      define this even if you do, but will ensure consistency.
186   INTERNAL_SIZE_T           (default: size_t)
187      Define to a 32-bit type (probably `unsigned int') if you are on a
188      64-bit machine, yet do not want or need to allow malloc requests of
189      greater than 2^31 to be handled. This saves space, especially for
190      very small chunks.
191   INTERNAL_LINUX_C_LIB      (default: NOT defined)
192      Defined only when compiled as part of Linux libc.
193      Also note that there is some odd internal name-mangling via defines
194      (for example, internally, `malloc' is named `mALLOc') needed
195      when compiling in this case. These look funny but don't otherwise
196      affect anything.
197   WIN32                     (default: undefined)
198      Define this on MS win (95, nt) platforms to compile in sbrk emulation.
199   LACKS_UNISTD_H            (default: undefined if not WIN32)
200      Define this if your system does not have a <unistd.h>.
201   LACKS_SYS_PARAM_H         (default: undefined if not WIN32)
202      Define this if your system does not have a <sys/param.h>.
203   MORECORE                  (default: sbrk)
204      The name of the routine to call to obtain more memory from the system.
205   MORECORE_FAILURE          (default: -1)
206      The value returned upon failure of MORECORE.
207   MORECORE_CLEARS           (default 1)
208      true (1) if the routine mapped to MORECORE zeroes out memory (which
209      holds for sbrk).
210   DEFAULT_TRIM_THRESHOLD
211   DEFAULT_TOP_PAD
212   DEFAULT_MMAP_THRESHOLD
213   DEFAULT_MMAP_MAX
214      Default values of tunable parameters (described in detail below)
215      controlling interaction with host system routines (sbrk, mmap, etc).
216      These values may also be changed dynamically via mallopt(). The
217      preset defaults are those that give best performance for typical
218      programs/systems.
219   USE_DL_PREFIX             (default: undefined)
220      Prefix all public routines with the string 'dl'.  Useful to
221      quickly avoid procedure declaration conflicts and linker symbol
222      conflicts with existing memory allocation routines.
223 
224 
225 */
226 
227 
228 
229 /* Preliminaries */
230 
231 #ifndef __STD_C
232 #ifdef __STDC__
233 #define __STD_C     1
234 #else
235 #if __cplusplus
236 #define __STD_C     1
237 #else
238 #define __STD_C     0
239 #endif /*__cplusplus*/
240 #endif /*__STDC__*/
241 #endif /*__STD_C*/
242 
243 #ifndef Void_t
244 #if (__STD_C || defined(WIN32))
245 #define Void_t      void
246 #else
247 #define Void_t      char
248 #endif
249 #endif /*Void_t*/
250 
251 #if __STD_C
252 #include <stddef.h>   /* for size_t */
253 #else
254 #include <sys/types.h>
255 #endif
256 
257 #ifdef __cplusplus
258 extern "C" {
259 #endif
260 
261 #include <stdio.h>    /* needed for malloc_stats */
262 
263 
264 /*
265   Compile-time options
266 */
267 
268 
269 /*
270     Debugging:
271 
272     Because freed chunks may be overwritten with link fields, this
273     malloc will often die when freed memory is overwritten by user
274     programs.  This can be very effective (albeit in an annoying way)
275     in helping track down dangling pointers.
276 
277     If you compile with -DDEBUG, a number of assertion checks are
278     enabled that will catch more memory errors. You probably won't be
279     able to make much sense of the actual assertion errors, but they
280     should help you locate incorrectly overwritten memory.  The
281     checking is fairly extensive, and will slow down execution
282     noticeably. Calling malloc_stats or mallinfo with DEBUG set will
283     attempt to check every non-mmapped allocated and free chunk in the
284     course of computing the summmaries. (By nature, mmapped regions
285     cannot be checked very much automatically.)
286 
287     Setting DEBUG may also be helpful if you are trying to modify
288     this code. The assertions in the check routines spell out in more
289     detail the assumptions and invariants underlying the algorithms.
290 
291 */
292 
293 /*
294   INTERNAL_SIZE_T is the word-size used for internal bookkeeping
295   of chunk sizes. On a 64-bit machine, you can reduce malloc
296   overhead by defining INTERNAL_SIZE_T to be a 32 bit `unsigned int'
297   at the expense of not being able to handle requests greater than
298   2^31. This limitation is hardly ever a concern; you are encouraged
299   to set this. However, the default version is the same as size_t.
300 */
301 
302 #ifndef INTERNAL_SIZE_T
303 #define INTERNAL_SIZE_T size_t
304 #endif
305 
306 /*
307   REALLOC_ZERO_BYTES_FREES should be set if a call to
308   realloc with zero bytes should be the same as a call to free.
309   Some people think it should. Otherwise, since this malloc
310   returns a unique pointer for malloc(0), so does realloc(p, 0).
311 */
312 
313 
314 /*   #define REALLOC_ZERO_BYTES_FREES */
315 
316 
317 /*
318   WIN32 causes an emulation of sbrk to be compiled in
319   mmap-based options are not currently supported in WIN32.
320 */
321 
322 /* #define WIN32 */
323 #ifdef WIN32
324 #define MORECORE wsbrk
325 #define HAVE_MMAP 0
326 
327 #define LACKS_UNISTD_H
328 #define LACKS_SYS_PARAM_H
329 
330 /*
331   Include 'windows.h' to get the necessary declarations for the
332   Microsoft Visual C++ data structures and routines used in the 'sbrk'
333   emulation.
334 
335   Define WIN32_LEAN_AND_MEAN so that only the essential Microsoft
336   Visual C++ header files are included.
337 */
338 #define WIN32_LEAN_AND_MEAN
339 #include <windows.h>
340 #endif
341 
342 
343 /*
344   HAVE_MEMCPY should be defined if you are not otherwise using
345   ANSI STD C, but still have memcpy and memset in your C library
346   and want to use them in calloc and realloc. Otherwise simple
347   macro versions are defined here.
348 
349   USE_MEMCPY should be defined as 1 if you actually want to
350   have memset and memcpy called. People report that the macro
351   versions are often enough faster than libc versions on many
352   systems that it is better to use them.
353 
354 */
355 
356 #define HAVE_MEMCPY
357 
358 #ifndef USE_MEMCPY
359 #ifdef HAVE_MEMCPY
360 #define USE_MEMCPY 1
361 #else
362 #define USE_MEMCPY 0
363 #endif
364 #endif
365 
366 #if (__STD_C || defined(HAVE_MEMCPY))
367 
368 #if __STD_C
369 void* memset(void*, int, size_t);
370 void* memcpy(void*, const void*, size_t);
371 #else
372 #ifdef WIN32
373 /* On Win32 platforms, 'memset()' and 'memcpy()' are already declared in */
374 /* 'windows.h' */
375 #else
376 Void_t* memset();
377 Void_t* memcpy();
378 #endif
379 #endif
380 #endif
381 
382 #if USE_MEMCPY
383 
384 /* The following macros are only invoked with (2n+1)-multiples of
385    INTERNAL_SIZE_T units, with a positive integer n. This is exploited
386    for fast inline execution when n is small. */
387 
388 #define MALLOC_ZERO(charp, nbytes)                                            \
389 do {                                                                          \
390   INTERNAL_SIZE_T mzsz = (nbytes);                                            \
391   if(mzsz <= 9*sizeof(mzsz)) {                                                \
392     INTERNAL_SIZE_T* mz = (INTERNAL_SIZE_T*) (charp);                         \
393     if(mzsz >= 5*sizeof(mzsz)) {     *mz++ = 0;                               \
394 				     *mz++ = 0;                               \
395       if(mzsz >= 7*sizeof(mzsz)) {   *mz++ = 0;                               \
396 				     *mz++ = 0;                               \
397 	if(mzsz >= 9*sizeof(mzsz)) { *mz++ = 0;                               \
398 				     *mz++ = 0; }}}                           \
399 				     *mz++ = 0;                               \
400 				     *mz++ = 0;                               \
401 				     *mz   = 0;                               \
402   } else memset((charp), 0, mzsz);                                            \
403 } while(0)
404 
405 #define MALLOC_COPY(dest,src,nbytes)                                          \
406 do {                                                                          \
407   INTERNAL_SIZE_T mcsz = (nbytes);                                            \
408   if(mcsz <= 9*sizeof(mcsz)) {                                                \
409     INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) (src);                        \
410     INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) (dest);                       \
411     if(mcsz >= 5*sizeof(mcsz)) {     *mcdst++ = *mcsrc++;                     \
412 				     *mcdst++ = *mcsrc++;                     \
413       if(mcsz >= 7*sizeof(mcsz)) {   *mcdst++ = *mcsrc++;                     \
414 				     *mcdst++ = *mcsrc++;                     \
415 	if(mcsz >= 9*sizeof(mcsz)) { *mcdst++ = *mcsrc++;                     \
416 				     *mcdst++ = *mcsrc++; }}}                 \
417 				     *mcdst++ = *mcsrc++;                     \
418 				     *mcdst++ = *mcsrc++;                     \
419 				     *mcdst   = *mcsrc  ;                     \
420   } else memcpy(dest, src, mcsz);                                             \
421 } while(0)
422 
423 #else /* !USE_MEMCPY */
424 
425 /* Use Duff's device for good zeroing/copying performance. */
426 
427 #define MALLOC_ZERO(charp, nbytes)                                            \
428 do {                                                                          \
429   INTERNAL_SIZE_T* mzp = (INTERNAL_SIZE_T*)(charp);                           \
430   long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn;                         \
431   if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; }             \
432   switch (mctmp) {                                                            \
433     case 0: for(;;) { *mzp++ = 0;                                             \
434     case 7:           *mzp++ = 0;                                             \
435     case 6:           *mzp++ = 0;                                             \
436     case 5:           *mzp++ = 0;                                             \
437     case 4:           *mzp++ = 0;                                             \
438     case 3:           *mzp++ = 0;                                             \
439     case 2:           *mzp++ = 0;                                             \
440     case 1:           *mzp++ = 0; if(mcn <= 0) break; mcn--; }                \
441   }                                                                           \
442 } while(0)
443 
444 #define MALLOC_COPY(dest,src,nbytes)                                          \
445 do {                                                                          \
446   INTERNAL_SIZE_T* mcsrc = (INTERNAL_SIZE_T*) src;                            \
447   INTERNAL_SIZE_T* mcdst = (INTERNAL_SIZE_T*) dest;                           \
448   long mctmp = (nbytes)/sizeof(INTERNAL_SIZE_T), mcn;                         \
449   if (mctmp < 8) mcn = 0; else { mcn = (mctmp-1)/8; mctmp %= 8; }             \
450   switch (mctmp) {                                                            \
451     case 0: for(;;) { *mcdst++ = *mcsrc++;                                    \
452     case 7:           *mcdst++ = *mcsrc++;                                    \
453     case 6:           *mcdst++ = *mcsrc++;                                    \
454     case 5:           *mcdst++ = *mcsrc++;                                    \
455     case 4:           *mcdst++ = *mcsrc++;                                    \
456     case 3:           *mcdst++ = *mcsrc++;                                    \
457     case 2:           *mcdst++ = *mcsrc++;                                    \
458     case 1:           *mcdst++ = *mcsrc++; if(mcn <= 0) break; mcn--; }       \
459   }                                                                           \
460 } while(0)
461 
462 #endif
463 
464 
465 /*
466   Define HAVE_MMAP to optionally make malloc() use mmap() to
467   allocate very large blocks.  These will be returned to the
468   operating system immediately after a free().
469 */
470 
471 #ifndef HAVE_MMAP
472 #define HAVE_MMAP 1
473 #endif
474 
475 /*
476   Define HAVE_MREMAP to make realloc() use mremap() to re-allocate
477   large blocks.  This is currently only possible on Linux with
478   kernel versions newer than 1.3.77.
479 */
480 
481 #ifndef HAVE_MREMAP
482 #ifdef INTERNAL_LINUX_C_LIB
483 #define HAVE_MREMAP 1
484 #else
485 #define HAVE_MREMAP 0
486 #endif
487 #endif
488 
489 #if HAVE_MMAP
490 
491 #include <unistd.h>
492 #include <fcntl.h>
493 #include <sys/mman.h>
494 
495 #if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
496 #define MAP_ANONYMOUS MAP_ANON
497 #endif
498 
499 #endif /* HAVE_MMAP */
500 
501 /*
502   Access to system page size. To the extent possible, this malloc
503   manages memory from the system in page-size units.
504 
505   The following mechanics for getpagesize were adapted from
506   bsd/gnu getpagesize.h
507 */
508 
509 #ifndef LACKS_UNISTD_H
510 #  include <unistd.h>
511 #endif
512 
513 #ifndef malloc_getpagesize
514 #  ifdef _SC_PAGESIZE         /* some SVR4 systems omit an underscore */
515 #    ifndef _SC_PAGE_SIZE
516 #      define _SC_PAGE_SIZE _SC_PAGESIZE
517 #    endif
518 #  endif
519 #  ifdef _SC_PAGE_SIZE
520 #    define malloc_getpagesize sysconf(_SC_PAGE_SIZE)
521 #  else
522 #    if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE)
523        extern size_t getpagesize();
524 #      define malloc_getpagesize getpagesize()
525 #    else
526 #      ifdef WIN32
527 #        define malloc_getpagesize (4096) /* TBD: Use 'GetSystemInfo' instead */
528 #      else
529 #        ifndef LACKS_SYS_PARAM_H
530 #          include <sys/param.h>
531 #        endif
532 #        ifdef EXEC_PAGESIZE
533 #          define malloc_getpagesize EXEC_PAGESIZE
534 #        else
535 #          ifdef NBPG
536 #            ifndef CLSIZE
537 #              define malloc_getpagesize NBPG
538 #            else
539 #              define malloc_getpagesize (NBPG * CLSIZE)
540 #            endif
541 #          else
542 #            ifdef NBPC
543 #              define malloc_getpagesize NBPC
544 #            else
545 #              ifdef PAGESIZE
546 #                define malloc_getpagesize PAGESIZE
547 #              else
548 #                define malloc_getpagesize (4096) /* just guess */
549 #              endif
550 #            endif
551 #          endif
552 #        endif
553 #      endif
554 #    endif
555 #  endif
556 #endif
557 
558 
559 /*
560 
561   This version of malloc supports the standard SVID/XPG mallinfo
562   routine that returns a struct containing the same kind of
563   information you can get from malloc_stats. It should work on
564   any SVID/XPG compliant system that has a /usr/include/malloc.h
565   defining struct mallinfo. (If you'd like to install such a thing
566   yourself, cut out the preliminary declarations as described above
567   and below and save them in a malloc.h file. But there's no
568   compelling reason to bother to do this.)
569 
570   The main declaration needed is the mallinfo struct that is returned
571   (by-copy) by mallinfo().  The SVID/XPG malloinfo struct contains a
572   bunch of fields, most of which are not even meaningful in this
573   version of malloc. Some of these fields are are instead filled by
574   mallinfo() with other numbers that might possibly be of interest.
