1 files changed, 189 insertions, 554 deletions

diff --git a/src/lib/libc/stdlib/malloc.c b/src/lib/libc/stdlib/malloc.c
index aedb4c8f0c..661265bb85 100644
--- a/src/lib/libc/stdlib/malloc.c
+++ b/src/lib/libc/stdlib/malloc.c
@@ -8,7 +8,7 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char rcsid[] = "$OpenBSD: malloc.c,v 1.70 2004/08/05 21:55:21 tdeval Exp $";
+static char rcsid[] = "$OpenBSD: malloc.c,v 1.71 2004/08/11 06:22:45 tdeval Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 /*
@@ -38,8 +38,6 @@ static char rcsid[] = "$OpenBSD: malloc.c,v 1.70 2004/08/05 21:55:21 tdeval Exp
 #define SOME_JUNK       0xd0            /* as in "Duh" :-) */
 
 #include <sys/types.h>
-#include <sys/time.h>
-#include <sys/resource.h>
 #include <sys/param.h>
 #include <sys/mman.h>
 #include <sys/uio.h>
@@ -81,11 +79,11 @@ static char rcsid[] = "$OpenBSD: malloc.c,v 1.70 2004/08/05 21:55:21 tdeval Exp
 struct pginfo {
     struct pginfo       *next;  /* next on the free list */
     void                *page;  /* Pointer to the page */
-    u_short              size;  /* size of this page's chunks */
-    u_short              shift; /* How far to shift for this size chunks */
-    u_short              free;  /* How many free chunks */
-    u_short              total; /* How many chunk */
-    u_long               bits[1]; /* Which chunks are free */
+    u_short             size;   /* size of this page's chunks */
+    u_short             shift;  /* How far to shift for this size chunks */
+    u_short             free;   /* How many free chunks */
+    u_short             total;  /* How many chunk */
+    u_long              bits[1]; /* Which chunks are free */
 };
 
 /*
@@ -96,8 +94,8 @@ struct pgfree {
     struct pgfree       *next;  /* next run of free pages */
     struct pgfree       *prev;  /* prev run of free pages */
     void                *page;  /* pointer to free pages */
-    void                *pdir;  /* pointer to the base page's dir */
-    size_t               size;  /* number of bytes free */
+    void                *end;   /* pointer to end of free pages */
+    u_long              size;   /* number of bytes free */
 };
 
 /*
@@ -142,8 +140,8 @@ struct pgfree {
 /* A mask for the offset inside a page.  */
 #define malloc_pagemask ((malloc_pagesize)-1)
 
-#define pageround(foo) (((foo) + (malloc_pagemask)) & ~malloc_pagemask)
-#define ptr2index(foo) (((u_long)(foo) >> malloc_pageshift)+malloc_pageshift)
+#define pageround(foo) (((foo) + (malloc_pagemask))&(~(malloc_pagemask)))
+#define ptr2index(foo) (((u_long)(foo) >> malloc_pageshift)-malloc_origo)
 
 /* fd of /dev/zero */
 #ifdef USE_DEV_ZERO
@@ -163,22 +161,8 @@ static unsigned int malloc_started;
 /* Number of free pages we cache */
 static unsigned int malloc_cache = 16;
 
-/* Structure used for linking discrete directory pages. */
-struct pdinfo {
-    struct pginfo       **base;
-    struct pdinfo        *prev;
-    struct pdinfo        *next;
-    u_long                dirnum;
-};
-static struct   pdinfo  *last_dir;      /* Caches to the last and previous */
-static struct   pdinfo  *prev_dir;      /* referenced directory pages.     */
-
-static size_t           pdi_off;
-static u_long           pdi_mod;
-#define PD_IDX(num)     ((num) / (malloc_pagesize/sizeof(struct pginfo *)))
-#define PD_OFF(num)     ((num) & ((malloc_pagesize/sizeof(struct pginfo *))-1))
-#define PI_IDX(index)   ((index) / pdi_mod)
-#define PI_OFF(index)   ((index) % pdi_mod)
+/* The offset from pagenumber to index into the page directory */
+static u_long malloc_origo;
 
 /* The last index in the page directory we care about */
 static u_long last_index;
@@ -247,144 +231,72 @@ void utrace(struct ut *, int);
 /* Status of malloc. */
 static int malloc_active;
 
-/* Allocated memory. */
-static size_t malloc_used;
-
-/* My last break. */
+/* my last break. */
 static void *malloc_brk;
 
-/* One location cache for free-list holders. */
+/* one location cache for free-list holders */
 static struct pgfree *px;
 
-/* Compile-time options. */
+/* compile-time options */
 char *malloc_options;
 
-/* Name of the current public function. */
+/* Name of the current public function */
 static char *malloc_func;
 
-/* Macro for mmap. */
+/* Macro for mmap */
 #define MMAP(size) \
         mmap((void *)0, (size), PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, \
             MMAP_FD, (off_t)0)
 
 /*
- * Necessary function declarations.
+ * Necessary function declarations
  */
+static int extend_pgdir(u_long index);
 static void *imalloc(size_t size);
 static void ifree(void *ptr);
 static void *irealloc(void *ptr, size_t size);
 static void *malloc_bytes(size_t size);
 
