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authorUlrich Drepper <drepper@redhat.com>2002-01-29 07:54:51 +0000
committerUlrich Drepper <drepper@redhat.com>2002-01-29 07:54:51 +0000
commitfa8d436c87f156d18208df3819fecee9fc1dbd9e (patch)
treee22f5754d69c0144f0945a26727c3984008f9d37 /malloc/hooks.c
parentdb2ebcef2428cb568315895f8fe3ef19d41735bc (diff)
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Update.
2002-01-18  Wolfram Gloger  <wg@malloc.de>

	* malloc/malloc.c: Rewrite, adapted from Doug Lea's malloc-2.7.0.c.
	* malloc/malloc.h: Likewise.
	* malloc/arena.c: New file.
	* malloc/hooks.c: New file.
	* malloc/tst-mallocstate.c: New file.
	* malloc/Makefile: Add new testcase tst-mallocstate.
	Add arena.c and hooks.c to distribute.  Fix commented CPPFLAGS.

2002-01-28  Ulrich Drepper  <drepper@redhat.com>

	* stdlib/msort.c: Remove last patch.  The optimization violates the
	same rule which qsort.c had problems with.

2002-01-27  Paul Eggert  <eggert@twinsun.com>

	* stdlib/qsort.c (_quicksort): Do not apply the comparison function
	to a pivot element that lies outside the array to be sorted, as
	ISO C99 requires that the comparison function be called only with
	addresses of array elements [PR libc/2880].
Diffstat (limited to 'malloc/hooks.c')
-rw-r--r--malloc/hooks.c631
1 files changed, 631 insertions, 0 deletions
diff --git a/malloc/hooks.c b/malloc/hooks.c
new file mode 100644
index 0000000000..28629eff80
--- /dev/null
+++ b/malloc/hooks.c
@@ -0,0 +1,631 @@
+/* Malloc implementation for multiple threads without lock contention.
+   Copyright (C) 2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Wolfram Gloger <wg@malloc.de>, 2001.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* $Id$ */
+
+#ifndef weak_variable
+#define weak_variable /**/
+#endif
+
+#ifndef DEFAULT_CHECK_ACTION
+#define DEFAULT_CHECK_ACTION 1
+#endif
+
+/* What to do if the standard debugging hooks are in place and a
+   corrupt pointer is detected: do nothing (0), print an error message
+   (1), or call abort() (2). */
+
+/* Hooks for debugging versions.  The initial hooks just call the
+   initialization routine, then do the normal work. */
+
+static Void_t*
+#if __STD_C
+malloc_hook_ini(size_t sz, const __malloc_ptr_t caller)
+#else
+malloc_hook_ini(sz, caller)
+     size_t sz; const __malloc_ptr_t caller;
+#endif
+{
+  __malloc_hook = NULL;
+  ptmalloc_init();
+  return public_mALLOc(sz);
+}
+
+static Void_t*
+#if __STD_C
+realloc_hook_ini(Void_t* ptr, size_t sz, const __malloc_ptr_t caller)
+#else
+realloc_hook_ini(ptr, sz, caller)
+     Void_t* ptr; size_t sz; const __malloc_ptr_t caller;
+#endif
+{
+  __malloc_hook = NULL;
+  __realloc_hook = NULL;
+  ptmalloc_init();
+  return public_rEALLOc(ptr, sz);
+}
+
+static Void_t*
+#if __STD_C
+memalign_hook_ini(size_t alignment, size_t sz, const __malloc_ptr_t caller)
+#else
+memalign_hook_ini(alignment, sz, caller)
+     size_t alignment; size_t sz; const __malloc_ptr_t caller;
+#endif
+{
+  __memalign_hook = NULL;
+  ptmalloc_init();
+  return public_mEMALIGn(alignment, sz);
+}
+
+void weak_variable (*__malloc_initialize_hook) __MALLOC_P ((void)) = NULL;
+void weak_variable (*__free_hook) __MALLOC_P ((__malloc_ptr_t __ptr,
+					       const __malloc_ptr_t)) = NULL;
+__malloc_ptr_t weak_variable (*__malloc_hook)
+ __MALLOC_P ((size_t __size, const __malloc_ptr_t)) = malloc_hook_ini;
+__malloc_ptr_t weak_variable (*__realloc_hook)
+ __MALLOC_P ((__malloc_ptr_t __ptr, size_t __size, const __malloc_ptr_t))
+     = realloc_hook_ini;
+__malloc_ptr_t weak_variable (*__memalign_hook)
+ __MALLOC_P ((size_t __alignment, size_t __size, const __malloc_ptr_t))
+     = memalign_hook_ini;
+void weak_variable (*__after_morecore_hook) __MALLOC_P ((void)) = NULL;
+
+
+static int check_action = DEFAULT_CHECK_ACTION;
+
+/* Whether we are using malloc checking.  */
+static int using_malloc_checking;
+
+/* A flag that is set by malloc_set_state, to signal that malloc checking
+   must not be enabled on the request from the user (via the MALLOC_CHECK_
+   environment variable).  It is reset by __malloc_check_init to tell
+   malloc_set_state that the user has requested malloc checking.