575 
576   HAVE_USR_INCLUDE_MALLOC_H should be set if you have a
577   /usr/include/malloc.h file that includes a declaration of struct
578   mallinfo.  If so, it is included; else an SVID2/XPG2 compliant
579   version is declared below.  These must be precisely the same for
580   mallinfo() to work.
581 
582 */
583 
584 /* #define HAVE_USR_INCLUDE_MALLOC_H */
585 
586 #if HAVE_USR_INCLUDE_MALLOC_H
587 #include "/usr/include/malloc.h"
588 #else
589 
590 /* SVID2/XPG mallinfo structure */
591 
592 struct mallinfo {
593   int arena;    /* total space allocated from system */
594   int ordblks;  /* number of non-inuse chunks */
595   int smblks;   /* unused -- always zero */
596   int hblks;    /* number of mmapped regions */
597   int hblkhd;   /* total space in mmapped regions */
598   int usmblks;  /* unused -- always zero */
599   int fsmblks;  /* unused -- always zero */
600   int uordblks; /* total allocated space */
601   int fordblks; /* total non-inuse space */
602   int keepcost; /* top-most, releasable (via malloc_trim) space */
603 };
604 
605 /* SVID2/XPG mallopt options */
606 
607 #define M_MXFAST  1    /* UNUSED in this malloc */
608 #define M_NLBLKS  2    /* UNUSED in this malloc */
609 #define M_GRAIN   3    /* UNUSED in this malloc */
610 #define M_KEEP    4    /* UNUSED in this malloc */
611 
612 #endif
613 
614 /* mallopt options that actually do something */
615 
616 #define M_TRIM_THRESHOLD    -1
617 #define M_TOP_PAD           -2
618 #define M_MMAP_THRESHOLD    -3
619 #define M_MMAP_MAX          -4
620 
621 
622 #ifndef DEFAULT_TRIM_THRESHOLD
623 #define DEFAULT_TRIM_THRESHOLD (128 * 1024)
624 #endif
625 
626 /*
627     M_TRIM_THRESHOLD is the maximum amount of unused top-most memory
628       to keep before releasing via malloc_trim in free().
629 
630       Automatic trimming is mainly useful in long-lived programs.
631       Because trimming via sbrk can be slow on some systems, and can
632       sometimes be wasteful (in cases where programs immediately
633       afterward allocate more large chunks) the value should be high
634       enough so that your overall system performance would improve by
635       releasing.
636 
637       The trim threshold and the mmap control parameters (see below)
638       can be traded off with one another. Trimming and mmapping are
639       two different ways of releasing unused memory back to the
640       system. Between these two, it is often possible to keep
641       system-level demands of a long-lived program down to a bare
642       minimum. For example, in one test suite of sessions measuring
643       the XF86 X server on Linux, using a trim threshold of 128K and a
644       mmap threshold of 192K led to near-minimal long term resource
645       consumption.
646 
647       If you are using this malloc in a long-lived program, it should
648       pay to experiment with these values.  As a rough guide, you
649       might set to a value close to the average size of a process
650       (program) running on your system.  Releasing this much memory
651       would allow such a process to run in memory.  Generally, it's
652       worth it to tune for trimming rather tham memory mapping when a
653       program undergoes phases where several large chunks are
654       allocated and released in ways that can reuse each other's
655       storage, perhaps mixed with phases where there are no such
656       chunks at all.  And in well-behaved long-lived programs,
657       controlling release of large blocks via trimming versus mapping
658       is usually faster.
659 
660       However, in most programs, these parameters serve mainly as
661       protection against the system-level effects of carrying around
662       massive amounts of unneeded memory. Since frequent calls to
663       sbrk, mmap, and munmap otherwise degrade performance, the default
664       parameters are set to relatively high values that serve only as
665       safeguards.
666 
667       The default trim value is high enough to cause trimming only in
668       fairly extreme (by current memory consumption standards) cases.
669       It must be greater than page size to have any useful effect.  To
670       disable trimming completely, you can set to (unsigned long)(-1);
671 
672 
673 */
674 
675 
676 #ifndef DEFAULT_TOP_PAD
677 #define DEFAULT_TOP_PAD        (0)
678 #endif
679 
680 /*
681     M_TOP_PAD is the amount of extra `padding' space to allocate or
682       retain whenever sbrk is called. It is used in two ways internally:
683 
684       * When sbrk is called to extend the top of the arena to satisfy
685 	a new malloc request, this much padding is added to the sbrk
686 	request.
687 
688       * When malloc_trim is called automatically from free(),
689 	it is used as the `pad' argument.
690 
691       In both cases, the actual amount of padding is rounded
692       so that the end of the arena is always a system page boundary.
693 
694       The main reason for using padding is to avoid calling sbrk so
695       often. Having even a small pad greatly reduces the likelihood
696       that nearly every malloc request during program start-up (or
697       after trimming) will invoke sbrk, which needlessly wastes
698       time.
699 
700       Automatic rounding-up to page-size units is normally sufficient
701       to avoid measurable overhead, so the default is 0.  However, in
702       systems where sbrk is relatively slow, it can pay to increase
703       this value, at the expense of carrying around more memory than
704       the program needs.
705 
706 */
707 
708 
709 #ifndef DEFAULT_MMAP_THRESHOLD
710 #define DEFAULT_MMAP_THRESHOLD (128 * 1024)
711 #endif
712 
713 /*
714 
715     M_MMAP_THRESHOLD is the request size threshold for using mmap()
716       to service a request. Requests of at least this size that cannot
717       be allocated using already-existing space will be serviced via mmap.
718       (If enough normal freed space already exists it is used instead.)
719 
720       Using mmap segregates relatively large chunks of memory so that
721       they can be individually obtained and released from the host
722       system. A request serviced through mmap is never reused by any
723       other request (at least not directly; the system may just so
724       happen to remap successive requests to the same locations).
725 
726       Segregating space in this way has the benefit that mmapped space
727       can ALWAYS be individually released back to the system, which
728       helps keep the system level memory demands of a long-lived
729       program low. Mapped memory can never become `locked' between
730       other chunks, as can happen with normally allocated chunks, which
731       menas that even trimming via malloc_trim would not release them.
732 
733       However, it has the disadvantages that:
734 
735 	 1. The space cannot be reclaimed, consolidated, and then
736 	    used to service later requests, as happens with normal chunks.
737 	 2. It can lead to more wastage because of mmap page alignment
738 	    requirements
739 	 3. It causes malloc performance to be more dependent on host
740 	    system memory management support routines which may vary in
741 	    implementation quality and may impose arbitrary
742 	    limitations. Generally, servicing a request via normal
743 	    malloc steps is faster than going through a system's mmap.
744 
745       All together, these considerations should lead you to use mmap
746       only for relatively large requests.
747 
748 
749 */
750 
751 
752 #ifndef DEFAULT_MMAP_MAX
753 #if HAVE_MMAP
754 #define DEFAULT_MMAP_MAX       (64)
755 #else
756 #define DEFAULT_MMAP_MAX       (0)
757 #endif
758 #endif
759 
760 /*
761     M_MMAP_MAX is the maximum number of requests to simultaneously
762       service using mmap. This parameter exists because:
763 
764 	 1. Some systems have a limited number of internal tables for
765 	    use by mmap.
766 	 2. In most systems, overreliance on mmap can degrade overall
767 	    performance.
768 	 3. If a program allocates many large regions, it is probably
769 	    better off using normal sbrk-based allocation routines that
770 	    can reclaim and reallocate normal heap memory. Using a
771 	    small value allows transition into this mode after the
772 	    first few allocations.
773 
774       Setting to 0 disables all use of mmap.  If HAVE_MMAP is not set,
775       the default value is 0, and attempts to set it to non-zero values
776       in mallopt will fail.
777 */
778 
779 
780 /*
781     USE_DL_PREFIX will prefix all public routines with the string 'dl'.
782       Useful to quickly avoid procedure declaration conflicts and linker
783       symbol conflicts with existing memory allocation routines.
784 
785 */
786 
787 /* #define USE_DL_PREFIX */
788 
789 
790 /*
791 
792   Special defines for linux libc
793 
794   Except when compiled using these special defines for Linux libc
795   using weak aliases, this malloc is NOT designed to work in
796   multithreaded applications.  No semaphores or other concurrency
797   control are provided to ensure that multiple malloc or free calls
798   don't run at the same time, which could be disasterous. A single
799   semaphore could be used across malloc, realloc, and free (which is
800   essentially the effect of the linux weak alias approach). It would
801   be hard to obtain finer granularity.
802 
803 */
804 
805 
806 #ifdef INTERNAL_LINUX_C_LIB
807 
808 #if __STD_C
809 
810 Void_t * __default_morecore_init (ptrdiff_t);
811 Void_t *(*__morecore)(ptrdiff_t) = __default_morecore_init;
812 
813 #else
814 
815 Void_t * __default_morecore_init ();
816 Void_t *(*__morecore)() = __default_morecore_init;
817 
818 #endif
819 
820 #define MORECORE (*__morecore)
821 #define MORECORE_FAILURE 0
822 #define MORECORE_CLEARS 1
823 
824 #else /* INTERNAL_LINUX_C_LIB */
825 
826 #if __STD_C
827 extern Void_t*     sbrk(ptrdiff_t);
828 #else
829 extern Void_t*     sbrk();
830 #endif
831 
832 #ifndef MORECORE
833 #define MORECORE sbrk
834 #endif
835 
836 #ifndef MORECORE_FAILURE
837 #define MORECORE_FAILURE -1
838 #endif
839 
840 #ifndef MORECORE_CLEARS
841 #define MORECORE_CLEARS 1
842 #endif
843 
844 #endif /* INTERNAL_LINUX_C_LIB */
845 
846 #if defined(INTERNAL_LINUX_C_LIB) && defined(__ELF__)
847 
848 #define cALLOc		__libc_calloc
849 #define fREe		__libc_free
850 #define mALLOc		__libc_malloc
851 #define mEMALIGn	__libc_memalign
852 #define rEALLOc		__libc_realloc
853 #define vALLOc		__libc_valloc
854 #define pvALLOc		__libc_pvalloc
855 #define mALLINFo	__libc_mallinfo
856 #define mALLOPt		__libc_mallopt
857 
858 #pragma weak calloc = __libc_calloc
859 #pragma weak free = __libc_free
860 #pragma weak cfree = __libc_free
861 #pragma weak malloc = __libc_malloc
862 #pragma weak memalign = __libc_memalign
863 #pragma weak realloc = __libc_realloc
864 #pragma weak valloc = __libc_valloc
865 #pragma weak pvalloc = __libc_pvalloc
866 #pragma weak mallinfo = __libc_mallinfo
867 #pragma weak mallopt = __libc_mallopt
868 
869 #else
870 
871 #ifdef USE_DL_PREFIX
872 #define cALLOc		dlcalloc
873 #define fREe		dlfree
874 #define mALLOc		dlmalloc
875 #define mEMALIGn	dlmemalign
876 #define rEALLOc		dlrealloc
877 #define vALLOc		dlvalloc
878 #define pvALLOc		dlpvalloc
879 #define mALLINFo	dlmallinfo
880 #define mALLOPt		dlmallopt
881 #else /* USE_DL_PREFIX */
882 #define cALLOc		calloc
883 #define fREe		free
884 #define mALLOc		malloc
885 #define mEMALIGn	memalign
886 #define rEALLOc		realloc
887 #define vALLOc		valloc
888 #define pvALLOc		pvalloc
889 #define mALLINFo	mallinfo
890 #define mALLOPt		mallopt
891 #endif /* USE_DL_PREFIX */
892 
893 #endif
894 
895 /* Public routines */
896 
897 #if __STD_C
898 
899 Void_t* mALLOc(size_t);
900 void    fREe(Void_t*);
901 Void_t* rEALLOc(Void_t*, size_t);
902 Void_t* mEMALIGn(size_t, size_t);
903 Void_t* vALLOc(size_t);
904 Void_t* pvALLOc(size_t);
905 Void_t* cALLOc(size_t, size_t);
906 void    cfree(Void_t*);
907 int     malloc_trim(size_t);
908 size_t  malloc_usable_size(Void_t*);
909 void    malloc_stats();
910 int     mALLOPt(int, int);
911 struct mallinfo mALLINFo(void);
912 #else
913 Void_t* mALLOc();
914 void    fREe();
915 Void_t* rEALLOc();
916 Void_t* mEMALIGn();
917 Void_t* vALLOc();
918 Void_t* pvALLOc();
919 Void_t* cALLOc();
920 void    cfree();
921 int     malloc_trim();
922 size_t  malloc_usable_size();
923 void    malloc_stats();
924 int     mALLOPt();
925 struct mallinfo mALLINFo();
926 #endif
927 
928 
929 #ifdef __cplusplus
930 };  /* end of extern "C" */
931 #endif
932 
933 /* ---------- To make a malloc.h, end cutting here ------------ */
934 #endif	/* 0 */			/* Moved to malloc.h */
935 
936 #include <malloc.h>
937 #include <asm/io.h>
938 
939 #ifdef DEBUG
940 #if __STD_C
941 static void malloc_update_mallinfo (void);
942 void malloc_stats (void);
943 #else
944 static void malloc_update_mallinfo ();
945 void malloc_stats();