-
-/*
- * Function for page directory lookup.
- */
-static int
-pdir_lookup(u_long index, struct pdinfo **pdi)
-{
-    struct pdinfo *spi;
-    u_long pidx = PI_IDX(index);
-
-    if (last_dir != NULL && PD_IDX(last_dir->dirnum) == pidx)
-            *pdi = last_dir;
-    else if (prev_dir != NULL && PD_IDX(prev_dir->dirnum) == pidx)
-            *pdi = prev_dir;
-    else if (last_dir != NULL && prev_dir != NULL) {
-        if ((PD_IDX(last_dir->dirnum) > pidx) ?
-          (PD_IDX(last_dir->dirnum) - pidx):(pidx - PD_IDX(last_dir->dirnum))
-          < (PD_IDX(prev_dir->dirnum) > pidx) ?
-          (PD_IDX(prev_dir->dirnum) - pidx):(pidx - PD_IDX(prev_dir->dirnum)))
-            *pdi = last_dir;
-        else
-            *pdi = prev_dir;
-
-        if (PD_IDX((*pdi)->dirnum) > pidx) {
-            for (spi=(*pdi)->prev;spi!=NULL && PD_IDX(spi->dirnum)>pidx;
-                 spi=spi->prev)
-                *pdi = spi;
-            if (spi != NULL)
-                *pdi = spi;
-        } else
-            for (spi=(*pdi)->next;spi!=NULL && PD_IDX(spi->dirnum)<=pidx;
-                 spi=spi->next)
-                *pdi = spi;
-    } else {
-        *pdi = (struct pdinfo *)((caddr_t)page_dir + pdi_off);
-        for (spi=*pdi;spi!=NULL && PD_IDX(spi->dirnum)<=pidx;spi=spi->next)
-            *pdi = spi;
-    }
-
-    return ((PD_IDX((*pdi)->dirnum) == pidx)?0:(PD_IDX((*pdi)->dirnum) > pidx)?1:-1);
-}
-
-
 #ifdef MALLOC_STATS
 void
 malloc_dump(FILE *fd)
 {
     struct pginfo **pd;
     struct pgfree *pf;
-    struct pdinfo *pi;
     int j;
 
     pd = page_dir;
-    pi = (struct pdinfo *)((caddr_t)pd + pdi_off);
 
     /* print out all the pages */
-    for(j=0;j<=last_index;) {
-        fprintf(fd, "%08lx %5d ", j << malloc_pageshift, j);
-        if (pd[PI_OFF(j)] == MALLOC_NOT_MINE) {
-            for(j++;j<=last_index && pd[PI_OFF(j)] == MALLOC_NOT_MINE;) {
-                if (!PI_OFF(++j)) {
-                    if ((pi = pi->next) == NULL ||
-                        PD_IDX(pi->dirnum) != PI_IDX(j)) break;
-                    pd = pi->base;
-                    j += pdi_mod;
-                }
-            }
+    for(j=0;j<=last_index;j++) {
+        fprintf(fd, "%08lx %5d ", (j+malloc_origo) << malloc_pageshift, j);
+        if (pd[j] == MALLOC_NOT_MINE) {
+            for(j++;j<=last_index && pd[j] == MALLOC_NOT_MINE;j++)
+                ;
             j--;
             fprintf(fd, ".. %5d not mine\n",    j);
-        } else if (pd[PI_OFF(j)] == MALLOC_FREE) {
-            for(j++;j<=last_index && pd[PI_OFF(j)] == MALLOC_FREE;) {
-                if (!PI_OFF(++j)) {
-                    if ((pi = pi->next) == NULL ||
-                        PD_IDX(pi->dirnum) != PI_IDX(j)) break;
-                    pd = pi->base;
-                    j += pdi_mod;
-                }
-            }
+        } else if (pd[j] == MALLOC_FREE) {
+            for(j++;j<=last_index && pd[j] == MALLOC_FREE;j++)
+                ;
             j--;
             fprintf(fd, ".. %5d free\n", j);
-        } else if (pd[PI_OFF(j)] == MALLOC_FIRST) {
-            for(j++;j<=last_index && pd[PI_OFF(j)] == MALLOC_FOLLOW;) {
-                if (!PI_OFF(++j)) {
-                    if ((pi = pi->next) == NULL ||
-                        PD_IDX(pi->dirnum) != PI_IDX(j)) break;
-                    pd = pi->base;
-                    j += pdi_mod;
-                }
-            }
+        } else if (pd[j] == MALLOC_FIRST) {
+            for(j++;j<=last_index && pd[j] == MALLOC_FOLLOW;j++)
+                ;
             j--;
             fprintf(fd, ".. %5d in use\n", j);
-        } else if (pd[PI_OFF(j)] < MALLOC_MAGIC) {
-            fprintf(fd, "(%p)\n", pd[PI_OFF(j)]);
+        } else if (pd[j] < MALLOC_MAGIC) {
+            fprintf(fd, "(%p)\n", pd[j]);
         } else {
             fprintf(fd, "%p %d (of %d) x %d @ %p --> %p\n",
-                pd[PI_OFF(j)], pd[PI_OFF(j)]->free, pd[PI_OFF(j)]->total,
-                pd[PI_OFF(j)]->size, pd[PI_OFF(j)]->page, pd[PI_OFF(j)]->next);
-        }
-        if (!PI_OFF(++j)) {
-            if ((pi = pi->next) == NULL)
-                break;
-            pd = pi->base;
-            j += (1 + PD_IDX(pi->dirnum) - PI_IDX(j)) * pdi_mod;
+                pd[j], pd[j]->free, pd[j]->total,
+                pd[j]->size, pd[j]->page, pd[j]->next);
         }
     }
 
     for(pf=free_list.next; pf; pf=pf->next) {
         fprintf(fd, "Free: @%p [%p...%p[ %ld ->%p <-%p\n",
-                pf, pf->page, pf->page + pf->size, pf->size,
-                pf->prev, pf->next);
+                pf, pf->page, pf->end, pf->size, pf->prev, pf->next);
         if (pf == pf->next) {
                 fprintf(fd, "Free_list loops\n");
                 break;
@@ -396,7 +308,10 @@ malloc_dump(FILE *fd)
     fprintf(fd, "Maxsize\t%d\n", malloc_maxsize);
     fprintf(fd, "Pagesize\t%lu\n", (u_long)malloc_pagesize);
     fprintf(fd, "Pageshift\t%d\n", malloc_pageshift);
-    fprintf(fd, "In use\t%lu\n", (u_long)malloc_used);
+    fprintf(fd, "FirstPage\t%ld\n", malloc_origo);
+    fprintf(fd, "LastPage\t%ld %lx\n", last_index+malloc_pageshift,
+        (last_index + malloc_pageshift) << malloc_pageshift);
+    fprintf(fd, "Break\t%ld\n", (u_long)sbrk(0) >> malloc_pageshift);
 }
 #endif /* MALLOC_STATS */
 