+
+   The purpose of this flag is to make sure that malloc checking is not
+   enabled when the heap to be restored was constructed without malloc
+   checking, and thus does not contain the required magic bytes.
+   Otherwise the heap would be corrupted by calls to free and realloc.  If
+   it turns out that the heap was created with malloc checking and the
+   user has requested it malloc_set_state just calls __malloc_check_init
+   again to enable it.  On the other hand, reusing such a heap without
+   further malloc checking is safe.  */
+static int disallow_malloc_check;
+
+/* Activate a standard set of debugging hooks. */
+void
+__malloc_check_init()
+{
+  if (disallow_malloc_check) {
+    disallow_malloc_check = 0;
+    return;
+  }
+  using_malloc_checking = 1;
+  __malloc_hook = malloc_check;
+  __free_hook = free_check;
+  __realloc_hook = realloc_check;
+  __memalign_hook = memalign_check;
+  if(check_action & 1)
+    fprintf(stderr, "malloc: using debugging hooks\n");
+}
+
+/* A simple, standard set of debugging hooks.  Overhead is `only' one
+   byte per chunk; still this will catch most cases of double frees or
+   overruns.  The goal here is to avoid obscure crashes due to invalid
+   usage, unlike in the MALLOC_DEBUG code. */
+
+#define MAGICBYTE(p) ( ( ((size_t)p >> 3) ^ ((size_t)p >> 11)) & 0xFF )
+
+/* Instrument a chunk with overrun detector byte(s) and convert it
+   into a user pointer with requested size sz. */
+
+static Void_t*
+internal_function
+#if __STD_C
+mem2mem_check(Void_t *ptr, size_t sz)
+#else
+mem2mem_check(ptr, sz) Void_t *ptr; size_t sz;
+#endif
+{
+  mchunkptr p;
+  unsigned char* m_ptr = (unsigned char*)BOUNDED_N(ptr, sz);
+  size_t i;
+
+  if (!ptr)
+    return ptr;
+  p = mem2chunk(ptr);
+  for(i = chunksize(p) - (chunk_is_mmapped(p) ? 2*SIZE_SZ+1 : SIZE_SZ+1);
+      i > sz;
+      i -= 0xFF) {
+    if(i-sz < 0x100) {
+      m_ptr[i] = (unsigned char)(i-sz);
+      break;
+    }
+    m_ptr[i] = 0xFF;
+  }
+  m_ptr[sz] = MAGICBYTE(p);
+  return (Void_t*)m_ptr;
+}
+
+/* Convert a pointer to be free()d or realloc()ed to a valid chunk
+   pointer.  If the provided pointer is not valid, return NULL. */
+
+static mchunkptr
+internal_function
+#if __STD_C
+mem2chunk_check(Void_t* mem)
+#else
+mem2chunk_check(mem) Void_t* mem;
+#endif
+{
+  mchunkptr p;
+  INTERNAL_SIZE_T sz, c;
+  unsigned char magic;
+
+  p = mem2chunk(mem);
+  if(!aligned_OK(p)) return NULL;
+  if( (char*)p>=mp_.sbrk_base &&
+      (char*)p<(mp_.sbrk_base+main_arena.system_mem) ) {
+    /* Must be a chunk in conventional heap memory. */
+    if(chunk_is_mmapped(p) ||
+       ( (sz = chunksize(p)),
+	 ((char*)p + sz)>=(mp_.sbrk_base+main_arena.system_mem) ) ||
+       sz<MINSIZE || sz&MALLOC_ALIGN_MASK || !inuse(p) ||
+       ( !prev_inuse(p) && (p->prev_size&MALLOC_ALIGN_MASK ||
+                            (long)prev_chunk(p)<(long)mp_.sbrk_base ||
+                            next_chunk(prev_chunk(p))!=p) ))
+      return NULL;
+    magic = MAGICBYTE(p);
+    for(sz += SIZE_SZ-1; (c = ((unsigned char*)p)[sz]) != magic; sz -= c) {
+      if(c<=0 || sz<(c+2*SIZE_SZ)) return NULL;
+    }
+    ((unsigned char*)p)[sz] ^= 0xFF;
+  } else {
+    unsigned long offset, page_mask = malloc_getpagesize-1;
+
+    /* mmap()ed chunks have MALLOC_ALIGNMENT or higher power-of-two
+       alignment relative to the beginning of a page.  Check this
+       first. */