946 #endif
947 #endif	/* DEBUG */
948 
949 DECLARE_GLOBAL_DATA_PTR;
950 
951 /*
952   Emulation of sbrk for WIN32
953   All code within the ifdef WIN32 is untested by me.
954 
955   Thanks to Martin Fong and others for supplying this.
956 */
957 
958 
959 #ifdef WIN32
960 
961 #define AlignPage(add) (((add) + (malloc_getpagesize-1)) & \
962 ~(malloc_getpagesize-1))
963 #define AlignPage64K(add) (((add) + (0x10000 - 1)) & ~(0x10000 - 1))
964 
965 /* resrve 64MB to insure large contiguous space */
966 #define RESERVED_SIZE (1024*1024*64)
967 #define NEXT_SIZE (2048*1024)
968 #define TOP_MEMORY ((unsigned long)2*1024*1024*1024)
969 
970 struct GmListElement;
971 typedef struct GmListElement GmListElement;
972 
973 struct GmListElement
974 {
975 	GmListElement* next;
976 	void* base;
977 };
978 
979 static GmListElement* head = 0;
980 static unsigned int gNextAddress = 0;
981 static unsigned int gAddressBase = 0;
982 static unsigned int gAllocatedSize = 0;
983 
984 static
985 GmListElement* makeGmListElement (void* bas)
986 {
987 	GmListElement* this;
988 	this = (GmListElement*)(void*)LocalAlloc (0, sizeof (GmListElement));
989 	assert (this);
990 	if (this)
991 	{
992 		this->base = bas;
993 		this->next = head;
994 		head = this;
995 	}
996 	return this;
997 }
998 
999 void gcleanup ()
1000 {
1001 	BOOL rval;
1002 	assert ( (head == NULL) || (head->base == (void*)gAddressBase));
1003 	if (gAddressBase && (gNextAddress - gAddressBase))
1004 	{
1005 		rval = VirtualFree ((void*)gAddressBase,
1006 							gNextAddress - gAddressBase,
1007 							MEM_DECOMMIT);
1008 	assert (rval);
1009 	}
1010 	while (head)
1011 	{
1012 		GmListElement* next = head->next;
1013 		rval = VirtualFree (head->base, 0, MEM_RELEASE);
1014 		assert (rval);
1015 		LocalFree (head);
1016 		head = next;
1017 	}
1018 }
1019 
1020 static
1021 void* findRegion (void* start_address, unsigned long size)
1022 {
1023 	MEMORY_BASIC_INFORMATION info;
1024 	if (size >= TOP_MEMORY) return NULL;
1025 
1026 	while ((unsigned long)start_address + size < TOP_MEMORY)
1027 	{
1028 		VirtualQuery (start_address, &info, sizeof (info));
1029 		if ((info.State == MEM_FREE) && (info.RegionSize >= size))
1030 			return start_address;
1031 		else
1032 		{
1033 			/* Requested region is not available so see if the */
1034 			/* next region is available.  Set 'start_address' */
1035 			/* to the next region and call 'VirtualQuery()' */
1036 			/* again. */
1037 
1038 			start_address = (char*)info.BaseAddress + info.RegionSize;
1039 
1040 			/* Make sure we start looking for the next region */
1041 			/* on the *next* 64K boundary.  Otherwise, even if */
1042 			/* the new region is free according to */
1043 			/* 'VirtualQuery()', the subsequent call to */
1044 			/* 'VirtualAlloc()' (which follows the call to */
1045 			/* this routine in 'wsbrk()') will round *down* */
1046 			/* the requested address to a 64K boundary which */
1047 			/* we already know is an address in the */
1048 			/* unavailable region.  Thus, the subsequent call */
1049 			/* to 'VirtualAlloc()' will fail and bring us back */
1050 			/* here, causing us to go into an infinite loop. */
1051 
1052 			start_address =
1053 				(void *) AlignPage64K((unsigned long) start_address);
1054 		}
1055 	}
1056 	return NULL;
1057 
1058 }
1059 
1060 
1061 void* wsbrk (long size)
1062 {
1063 	void* tmp;
1064 	if (size > 0)
1065 	{
1066 		if (gAddressBase == 0)
1067 		{
1068 			gAllocatedSize = max (RESERVED_SIZE, AlignPage (size));
1069 			gNextAddress = gAddressBase =
1070 				(unsigned int)VirtualAlloc (NULL, gAllocatedSize,
1071 											MEM_RESERVE, PAGE_NOACCESS);
1072 		} else if (AlignPage (gNextAddress + size) > (gAddressBase +
1073 gAllocatedSize))
1074 		{
1075 			long new_size = max (NEXT_SIZE, AlignPage (size));
1076 			void* new_address = (void*)(gAddressBase+gAllocatedSize);
1077 			do
1078 			{
1079 				new_address = findRegion (new_address, new_size);
1080 
1081 				if (new_address == 0)
1082 					return (void*)-1;
1083 
1084 				gAddressBase = gNextAddress =
1085 					(unsigned int)VirtualAlloc (new_address, new_size,
1086 												MEM_RESERVE, PAGE_NOACCESS);
1087 				/* repeat in case of race condition */
1088 				/* The region that we found has been snagged */
1089 				/* by another thread */
1090 			}
1091 			while (gAddressBase == 0);
1092 
1093 			assert (new_address == (void*)gAddressBase);
1094 
1095 			gAllocatedSize = new_size;
1096 
1097 			if (!makeGmListElement ((void*)gAddressBase))
1098 				return (void*)-1;
1099 		}
1100 		if ((size + gNextAddress) > AlignPage (gNextAddress))
1101 		{
1102 			void* res;
1103 			res = VirtualAlloc ((void*)AlignPage (gNextAddress),
1104 								(size + gNextAddress -
1105 								 AlignPage (gNextAddress)),
1106 								MEM_COMMIT, PAGE_READWRITE);
1107 			if (res == 0)
1108 				return (void*)-1;
1109 		}
1110 		tmp = (void*)gNextAddress;
1111 		gNextAddress = (unsigned int)tmp + size;
1112 		return tmp;
1113 	}
1114 	else if (size < 0)
1115 	{
1116 		unsigned int alignedGoal = AlignPage (gNextAddress + size);
1117 		/* Trim by releasing the virtual memory */
1118 		if (alignedGoal >= gAddressBase)
1119 		{
1120 			VirtualFree ((void*)alignedGoal, gNextAddress - alignedGoal,
1121 						 MEM_DECOMMIT);
1122 			gNextAddress = gNextAddress + size;
1123 			return (void*)gNextAddress;
1124 		}
1125 		else
1126 		{
1127 			VirtualFree ((void*)gAddressBase, gNextAddress - gAddressBase,
1128 						 MEM_DECOMMIT);
1129 			gNextAddress = gAddressBase;
1130 			return (void*)-1;
1131 		}
1132 	}
1133 	else
1134 	{
1135 		return (void*)gNextAddress;
1136 	}
1137 }
1138 
1139 #endif
1140 
1141 
1142 
1143 /*
1144   Type declarations
1145 */
1146 
1147 
1148 struct malloc_chunk
1149 {
1150   INTERNAL_SIZE_T prev_size; /* Size of previous chunk (if free). */
1151   INTERNAL_SIZE_T size;      /* Size in bytes, including overhead. */
1152   struct malloc_chunk* fd;   /* double links -- used only if free. */
1153   struct malloc_chunk* bk;
1154 } __attribute__((__may_alias__)) ;
1155 
1156 typedef struct malloc_chunk* mchunkptr;
1157 
1158 /*
1159 
1160    malloc_chunk details:
1161 
1162     (The following includes lightly edited explanations by Colin Plumb.)
1163 
1164     Chunks of memory are maintained using a `boundary tag' method as
1165     described in e.g., Knuth or Standish.  (See the paper by Paul
1166     Wilson ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a
1167     survey of such techniques.)  Sizes of free chunks are stored both
1168     in the front of each chunk and at the end.  This makes
1169     consolidating fragmented chunks into bigger chunks very fast.  The
1170     size fields also hold bits representing whether chunks are free or
1171     in use.
1172 
1173     An allocated chunk looks like this:
1174 
1175 
1176     chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1177 	    |             Size of previous chunk, if allocated            | |
1178 	    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1179 	    |             Size of chunk, in bytes                         |P|
1180       mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1181 	    |             User data starts here...                          .
1182 	    .                                                               .
1183 	    .             (malloc_usable_space() bytes)                     .
1184 	    .                                                               |
1185 nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1186 	    |             Size of chunk                                     |
1187 	    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1188 
1189 
1190     Where "chunk" is the front of the chunk for the purpose of most of
1191     the malloc code, but "mem" is the pointer that is returned to the
1192     user.  "Nextchunk" is the beginning of the next contiguous chunk.
1193 
1194     Chunks always begin on even word boundries, so the mem portion
1195     (which is returned to the user) is also on an even word boundary, and
1196     thus double-word aligned.
1197 
1198     Free chunks are stored in circular doubly-linked lists, and look like this:
1199 
1200     chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1201 	    |             Size of previous chunk                            |
1202 	    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1203     `head:' |             Size of chunk, in bytes                         |P|
1204       mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1205 	    |             Forward pointer to next chunk in list             |
1206 	    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1207 	    |             Back pointer to previous chunk in list            |
1208 	    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1209 	    |             Unused space (may be 0 bytes long)                .
1210 	    .                                                               .
1211 	    .                                                               |
1212 nextchunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1213     `foot:' |             Size of chunk, in bytes                           |
1214 	    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1215 
1216     The P (PREV_INUSE) bit, stored in the unused low-order bit of the
1217     chunk size (which is always a multiple of two words), is an in-use
1218     bit for the *previous* chunk.  If that bit is *clear*, then the
1219     word before the current chunk size contains the previous chunk
1220     size, and can be used to find the front of the previous chunk.
1221     (The very first chunk allocated always has this bit set,
1222     preventing access to non-existent (or non-owned) memory.)
1223 
1224     Note that the `foot' of the current chunk is actually represented
1225     as the prev_size of the NEXT chunk. (This makes it easier to
1226     deal with alignments etc).
1227 
1228     The two exceptions to all this are
1229 
1230      1. The special chunk `top', which doesn't bother using the
1231 	trailing size field since there is no
1232 	next contiguous chunk that would have to index off it. (After
1233 	initialization, `top' is forced to always exist.  If it would
1234 	become less than MINSIZE bytes long, it is replenished via
1235 	malloc_extend_top.)
1236 
1237      2. Chunks allocated via mmap, which have the second-lowest-order
1238 	bit (IS_MMAPPED) set in their size fields.  Because they are
1239 	never merged or traversed from any other chunk, they have no
1240 	foot size or inuse information.
1241 
1242     Available chunks are kept in any of several places (all declared below):
1243 
1244     * `av': An array of chunks serving as bin headers for consolidated
1245        chunks. Each bin is doubly linked.  The bins are approximately
1246        proportionally (log) spaced.  There are a lot of these bins
1247        (128). This may look excessive, but works very well in
1248        practice.  All procedures maintain the invariant that no
1249        consolidated chunk physically borders another one. Chunks in
1250        bins are kept in size order, with ties going to the
1251        approximately least recently used chunk.
1252 
1253        The chunks in each bin are maintained in decreasing sorted order by
1254        size.  This is irrelevant for the small bins, which all contain
1255        the same-sized chunks, but facilitates best-fit allocation for
1256        larger chunks. (These lists are just sequential. Keeping them in
1257        order almost never requires enough traversal to warrant using
1258        fancier ordered data structures.)  Chunks of the same size are
1259        linked with the most recently freed at the front, and allocations
1260        are taken from the back.  This results in LRU or FIFO allocation
1261        order, which tends to give each chunk an equal opportunity to be
1262        consolidated with adjacent freed chunks, resulting in larger free
1263        chunks and less fragmentation.
1264 
1265     * `top': The top-most available chunk (i.e., the one bordering the
1266        end of available memory) is treated specially. It is never
1267        included in any bin, is used only if no other chunk is
1268        available, and is released back to the system if it is very
1269        large (see M_TRIM_THRESHOLD).
1270 
1271     * `last_remainder': A bin holding only the remainder of the
1272        most recently split (non-top) chunk. This bin is checked
1273        before other non-fitting chunks, so as to provide better
1274        locality for runs of sequentially allocated chunks.
1275 
1276     *  Implicitly, through the host system's memory mapping tables.
1277        If supported, requests greater than a threshold are usually
1278        serviced via calls to mmap, and then later released via munmap.
1279 
1280 */
1281 
1282 /*  sizes, alignments */
1283 
1284 #define SIZE_SZ                (sizeof(INTERNAL_SIZE_T))
1285 #define MALLOC_ALIGNMENT       (SIZE_SZ + SIZE_SZ)
1286 #define MALLOC_ALIGN_MASK      (MALLOC_ALIGNMENT - 1)
1287 #define MINSIZE                (sizeof(struct malloc_chunk))
1288 
1289 /* conversion from malloc headers to user pointers, and back */
1290 
1291 #define chunk2mem(p)   ((Void_t*)((char*)(p) + 2*SIZE_SZ))
1292 #define mem2chunk(mem) ((mchunkptr)((char*)(mem) - 2*SIZE_SZ))
1293 
1294 /* pad request bytes into a usable size */
1295 
1296 #define request2size(req) \
1297  (((long)((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) < \
1298   (long)(MINSIZE + MALLOC_ALIGN_MASK)) ? MINSIZE : \
1299    (((req) + (SIZE_SZ + MALLOC_ALIGN_MASK)) & ~(MALLOC_ALIGN_MASK)))
1300 
1301 /* Check if m has acceptable alignment */
1302 
1303 #define aligned_OK(m)    (((unsigned long)((m)) & (MALLOC_ALIGN_MASK)) == 0)
1304 
1305 
1306 
1307 
1308 /*
1309   Physical chunk operations
1310 */
1311 
1312 
1313 /* size field is or'ed with PREV_INUSE when previous adjacent chunk in use */
1314 
1315 #define PREV_INUSE 0x1
1316 
1317 /* size field is or'ed with IS_MMAPPED if the chunk was obtained with mmap() */
1318 
1319 #define IS_MMAPPED 0x2
1320 
1321 /* Bits to mask off when extracting size */
1322 
1323 #define SIZE_BITS (PREV_INUSE|IS_MMAPPED)
1324 
1325 
1326 /* Ptr to next physical malloc_chunk. */
1327 
1328 #define next_chunk(p) ((mchunkptr)( ((char*)(p)) + ((p)->size & ~PREV_INUSE) ))
1329 
1330 /* Ptr to previous physical malloc_chunk */
1331 
1332 #define prev_chunk(p)\
1333    ((mchunkptr)( ((char*)(p)) - ((p)->prev_size) ))
1334 
1335 
1336 /* Treat space at ptr + offset as a chunk */
1337 
1338 #define chunk_at_offset(p, s)  ((mchunkptr)(((char*)(p)) + (s)))
1339 
1340 
1341 
1342 
1343 /*
1344   Dealing with use bits
1345 */
1346 
1347 /* extract p's inuse bit */
1348 
1349 #define inuse(p)\
1350 ((((mchunkptr)(((char*)(p))+((p)->size & ~PREV_INUSE)))->size) & PREV_INUSE)
1351 
1352 /* extract inuse bit of previous chunk */
1353 
1354 #define prev_inuse(p)  ((p)->size & PREV_INUSE)
1355 
1356 /* check for mmap()'ed chunk */
1357 
1358 #define chunk_is_mmapped(p) ((p)->size & IS_MMAPPED)
1359 
1360 /* set/clear chunk as in use without otherwise disturbing */
1361 
1362 #define set_inuse(p)\
1363 ((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size |= PREV_INUSE
1364 
1365 #define clear_inuse(p)\
1366 ((mchunkptr)(((char*)(p)) + ((p)->size & ~PREV_INUSE)))->size &= ~(PREV_INUSE)
1367 
1368 /* check/set/clear inuse bits in known places */
1369 
1370 #define inuse_bit_at_offset(p, s)\
1371  (((mchunkptr)(((char*)(p)) + (s)))->size & PREV_INUSE)
1372 
1373 #define set_inuse_bit_at_offset(p, s)\
1374  (((mchunkptr)(((char*)(p)) + (s)))->size |= PREV_INUSE)
1375 
1376 #define clear_inuse_bit_at_offset(p, s)\
1377  (((mchunkptr)(((char*)(p)) + (s)))->size &= ~(PREV_INUSE))
1378 
1379 
1380 
1381 
1382 /*
1383   Dealing with size fields
1384 */
1385 
1386 /* Get size, ignoring use bits */
1387 
1388 #define chunksize(p)          ((p)->size & ~(SIZE_BITS))
1389 
1390 /* Set size at head, without disturbing its use bit */
1391 
1392 #define set_head_size(p, s)   ((p)->size = (((p)->size & PREV_INUSE) | (s)))
1393 
1394 /* Set size/use ignoring previous bits in header */
1395 
1396 #define set_head(p, s)        ((p)->size = (s))
1397 
1398 /* Set size at footer (only when chunk is not in use) */
1399 
1400 #define set_foot(p, s)   (((mchunkptr)((char*)(p) + (s)))->prev_size = (s))
1401 
1402 
1403 
1404 
1405 
1406 /*
1407    Bins
1408 
1409     The bins, `av_' are an array of pairs of pointers serving as the
1410     heads of (initially empty) doubly-linked lists of chunks, laid out
1411     in a way so that each pair can be treated as if it were in a
1412     malloc_chunk. (This way, the fd/bk offsets for linking bin heads
1413     and chunks are the same).