@@ -424,8 +339,7 @@ wrterror(char *p)
         malloc_dump(stderr);
 #endif /* MALLOC_STATS */
     malloc_active--;
-    if (malloc_abort)
-        abort();
+    abort();
 }
 
 static void
@@ -471,86 +385,89 @@ malloc_exit(void)
 static void *
 map_pages(size_t pages)
 {
-    struct pdinfo *pi, *spi;
-    struct pginfo **pd;
-    u_long pidx,lidx;
-    void *result, *tail;
-    u_long index;
+    caddr_t result, tail;
 
+    result = (caddr_t)pageround((u_long)sbrk(0));
     pages <<= malloc_pageshift;
-    result = MMAP(pages + malloc_guard);
-    if (result == MAP_FAILED) {
-        errno = ENOMEM;
+    if (pages > SIZE_T_MAX - (size_t)result) {
 #ifdef MALLOC_EXTRA_SANITY
-        wrtwarning("(ES): map_pages fails\n");
+        wrtwarning("(ES): overflow in map_pages fails\n");
 #endif /* MALLOC_EXTRA_SANITY */
+        errno = ENOMEM;
         return (NULL);
     }
     tail = result + pages + malloc_guard;
-    if (malloc_guard)
-        mprotect(result + pages, malloc_guard, PROT_NONE);
-
-    if (tail > malloc_brk)
-        malloc_brk = tail;
-    if ((index = ptr2index(tail) - 1) > last_index)
-        last_index = index;
-
-    /* Insert directory pages, if needed. */
-    pidx = PI_IDX(ptr2index(result));
-    lidx = PI_IDX(index);
 
-    pdir_lookup(ptr2index(result), &pi);
-
-    for (index=pidx,spi=pi;index<=lidx;index++) {
-        if (pi == NULL || PD_IDX(pi->dirnum) != index) {
-            if ((pd = MMAP(malloc_pagesize)) == MAP_FAILED) {
-                errno = ENOMEM;
-                munmap(result, tail - result);
+    if (brk(tail) == (char *)-1) {
 #ifdef MALLOC_EXTRA_SANITY
-                wrtwarning("(ES): map_pages fails\n");
-#endif /* MALLOC_EXTRA_SANITY */
-                return (NULL);
-            }
-            memset(pd, 0, malloc_pagesize);
-            pi = (struct pdinfo *)((caddr_t)pd + pdi_off);
-            pi->base = pd;
-            pi->prev = spi;
-            pi->next = spi->next;
-            pi->dirnum = index * (malloc_pagesize/sizeof(struct pginfo *));
-
-            if (spi->next != NULL)
-                spi->next->prev = pi;
-            spi->next = pi;
-        }
-        if (index > pidx && index < lidx) {
-            pi->dirnum += pdi_mod;
-        } else if (index == pidx) {
-            if (pidx == lidx) {
-                pi->dirnum += (tail - result) >> malloc_pageshift;
-            } else {
-                pi->dirnum += pdi_mod - PI_OFF(ptr2index(result));
-            }
-        } else {
-            pi->dirnum += PI_OFF(ptr2index(tail - 1)) + 1;
-        }
-#ifdef  MALLOC_EXTRA_SANITY
-        if (PD_OFF(pi->dirnum) > pdi_mod || PD_IDX(pi->dirnum) > index) {
-            wrterror("(ES): pages directory overflow\n");
-            errno = EFAULT;
-            return (NULL);
-        }
+        wrtwarning("(ES): map_pages fails\n");
 #endif /* MALLOC_EXTRA_SANITY */
-        if (index == pidx && pi != last_dir) {
-           prev_dir = last_dir;
-           last_dir = pi;
-        }
-        spi = pi;
-        pi = spi->next;
+        return (NULL);
     }
+    if (malloc_guard)
+        mprotect(result + pages, malloc_pagesize, PROT_NONE);
+
+    last_index = ptr2index(tail) - 1;
+    malloc_brk = tail;
+
+    if ((last_index+1) >= malloc_ninfo && !extend_pgdir(last_index))
+        return (NULL);
 