+    offset = (unsigned long)mem & page_mask;
+    if((offset!=MALLOC_ALIGNMENT && offset!=0 && offset!=0x10 &&
+        offset!=0x20 && offset!=0x40 && offset!=0x80 && offset!=0x100 &&
+        offset!=0x200 && offset!=0x400 && offset!=0x800 && offset!=0x1000 &&
+        offset<0x2000) ||
+       !chunk_is_mmapped(p) || (p->size & PREV_INUSE) ||
+       ( (((unsigned long)p - p->prev_size) & page_mask) != 0 ) ||
+       ( (sz = chunksize(p)), ((p->prev_size + sz) & page_mask) != 0 ) )
+      return NULL;
+    magic = MAGICBYTE(p);
+    for(sz -= 1; (c = ((unsigned char*)p)[sz]) != magic; sz -= c) {
+      if(c<=0 || sz<(c+2*SIZE_SZ)) return NULL;
+    }
+    ((unsigned char*)p)[sz] ^= 0xFF;
+  }
+  return p;
+}
+
+/* Check for corruption of the top chunk, and try to recover if
+   necessary. */
+
+static int
+internal_function
+#if __STD_C
+top_check(void)
+#else
+top_check()
+#endif
+{
+  mchunkptr t = top(&main_arena);
+  char* brk, * new_brk;
+  INTERNAL_SIZE_T front_misalign, sbrk_size;
+  unsigned long pagesz = malloc_getpagesize;
+
+  if((char*)t + chunksize(t) == mp_.sbrk_base + main_arena.system_mem ||
+     t == initial_top(&main_arena)) return 0;
+
+  if(check_action & 1)
+    fprintf(stderr, "malloc: top chunk is corrupt\n");
+  if(check_action & 2)
+    abort();
+
+  /* Try to set up a new top chunk. */
+  brk = MORECORE(0);
+  front_misalign = (unsigned long)chunk2mem(brk) & MALLOC_ALIGN_MASK;
+  if (front_misalign > 0)
+    front_misalign = MALLOC_ALIGNMENT - front_misalign;
+  sbrk_size = front_misalign + mp_.top_pad + MINSIZE;
+  sbrk_size += pagesz - ((unsigned long)(brk + sbrk_size) & (pagesz - 1));
+  new_brk = (char*)(MORECORE (sbrk_size));
+  if (new_brk == (char*)(MORECORE_FAILURE)) return -1;
+  /* Call the `morecore' hook if necessary.  */
+  if (__after_morecore_hook)
+    (*__after_morecore_hook) ();
+  main_arena.system_mem = (new_brk - mp_.sbrk_base) + sbrk_size;
+
+  top(&main_arena) = (mchunkptr)(brk + front_misalign);
+  set_head(top(&main_arena), (sbrk_size - front_misalign) | PREV_INUSE);
+
+  return 0;
+}
+
+static Void_t*
+#if __STD_C
+malloc_check(size_t sz, const Void_t *caller)
+#else
+malloc_check(sz, caller) size_t sz; const Void_t *caller;
+#endif
+{
+  Void_t *victim;
+
+  (void)mutex_lock(&main_arena.mutex);
+  victim = (top_check() >= 0) ? _int_malloc(&main_arena, sz+1) : NULL;
+  (void)mutex_unlock(&main_arena.mutex);
+  return mem2mem_check(victim, sz);
+}
+
+static void
+#if __STD_C
+free_check(Void_t* mem, const Void_t *caller)
+#else
+free_check(mem, caller) Void_t* mem; const Void_t *caller;
+#endif
+{
+  mchunkptr p;
+
+  if(!mem) return;
+  (void)mutex_lock(&main_arena.mutex);
+  p = mem2chunk_check(mem);
+  if(!p) {
+    (void)mutex_unlock(&main_arena.mutex);
+    if(check_action & 1)
+      fprintf(stderr, "free(): invalid pointer %p!\n", mem);
+    if(check_action & 2)
+      abort();
+    return;
+  }
+#if HAVE_MMAP
+  if (chunk_is_mmapped(p)) {
+    (void)mutex_unlock(&main_arena.mutex);
+    munmap_chunk(p);
+    return;
+  }
+#endif
+#if 0 /* Erase freed memory. */
+  memset(mem, 0, chunksize(p) - (SIZE_SZ+1));
+#endif
+  _int_free(&main_arena, mem);
+  (void)mutex_unlock(&main_arena.mutex);
+}
+
+static Void_t*
+#if __STD_C
+realloc_check(Void_t* oldmem, size_t bytes, const Void_t *caller)
+#else
+realloc_check(oldmem, bytes, caller)
+     Void_t* oldmem; size_t bytes; const Void_t *caller;
+#endif
+{