1414 
1415     Bins for sizes < 512 bytes contain chunks of all the same size, spaced
1416     8 bytes apart. Larger bins are approximately logarithmically
1417     spaced. (See the table below.) The `av_' array is never mentioned
1418     directly in the code, but instead via bin access macros.
1419 
1420     Bin layout:
1421 
1422     64 bins of size       8
1423     32 bins of size      64
1424     16 bins of size     512
1425      8 bins of size    4096
1426      4 bins of size   32768
1427      2 bins of size  262144
1428      1 bin  of size what's left
1429 
1430     There is actually a little bit of slop in the numbers in bin_index
1431     for the sake of speed. This makes no difference elsewhere.
1432 
1433     The special chunks `top' and `last_remainder' get their own bins,
1434     (this is implemented via yet more trickery with the av_ array),
1435     although `top' is never properly linked to its bin since it is
1436     always handled specially.
1437 
1438 */
1439 
1440 #define NAV             128   /* number of bins */
1441 
1442 typedef struct malloc_chunk* mbinptr;
1443 
1444 /* access macros */
1445 
1446 #define bin_at(i)      ((mbinptr)((char*)&(av_[2*(i) + 2]) - 2*SIZE_SZ))
1447 #define next_bin(b)    ((mbinptr)((char*)(b) + 2 * sizeof(mbinptr)))
1448 #define prev_bin(b)    ((mbinptr)((char*)(b) - 2 * sizeof(mbinptr)))
1449 
1450 /*
1451    The first 2 bins are never indexed. The corresponding av_ cells are instead
1452    used for bookkeeping. This is not to save space, but to simplify
1453    indexing, maintain locality, and avoid some initialization tests.
1454 */
1455 
1456 #define top            (av_[2])          /* The topmost chunk */
1457 #define last_remainder (bin_at(1))       /* remainder from last split */
1458 
1459 
1460 /*
1461    Because top initially points to its own bin with initial
1462    zero size, thus forcing extension on the first malloc request,
1463    we avoid having any special code in malloc to check whether
1464    it even exists yet. But we still need to in malloc_extend_top.
1465 */
1466 
1467 #define initial_top    ((mchunkptr)(bin_at(0)))
1468 
1469 /* Helper macro to initialize bins */
1470 
1471 #define IAV(i)  bin_at(i), bin_at(i)
1472 
1473 static mbinptr av_[NAV * 2 + 2] = {
1474  NULL, NULL,
1475  IAV(0),   IAV(1),   IAV(2),   IAV(3),   IAV(4),   IAV(5),   IAV(6),   IAV(7),
1476  IAV(8),   IAV(9),   IAV(10),  IAV(11),  IAV(12),  IAV(13),  IAV(14),  IAV(15),
1477  IAV(16),  IAV(17),  IAV(18),  IAV(19),  IAV(20),  IAV(21),  IAV(22),  IAV(23),
1478  IAV(24),  IAV(25),  IAV(26),  IAV(27),  IAV(28),  IAV(29),  IAV(30),  IAV(31),
1479  IAV(32),  IAV(33),  IAV(34),  IAV(35),  IAV(36),  IAV(37),  IAV(38),  IAV(39),
1480  IAV(40),  IAV(41),  IAV(42),  IAV(43),  IAV(44),  IAV(45),  IAV(46),  IAV(47),
1481  IAV(48),  IAV(49),  IAV(50),  IAV(51),  IAV(52),  IAV(53),  IAV(54),  IAV(55),
1482  IAV(56),  IAV(57),  IAV(58),  IAV(59),  IAV(60),  IAV(61),  IAV(62),  IAV(63),
1483  IAV(64),  IAV(65),  IAV(66),  IAV(67),  IAV(68),  IAV(69),  IAV(70),  IAV(71),
1484  IAV(72),  IAV(73),  IAV(74),  IAV(75),  IAV(76),  IAV(77),  IAV(78),  IAV(79),
1485  IAV(80),  IAV(81),  IAV(82),  IAV(83),  IAV(84),  IAV(85),  IAV(86),  IAV(87),
1486  IAV(88),  IAV(89),  IAV(90),  IAV(91),  IAV(92),  IAV(93),  IAV(94),  IAV(95),
1487  IAV(96),  IAV(97),  IAV(98),  IAV(99),  IAV(100), IAV(101), IAV(102), IAV(103),
1488  IAV(104), IAV(105), IAV(106), IAV(107), IAV(108), IAV(109), IAV(110), IAV(111),
1489  IAV(112), IAV(113), IAV(114), IAV(115), IAV(116), IAV(117), IAV(118), IAV(119),
1490  IAV(120), IAV(121), IAV(122), IAV(123), IAV(124), IAV(125), IAV(126), IAV(127)
1491 };
1492 
1493 #ifdef CONFIG_NEEDS_MANUAL_RELOC
1494 static void malloc_bin_reloc(void)
1495 {
1496 	mbinptr *p = &av_[2];
1497 	size_t i;
1498 
1499 	for (i = 2; i < ARRAY_SIZE(av_); ++i, ++p)
1500 		*p = (mbinptr)((ulong)*p + gd->reloc_off);
1501 }
1502 #else
1503 static inline void malloc_bin_reloc(void) {}
1504 #endif
1505 
1506 ulong mem_malloc_start = 0;
1507 ulong mem_malloc_end = 0;
1508 ulong mem_malloc_brk = 0;
1509 
1510 void *sbrk(ptrdiff_t increment)
1511 {
1512 	ulong old = mem_malloc_brk;
1513 	ulong new = old + increment;
1514 
1515 	/*
1516 	 * if we are giving memory back make sure we clear it out since
1517 	 * we set MORECORE_CLEARS to 1
1518 	 */
1519 	if (increment < 0)
1520 		memset((void *)new, 0, -increment);
1521 
1522 	if ((new < mem_malloc_start) || (new > mem_malloc_end))
1523 		return (void *)MORECORE_FAILURE;
1524 
1525 	mem_malloc_brk = new;
1526 
1527 	return (void *)old;
1528 }
1529 
1530 void mem_malloc_init(ulong start, ulong size)
1531 {
1532 	mem_malloc_start = start;
1533 	mem_malloc_end = start + size;
1534 	mem_malloc_brk = start;
1535 
1536 	debug("using memory %#lx-%#lx for malloc()\n", mem_malloc_start,
1537 	      mem_malloc_end);
1538 #ifdef CONFIG_SYS_MALLOC_CLEAR_ON_INIT
1539 	memset((void *)mem_malloc_start, 0x0, size);
1540 #endif
1541 	malloc_bin_reloc();
1542 }
1543 
1544 /* field-extraction macros */
1545 
1546 #define first(b) ((b)->fd)
1547 #define last(b)  ((b)->bk)
1548 
1549 /*
1550   Indexing into bins
1551 */
1552 
1553 #define bin_index(sz)                                                          \
1554 (((((unsigned long)(sz)) >> 9) ==    0) ?       (((unsigned long)(sz)) >>  3): \
1555  ((((unsigned long)(sz)) >> 9) <=    4) ?  56 + (((unsigned long)(sz)) >>  6): \
1556  ((((unsigned long)(sz)) >> 9) <=   20) ?  91 + (((unsigned long)(sz)) >>  9): \
1557  ((((unsigned long)(sz)) >> 9) <=   84) ? 110 + (((unsigned long)(sz)) >> 12): \
1558  ((((unsigned long)(sz)) >> 9) <=  340) ? 119 + (((unsigned long)(sz)) >> 15): \
1559  ((((unsigned long)(sz)) >> 9) <= 1364) ? 124 + (((unsigned long)(sz)) >> 18): \
1560 					  126)
1561 /*
1562   bins for chunks < 512 are all spaced 8 bytes apart, and hold
1563   identically sized chunks. This is exploited in malloc.
1564 */
1565 
1566 #define MAX_SMALLBIN         63
1567 #define MAX_SMALLBIN_SIZE   512
1568 #define SMALLBIN_WIDTH        8
1569 
1570 #define smallbin_index(sz)  (((unsigned long)(sz)) >> 3)
1571 
1572 /*
1573    Requests are `small' if both the corresponding and the next bin are small
1574 */
1575 
1576 #define is_small_request(nb) (nb < MAX_SMALLBIN_SIZE - SMALLBIN_WIDTH)
1577 
1578 
1579 
1580 /*
1581     To help compensate for the large number of bins, a one-level index
1582     structure is used for bin-by-bin searching.  `binblocks' is a
1583     one-word bitvector recording whether groups of BINBLOCKWIDTH bins
1584     have any (possibly) non-empty bins, so they can be skipped over
1585     all at once during during traversals. The bits are NOT always
1586     cleared as soon as all bins in a block are empty, but instead only
1587     when all are noticed to be empty during traversal in malloc.
1588 */
1589 
1590 #define BINBLOCKWIDTH     4   /* bins per block */
1591 
1592 #define binblocks_r     ((INTERNAL_SIZE_T)av_[1]) /* bitvector of nonempty blocks */
1593 #define binblocks_w     (av_[1])
1594 
1595 /* bin<->block macros */
1596 
1597 #define idx2binblock(ix)    ((unsigned)1 << (ix / BINBLOCKWIDTH))
1598 #define mark_binblock(ii)   (binblocks_w = (mbinptr)(binblocks_r | idx2binblock(ii)))
1599 #define clear_binblock(ii)  (binblocks_w = (mbinptr)(binblocks_r & ~(idx2binblock(ii))))
1600 
1601 
1602 
1603 
1604 
1605 /*  Other static bookkeeping data */
1606 
1607 /* variables holding tunable values */
1608 
1609 static unsigned long trim_threshold   = DEFAULT_TRIM_THRESHOLD;
1610 static unsigned long top_pad          = DEFAULT_TOP_PAD;
1611 static unsigned int  n_mmaps_max      = DEFAULT_MMAP_MAX;
1612 static unsigned long mmap_threshold   = DEFAULT_MMAP_THRESHOLD;
1613 
1614 /* The first value returned from sbrk */
1615 static char* sbrk_base = (char*)(-1);
1616 
1617 /* The maximum memory obtained from system via sbrk */
1618 static unsigned long max_sbrked_mem = 0;
1619 
1620 /* The maximum via either sbrk or mmap */
1621 static unsigned long max_total_mem = 0;
1622 
1623 /* internal working copy of mallinfo */
1624 static struct mallinfo current_mallinfo = {  0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
1625 
1626 /* The total memory obtained from system via sbrk */
1627 #define sbrked_mem  (current_mallinfo.arena)
1628 
1629 /* Tracking mmaps */
1630 
1631 #ifdef DEBUG
1632 static unsigned int n_mmaps = 0;
1633 #endif	/* DEBUG */
1634 static unsigned long mmapped_mem = 0;
1635 #if HAVE_MMAP
1636 static unsigned int max_n_mmaps = 0;
1637 static unsigned long max_mmapped_mem = 0;
1638 #endif
1639 
1640 
1641 
1642 /*
1643   Debugging support
1644 */
1645 
1646 #ifdef DEBUG
1647 
1648 
1649 /*
1650   These routines make a number of assertions about the states
1651   of data structures that should be true at all times. If any
1652   are not true, it's very likely that a user program has somehow
1653   trashed memory. (It's also possible that there is a coding error
1654   in malloc. In which case, please report it!)
1655 */
1656 
1657 #if __STD_C
1658 static void do_check_chunk(mchunkptr p)
1659 #else
1660 static void do_check_chunk(p) mchunkptr p;
1661 #endif
1662 {
1663   INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
1664 
1665   /* No checkable chunk is mmapped */
1666   assert(!chunk_is_mmapped(p));
1667 
1668   /* Check for legal address ... */
1669   assert((char*)p >= sbrk_base);
1670   if (p != top)
1671     assert((char*)p + sz <= (char*)top);
1672   else
1673     assert((char*)p + sz <= sbrk_base + sbrked_mem);
1674 
1675 }
1676 
1677 
1678 #if __STD_C
1679 static void do_check_free_chunk(mchunkptr p)
1680 #else
1681 static void do_check_free_chunk(p) mchunkptr p;
1682 #endif
1683 {
1684   INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
1685   mchunkptr next = chunk_at_offset(p, sz);
1686 
1687   do_check_chunk(p);
1688 
1689   /* Check whether it claims to be free ... */
1690   assert(!inuse(p));
1691 
1692   /* Unless a special marker, must have OK fields */
1693   if ((long)sz >= (long)MINSIZE)
1694   {
1695     assert((sz & MALLOC_ALIGN_MASK) == 0);
1696     assert(aligned_OK(chunk2mem(p)));
1697     /* ... matching footer field */
1698     assert(next->prev_size == sz);
1699     /* ... and is fully consolidated */
1700     assert(prev_inuse(p));
1701     assert (next == top || inuse(next));
1702 
1703     /* ... and has minimally sane links */
1704     assert(p->fd->bk == p);
1705     assert(p->bk->fd == p);
1706   }
1707   else /* markers are always of size SIZE_SZ */
1708     assert(sz == SIZE_SZ);
1709 }
1710 
1711 #if __STD_C
1712 static void do_check_inuse_chunk(mchunkptr p)
1713 #else
1714 static void do_check_inuse_chunk(p) mchunkptr p;
1715 #endif
1716 {
1717   mchunkptr next = next_chunk(p);
1718   do_check_chunk(p);
1719 
1720   /* Check whether it claims to be in use ... */
1721   assert(inuse(p));
1722 
1723   /* ... and is surrounded by OK chunks.
1724     Since more things can be checked with free chunks than inuse ones,
1725     if an inuse chunk borders them and debug is on, it's worth doing them.