     return (result);
 }
 
+/*
+ * Extend page directory
+ */
+static int
+extend_pgdir(u_long index)
+{
+    struct  pginfo **new, **old;
+    size_t i, oldlen;
+
+    /* Make it this many pages */
+    i = index * sizeof *page_dir;
+    i /= malloc_pagesize;
+    i += 2;
+
+    /* remember the old mapping size */
+    oldlen = malloc_ninfo * sizeof *page_dir;
+
+    /*
+     * NOTE: we allocate new pages and copy the directory rather than tempt
+     * fate by trying to "grow" the region.. There is nothing to prevent
+     * us from accidently re-mapping space that's been allocated by our caller
+     * via dlopen() or other mmap().
+     *
+     * The copy problem is not too bad, as there is 4K of page index per
+     * 4MB of malloc arena.
+     *
+     * We can totally avoid the copy if we open a file descriptor to associate
+     * the anon mappings with.  Then, when we remap the pages at the new
+     * address, the old pages will be "magically" remapped..  But this means
+     * keeping open a "secret" file descriptor.....
+     */
+
+    /* Get new pages */
+    new = (struct pginfo**) MMAP(i * malloc_pagesize);
+    if (new == MAP_FAILED)
+        return (0);
+
+    /* Copy the old stuff */
+    memcpy(new, page_dir,
+            malloc_ninfo * sizeof *page_dir);
+
+    /* register the new size */
+    malloc_ninfo = i * malloc_pagesize / sizeof *page_dir;
+
+    /* swap the pointers */
+    old = page_dir;
+    page_dir = new;
+
+    /* Now free the old stuff */
+    munmap(old, oldlen);
+    return (1);
+}
 
 /*
  * Initialize the world
@@ -603,12 +520,12 @@ malloc_init(void)
                 case 'h': malloc_hint    = 0; break;
                 case 'H': malloc_hint    = 1; break;
 #endif /* __FreeBSD__ */
+                case 'r': malloc_realloc = 0; break;
+                case 'R': malloc_realloc = 1; break;
                 case 'j': malloc_junk    = 0; break;
                 case 'J': malloc_junk    = 1; break;
                 case 'n': malloc_silent  = 0; break;
                 case 'N': malloc_silent  = 1; break;
-                case 'r': malloc_realloc = 0; break;
-                case 'R': malloc_realloc = 1; break;
 #ifdef __FreeBSD__
                 case 'u': malloc_utrace  = 0; break;
                 case 'U': malloc_utrace  = 1; break;
@@ -644,21 +561,17 @@ malloc_init(void)
     /* Allocate one page for the page directory */
     page_dir = (struct pginfo **) MMAP(malloc_pagesize);
 
-    if (page_dir == MAP_FAILED) {
+    if (page_dir == MAP_FAILED)
         wrterror("mmap(2) failed, check limits\n");
-        errno = ENOMEM;
-        return;
-    }
 
-    pdi_off = (malloc_pagesize - sizeof(struct pdinfo)) & ~(malloc_minsize - 1);
-    pdi_mod = pdi_off / sizeof(struct pginfo *);
-
-    last_dir = (struct pdinfo *)((caddr_t)page_dir + pdi_off);
-    last_dir->base = page_dir;
-    last_dir->prev = last_dir->next = NULL;
-    last_dir->dirnum = malloc_pageshift;
+    /*
+     * We need a maximum of malloc_pageshift buckets, steal these from the
+     * front of the page_directory;
+     */
+    malloc_origo = ((u_long)pageround((u_long)sbrk(0))) >> malloc_pageshift;
+    malloc_origo -= malloc_pageshift;
 
-    malloc_ninfo = pdi_mod;
+    malloc_ninfo = malloc_pagesize / sizeof *page_dir;
 
     /* Been here, done that */
     malloc_started++;
@@ -670,6 +583,11 @@ malloc_init(void)
 
     malloc_cache <<= malloc_pageshift;
 
+    /*
+     * This is a nice hack from Kaleb Keithly (kaleb@x.org).
+     * We can sbrk(2) further back when we keep this on a low address.
+     */
+    px = (struct pgfree *) imalloc (sizeof *px);
     errno = save_errno;
 }
 
@@ -681,66 +599,30 @@ malloc_pages(size_t size)
 {
     void *p, *delay_free = NULL;
     int i;
-    struct rlimit rl;
-    struct pginfo **pd;
-    struct pdinfo *pi;
-    u_long pidx;
-    void *tp;
     struct pgfree *pf;
     u_long index;
-    int m;
 
     size = pageround(size) + malloc_guard;
 
     p = NULL;
     /* Look for free pages before asking for more */
-    for (pf = free_list.next; pf; pf = pf->next) {
+    for(pf = free_list.next; pf; pf = pf->next) {
 
 #ifdef MALLOC_EXTRA_SANITY
-        if (pf->size & malloc_pagemask) {
+        if (pf->size & malloc_pagemask)
             wrterror("(ES): junk length entry on free_list\n");
-            errno = EFAULT;
-            return (NULL);
-        }
-        if (!pf->size) {
+        if (!pf->size)
             wrterror("(ES): zero length entry on free_list\n");
-            errno = EFAULT;
-            return (NULL);
-        }
-        if (pf->page > (pf->page + pf->size)) {
+        if (pf->page == pf->end)
+            wrterror("(ES): zero entry on free_list\n");
+        if (pf->page > pf->end)
             wrterror("(ES): sick entry on free_list\n");
-            errno = EFAULT;
-            return (NULL);
-        }
-        if ((pi = pf->pdir) == NULL) {
-            wrterror("(ES): invalid page directory on free-list\n");
-            errno = EFAULT;
-            return (NULL);
-        }
-        if ((pidx = PI_IDX(ptr2index(pf->page))) != PD_IDX(pi->dirnum)) {
-            wrterror("(ES): directory index mismatch on free-list\n");
-            errno = EFAULT;
-            return (NULL);
-        }
-        pd = pi->base;
-        if (pd[PI_OFF(ptr2index(pf->page))] != MALLOC_FREE) {
+        if ((void*)pf->page >= (void*)sbrk(0))
+            wrterror("(ES): entry on free_list past brk\n");
+        if (page_dir[ptr2index(pf->page)] != MALLOC_FREE)
             wrterror("(ES): non-free first page on free-list\n");
-            errno = EFAULT;
-            return (NULL);
-        }
-        pidx = PI_IDX(ptr2index((pf->page)+(pf->size))-1);
-        for (pi=pf->pdir; pi!=NULL && PD_IDX(pi->dirnum)<pidx; pi=pi->next);
-        if (pi == NULL || PD_IDX(pi->dirnum) != pidx) {
-            wrterror("(ES): last page not referenced in page directory\n");
-            errno = EFAULT;
-            return (NULL);
-        }
-        pd = pi->base;
-        if (pd[PI_OFF(ptr2index((pf->page)+(pf->size))-1)] != MALLOC_FREE) {
+        if (page_dir[ptr2index(pf->end)-1] != MALLOC_FREE)
             wrterror("(ES): non-free last page on free-list\n");
-            errno = EFAULT;
-            return (NULL);
-        }
 #endif /* MALLOC_EXTRA_SANITY */
 
