Latest changes from FreeBSD

src/lib/libc/stdlib/malloc.3

@@ -33,11 +33,11 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"	$OpenBSD: malloc.3,v 1.3 1996/08/21 03:12:18 downsj Exp $
+.\"	$OpenBSD: malloc.3,v 1.4 1996/09/26 04:19:41 tholo Exp $
 .\"
-.Dd June 4, 1993
+.Dd August 27, 1996
 .Dt MALLOC 3
-.Os BSD 4
+.Os OpenBSD
 .Sh NAME
 .Nm malloc ,
 .Nd general memory allocation function
@@ -58,6 +58,8 @@
 .Fn cfree "void *ptr"
 .Ft void *
 .Fn realloc "void *ptr" "size_t size"
+.Ft char *
+.Va malloc_options
 .Sh DESCRIPTION
 The
 .Fn malloc
@@ -120,11 +122,13 @@ is zero and
 .Fa ptr
 is not a null pointer, the object it points to is freed.
 .Pp
-
-.Sh ENVIRONMENT
-This malloc will check the environment for a variable called
-.Em MALLOC_OPTIONS
-and scan it for flags.
+Malloc will first look for a symbolic link called
+.Pa /etc/malloc.conf
+and next check the environment for a variable called
+.Ev MALLOC_OPTIONS
+and finally for the global variable
+.Va malloc_options
+and scan them for flags in that order.
 Flags are single letters, uppercase means on, lowercase means off.
 .Bl -tag -width indent
 .It A
@@ -142,21 +146,42 @@ order to have any effect.
 ``junk'' fill some junk into the area allocated.
 Currently junk is bytes of 0xd0, this is pronounced ``Duh'' :-)
 
+.It H
+``hint'' pass a hint to the kernel about pages we don't use.  If the
+machine is paging a lot this may help a bit.
+
 .It R
 ``realloc'' always reallocate when
 .Fn realloc
 is called, even if the initial allocation was big enough.
 This can substantially aid in compacting memory.
 
+.It U
+``utrace'' generate entries for ktrace(1) for all operations.
+Consult the source for this one.
+
 .It Z
 ``zero'' fill some junk into the area allocated (see ``J''),
 except for the exact length the user asked for, which is zeroed.
 
+.It <
+``Half the cache size'' Reduce the size of the cache by a factor of two.
+
+.It >
+``Double the cache size'' Double the size of the cache by a factor of two.
 .El
 .Pp
+So to set a systemwide reduction of cache size and coredumps on problems
+one would:
+.Li ln -s 'A<' /etc/malloc.conf
+.Pp
 The ``J'' and ``Z'' is mostly for testing and debugging,
 if a program changes behavior if either of these options are used,
 it is buggy.
+.Pp
+The default cache size is 16 pages.
+.Sh ENVIRONMENT
+See above.
 .Sh RETURN VALUES
 The
 .Fn malloc
@@ -172,12 +197,89 @@ The
 .Fn realloc
 function returns either a null pointer or a pointer
 to the possibly moved allocated space.
+.Sh MESSAGES
+If 
+.Fn malloc ,
+.Fn free
+or 
+.Fn realloc
+detects an error or warning condition,
+a message will be printed to filedescriptor
+2 (not using stdio).
+Errors will always result in the process being 
+.Xr abort 2 'ed,
+If the ``A'' option has been specified, also warnings will
+.Xr abort 2 
+the process.
+.Pp
+Here is a brief description of the error messages and what they mean:
+.Pp
+``(ES): mumble mumble mumble'':
+malloc have been compiled with -DEXTRA_SANITY and something looks
+fishy in there.  Consult sources and or wizards.
+.Pp
+``allocation failed''
+if the ``A'' option is specified it is an error for
+.Fn malloc
+or 
+.Fn realloc
+to return NULL.
+.Pp
+``mmap(2) failed, check limits.''
+This is a rather weird condition that is most likely to mean that
+the system is seriously overloaded or that your ulimits are sick.
+.Pp
+``freelist is destroyed.''
+mallocs internal freelist has been stomped on.
+.Pp
+Here is a brief description of the warning messages and what they mean:
+.Pp
+``chunk/page is already free.''
+A pointer to a free chunk is attempted freed again.
+.Pp
+``junk pointer, too high to make sense.''
+The pointer doesn't make sense.  It's above the area of memory that
+malloc knows something about.
+This could be a pointer from some
+.Xr mmap 2 'ed 
+memory.
+.Pp
+``junk pointer, too low to make sense.''
+The pointer doesn't make sense.  It's below the area of memory that
+malloc knows something about.
+This pointer probably came from your data or bss segments.
+.Pp
+``malloc() has never been called.''
+Nothing has ever been allocated, yet something is being freed or
+realloc'ed.
+.Pp
+``modified (chunk-/page-) pointer.''
+The pointer passed to free or realloc has been modified.
+.Pp
+``pointer to wrong page.''
+The pointer that malloc is trying to free is not pointing to
+a sensible page.
+.Pp
+``recursive call.''
+You have tried to call recursively into these functions.
+I can only imagine this as happening if you call one of these
+functions from a signal function, which happens to be called
+while you're already in here.
+Well, sorry to say: that's not supported.
+If this is a problem for you I'd like to hear about it.  It
+would be possible to add a sigblock() around this package,
+but it would have a performance penalty that is not acceptable
+as the default.
+.Pp
+``unknown char in MALLOC_OPTIONS''
+we found something we didn't understand.
 .Sh SEE ALSO
 .Xr brk 2 ,
 .Xr alloca 3 ,
 .Xr calloc 3 ,
 .Xr getpagesize 3 ,
 .Xr memory 3
+.Pa /usr/share/doc/papers/malloc.ascii.gz
 .Sh STANDARDS
 The
 .Fn malloc