1726   */
1727   if (!prev_inuse(p))
1728   {
1729     mchunkptr prv = prev_chunk(p);
1730     assert(next_chunk(prv) == p);
1731     do_check_free_chunk(prv);
1732   }
1733   if (next == top)
1734   {
1735     assert(prev_inuse(next));
1736     assert(chunksize(next) >= MINSIZE);
1737   }
1738   else if (!inuse(next))
1739     do_check_free_chunk(next);
1740 
1741 }
1742 
1743 #if __STD_C
1744 static void do_check_malloced_chunk(mchunkptr p, INTERNAL_SIZE_T s)
1745 #else
1746 static void do_check_malloced_chunk(p, s) mchunkptr p; INTERNAL_SIZE_T s;
1747 #endif
1748 {
1749   INTERNAL_SIZE_T sz = p->size & ~PREV_INUSE;
1750   long room = sz - s;
1751 
1752   do_check_inuse_chunk(p);
1753 
1754   /* Legal size ... */
1755   assert((long)sz >= (long)MINSIZE);
1756   assert((sz & MALLOC_ALIGN_MASK) == 0);
1757   assert(room >= 0);
1758   assert(room < (long)MINSIZE);
1759 
1760   /* ... and alignment */
1761   assert(aligned_OK(chunk2mem(p)));
1762 
1763 
1764   /* ... and was allocated at front of an available chunk */
1765   assert(prev_inuse(p));
1766 
1767 }
1768 
1769 
1770 #define check_free_chunk(P)  do_check_free_chunk(P)
1771 #define check_inuse_chunk(P) do_check_inuse_chunk(P)
1772 #define check_chunk(P) do_check_chunk(P)
1773 #define check_malloced_chunk(P,N) do_check_malloced_chunk(P,N)
1774 #else
1775 #define check_free_chunk(P)
1776 #define check_inuse_chunk(P)
1777 #define check_chunk(P)
1778 #define check_malloced_chunk(P,N)
1779 #endif
1780 
1781 
1782 
1783 /*
1784   Macro-based internal utilities
1785 */
1786 
1787 
1788 /*
1789   Linking chunks in bin lists.
1790   Call these only with variables, not arbitrary expressions, as arguments.
1791 */
1792 
1793 /*
1794   Place chunk p of size s in its bin, in size order,
1795   putting it ahead of others of same size.
1796 */
1797 
1798 
1799 #define frontlink(P, S, IDX, BK, FD)                                          \
1800 {                                                                             \
1801   if (S < MAX_SMALLBIN_SIZE)                                                  \
1802   {                                                                           \
1803     IDX = smallbin_index(S);                                                  \
1804     mark_binblock(IDX);                                                       \
1805     BK = bin_at(IDX);                                                         \
1806     FD = BK->fd;                                                              \
1807     P->bk = BK;                                                               \
1808     P->fd = FD;                                                               \
1809     FD->bk = BK->fd = P;                                                      \
1810   }                                                                           \
1811   else                                                                        \
1812   {                                                                           \
1813     IDX = bin_index(S);                                                       \
1814     BK = bin_at(IDX);                                                         \
1815     FD = BK->fd;                                                              \
1816     if (FD == BK) mark_binblock(IDX);                                         \
1817     else                                                                      \
1818     {                                                                         \
1819       while (FD != BK && S < chunksize(FD)) FD = FD->fd;                      \
1820       BK = FD->bk;                                                            \
1821     }                                                                         \
1822     P->bk = BK;                                                               \
1823     P->fd = FD;                                                               \
1824     FD->bk = BK->fd = P;                                                      \
1825   }                                                                           \
1826 }
1827 
1828 
1829 /* take a chunk off a list */
1830 
1831 #define unlink(P, BK, FD)                                                     \
1832 {                                                                             \
1833   BK = P->bk;                                                                 \
1834   FD = P->fd;                                                                 \
1835   FD->bk = BK;                                                                \
1836   BK->fd = FD;                                                                \
1837 }                                                                             \
1838 
1839 /* Place p as the last remainder */
1840 
1841 #define link_last_remainder(P)                                                \
1842 {                                                                             \
1843   last_remainder->fd = last_remainder->bk =  P;                               \
1844   P->fd = P->bk = last_remainder;                                             \
1845 }
1846 
1847 /* Clear the last_remainder bin */
1848 
1849 #define clear_last_remainder \
1850   (last_remainder->fd = last_remainder->bk = last_remainder)
1851 
1852 
1853 
1854 
1855 
1856 /* Routines dealing with mmap(). */
1857 
1858 #if HAVE_MMAP
1859 
1860 #if __STD_C
1861 static mchunkptr mmap_chunk(size_t size)
1862 #else
1863 static mchunkptr mmap_chunk(size) size_t size;
1864 #endif
1865 {
1866   size_t page_mask = malloc_getpagesize - 1;
1867   mchunkptr p;
1868 
1869 #ifndef MAP_ANONYMOUS
1870   static int fd = -1;
1871 #endif
1872 
1873   if(n_mmaps >= n_mmaps_max) return 0; /* too many regions */
1874 
1875   /* For mmapped chunks, the overhead is one SIZE_SZ unit larger, because
1876    * there is no following chunk whose prev_size field could be used.
1877    */
1878   size = (size + SIZE_SZ + page_mask) & ~page_mask;
1879 
1880 #ifdef MAP_ANONYMOUS
1881   p = (mchunkptr)mmap(0, size, PROT_READ|PROT_WRITE,
1882 		      MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
1883 #else /* !MAP_ANONYMOUS */
1884   if (fd < 0)
1885   {
1886     fd = open("/dev/zero", O_RDWR);
1887     if(fd < 0) return 0;
1888   }
1889   p = (mchunkptr)mmap(0, size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
1890 #endif
1891 
1892   if(p == (mchunkptr)-1) return 0;
1893 
1894   n_mmaps++;
1895   if (n_mmaps > max_n_mmaps) max_n_mmaps = n_mmaps;
1896 
1897   /* We demand that eight bytes into a page must be 8-byte aligned. */
1898   assert(aligned_OK(chunk2mem(p)));
1899 
1900   /* The offset to the start of the mmapped region is stored
1901    * in the prev_size field of the chunk; normally it is zero,
1902    * but that can be changed in memalign().
1903    */
1904   p->prev_size = 0;
1905   set_head(p, size|IS_MMAPPED);
1906 
1907   mmapped_mem += size;
1908   if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem)
1909     max_mmapped_mem = mmapped_mem;
1910   if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
1911     max_total_mem = mmapped_mem + sbrked_mem;
1912   return p;
1913 }
1914 
1915 #if __STD_C
1916 static void munmap_chunk(mchunkptr p)
1917 #else
1918 static void munmap_chunk(p) mchunkptr p;
1919 #endif
1920 {
1921   INTERNAL_SIZE_T size = chunksize(p);
1922   int ret;
1923 
1924   assert (chunk_is_mmapped(p));
1925   assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem));
1926   assert((n_mmaps > 0));
1927   assert(((p->prev_size + size) & (malloc_getpagesize-1)) == 0);
1928 
1929   n_mmaps--;
1930   mmapped_mem -= (size + p->prev_size);
1931 
1932   ret = munmap((char *)p - p->prev_size, size + p->prev_size);
1933 
1934   /* munmap returns non-zero on failure */
1935   assert(ret == 0);
1936 }
1937 
1938 #if HAVE_MREMAP
1939 
1940 #if __STD_C
1941 static mchunkptr mremap_chunk(mchunkptr p, size_t new_size)
1942 #else
1943 static mchunkptr mremap_chunk(p, new_size) mchunkptr p; size_t new_size;
1944 #endif
1945 {
1946   size_t page_mask = malloc_getpagesize - 1;
1947   INTERNAL_SIZE_T offset = p->prev_size;
1948   INTERNAL_SIZE_T size = chunksize(p);
1949   char *cp;
1950 
1951   assert (chunk_is_mmapped(p));
1952   assert(! ((char*)p >= sbrk_base && (char*)p < sbrk_base + sbrked_mem));
1953   assert((n_mmaps > 0));
1954   assert(((size + offset) & (malloc_getpagesize-1)) == 0);
1955 
1956   /* Note the extra SIZE_SZ overhead as in mmap_chunk(). */
1957   new_size = (new_size + offset + SIZE_SZ + page_mask) & ~page_mask;
1958 
1959   cp = (char *)mremap((char *)p - offset, size + offset, new_size, 1);
1960 
1961   if (cp == (char *)-1) return 0;
1962 
1963   p = (mchunkptr)(cp + offset);
1964 
1965   assert(aligned_OK(chunk2mem(p)));
1966 
1967   assert((p->prev_size == offset));
1968   set_head(p, (new_size - offset)|IS_MMAPPED);
1969 
1970   mmapped_mem -= size + offset;
1971   mmapped_mem += new_size;
1972   if ((unsigned long)mmapped_mem > (unsigned long)max_mmapped_mem)
1973     max_mmapped_mem = mmapped_mem;
1974   if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
1975     max_total_mem = mmapped_mem + sbrked_mem;
1976   return p;
1977 }
1978 
1979 #endif /* HAVE_MREMAP */
1980 
1981 #endif /* HAVE_MMAP */
1982 
1983 
1984 
1985 
1986 /*
1987   Extend the top-most chunk by obtaining memory from system.
1988   Main interface to sbrk (but see also malloc_trim).
1989 */
1990 
1991 #if __STD_C
1992 static void malloc_extend_top(INTERNAL_SIZE_T nb)
1993 #else
1994 static void malloc_extend_top(nb) INTERNAL_SIZE_T nb;
1995 #endif
1996 {
1997   char*     brk;                  /* return value from sbrk */
1998   INTERNAL_SIZE_T front_misalign; /* unusable bytes at front of sbrked space */
1999   INTERNAL_SIZE_T correction;     /* bytes for 2nd sbrk call */
2000   char*     new_brk;              /* return of 2nd sbrk call */
2001   INTERNAL_SIZE_T top_size;       /* new size of top chunk */
2002 
2003   mchunkptr old_top     = top;  /* Record state of old top */
2004   INTERNAL_SIZE_T old_top_size = chunksize(old_top);
2005   char*     old_end      = (char*)(chunk_at_offset(old_top, old_top_size));
2006 
2007   /* Pad request with top_pad plus minimal overhead */
2008 
2009   INTERNAL_SIZE_T    sbrk_size     = nb + top_pad + MINSIZE;
2010   unsigned long pagesz    = malloc_getpagesize;
2011 
2012   /* If not the first time through, round to preserve page boundary */
2013   /* Otherwise, we need to correct to a page size below anyway. */
2014   /* (We also correct below if an intervening foreign sbrk call.) */
2015 
2016   if (sbrk_base != (char*)(-1))
2017     sbrk_size = (sbrk_size + (pagesz - 1)) & ~(pagesz - 1);
2018 
2019   brk = (char*)(MORECORE (sbrk_size));
2020 
2021   /* Fail if sbrk failed or if a foreign sbrk call killed our space */
2022   if (brk == (char*)(MORECORE_FAILURE) ||
2023       (brk < old_end && old_top != initial_top))
2024     return;
2025 
2026   sbrked_mem += sbrk_size;
2027 
2028   if (brk == old_end) /* can just add bytes to current top */
2029   {
2030     top_size = sbrk_size + old_top_size;
2031     set_head(top, top_size | PREV_INUSE);
2032   }
2033   else
2034   {
2035     if (sbrk_base == (char*)(-1))  /* First time through. Record base */
2036       sbrk_base = brk;
2037     else  /* Someone else called sbrk().  Count those bytes as sbrked_mem. */
2038       sbrked_mem += brk - (char*)old_end;
2039 
2040     /* Guarantee alignment of first new chunk made from this space */
2041     front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK;
2042     if (front_misalign > 0)
2043     {
2044       correction = (MALLOC_ALIGNMENT) - front_misalign;
2045       brk += correction;
2046     }
2047     else
2048       correction = 0;
2049 
2050     /* Guarantee the next brk will be at a page boundary */
2051 
2052     correction += ((((unsigned long)(brk + sbrk_size))+(pagesz-1)) &
2053 		   ~(pagesz - 1)) - ((unsigned long)(brk + sbrk_size));
2054 
2055     /* Allocate correction */
2056     new_brk = (char*)(MORECORE (correction));
2057     if (new_brk == (char*)(MORECORE_FAILURE)) return;
2058 
2059     sbrked_mem += correction;
2060 
2061     top = (mchunkptr)brk;
2062     top_size = new_brk - brk + correction;
2063     set_head(top, top_size | PREV_INUSE);
2064 
2065     if (old_top != initial_top)
2066     {
2067 
2068       /* There must have been an intervening foreign sbrk call. */
2069       /* A double fencepost is necessary to prevent consolidation */
2070 
2071       /* If not enough space to do this, then user did something very wrong */
2072       if (old_top_size < MINSIZE)
2073       {
2074 	set_head(top, PREV_INUSE); /* will force null return from malloc */
2075 	return;
2076       }
2077 
2078       /* Also keep size a multiple of MALLOC_ALIGNMENT */
2079       old_top_size = (old_top_size - 3*SIZE_SZ) & ~MALLOC_ALIGN_MASK;
2080       set_head_size(old_top, old_top_size);
2081       chunk_at_offset(old_top, old_top_size          )->size =
2082 	SIZE_SZ|PREV_INUSE;
2083       chunk_at_offset(old_top, old_top_size + SIZE_SZ)->size =
2084 	SIZE_SZ|PREV_INUSE;
2085       /* If possible, release the rest. */
2086       if (old_top_size >= MINSIZE)
2087 	fREe(chunk2mem(old_top));
2088     }
2089   }
2090 
2091   if ((unsigned long)sbrked_mem > (unsigned long)max_sbrked_mem)
2092     max_sbrked_mem = sbrked_mem;
2093   if ((unsigned long)(mmapped_mem + sbrked_mem) > (unsigned long)max_total_mem)
2094     max_total_mem = mmapped_mem + sbrked_mem;
2095 
2096   /* We always land on a page boundary */
2097   assert(((unsigned long)((char*)top + top_size) & (pagesz - 1)) == 0);
2098 }
2099 
2100 
2101 
2102 
2103 /* Main public routines */
2104 
2105 
2106 /*
2107   Malloc Algorthim:
2108 
2109     The requested size is first converted into a usable form, `nb'.
2110     This currently means to add 4 bytes overhead plus possibly more to
2111     obtain 8-byte alignment and/or to obtain a size of at least
2112     MINSIZE (currently 16 bytes), the smallest allocatable size.
2113     (All fits are considered `exact' if they are within MINSIZE bytes.)
2114 
2115     From there, the first successful of the following steps is taken:
2116 
2117       1. The bin corresponding to the request size is scanned, and if
2118 	 a chunk of exactly the right size is found, it is taken.
2119 
2120       2. The most recently remaindered chunk is used if it is big
2121 	 enough.  This is a form of (roving) first fit, used only in
2122 	 the absence of exact fits. Runs of consecutive requests use
2123 	 the remainder of the chunk used for the previous such request
2124 	 whenever possible. This limited use of a first-fit style
2125 	 allocation strategy tends to give contiguous chunks
2126 	 coextensive lifetimes, which improves locality and can reduce
2127 	 fragmentation in the long run.
2128 
2129       3. Other bins are scanned in increasing size order, using a
2130 	 chunk big enough to fulfill the request, and splitting off
2131 	 any remainder.  This search is strictly by best-fit; i.e.,
2132 	 the smallest (with ties going to approximately the least
2133 	 recently used) chunk that fits is selected.