         if (pf->size < size)
@@ -748,7 +630,6 @@ malloc_pages(size_t size)
 
         if (pf->size == size) {
             p = pf->page;
-            pi = pf->pdir;
             if (pf->next != NULL)
                     pf->next->prev = pf->prev;
             pf->prev->next = pf->next;
@@ -759,34 +640,17 @@ malloc_pages(size_t size)
         p = pf->page;
         pf->page = (char *)pf->page + size;
         pf->size -= size;
-        pidx = PI_IDX(ptr2index(pf->page));
-        for (pi=pf->pdir; pi!=NULL && PD_IDX(pi->dirnum)<pidx; pi=pi->next);
-        if (pi == NULL || PD_IDX(pi->dirnum) != pidx) {
-            wrterror("(ES): hole in directories\n");
-            errno = EFAULT;
-            return (NULL);
-        }
-        tp = pf->pdir;
-        pf->pdir = pi;
-        pi = tp;
         break;
     }
 
     size -= malloc_guard;
 
-#ifdef  MALLOC_EXTRA_SANITY
-    if (p != NULL && pi != NULL) {
-        pidx = PD_IDX(pi->dirnum);
-        pd = pi->base;
-    }
-    if (p != NULL && pd[PI_OFF(ptr2index(p))] != MALLOC_FREE) {
+#ifdef MALLOC_EXTRA_SANITY
+    if (p != NULL && page_dir[ptr2index(p)] != MALLOC_FREE)
         wrterror("(ES): allocated non-free page on free-list\n");
-        errno = EFAULT;
-        return (NULL);
-    }
 #endif /* MALLOC_EXTRA_SANITY */
 
-    if (p != NULL && (malloc_guard || malloc_freeprot))
+    if ((malloc_guard || malloc_freeprot) && p != NULL)
         mprotect(p, size, PROT_READ|PROT_WRITE);
 
     size >>= malloc_pageshift;
@@ -798,53 +662,9 @@ malloc_pages(size_t size)
     if (p != NULL) {
 
         index = ptr2index(p);
-        pidx = PI_IDX(index);
-        pdir_lookup(index, &pi);
-#ifdef  MALLOC_EXTRA_SANITY
-        if (pi == NULL || PD_IDX(pi->dirnum) != pidx) {
-            wrterror("(ES): mapped pages not found in directory\n");
-            errno = EFAULT;
-            return (NULL);
-        }
-#endif /* MALLOC_EXTRA_SANITY */
-        if (pi != last_dir) {
-            prev_dir = last_dir;
-            last_dir = pi;
-        }
-        pd = pi->base;
-        pd[PI_OFF(index)] = MALLOC_FIRST;
-        for (i=1;i<size;i++) {
-            if (!PI_OFF(index+i)) {
-                pidx++;
-                pi = pi->next;
-#ifdef  MALLOC_EXTRA_SANITY
-                if (pi == NULL || PD_IDX(pi->dirnum) != pidx) {
-                    wrterror("(ES): hole in mapped pages directory\n");
-                    errno = EFAULT;
-                    return (NULL);
-                }
-#endif /* MALLOC_EXTRA_SANITY */
-                pd = pi->base;
-            }
-            pd[PI_OFF(index+i)] = MALLOC_FOLLOW;
-        }
-        if (malloc_guard) {
-            if (!PI_OFF(index+i)) {
-                pidx++;
-                pi = pi->next;
-#ifdef  MALLOC_EXTRA_SANITY
-                if (pi == NULL || PD_IDX(pi->dirnum) != pidx) {
-                    wrterror("(ES): hole in mapped pages directory\n");
-                    errno = EFAULT;
-                    return (NULL);
-                }
-#endif /* MALLOC_EXTRA_SANITY */
-                pd = pi->base;
-            }
-            pd[PI_OFF(index+i)] = MALLOC_FIRST;
-        }
-
-        malloc_used += size << malloc_pageshift;
+        page_dir[index] = MALLOC_FIRST;
+        for (i=1;i<size;i++)
+            page_dir[index+i] = MALLOC_FOLLOW;
 
         if (malloc_junk)
             memset(p, SOME_JUNK, size << malloc_pageshift);
@@ -867,10 +687,7 @@ malloc_pages(size_t size)
 static __inline__ int
 malloc_make_chunks(int bits)
 {
-    struct pginfo *bp;
-    struct pginfo **pd;
-    struct pdinfo *pi;
-    u_long pidx;
+    struct  pginfo *bp;
     void *pp;
     int i, k, l;
 
@@ -948,21 +765,7 @@ malloc_make_chunks(int bits)
 