+  mchunkptr oldp, newp = 0;
+  INTERNAL_SIZE_T nb, oldsize;
+  Void_t* newmem = 0;
+
+  if (oldmem == 0) return malloc_check(bytes, NULL);
+  (void)mutex_lock(&main_arena.mutex);
+  oldp = mem2chunk_check(oldmem);
+  (void)mutex_unlock(&main_arena.mutex);
+  if(!oldp) {
+    if(check_action & 1)
+      fprintf(stderr, "realloc(): invalid pointer %p!\n", oldmem);
+    if(check_action & 2)
+      abort();
+    return malloc_check(bytes, NULL);
+  }
+  oldsize = chunksize(oldp);
+
+  checked_request2size(bytes+1, nb);
+  (void)mutex_lock(&main_arena.mutex);
+
+#if HAVE_MMAP
+  if (chunk_is_mmapped(oldp)) {
+#if HAVE_MREMAP
+    newp = mremap_chunk(oldp, nb);
+    if(!newp) {
+#endif
+      /* Note the extra SIZE_SZ overhead. */
+      if(oldsize - SIZE_SZ >= nb)
+	newmem = oldmem; /* do nothing */
+      else {
+        /* Must alloc, copy, free. */
+        if (top_check() >= 0)
+	  newmem = _int_malloc(&main_arena, bytes+1);
+        if (newmem) {
+          MALLOC_COPY(BOUNDED_N(newmem, bytes+1), oldmem, oldsize - 2*SIZE_SZ);
+          munmap_chunk(oldp);
+        }
+      }
+#if HAVE_MREMAP
+    }
+#endif
+  } else {
+#endif /* HAVE_MMAP */
+    if (top_check() >= 0)
+      newmem = _int_realloc(&main_arena, oldmem, bytes+1);
+#if 0 /* Erase freed memory. */
+    if(newmem)
+      newp = mem2chunk(newmem);
+    nb = chunksize(newp);
+    if(oldp<newp || oldp>=chunk_at_offset(newp, nb)) {
+      memset((char*)oldmem + 2*sizeof(mbinptr), 0,
+             oldsize - (2*sizeof(mbinptr)+2*SIZE_SZ+1));
+    } else if(nb > oldsize+SIZE_SZ) {
+      memset((char*)BOUNDED_N(chunk2mem(newp), bytes) + oldsize,
+	     0, nb - (oldsize+SIZE_SZ));
+    }
+#endif
+#if HAVE_MMAP
+  }
+#endif
+  (void)mutex_unlock(&main_arena.mutex);
+
+  return mem2mem_check(newmem, bytes);
+}
+
+static Void_t*
+#if __STD_C
+memalign_check(size_t alignment, size_t bytes, const Void_t *caller)
+#else
+memalign_check(alignment, bytes, caller)
+     size_t alignment; size_t bytes; const Void_t *caller;
+#endif
+{
+  INTERNAL_SIZE_T nb;
+  Void_t* mem;
+
+  if (alignment <= MALLOC_ALIGNMENT) return malloc_check(bytes, NULL);
+  if (alignment <  MINSIZE) alignment = MINSIZE;
+
+  checked_request2size(bytes+1, nb);
+  (void)mutex_lock(&main_arena.mutex);
+  mem = (top_check() >= 0) ? _int_memalign(&main_arena, alignment, bytes+1) :
+    NULL;
+  (void)mutex_unlock(&main_arena.mutex);
+  return mem2mem_check(mem, bytes);
+}
+
+#ifndef NO_THREADS
+
+/* The following hooks are used when the global initialization in
+   ptmalloc_init() hasn't completed yet. */
+
+static Void_t*
+#if __STD_C
+malloc_starter(size_t sz, const Void_t *caller)
+#else
+malloc_starter(sz, caller) size_t sz; const Void_t *caller;
+#endif
+{
+  Void_t* victim;
+
+  victim = _int_malloc(&main_arena, sz);
+
+  return victim ? BOUNDED_N(victim, sz) : 0;
+}
+
+static void
+#if __STD_C
+free_starter(Void_t* mem, const Void_t *caller)
+#else
+free_starter(mem, caller) Void_t* mem; const Void_t *caller;
+#endif
+{
+  mchunkptr p;
+
+  if(!mem) return;
+  p = mem2chunk(mem);
+#if HAVE_MMAP
+  if (chunk_is_mmapped(p)) {
+    munmap_chunk(p);
+    return;
+  }
+#endif
+  _int_free(&main_arena, mem);
+}
+
+#endif /* NO_THREADS */
+
+
+/* Get/set state: malloc_get_state() records the current state of all
+   malloc variables (_except_ for the actual heap contents and `hook'
+   function pointers) in a system dependent, opaque data structure.