2134 
2135       4. If large enough, the chunk bordering the end of memory
2136 	 (`top') is split off. (This use of `top' is in accord with
2137 	 the best-fit search rule.  In effect, `top' is treated as
2138 	 larger (and thus less well fitting) than any other available
2139 	 chunk since it can be extended to be as large as necessary
2140 	 (up to system limitations).
2141 
2142       5. If the request size meets the mmap threshold and the
2143 	 system supports mmap, and there are few enough currently
2144 	 allocated mmapped regions, and a call to mmap succeeds,
2145 	 the request is allocated via direct memory mapping.
2146 
2147       6. Otherwise, the top of memory is extended by
2148 	 obtaining more space from the system (normally using sbrk,
2149 	 but definable to anything else via the MORECORE macro).
2150 	 Memory is gathered from the system (in system page-sized
2151 	 units) in a way that allows chunks obtained across different
2152 	 sbrk calls to be consolidated, but does not require
2153 	 contiguous memory. Thus, it should be safe to intersperse
2154 	 mallocs with other sbrk calls.
2155 
2156 
2157       All allocations are made from the the `lowest' part of any found
2158       chunk. (The implementation invariant is that prev_inuse is
2159       always true of any allocated chunk; i.e., that each allocated
2160       chunk borders either a previously allocated and still in-use chunk,
2161       or the base of its memory arena.)
2162 
2163 */
2164 
2165 #if __STD_C
2166 Void_t* mALLOc(size_t bytes)
2167 #else
2168 Void_t* mALLOc(bytes) size_t bytes;
2169 #endif
2170 {
2171   mchunkptr victim;                  /* inspected/selected chunk */
2172   INTERNAL_SIZE_T victim_size;       /* its size */
2173   int       idx;                     /* index for bin traversal */
2174   mbinptr   bin;                     /* associated bin */
2175   mchunkptr remainder;               /* remainder from a split */
2176   long      remainder_size;          /* its size */
2177   int       remainder_index;         /* its bin index */
2178   unsigned long block;               /* block traverser bit */
2179   int       startidx;                /* first bin of a traversed block */
2180   mchunkptr fwd;                     /* misc temp for linking */
2181   mchunkptr bck;                     /* misc temp for linking */
2182   mbinptr q;                         /* misc temp */
2183 
2184   INTERNAL_SIZE_T nb;
2185 
2186 #ifdef CONFIG_SYS_MALLOC_F_LEN
2187 	if (gd && !(gd->flags & GD_FLG_FULL_MALLOC_INIT))
2188 		return malloc_simple(bytes);
2189 #endif
2190 
2191   /* check if mem_malloc_init() was run */
2192   if ((mem_malloc_start == 0) && (mem_malloc_end == 0)) {
2193     /* not initialized yet */
2194     return NULL;
2195   }
2196 
2197   if ((long)bytes < 0) return NULL;
2198 
2199   nb = request2size(bytes);  /* padded request size; */
2200 
2201   /* Check for exact match in a bin */
2202 
2203   if (is_small_request(nb))  /* Faster version for small requests */
2204   {
2205     idx = smallbin_index(nb);
2206 
2207     /* No traversal or size check necessary for small bins.  */
2208 
2209     q = bin_at(idx);
2210     victim = last(q);
2211 
2212     /* Also scan the next one, since it would have a remainder < MINSIZE */
2213     if (victim == q)
2214     {
2215       q = next_bin(q);
2216       victim = last(q);
2217     }
2218     if (victim != q)
2219     {
2220       victim_size = chunksize(victim);
2221       unlink(victim, bck, fwd);
2222       set_inuse_bit_at_offset(victim, victim_size);
2223       check_malloced_chunk(victim, nb);
2224       return chunk2mem(victim);
2225     }
2226 
2227     idx += 2; /* Set for bin scan below. We've already scanned 2 bins. */
2228 
2229   }
2230   else
2231   {
2232     idx = bin_index(nb);
2233     bin = bin_at(idx);
2234 
2235     for (victim = last(bin); victim != bin; victim = victim->bk)
2236     {
2237       victim_size = chunksize(victim);
2238       remainder_size = victim_size - nb;
2239 
2240       if (remainder_size >= (long)MINSIZE) /* too big */
2241       {
2242 	--idx; /* adjust to rescan below after checking last remainder */
2243 	break;
2244       }
2245 
2246       else if (remainder_size >= 0) /* exact fit */
2247       {
2248 	unlink(victim, bck, fwd);
2249 	set_inuse_bit_at_offset(victim, victim_size);
2250 	check_malloced_chunk(victim, nb);
2251 	return chunk2mem(victim);
2252       }
2253     }
2254 
2255     ++idx;
2256 
2257   }
2258 
2259   /* Try to use the last split-off remainder */
2260 
2261   if ( (victim = last_remainder->fd) != last_remainder)
2262   {
2263     victim_size = chunksize(victim);
2264     remainder_size = victim_size - nb;
2265 
2266     if (remainder_size >= (long)MINSIZE) /* re-split */
2267     {
2268       remainder = chunk_at_offset(victim, nb);
2269       set_head(victim, nb | PREV_INUSE);
2270       link_last_remainder(remainder);
2271       set_head(remainder, remainder_size | PREV_INUSE);
2272       set_foot(remainder, remainder_size);
2273       check_malloced_chunk(victim, nb);
2274       return chunk2mem(victim);
2275     }
2276 
2277     clear_last_remainder;
2278 
2279     if (remainder_size >= 0)  /* exhaust */
2280     {
2281       set_inuse_bit_at_offset(victim, victim_size);
2282       check_malloced_chunk(victim, nb);
2283       return chunk2mem(victim);
2284     }
2285 
2286     /* Else place in bin */
2287 
2288     frontlink(victim, victim_size, remainder_index, bck, fwd);
2289   }
2290 
2291   /*
2292      If there are any possibly nonempty big-enough blocks,
2293      search for best fitting chunk by scanning bins in blockwidth units.
2294   */
2295 
2296   if ( (block = idx2binblock(idx)) <= binblocks_r)
2297   {
2298 
2299     /* Get to the first marked block */
2300 
2301     if ( (block & binblocks_r) == 0)
2302     {
2303       /* force to an even block boundary */
2304       idx = (idx & ~(BINBLOCKWIDTH - 1)) + BINBLOCKWIDTH;
2305       block <<= 1;
2306       while ((block & binblocks_r) == 0)
2307       {
2308 	idx += BINBLOCKWIDTH;
2309 	block <<= 1;
2310       }
2311     }
2312 
2313     /* For each possibly nonempty block ... */
2314     for (;;)
2315     {
2316       startidx = idx;          /* (track incomplete blocks) */
2317       q = bin = bin_at(idx);
2318 
2319       /* For each bin in this block ... */
2320       do
2321       {
2322 	/* Find and use first big enough chunk ... */
2323 
2324 	for (victim = last(bin); victim != bin; victim = victim->bk)
2325 	{
2326 	  victim_size = chunksize(victim);
2327 	  remainder_size = victim_size - nb;
2328 
2329 	  if (remainder_size >= (long)MINSIZE) /* split */
2330 	  {
2331 	    remainder = chunk_at_offset(victim, nb);
2332 	    set_head(victim, nb | PREV_INUSE);
2333 	    unlink(victim, bck, fwd);
2334 	    link_last_remainder(remainder);
2335 	    set_head(remainder, remainder_size | PREV_INUSE);
2336 	    set_foot(remainder, remainder_size);
2337 	    check_malloced_chunk(victim, nb);
2338 	    return chunk2mem(victim);
2339 	  }
2340 
2341 	  else if (remainder_size >= 0)  /* take */
2342 	  {
2343 	    set_inuse_bit_at_offset(victim, victim_size);
2344 	    unlink(victim, bck, fwd);
2345 	    check_malloced_chunk(victim, nb);
2346 	    return chunk2mem(victim);
2347 	  }
2348 
2349 	}
2350 
2351        bin = next_bin(bin);
2352 
2353       } while ((++idx & (BINBLOCKWIDTH - 1)) != 0);
2354 
2355       /* Clear out the block bit. */
2356 
2357       do   /* Possibly backtrack to try to clear a partial block */
2358       {
2359 	if ((startidx & (BINBLOCKWIDTH - 1)) == 0)
2360 	{
2361 	  av_[1] = (mbinptr)(binblocks_r & ~block);
2362 	  break;
2363 	}
2364 	--startidx;
2365        q = prev_bin(q);
2366       } while (first(q) == q);
2367 
2368       /* Get to the next possibly nonempty block */
2369 
2370       if ( (block <<= 1) <= binblocks_r && (block != 0) )
2371       {
2372 	while ((block & binblocks_r) == 0)
2373 	{
2374 	  idx += BINBLOCKWIDTH;
2375 	  block <<= 1;
2376 	}
2377       }
2378       else
2379 	break;
2380     }
2381   }
2382 
2383 
2384   /* Try to use top chunk */
2385 
2386   /* Require that there be a remainder, ensuring top always exists  */
2387   if ( (remainder_size = chunksize(top) - nb) < (long)MINSIZE)
2388   {
2389 
2390 #if HAVE_MMAP
2391     /* If big and would otherwise need to extend, try to use mmap instead */
2392     if ((unsigned long)nb >= (unsigned long)mmap_threshold &&
2393 	(victim = mmap_chunk(nb)) != 0)
2394       return chunk2mem(victim);
2395 #endif
2396 
2397     /* Try to extend */
2398     malloc_extend_top(nb);
2399     if ( (remainder_size = chunksize(top) - nb) < (long)MINSIZE)
2400       return NULL; /* propagate failure */
2401   }
2402 
2403   victim = top;
2404   set_head(victim, nb | PREV_INUSE);
2405   top = chunk_at_offset(victim, nb);
2406   set_head(top, remainder_size | PREV_INUSE);
2407   check_malloced_chunk(victim, nb);
2408   return chunk2mem(victim);
2409 
2410 }
2411 
2412 
2413 
2414 
2415 /*
2416 
2417   free() algorithm :
2418 
2419     cases:
2420 
2421        1. free(0) has no effect.
2422 
2423        2. If the chunk was allocated via mmap, it is release via munmap().
2424 
2425        3. If a returned chunk borders the current high end of memory,
2426 	  it is consolidated into the top, and if the total unused
2427 	  topmost memory exceeds the trim threshold, malloc_trim is
2428 	  called.
2429 
2430        4. Other chunks are consolidated as they arrive, and
2431 	  placed in corresponding bins. (This includes the case of
2432 	  consolidating with the current `last_remainder').
2433 
2434 */
2435 
2436 
2437 #if __STD_C
2438 void fREe(Void_t* mem)
2439 #else
2440 void fREe(mem) Void_t* mem;
2441 #endif
2442 {
2443   mchunkptr p;         /* chunk corresponding to mem */
2444   INTERNAL_SIZE_T hd;  /* its head field */
2445   INTERNAL_SIZE_T sz;  /* its size */
2446   int       idx;       /* its bin index */
2447   mchunkptr next;      /* next contiguous chunk */
2448   INTERNAL_SIZE_T nextsz; /* its size */
2449   INTERNAL_SIZE_T prevsz; /* size of previous contiguous chunk */
2450   mchunkptr bck;       /* misc temp for linking */
2451   mchunkptr fwd;       /* misc temp for linking */
2452   int       islr;      /* track whether merging with last_remainder */
2453 
2454 #ifdef CONFIG_SYS_MALLOC_F_LEN
2455 	/* free() is a no-op - all the memory will be freed on relocation */
2456 	if (!(gd->flags & GD_FLG_FULL_MALLOC_INIT))
2457 		return;
2458 #endif
2459 
2460   if (mem == NULL)                              /* free(0) has no effect */
2461     return;
2462 
2463   p = mem2chunk(mem);
2464   hd = p->size;
2465 
2466 #if HAVE_MMAP
2467   if (hd & IS_MMAPPED)                       /* release mmapped memory. */
2468   {
2469     munmap_chunk(p);
2470     return;
2471   }
2472 #endif
2473 
2474   check_inuse_chunk(p);
2475 
2476   sz = hd & ~PREV_INUSE;
2477   next = chunk_at_offset(p, sz);
2478   nextsz = chunksize(next);
2479 
2480   if (next == top)                            /* merge with top */
2481   {
2482     sz += nextsz;
2483 
2484     if (!(hd & PREV_INUSE))                    /* consolidate backward */
2485     {
2486       prevsz = p->prev_size;
2487       p = chunk_at_offset(p, -((long) prevsz));
2488       sz += prevsz;
2489       unlink(p, bck, fwd);
2490     }
2491 
2492     set_head(p, sz | PREV_INUSE);
2493     top = p;
2494     if ((unsigned long)(sz) >= (unsigned long)trim_threshold)
2495       malloc_trim(top_pad);
2496     return;
2497   }
2498 
2499   set_head(next, nextsz);                    /* clear inuse bit */
2500 
2501   islr = 0;
2502 
2503   if (!(hd & PREV_INUSE))                    /* consolidate backward */
2504   {
2505     prevsz = p->prev_size;
2506     p = chunk_at_offset(p, -((long) prevsz));
2507     sz += prevsz;
2508 
2509     if (p->fd == last_remainder)             /* keep as last_remainder */
2510       islr = 1;
2511     else
2512       unlink(p, bck, fwd);
2513   }
2514 
2515   if (!(inuse_bit_at_offset(next, nextsz)))   /* consolidate forward */
2516   {
2517     sz += nextsz;
2518 
2519     if (!islr && next->fd == last_remainder)  /* re-insert last_remainder */
2520     {
2521       islr = 1;
2522       link_last_remainder(p);
2523     }
2524     else
2525       unlink(next, bck, fwd);
2526   }
2527 
2528 
2529   set_head(p, sz | PREV_INUSE);
2530   set_foot(p, sz);
2531   if (!islr)
2532     frontlink(p, sz, idx, bck, fwd);
2533 }
2534 
2535 
2536 
2537 
2538 
2539 /*
2540 
2541   Realloc algorithm:
2542 
2543     Chunks that were obtained via mmap cannot be extended or shrunk
2544     unless HAVE_MREMAP is defined, in which case mremap is used.
2545     Otherwise, if their reallocation is for additional space, they are
2546     copied.  If for less, they are just left alone.
2547 
2548     Otherwise, if the reallocation is for additional space, and the
2549     chunk can be extended, it is, else a malloc-copy-free sequence is
2550     taken.  There are several different ways that a chunk could be
2551     extended. All are tried:
2552 
2553        * Extending forward into following adjacent free chunk.
2554        * Shifting backwards, joining preceding adjacent space
2555        * Both shifting backwards and extending forward.
2556        * Extending into newly sbrked space
2557 
2558     Unless the #define REALLOC_ZERO_BYTES_FREES is set, realloc with a
2559     size argument of zero (re)allocates a minimum-sized chunk.
2560 
2561     If the reallocation is for less space, and the new request is for
2562     a `small' (<512 bytes) size, then the newly unused space is lopped
2563     off and freed.
2564 
2565     The old unix realloc convention of allowing the last-free'd chunk
2566     to be used as an argument to realloc is no longer supported.