     /* MALLOC_LOCK */
 
-    pidx = PI_IDX(ptr2index(pp));
-    pdir_lookup(ptr2index(pp), &pi);
-#ifdef  MALLOC_EXTRA_SANITY
-    if (pi == NULL || PD_IDX(pi->dirnum) != pidx) {
-        wrterror("(ES): mapped pages not found in directory\n");
-        errno = EFAULT;
-        return (0);
-    }
-#endif /* MALLOC_EXTRA_SANITY */
-    if (pi != last_dir) {
-        prev_dir = last_dir;
-        last_dir = pi;
-    }
-    pd = pi->base;
-    pd[PI_OFF(ptr2index(pp))] = bp;
+    page_dir[ptr2index(pp)] = bp;
 
     bp->next = page_dir[bits];
     page_dir[bits] = bp;
@@ -1016,7 +819,7 @@ malloc_bytes(size_t size)
         u += u;
         k++;
     }
-
+    
     if (malloc_guard) {
         /* Walk to a random position. */
         i = arc4random() % bp->free;
@@ -1029,14 +832,11 @@ malloc_bytes(size_t size)
                 k = 0;
             }
 #ifdef  MALLOC_EXTRA_SANITY
-            if (lp - bp->bits > (bp->total - 1) / MALLOC_BITS) {
+        if (lp - bp->bits > (bp->total - 1) / MALLOC_BITS)
                 wrterror("chunk overflow\n");
-                errno = EFAULT;
-                return (NULL);
-            }
 #endif  /* MALLOC_EXTRA_SANITY */
-            if (*lp & u)
-                i--;
+        if (*lp & u)
+            i--;
         }
     }
     *lp ^= u;
@@ -1096,11 +896,9 @@ static void *
 irealloc(void *ptr, size_t size)
 {
     void *p;
-    u_long osize, index, i;
+    u_long osize, index;
     struct pginfo **mp;
-    struct pginfo **pd;
-    struct pdinfo *pi;
-    u_long pidx;
+    int i;
 
     if (suicide)
         abort();
@@ -1122,22 +920,7 @@ irealloc(void *ptr, size_t size)
         return (NULL);
     }
 
-    pidx = PI_IDX(index);
-    pdir_lookup(index, &pi);
-#ifdef  MALLOC_EXTRA_SANITY
-    if (pi == NULL || PD_IDX(pi->dirnum) != pidx) {
-        wrterror("(ES): mapped pages not found in directory\n");
-        errno = EFAULT;
-        return (NULL);
-    }
-#endif /* MALLOC_EXTRA_SANITY */
-    if (pi != last_dir) {
-        prev_dir = last_dir;
-        last_dir = pi;
-    }
-
-    pd = pi->base;
-    mp = &pd[PI_OFF(index)];
+    mp = &page_dir[index];
 
     if (*mp == MALLOC_FIRST) {                  /* Page allocation */
 
@@ -1148,25 +931,8 @@ irealloc(void *ptr, size_t size)
         }
 
         /* Find the size in bytes */
-        i = index;
-        if (!PI_OFF(++i)) {
-            pi = pi->next;
-            if (pi != NULL && PD_IDX(pi->dirnum) != PI_IDX(i))
-                pi = NULL;
-            if (pi != NULL)
-                pd = pi->base;
-        }
-        for (osize = malloc_pagesize;
-             pi != NULL && pd[PI_OFF(i)] == MALLOC_FOLLOW;) {
+        for (osize = malloc_pagesize; *(++mp) == MALLOC_FOLLOW;)
             osize += malloc_pagesize;
-            if (!PI_OFF(++i)) {
-                pi = pi->next;
-                if (pi != NULL && PD_IDX(pi->dirnum) != PI_IDX(i))
-                    pi = NULL;
-                if (pi != NULL)
-                    pd = pi->base;
-            }
-        }
 
         if (!malloc_realloc &&                  /* Unless we have to, */
           size <= osize &&                      /* .. or are too small, */
@@ -1222,7 +988,6 @@ irealloc(void *ptr, size_t size)
         }
         ifree(ptr);
     }
-
     return (p);
 }
 
@@ -1234,9 +999,6 @@ static __inline__ void
 free_pages(void *ptr, u_long index, struct pginfo *info)
 {
     u_long i, l;
-    struct pginfo **pd;
-    struct pdinfo *pi, *spi;
-    u_long pidx, lidx;
     struct pgfree *pf, *pt=NULL;
     void *tail;
 
@@ -1256,77 +1018,40 @@ free_pages(void *ptr, u_long index, struct pginfo *info)
     }
 
     /* Count how many pages and mark them free at the same time */
-    pidx = PI_IDX(index);
-    pdir_lookup(index, &pi);
-#ifdef  MALLOC_EXTRA_SANITY
-    if (pi == NULL || PD_IDX(pi->dirnum) != pidx) {
-        wrterror("(ES): mapped pages not found in directory\n");
-        errno = EFAULT;
-        return;
-    }
-#endif /* MALLOC_EXTRA_SANITY */
-
-    spi = pi;           /* Save page index for start of region. */
-
-    pd = pi->base;
-    pd[PI_OFF(index)] = MALLOC_FREE;
-    i = 1;
-    if (!PI_OFF(index+i)) {
-        pi = pi->next;
-        if (pi == NULL || PD_IDX(pi->dirnum) != PI_IDX(index+i))
-            pi = NULL;
-        else
-            pd = pi->base;
-    }
-    while (pi != NULL && pd[PI_OFF(index+i)] == MALLOC_FOLLOW) {
-        pd[PI_OFF(index+i)] = MALLOC_FREE;
-        i++;
-        if (!PI_OFF(index+i)) {
-            if ((pi=pi->next) == NULL || PD_IDX(pi->dirnum) != PI_IDX(index+i))
-                pi = NULL;
-            else
-                pd = pi->base;
-        }
-    }
+    page_dir[index] = MALLOC_FREE;
+    for (i = 1; page_dir[index+i] == MALLOC_FOLLOW; i++)
+        page_dir[index + i] = MALLOC_FREE;
 
     l = i << malloc_pageshift;
 
     if (malloc_junk)
         memset(ptr, SOME_JUNK, l);
 