+   This data structure is dynamically allocated and can be free()d
+   after use.  malloc_set_state() restores the state of all malloc
+   variables to the previously obtained state.  This is especially
+   useful when using this malloc as part of a shared library, and when
+   the heap contents are saved/restored via some other method.  The
+   primary example for this is GNU Emacs with its `dumping' procedure.
+   `Hook' function pointers are never saved or restored by these
+   functions, with two exceptions: If malloc checking was in use when
+   malloc_get_state() was called, then malloc_set_state() calls
+   __malloc_check_init() if possible; if malloc checking was not in
+   use in the recorded state but the user requested malloc checking,
+   then the hooks are reset to 0.  */
+
+#define MALLOC_STATE_MAGIC   0x444c4541l
+#define MALLOC_STATE_VERSION (0*0x100l + 2l) /* major*0x100 + minor */
+
+struct malloc_save_state {
+  long          magic;
+  long          version;
+  mbinptr       av[NBINS * 2 + 2];
+  char*         sbrk_base;
+  int           sbrked_mem_bytes;
+  unsigned long trim_threshold;
+  unsigned long top_pad;
+  unsigned int  n_mmaps_max;
+  unsigned long mmap_threshold;
+  int           check_action;
+  unsigned long max_sbrked_mem;
+  unsigned long max_total_mem;
+  unsigned int  n_mmaps;
+  unsigned int  max_n_mmaps;
+  unsigned long mmapped_mem;
+  unsigned long max_mmapped_mem;
+  int           using_malloc_checking;
+};
+
+Void_t*
+public_gET_STATe(void)
+{
+  struct malloc_save_state* ms;
+  int i;
+  mbinptr b;
+
+  ms = (struct malloc_save_state*)public_mALLOc(sizeof(*ms));
+  if (!ms)
+    return 0;
+  (void)mutex_lock(&main_arena.mutex);
+  malloc_consolidate(&main_arena);
+  ms->magic = MALLOC_STATE_MAGIC;
+  ms->version = MALLOC_STATE_VERSION;
+  ms->av[0] = 0;
+  ms->av[1] = 0; /* used to be binblocks, now no longer used */
+  ms->av[2] = top(&main_arena);
+  ms->av[3] = 0; /* used to be undefined */
+  for(i=1; i<NBINS; i++) {
+    b = bin_at(&main_arena, i);
+    if(first(b) == b)
+      ms->av[2*i+2] = ms->av[2*i+3] = 0; /* empty bin */
+    else {
+      ms->av[2*i+2] = first(b);
+      ms->av[2*i+3] = last(b);
+    }
+  }
+  ms->sbrk_base = mp_.sbrk_base;
+  ms->sbrked_mem_bytes = main_arena.system_mem;
+  ms->trim_threshold = mp_.trim_threshold;
+  ms->top_pad = mp_.top_pad;
+  ms->n_mmaps_max = mp_.n_mmaps_max;
+  ms->mmap_threshold = mp_.mmap_threshold;
+  ms->check_action = check_action;
+  ms->max_sbrked_mem = main_arena.max_system_mem;
+#ifdef NO_THREADS
+  ms->max_total_mem = max_total_mem;
+#else
+  ms->max_total_mem = 0;
+#endif
+  ms->n_mmaps = mp_.n_mmaps;
+  ms->max_n_mmaps = mp_.max_n_mmaps;
+  ms->mmapped_mem = mp_.mmapped_mem;
+  ms->max_mmapped_mem = mp_.max_mmapped_mem;
+  ms->using_malloc_checking = using_malloc_checking;