2567     I don't know of any programs still relying on this feature,
2568     and allowing it would also allow too many other incorrect
2569     usages of realloc to be sensible.
2570 
2571 
2572 */
2573 
2574 
2575 #if __STD_C
2576 Void_t* rEALLOc(Void_t* oldmem, size_t bytes)
2577 #else
2578 Void_t* rEALLOc(oldmem, bytes) Void_t* oldmem; size_t bytes;
2579 #endif
2580 {
2581   INTERNAL_SIZE_T    nb;      /* padded request size */
2582 
2583   mchunkptr oldp;             /* chunk corresponding to oldmem */
2584   INTERNAL_SIZE_T    oldsize; /* its size */
2585 
2586   mchunkptr newp;             /* chunk to return */
2587   INTERNAL_SIZE_T    newsize; /* its size */
2588   Void_t*   newmem;           /* corresponding user mem */
2589 
2590   mchunkptr next;             /* next contiguous chunk after oldp */
2591   INTERNAL_SIZE_T  nextsize;  /* its size */
2592 
2593   mchunkptr prev;             /* previous contiguous chunk before oldp */
2594   INTERNAL_SIZE_T  prevsize;  /* its size */
2595 
2596   mchunkptr remainder;        /* holds split off extra space from newp */
2597   INTERNAL_SIZE_T  remainder_size;   /* its size */
2598 
2599   mchunkptr bck;              /* misc temp for linking */
2600   mchunkptr fwd;              /* misc temp for linking */
2601 
2602 #ifdef REALLOC_ZERO_BYTES_FREES
2603   if (bytes == 0) { fREe(oldmem); return 0; }
2604 #endif
2605 
2606   if ((long)bytes < 0) return NULL;
2607 
2608   /* realloc of null is supposed to be same as malloc */
2609   if (oldmem == NULL) return mALLOc(bytes);
2610 
2611 #ifdef CONFIG_SYS_MALLOC_F_LEN
2612 	if (!(gd->flags & GD_FLG_FULL_MALLOC_INIT)) {
2613 		/* This is harder to support and should not be needed */
2614 		panic("pre-reloc realloc() is not supported");
2615 	}
2616 #endif
2617 
2618   newp    = oldp    = mem2chunk(oldmem);
2619   newsize = oldsize = chunksize(oldp);
2620 
2621 
2622   nb = request2size(bytes);
2623 
2624 #if HAVE_MMAP
2625   if (chunk_is_mmapped(oldp))
2626   {
2627 #if HAVE_MREMAP
2628     newp = mremap_chunk(oldp, nb);
2629     if(newp) return chunk2mem(newp);
2630 #endif
2631     /* Note the extra SIZE_SZ overhead. */
2632     if(oldsize - SIZE_SZ >= nb) return oldmem; /* do nothing */
2633     /* Must alloc, copy, free. */
2634     newmem = mALLOc(bytes);
2635     if (newmem == 0) return 0; /* propagate failure */
2636     MALLOC_COPY(newmem, oldmem, oldsize - 2*SIZE_SZ);
2637     munmap_chunk(oldp);
2638     return newmem;
2639   }
2640 #endif
2641 
2642   check_inuse_chunk(oldp);
2643 
2644   if ((long)(oldsize) < (long)(nb))
2645   {
2646 
2647     /* Try expanding forward */
2648 
2649     next = chunk_at_offset(oldp, oldsize);
2650     if (next == top || !inuse(next))
2651     {
2652       nextsize = chunksize(next);
2653 
2654       /* Forward into top only if a remainder */
2655       if (next == top)
2656       {
2657 	if ((long)(nextsize + newsize) >= (long)(nb + MINSIZE))
2658 	{
2659 	  newsize += nextsize;
2660 	  top = chunk_at_offset(oldp, nb);
2661 	  set_head(top, (newsize - nb) | PREV_INUSE);
2662 	  set_head_size(oldp, nb);
2663 	  return chunk2mem(oldp);
2664 	}
2665       }
2666 
2667       /* Forward into next chunk */
2668       else if (((long)(nextsize + newsize) >= (long)(nb)))
2669       {
2670 	unlink(next, bck, fwd);
2671 	newsize  += nextsize;
2672 	goto split;
2673       }
2674     }
2675     else
2676     {
2677       next = NULL;
2678       nextsize = 0;
2679     }
2680 
2681     /* Try shifting backwards. */
2682 
2683     if (!prev_inuse(oldp))
2684     {
2685       prev = prev_chunk(oldp);
2686       prevsize = chunksize(prev);
2687 
2688       /* try forward + backward first to save a later consolidation */
2689 
2690       if (next != NULL)
2691       {
2692 	/* into top */
2693 	if (next == top)
2694 	{
2695 	  if ((long)(nextsize + prevsize + newsize) >= (long)(nb + MINSIZE))
2696 	  {
2697 	    unlink(prev, bck, fwd);
2698 	    newp = prev;
2699 	    newsize += prevsize + nextsize;
2700 	    newmem = chunk2mem(newp);
2701 	    MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2702 	    top = chunk_at_offset(newp, nb);
2703 	    set_head(top, (newsize - nb) | PREV_INUSE);
2704 	    set_head_size(newp, nb);
2705 	    return newmem;
2706 	  }
2707 	}
2708 
2709 	/* into next chunk */
2710 	else if (((long)(nextsize + prevsize + newsize) >= (long)(nb)))
2711 	{
2712 	  unlink(next, bck, fwd);
2713 	  unlink(prev, bck, fwd);
2714 	  newp = prev;
2715 	  newsize += nextsize + prevsize;
2716 	  newmem = chunk2mem(newp);
2717 	  MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2718 	  goto split;
2719 	}
2720       }
2721 
2722       /* backward only */
2723       if (prev != NULL && (long)(prevsize + newsize) >= (long)nb)
2724       {
2725 	unlink(prev, bck, fwd);
2726 	newp = prev;
2727 	newsize += prevsize;
2728 	newmem = chunk2mem(newp);
2729 	MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2730 	goto split;
2731       }
2732     }
2733 
2734     /* Must allocate */
2735 
2736     newmem = mALLOc (bytes);
2737 
2738     if (newmem == NULL)  /* propagate failure */
2739       return NULL;
2740 
2741     /* Avoid copy if newp is next chunk after oldp. */
2742     /* (This can only happen when new chunk is sbrk'ed.) */
2743 
2744     if ( (newp = mem2chunk(newmem)) == next_chunk(oldp))
2745     {
2746       newsize += chunksize(newp);
2747       newp = oldp;
2748       goto split;
2749     }
2750 
2751     /* Otherwise copy, free, and exit */
2752     MALLOC_COPY(newmem, oldmem, oldsize - SIZE_SZ);
2753     fREe(oldmem);
2754     return newmem;
2755   }
2756 
2757 
2758  split:  /* split off extra room in old or expanded chunk */
2759 
2760   if (newsize - nb >= MINSIZE) /* split off remainder */
2761   {
2762     remainder = chunk_at_offset(newp, nb);
2763     remainder_size = newsize - nb;
2764     set_head_size(newp, nb);
2765     set_head(remainder, remainder_size | PREV_INUSE);
2766     set_inuse_bit_at_offset(remainder, remainder_size);
2767     fREe(chunk2mem(remainder)); /* let free() deal with it */
2768   }
2769   else
2770   {
2771     set_head_size(newp, newsize);
2772     set_inuse_bit_at_offset(newp, newsize);
2773   }
2774 
2775   check_inuse_chunk(newp);
2776   return chunk2mem(newp);
2777 }
2778 
2779 
2780 
2781 
2782 /*
2783 
2784   memalign algorithm:
2785 
2786     memalign requests more than enough space from malloc, finds a spot
2787     within that chunk that meets the alignment request, and then
2788     possibly frees the leading and trailing space.
2789 
2790     The alignment argument must be a power of two. This property is not
2791     checked by memalign, so misuse may result in random runtime errors.
2792 
2793     8-byte alignment is guaranteed by normal malloc calls, so don't
2794     bother calling memalign with an argument of 8 or less.
2795 
2796     Overreliance on memalign is a sure way to fragment space.
2797 
2798 */
2799 
2800 
2801 #if __STD_C
2802 Void_t* mEMALIGn(size_t alignment, size_t bytes)
2803 #else
2804 Void_t* mEMALIGn(alignment, bytes) size_t alignment; size_t bytes;
2805 #endif
2806 {
2807   INTERNAL_SIZE_T    nb;      /* padded  request size */
2808   char*     m;                /* memory returned by malloc call */
2809   mchunkptr p;                /* corresponding chunk */
2810   char*     brk;              /* alignment point within p */
2811   mchunkptr newp;             /* chunk to return */
2812   INTERNAL_SIZE_T  newsize;   /* its size */
2813   INTERNAL_SIZE_T  leadsize;  /* leading space befor alignment point */
2814   mchunkptr remainder;        /* spare room at end to split off */
2815   long      remainder_size;   /* its size */
2816 
2817   if ((long)bytes < 0) return NULL;
2818 
2819   /* If need less alignment than we give anyway, just relay to malloc */
2820 
2821   if (alignment <= MALLOC_ALIGNMENT) return mALLOc(bytes);
2822 
2823   /* Otherwise, ensure that it is at least a minimum chunk size */
2824 
2825   if (alignment <  MINSIZE) alignment = MINSIZE;
2826 
2827   /* Call malloc with worst case padding to hit alignment. */
2828 
2829   nb = request2size(bytes);
2830   m  = (char*)(mALLOc(nb + alignment + MINSIZE));
2831 
2832   if (m == NULL) return NULL; /* propagate failure */
2833 
2834   p = mem2chunk(m);
2835 
2836   if ((((unsigned long)(m)) % alignment) == 0) /* aligned */
2837   {
2838 #if HAVE_MMAP
2839     if(chunk_is_mmapped(p))
2840       return chunk2mem(p); /* nothing more to do */
2841 #endif
2842   }
2843   else /* misaligned */
2844   {
2845     /*
2846       Find an aligned spot inside chunk.
2847       Since we need to give back leading space in a chunk of at
2848       least MINSIZE, if the first calculation places us at
2849       a spot with less than MINSIZE leader, we can move to the
2850       next aligned spot -- we've allocated enough total room so that
2851       this is always possible.
2852     */
2853 
2854     brk = (char*)mem2chunk(((unsigned long)(m + alignment - 1)) & -((signed) alignment));
2855     if ((long)(brk - (char*)(p)) < MINSIZE) brk = brk + alignment;
2856 
2857     newp = (mchunkptr)brk;
2858     leadsize = brk - (char*)(p);
2859     newsize = chunksize(p) - leadsize;
2860 
2861 #if HAVE_MMAP
2862     if(chunk_is_mmapped(p))
2863     {
2864       newp->prev_size = p->prev_size + leadsize;
2865       set_head(newp, newsize|IS_MMAPPED);
2866       return chunk2mem(newp);
2867     }
2868 #endif
2869 
2870     /* give back leader, use the rest */
2871 
2872     set_head(newp, newsize | PREV_INUSE);
2873     set_inuse_bit_at_offset(newp, newsize);
2874     set_head_size(p, leadsize);
2875     fREe(chunk2mem(p));
2876     p = newp;
2877 
2878     assert (newsize >= nb && (((unsigned long)(chunk2mem(p))) % alignment) == 0);
2879   }
2880 
2881   /* Also give back spare room at the end */
2882 
2883   remainder_size = chunksize(p) - nb;
2884 
2885   if (remainder_size >= (long)MINSIZE)
2886   {
2887     remainder = chunk_at_offset(p, nb);
2888     set_head(remainder, remainder_size | PREV_INUSE);
2889     set_head_size(p, nb);
2890     fREe(chunk2mem(remainder));
2891   }
2892 
2893   check_inuse_chunk(p);
2894   return chunk2mem(p);
2895 
2896 }
2897 
2898 
2899 
2900 
2901 /*
2902     valloc just invokes memalign with alignment argument equal
2903     to the page size of the system (or as near to this as can
2904     be figured out from all the includes/defines above.)
2905 */
2906 
2907 #if __STD_C
2908 Void_t* vALLOc(size_t bytes)
2909 #else
2910 Void_t* vALLOc(bytes) size_t bytes;
2911 #endif
2912 {
2913   return mEMALIGn (malloc_getpagesize, bytes);
2914 }
2915 
2916 /*
2917   pvalloc just invokes valloc for the nearest pagesize
2918   that will accommodate request
2919 */
2920 
2921 
2922 #if __STD_C
2923 Void_t* pvALLOc(size_t bytes)
2924 #else
2925 Void_t* pvALLOc(bytes) size_t bytes;
2926 #endif
2927 {
2928   size_t pagesize = malloc_getpagesize;
2929   return mEMALIGn (pagesize, (bytes + pagesize - 1) & ~(pagesize - 1));
2930 }
2931 
2932 /*
2933 
2934   calloc calls malloc, then zeroes out the allocated chunk.
2935 
2936 */
2937 
2938 #if __STD_C
2939 Void_t* cALLOc(size_t n, size_t elem_size)
2940 #else
2941 Void_t* cALLOc(n, elem_size) size_t n; size_t elem_size;
2942 #endif
2943 {
2944   mchunkptr p;
2945   INTERNAL_SIZE_T csz;
2946 
2947   INTERNAL_SIZE_T sz = n * elem_size;
2948 
2949 
2950   /* check if expand_top called, in which case don't need to clear */
2951 #ifdef CONFIG_SYS_MALLOC_CLEAR_ON_INIT
2952 #if MORECORE_CLEARS
2953   mchunkptr oldtop = top;
2954   INTERNAL_SIZE_T oldtopsize = chunksize(top);
2955 #endif
2956 #endif
2957   Void_t* mem = mALLOc (sz);
2958 
2959   if ((long)n < 0) return NULL;
2960 
2961   if (mem == NULL)
2962     return NULL;
2963   else
2964   {
2965 #ifdef CONFIG_SYS_MALLOC_F_LEN
2966 	if (!(gd->flags & GD_FLG_FULL_MALLOC_INIT)) {
2967 		MALLOC_ZERO(mem, sz);
2968 		return mem;
2969 	}
2970 #endif
2971     p = mem2chunk(mem);
2972 
2973     /* Two optional cases in which clearing not necessary */
2974 
2975 
2976 #if HAVE_MMAP
2977     if (chunk_is_mmapped(p)) return mem;
2978 #endif
2979 
2980     csz = chunksize(p);
2981 
2982 #ifdef CONFIG_SYS_MALLOC_CLEAR_ON_INIT
2983 #if MORECORE_CLEARS
2984     if (p == oldtop && csz > oldtopsize)
2985     {
2986       /* clear only the bytes from non-freshly-sbrked memory */
2987       csz = oldtopsize;
2988     }
2989 #endif
2990 #endif
2991 
2992     MALLOC_ZERO(mem, csz - SIZE_SZ);
2993     return mem;
2994   }
2995 }
2996 
2997 /*
2998 
2999   cfree just calls free. It is needed/defined on some systems
3000   that pair it with calloc, presumably for odd historical reasons.