-    malloc_used -= l;
-    if (malloc_guard) {
-#ifdef  MALLOC_EXTRA_SANITY
-        if (pi == NULL || PD_IDX(pi->dirnum) != PI_IDX(index+i)) {
-            wrterror("(ES): hole in mapped pages directory\n");
-            errno = EFAULT;
-            return;
-        }
-#endif /* MALLOC_EXTRA_SANITY */
-        pd[PI_OFF(index+i)] = MALLOC_FREE;
-        l += malloc_guard;
-    }
-    tail = (char *)ptr + l;
-
 #if defined(__FreeBSD__) || (defined(__OpenBSD__) && defined(MADV_FREE))
     if (malloc_hint)
         madvise(ptr, l, MADV_FREE);
 #endif
 
+    if (malloc_guard) {
+        page_dir[index + i] = MALLOC_FREE;
+        l += malloc_guard;
+    }
+    tail = (char *)ptr+l;
+
     if (malloc_freeprot)
-        mprotect(ptr, l, PROT_NONE);
+        mprotect(ptr, tail - ptr, PROT_NONE);
 
-    /* Add to free-list. */
+    /* add to free-list */
     if (px == NULL)
         px = imalloc(sizeof *px);       /* This cannot fail... */
     px->page = ptr;
-    px->pdir = spi;
+    px->end = tail;
     px->size = l;
 
     if (free_list.next == NULL) {
 
-        /* Nothing on free list, put this at head. */
-        px->next = NULL;
+        /* Nothing on free list, put this at head */
+        px->next = free_list.next;
         px->prev = &free_list;
         free_list.next = px;
         pf = px;
@@ -1336,9 +1061,9 @@ free_pages(void *ptr, u_long index, struct pginfo *info)
 
         /* Find the right spot, leave pf pointing to the modified entry. */
 
-        for(pf = free_list.next; (pf->page+pf->size) < ptr && pf->next != NULL;
+        for(pf = free_list.next; pf->end < ptr && pf->next != NULL;
             pf = pf->next)
-            ; /* Race ahead here. */
+            ; /* Race ahead here */
 
         if (pf->page > tail) {
             /* Insert before entry */
@@ -1348,24 +1073,25 @@ free_pages(void *ptr, u_long index, struct pginfo *info)
             px->prev->next = px;
             pf = px;
             px = NULL;
-        } else if ((pf->page + pf->size) == ptr ) {
-            /* Append to the previous entry. */
+        } else if (pf->end == ptr ) {
+            /* Append to the previous entry */
+            pf->end = (char *)pf->end + l;
             pf->size += l;
-            if (pf->next != NULL && (pf->page + pf->size) == pf->next->page ) {
+            if (pf->next != NULL && pf->end == pf->next->page ) {
                 /* And collapse the next too. */
                 pt = pf->next;
+                pf->end = pt->end;
                 pf->size += pt->size;
                 pf->next = pt->next;
                 if (pf->next != NULL)
                     pf->next->prev = pf;
             }
         } else if (pf->page == tail) {
-            /* Prepend to entry. */
+            /* Prepend to entry */
             pf->size += l;
             pf->page = ptr;
-            pf->pdir = spi;
         } else if (pf->next == NULL) {
-            /* Append at tail of chain. */
+            /* Append at tail of chain */
             px->next = NULL;
             px->prev = pf;
             pf->next = px;
@@ -1373,80 +1099,34 @@ free_pages(void *ptr, u_long index, struct pginfo *info)
             px = NULL;
         } else {
             wrterror("freelist is destroyed\n");
-            errno = EFAULT;
-            return;
         }
     }
 
-    if (pf->pdir != last_dir) {
-        prev_dir = last_dir;
-        last_dir = pf->pdir;
-    }
-
     /* Return something to OS ? */
     if (pf->next == NULL &&                     /* If we're the last one, */
       pf->size > malloc_cache &&                /* ..and the cache is full, */
-      (pf->page + pf->size) == malloc_brk) {    /* ..and none behind us, */
+      pf->end == malloc_brk &&                  /* ..and none behind us, */
+      malloc_brk == sbrk(0)) {                  /* ..and it's OK to do... */
 
         /*
          * Keep the cache intact.  Notice that the '>' above guarantees that
          * the pf will always have at least one page afterwards.
          */
-        if (munmap((char *)pf->page + malloc_cache, pf->size - malloc_cache)!=0)
-            goto not_return;
-        tail = pf->page + pf->size;
-        lidx = ptr2index(tail) - 1;
+        pf->end = (char *)pf->page + malloc_cache;
         pf->size = malloc_cache;
 
-        malloc_brk = pf->page + malloc_cache;
-
-        index = ptr2index(malloc_brk);
-
-        pidx = PI_IDX(index);
-        if (prev_dir != NULL && PD_IDX(prev_dir->dirnum) >= pidx)
-                prev_dir = NULL;        /* Will be wiped out below ! */
+        brk(pf->end);
+        malloc_brk = pf->end;
 
-        for (pi=pf->pdir; pi!=NULL && PD_IDX(pi->dirnum)<pidx; pi=pi->next);
+        index = ptr2index(pf->end);
 