+  (void)mutex_unlock(&main_arena.mutex);
+  return (Void_t*)ms;
+}
+
+int
+public_sET_STATe(Void_t* msptr)
+{
+  struct malloc_save_state* ms = (struct malloc_save_state*)msptr;
+  int i;
+  mbinptr b;
+
+  disallow_malloc_check = 1;
+  ptmalloc_init();
+  if(ms->magic != MALLOC_STATE_MAGIC) return -1;
+  /* Must fail if the major version is too high. */
+  if((ms->version & ~0xffl) > (MALLOC_STATE_VERSION & ~0xffl)) return -2;
+  (void)mutex_lock(&main_arena.mutex);
+  /* There are no fastchunks.  */
+  clear_fastchunks(&main_arena);
+  set_max_fast(&main_arena, DEFAULT_MXFAST);
+  for (i=0; i<NFASTBINS; ++i)
+    main_arena.fastbins[i] = 0;
+  for (i=0; i<BINMAPSIZE; ++i)
+    main_arena.binmap[i] = 0;
+  top(&main_arena) = ms->av[2];
+  main_arena.last_remainder = 0;
+  for(i=1; i<NBINS; i++) {
+    b = bin_at(&main_arena, i);
+    if(ms->av[2*i+2] == 0) {
+      assert(ms->av[2*i+3] == 0);
+      first(b) = last(b) = b;
+    } else {
+      if(i<NSMALLBINS || (largebin_index(chunksize(ms->av[2*i+2]))==i &&
+			  largebin_index(chunksize(ms->av[2*i+3]))==i)) {
+	first(b) = ms->av[2*i+2];
+	last(b) = ms->av[2*i+3];
+	/* Make sure the links to the bins within the heap are correct.  */
+	first(b)->bk = b;
+	last(b)->fd = b;
+	/* Set bit in binblocks.  */
+	mark_bin(&main_arena, i);
+      } else {
+	/* Oops, index computation from chunksize must have changed.
+           Link the whole list into unsorted_chunks.  */
+	first(b) = last(b) = b;
+	b = unsorted_chunks(&main_arena);
+	ms->av[2*i+2]->bk = b;
+	ms->av[2*i+3]->fd = b->fd;
+	b->fd->bk = ms->av[2*i+3];
+	b->fd = ms->av[2*i+2];
+      }
+    }
+  }
+  mp_.sbrk_base = ms->sbrk_base;
+  main_arena.system_mem = ms->sbrked_mem_bytes;
+  mp_.trim_threshold = ms->trim_threshold;
+  mp_.top_pad = ms->top_pad;
+  mp_.n_mmaps_max = ms->n_mmaps_max;
+  mp_.mmap_threshold = ms->mmap_threshold;
+  check_action = ms->check_action;
+  main_arena.max_system_mem = ms->max_sbrked_mem;
+#ifdef NO_THREADS
+  mp_.max_total_mem = ms->max_total_mem;
+#endif
+  mp_.n_mmaps = ms->n_mmaps;
+  mp_.max_n_mmaps = ms->max_n_mmaps;
+  mp_.mmapped_mem = ms->mmapped_mem;
+  mp_.max_mmapped_mem = ms->max_mmapped_mem;
+  /* add version-dependent code here */
+  if (ms->version >= 1) {
+    /* Check whether it is safe to enable malloc checking, or whether
+       it is necessary to disable it.  */
+    if (ms->using_malloc_checking && !using_malloc_checking &&
+        !disallow_malloc_check)
+      __malloc_check_init ();
+    else if (!ms->using_malloc_checking && using_malloc_checking) {
+      __malloc_hook = 0;
+      __free_hook = 0;
+      __realloc_hook = 0;
+      __memalign_hook = 0;
+      using_malloc_checking = 0;
+    }
+  }
+  check_malloc_state(&main_arena);
+
+  (void)mutex_unlock(&main_arena.mutex);
+  return 0;
+}
+
+/*
+ * Local variables:
+ * c-basic-offset: 2
+ * End:
+ */