3001 
3002 */
3003 
3004 #if !defined(INTERNAL_LINUX_C_LIB) || !defined(__ELF__)
3005 #if __STD_C
3006 void cfree(Void_t *mem)
3007 #else
3008 void cfree(mem) Void_t *mem;
3009 #endif
3010 {
3011   fREe(mem);
3012 }
3013 #endif
3014 
3015 
3016 
3017 /*
3018 
3019     Malloc_trim gives memory back to the system (via negative
3020     arguments to sbrk) if there is unused memory at the `high' end of
3021     the malloc pool. You can call this after freeing large blocks of
3022     memory to potentially reduce the system-level memory requirements
3023     of a program. However, it cannot guarantee to reduce memory. Under
3024     some allocation patterns, some large free blocks of memory will be
3025     locked between two used chunks, so they cannot be given back to
3026     the system.
3027 
3028     The `pad' argument to malloc_trim represents the amount of free
3029     trailing space to leave untrimmed. If this argument is zero,
3030     only the minimum amount of memory to maintain internal data
3031     structures will be left (one page or less). Non-zero arguments
3032     can be supplied to maintain enough trailing space to service
3033     future expected allocations without having to re-obtain memory
3034     from the system.
3035 
3036     Malloc_trim returns 1 if it actually released any memory, else 0.
3037 
3038 */
3039 
3040 #if __STD_C
3041 int malloc_trim(size_t pad)
3042 #else
3043 int malloc_trim(pad) size_t pad;
3044 #endif
3045 {
3046   long  top_size;        /* Amount of top-most memory */
3047   long  extra;           /* Amount to release */
3048   char* current_brk;     /* address returned by pre-check sbrk call */
3049   char* new_brk;         /* address returned by negative sbrk call */
3050 
3051   unsigned long pagesz = malloc_getpagesize;
3052 
3053   top_size = chunksize(top);
3054   extra = ((top_size - pad - MINSIZE + (pagesz-1)) / pagesz - 1) * pagesz;
3055 
3056   if (extra < (long)pagesz)  /* Not enough memory to release */
3057     return 0;
3058 
3059   else
3060   {
3061     /* Test to make sure no one else called sbrk */
3062     current_brk = (char*)(MORECORE (0));
3063     if (current_brk != (char*)(top) + top_size)
3064       return 0;     /* Apparently we don't own memory; must fail */
3065 
3066     else
3067     {
3068       new_brk = (char*)(MORECORE (-extra));
3069 
3070       if (new_brk == (char*)(MORECORE_FAILURE)) /* sbrk failed? */
3071       {
3072 	/* Try to figure out what we have */
3073 	current_brk = (char*)(MORECORE (0));
3074 	top_size = current_brk - (char*)top;
3075 	if (top_size >= (long)MINSIZE) /* if not, we are very very dead! */
3076 	{
3077 	  sbrked_mem = current_brk - sbrk_base;
3078 	  set_head(top, top_size | PREV_INUSE);
3079 	}
3080 	check_chunk(top);
3081 	return 0;
3082       }
3083 
3084       else
3085       {
3086 	/* Success. Adjust top accordingly. */
3087 	set_head(top, (top_size - extra) | PREV_INUSE);
3088 	sbrked_mem -= extra;
3089 	check_chunk(top);
3090 	return 1;
3091       }
3092     }
3093   }
3094 }
3095 
3096 
3097 
3098 /*
3099   malloc_usable_size:
3100 
3101     This routine tells you how many bytes you can actually use in an
3102     allocated chunk, which may be more than you requested (although
3103     often not). You can use this many bytes without worrying about
3104     overwriting other allocated objects. Not a particularly great
3105     programming practice, but still sometimes useful.
3106 
3107 */
3108 
3109 #if __STD_C
3110 size_t malloc_usable_size(Void_t* mem)
3111 #else
3112 size_t malloc_usable_size(mem) Void_t* mem;
3113 #endif
3114 {
3115   mchunkptr p;
3116   if (mem == NULL)
3117     return 0;
3118   else
3119   {
3120     p = mem2chunk(mem);
3121     if(!chunk_is_mmapped(p))
3122     {
3123       if (!inuse(p)) return 0;
3124       check_inuse_chunk(p);
3125       return chunksize(p) - SIZE_SZ;
3126     }
3127     return chunksize(p) - 2*SIZE_SZ;
3128   }
3129 }
3130 
3131 
3132 
3133 
3134 /* Utility to update current_mallinfo for malloc_stats and mallinfo() */
3135 
3136 #ifdef DEBUG
3137 static void malloc_update_mallinfo()
3138 {
3139   int i;
3140   mbinptr b;
3141   mchunkptr p;
3142 #ifdef DEBUG
3143   mchunkptr q;
3144 #endif
3145 
3146   INTERNAL_SIZE_T avail = chunksize(top);
3147   int   navail = ((long)(avail) >= (long)MINSIZE)? 1 : 0;
3148 
3149   for (i = 1; i < NAV; ++i)
3150   {
3151     b = bin_at(i);
3152     for (p = last(b); p != b; p = p->bk)
3153     {
3154 #ifdef DEBUG
3155       check_free_chunk(p);
3156       for (q = next_chunk(p);
3157 	   q < top && inuse(q) && (long)(chunksize(q)) >= (long)MINSIZE;
3158 	   q = next_chunk(q))
3159 	check_inuse_chunk(q);
3160 #endif
3161       avail += chunksize(p);
3162       navail++;
3163     }
3164   }
3165 
3166   current_mallinfo.ordblks = navail;
3167   current_mallinfo.uordblks = sbrked_mem - avail;
3168   current_mallinfo.fordblks = avail;
3169   current_mallinfo.hblks = n_mmaps;
3170   current_mallinfo.hblkhd = mmapped_mem;
3171   current_mallinfo.keepcost = chunksize(top);
3172 
3173 }
3174 #endif	/* DEBUG */
3175 
3176 
3177 
3178 /*
3179 
3180   malloc_stats:
3181 
3182     Prints on the amount of space obtain from the system (both
3183     via sbrk and mmap), the maximum amount (which may be more than
3184     current if malloc_trim and/or munmap got called), the maximum
3185     number of simultaneous mmap regions used, and the current number
3186     of bytes allocated via malloc (or realloc, etc) but not yet
3187     freed. (Note that this is the number of bytes allocated, not the
3188     number requested. It will be larger than the number requested
3189     because of alignment and bookkeeping overhead.)
3190 
3191 */
3192 
3193 #ifdef DEBUG
3194 void malloc_stats()
3195 {
3196   malloc_update_mallinfo();
3197   printf("max system bytes = %10u\n",
3198 	  (unsigned int)(max_total_mem));
3199   printf("system bytes     = %10u\n",
3200 	  (unsigned int)(sbrked_mem + mmapped_mem));
3201   printf("in use bytes     = %10u\n",
3202 	  (unsigned int)(current_mallinfo.uordblks + mmapped_mem));
3203 #if HAVE_MMAP
3204   printf("max mmap regions = %10u\n",
3205 	  (unsigned int)max_n_mmaps);
3206 #endif
3207 }
3208 #endif	/* DEBUG */
3209 
3210 /*
3211   mallinfo returns a copy of updated current mallinfo.
3212 */
3213 
3214 #ifdef DEBUG
3215 struct mallinfo mALLINFo()
3216 {
3217   malloc_update_mallinfo();
3218   return current_mallinfo;
3219 }
3220 #endif	/* DEBUG */
3221 
3222 
3223 
3224 
3225 /*
3226   mallopt:
3227 
3228     mallopt is the general SVID/XPG interface to tunable parameters.
3229     The format is to provide a (parameter-number, parameter-value) pair.
3230     mallopt then sets the corresponding parameter to the argument
3231     value if it can (i.e., so long as the value is meaningful),
3232     and returns 1 if successful else 0.
3233 
3234     See descriptions of tunable parameters above.
3235 
3236 */
3237 
3238 #if __STD_C
3239 int mALLOPt(int param_number, int value)
3240 #else
3241 int mALLOPt(param_number, value) int param_number; int value;
3242 #endif
3243 {
3244   switch(param_number)
3245   {
3246     case M_TRIM_THRESHOLD:
3247       trim_threshold = value; return 1;
3248     case M_TOP_PAD:
3249       top_pad = value; return 1;
3250     case M_MMAP_THRESHOLD:
3251       mmap_threshold = value; return 1;
3252     case M_MMAP_MAX:
3253 #if HAVE_MMAP
3254       n_mmaps_max = value; return 1;
3255 #else
3256       if (value != 0) return 0; else  n_mmaps_max = value; return 1;
3257 #endif
3258 
3259     default:
3260       return 0;
3261   }
3262 }
3263 
3264 int initf_malloc(void)
3265 {
3266 #ifdef CONFIG_SYS_MALLOC_F_LEN
3267 	assert(gd->malloc_base);	/* Set up by crt0.S */
3268 	gd->malloc_limit = CONFIG_SYS_MALLOC_F_LEN;
3269 	gd->malloc_ptr = 0;
3270 #endif
3271 
3272 	return 0;
3273 }
3274 
3275 /*
3276 
3277 History:
3278 
3279     V2.6.6 Sun Dec  5 07:42:19 1999  Doug Lea  (dl at gee)
3280       * return null for negative arguments
3281       * Added Several WIN32 cleanups from Martin C. Fong <mcfong@yahoo.com>
3282 	 * Add 'LACKS_SYS_PARAM_H' for those systems without 'sys/param.h'
3283 	  (e.g. WIN32 platforms)
3284 	 * Cleanup up header file inclusion for WIN32 platforms
3285 	 * Cleanup code to avoid Microsoft Visual C++ compiler complaints
3286 	 * Add 'USE_DL_PREFIX' to quickly allow co-existence with existing
3287 	   memory allocation routines
3288 	 * Set 'malloc_getpagesize' for WIN32 platforms (needs more work)
3289 	 * Use 'assert' rather than 'ASSERT' in WIN32 code to conform to
3290 	   usage of 'assert' in non-WIN32 code
3291 	 * Improve WIN32 'sbrk()' emulation's 'findRegion()' routine to
3292 	   avoid infinite loop
3293       * Always call 'fREe()' rather than 'free()'
3294 
3295     V2.6.5 Wed Jun 17 15:57:31 1998  Doug Lea  (dl at gee)
3296       * Fixed ordering problem with boundary-stamping
3297 
3298     V2.6.3 Sun May 19 08:17:58 1996  Doug Lea  (dl at gee)
3299       * Added pvalloc, as recommended by H.J. Liu
3300       * Added 64bit pointer support mainly from Wolfram Gloger
3301       * Added anonymously donated WIN32 sbrk emulation
3302       * Malloc, calloc, getpagesize: add optimizations from Raymond Nijssen
3303       * malloc_extend_top: fix mask error that caused wastage after
3304 	foreign sbrks
3305       * Add linux mremap support code from HJ Liu
3306 
3307     V2.6.2 Tue Dec  5 06:52:55 1995  Doug Lea  (dl at gee)
3308       * Integrated most documentation with the code.
3309       * Add support for mmap, with help from
3310 	Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
3311       * Use last_remainder in more cases.
3312       * Pack bins using idea from  colin@nyx10.cs.du.edu
3313       * Use ordered bins instead of best-fit threshhold
3314       * Eliminate block-local decls to simplify tracing and debugging.
3315       * Support another case of realloc via move into top
3316       * Fix error occuring when initial sbrk_base not word-aligned.
3317       * Rely on page size for units instead of SBRK_UNIT to
3318 	avoid surprises about sbrk alignment conventions.
3319       * Add mallinfo, mallopt. Thanks to Raymond Nijssen
3320 	(raymond@es.ele.tue.nl) for the suggestion.
3321       * Add `pad' argument to malloc_trim and top_pad mallopt parameter.
3322       * More precautions for cases where other routines call sbrk,
3323 	courtesy of Wolfram Gloger (Gloger@lrz.uni-muenchen.de).
3324       * Added macros etc., allowing use in linux libc from
3325 	H.J. Lu (hjl@gnu.ai.mit.edu)
3326       * Inverted this history list
3327 
3328     V2.6.1 Sat Dec  2 14:10:57 1995  Doug Lea  (dl at gee)
3329       * Re-tuned and fixed to behave more nicely with V2.6.0 changes.
3330       * Removed all preallocation code since under current scheme
3331 	the work required to undo bad preallocations exceeds
3332 	the work saved in good cases for most test programs.
3333       * No longer use return list or unconsolidated bins since
3334 	no scheme using them consistently outperforms those that don't
3335 	given above changes.
3336       * Use best fit for very large chunks to prevent some worst-cases.
3337       * Added some support for debugging
3338 
3339     V2.6.0 Sat Nov  4 07:05:23 1995  Doug Lea  (dl at gee)
3340       * Removed footers when chunks are in use. Thanks to
3341 	Paul Wilson (wilson@cs.texas.edu) for the suggestion.
3342 
3343     V2.5.4 Wed Nov  1 07:54:51 1995  Doug Lea  (dl at gee)
3344       * Added malloc_trim, with help from Wolfram Gloger
3345 	(wmglo@Dent.MED.Uni-Muenchen.DE).
3346 
3347     V2.5.3 Tue Apr 26 10:16:01 1994  Doug Lea  (dl at g)
3348 
3349     V2.5.2 Tue Apr  5 16:20:40 1994  Doug Lea  (dl at g)
3350       * realloc: try to expand in both directions
3351       * malloc: swap order of clean-bin strategy;
3352       * realloc: only conditionally expand backwards
3353       * Try not to scavenge used bins
3354       * Use bin counts as a guide to preallocation
3355       * Occasionally bin return list chunks in first scan
3356       * Add a few optimizations from colin@nyx10.cs.du.edu
3357 
3358     V2.5.1 Sat Aug 14 15:40:43 1993  Doug Lea  (dl at g)
3359       * faster bin computation & slightly different binning
3360       * merged all consolidations to one part of malloc proper
3361 	 (eliminating old malloc_find_space & malloc_clean_bin)
3362       * Scan 2 returns chunks (not just 1)
3363       * Propagate failure in realloc if malloc returns 0
3364       * Add stuff to allow compilation on non-ANSI compilers
3365 	  from kpv@research.att.com
3366 
3367     V2.5 Sat Aug  7 07:41:59 1993  Doug Lea  (dl at g.oswego.edu)
3368       * removed potential for odd address access in prev_chunk
3369       * removed dependency on getpagesize.h
3370       * misc cosmetics and a bit more internal documentation
3371       * anticosmetics: mangled names in macros to evade debugger strangeness
3372       * tested on sparc, hp-700, dec-mips, rs6000
3373 	  with gcc & native cc (hp, dec only) allowing
3374 	  Detlefs & Zorn comparison study (in SIGPLAN Notices.)
3375 
3376     Trial version Fri Aug 28 13:14:29 1992  Doug Lea  (dl at g.oswego.edu)
3377       * Based loosely on libg++-1.2X malloc. (It retains some of the overall
3378 	 structure of old version,  but most details differ.)
3379 
3380 */
3381