-        if (pi != NULL && PD_IDX(pi->dirnum) == pidx) {
-            pd = pi->base;
-
-            for(i=index;i <= last_index;) {
-                if (pd[PI_OFF(i)] != MALLOC_NOT_MINE) {
-                    pd[PI_OFF(i)] = MALLOC_NOT_MINE;
-#ifdef  MALLOC_EXTRA_SANITY
-                    if (!PD_OFF(pi->dirnum)) {
-                        wrterror("(ES): pages directory underflow\n");
-                        errno = EFAULT;
-                        return;
-                    }
-#endif /* MALLOC_EXTRA_SANITY */
-                    pi->dirnum--;
-                }
-                i++;
-                if (!PI_OFF(i)) {
-                    /* If no page in that dir, free directory page. */
-                    if (!PD_OFF(pi->dirnum)) {
-                        /* Remove from list. */
-                        pi->prev->next = pi->next;
-                        if (pi->next != NULL)
-                            pi->next->prev = pi->prev;
-                        pi = pi->next;
-                        munmap(pd, malloc_pagesize);
-                    } else
-                        pi = pi->next;
-                    if (pi == NULL || PD_IDX(pi->dirnum) != PI_IDX(i))
-                        break;
-                    pd = pi->base;
-                }
-            }
-        }
+        for(i=index;i <= last_index;)
+            page_dir[i++] = MALLOC_NOT_MINE;
 
         last_index = index - 1;
 
         /* XXX: We could realloc/shrink the pagedir here I guess. */
     }
-not_return:
     if (pt != NULL)
         ifree(pt);
 }
@@ -1461,9 +1141,6 @@ free_bytes(void *ptr, int index, struct pginfo *info)
 {
     int i;
     struct pginfo **mp;
-    struct pginfo **pd;
-    struct pdinfo *pi;
-    u_long pidx;
     void *vp;
 
     /* Find the chunk number on the page */
@@ -1495,8 +1172,7 @@ free_bytes(void *ptr, int index, struct pginfo *info)
         /* Page became non-full */
 
         /* Insert in address order */
-        while (*mp != NULL && (*mp)->next != NULL &&
-               (*mp)->next->page < info->page)
+        while (*mp && (*mp)->next && (*mp)->next->page < info->page)
             mp = &(*mp)->next;
         info->next = *mp;
         *mp = info;
@@ -1510,32 +1186,14 @@ free_bytes(void *ptr, int index, struct pginfo *info)
     while (*mp != info) {
         mp = &((*mp)->next);
 #ifdef MALLOC_EXTRA_SANITY
-        if (!*mp) {
-            wrterror("(ES): Not on queue\n");
-            errno = EFAULT;
-            return;
-        }
+        if (!*mp)
+                wrterror("(ES): Not on queue\n");
 #endif /* MALLOC_EXTRA_SANITY */
     }
     *mp = info->next;
 
     /* Free the page & the info structure if need be */
-    pidx = PI_IDX(ptr2index(info->page));
-    pdir_lookup(ptr2index(info->page), &pi);
-#ifdef  MALLOC_EXTRA_SANITY
-    if (pi == NULL || PD_IDX(pi->dirnum) != pidx) {
-        wrterror("(ES): mapped pages not found in directory\n");
-        errno = EFAULT;
-        return;
-    }
-#endif /* MALLOC_EXTRA_SANITY */
-    if (pi != last_dir) {
-        prev_dir = last_dir;
-        last_dir = pi;
-    }
-
-    pd = pi->base;
-    pd[PI_OFF(ptr2index(info->page))] = MALLOC_FIRST;
+    page_dir[ptr2index(info->page)] = MALLOC_FIRST;
 
     /* If the page was mprotected, unprotect it before releasing it */
     if (info->size == 0) {
@@ -1553,9 +1211,6 @@ static void
 ifree(void *ptr)
 {
     struct pginfo *info;
-    struct pginfo **pd;
-    struct pdinfo *pi;
-    u_long pidx;
     u_long index;
 
     /* This is legal */
@@ -1583,22 +1238,7 @@ ifree(void *ptr)
         return;
     }
 
-    pidx = PI_IDX(index);
-    pdir_lookup(index, &pi);
-#ifdef  MALLOC_EXTRA_SANITY
-    if (pi == NULL || PD_IDX(pi->dirnum) != pidx) {
-        wrterror("(ES): mapped pages not found in directory\n");
-        errno = EFAULT;
-        return;
-    }
-#endif /* MALLOC_EXTRA_SANITY */
-    if (pi != last_dir) {
-        prev_dir = last_dir;
-        last_dir = pi;
-    }
-
-    pd = pi->base;
-    info = pd[PI_OFF(index)];
+    info = page_dir[index];
 
     if (info < MALLOC_MAGIC)
         free_pages(ptr, index, info);
@@ -1617,10 +1257,9 @@ malloc_recurse(void)
 {
     static int noprint;
 
-    if (noprint == 0) {
-        noprint = 1;
+    if (noprint == 0)
         wrtwarning("recursive call\n");
-    }
+    noprint = 1;
     malloc_active--;
     _MALLOC_UNLOCK();
     errno = EDEADLK;
@@ -1644,10 +1283,8 @@ malloc(size_t size)
     UTRACE(0, size, r);
     malloc_active--;
     _MALLOC_UNLOCK();
-    if (malloc_xmalloc && r == NULL) {
+    if (malloc_xmalloc && r == NULL)
         wrterror("out of memory\n");
-        errno = ENOMEM;
-    }
     return (r);
 }
 
@@ -1686,9 +1323,7 @@ realloc(void *ptr, size_t size)
     UTRACE(ptr, size, r);
     malloc_active--;
     _MALLOC_UNLOCK();
-    if (malloc_xmalloc && r == NULL) {
+    if (malloc_xmalloc && r == NULL)
         wrterror("out of memory\n");
-        errno = ENOMEM;
-    }
     return (r);
 }