src/lib/libc/stdlib/malloc.c

@@ -8,12 +8,15 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char rcsid[] = "$OpenBSD: malloc.c,v 1.13 1996/09/19 20:38:48 tholo Exp $";
+static char rcsid[] = "$OpenBSD: malloc.c,v 1.14 1996/09/26 04:19:42 tholo Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 /*
- * Defining EXTRA_SANITY will enable some checks which are related
- * to internal conditions and consistency in malloc.c
+ * Defining EXTRA_SANITY will enable extra checks which are related
+ * to internal conditions and consistency in malloc.c. This has a
+ * noticeable runtime performance hit, and generally will not do you
+ * any good unless you fiddle with the internals of malloc or want
+ * to catch random pointer corruption as early as possible.
  */
 #undef EXTRA_SANITY
 
@@ -29,23 +32,23 @@ static char rcsid[] = "$OpenBSD: malloc.c,v 1.13 1996/09/19 20:38:48 tholo Exp $
 #endif
 
 /*
- * What to use for Junk
+ * What to use for Junk.  This is the byte value we use to fill with
+ * when the 'J' option is enabled.
  */
 #define SOME_JUNK	0xd0		/* as in "Duh" :-) */
 
+/*
+ * No user serviceable parts behind this point.
+ */
+
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
-#include <memory.h>
 #include <errno.h>
-#include <err.h>
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/mman.h>
-#ifdef _THREAD_SAFE
-#include <pthread.h>
-#include "pthread_private.h"
-#endif
 
 /*
  * If these weren't defined here, they would be calculated on the fly,
@@ -108,14 +111,14 @@ struct pgfree {
  * We might as well use them.  There are C-language backups, but
  * they are considerably slower.
  */
-#ifdef __i386__
+#if defined(__i386__) && defined(__GNUC__)
 #define ffs _ffs
 static __inline int
 _ffs(input)
 	unsigned input;
 {
 	int result;
-	__asm("bsfl %1,%0" : "=r" (result) : "r" (input));
+	__asm("bsfl %1, %0" : "=r" (result) : "r" (input));
 	return result+1;
 }
 
@@ -125,7 +128,7 @@ _fls(input)
 	unsigned input;
 {
 	int result;
-	__asm("bsrl %1,%0" : "=r" (result) : "r" (input));
+	__asm("bsrl %1, %0" : "=r" (result) : "r" (input));
 	return result+1;
 }
 
@@ -135,7 +138,7 @@ _set_bit(pi, bit)
 	struct pginfo *pi;
 	int bit;
 {
-	__asm("btsl %0,(%1)" :
+	__asm("btsl %0, (%1)" :
 	: "r" (bit & (MALLOC_BITS-1)), "r" (pi->bits+(bit/MALLOC_BITS)));
 }
 
@@ -145,11 +148,11 @@ _clr_bit(pi, bit)
 	struct pginfo *pi;
 	int bit;
 {
-	__asm("btcl %0,(%1)" :
+	__asm("btcl %0, (%1)" :
 	: "r" (bit & (MALLOC_BITS-1)), "r" (pi->bits+(bit/MALLOC_BITS)));
 }
 
-#endif /* __i386__ */
+#endif /* __i386__ && __GNUC__ */
 
 /*
  * Set to one when malloc_init has been called
@@ -165,17 +168,13 @@ static	unsigned	initialized;
 static	unsigned        malloc_pagesize;
 #endif /* malloc_pagesize */
 
-/*
- * A mask for the offset inside a page.
- */
+/* 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_origo)
 
-/*
- * malloc_pagesize == 1 << malloc_pageshift
- */
+/* malloc_pagesize == 1 << malloc_pageshift */
 #ifndef malloc_pageshift
 static	unsigned	malloc_pageshift;
 #endif /* malloc_pageshift */
@@ -197,85 +196,78 @@ static	unsigned  malloc_minsize;
 static	unsigned  malloc_maxsize;
 #endif /* malloc_maxsize */
 
-/*
- * The minimum size (in bytes) of the free page cache.
- */
-#ifndef malloc_cache
-static	unsigned  malloc_cache;
-#endif /* malloc_cache */
+/* The minimum size (in pages) of the free page cache.  */
+static	unsigned  malloc_cache = 16;
 
-/*
- * The offset from pagenumber to index into the page directory
- */
+/* 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
- */
+/* The last index in the page directory we care about */
 static	u_long  last_index;
 
-/*
- * Pointer to page directory.
- * Allocated "as if with" malloc
- */
+/* Pointer to page directory. Allocated "as if with" malloc */
 static	struct	pginfo **page_dir;
 
-/*
- * How many slots in the page directory
- */
+/* How many slots in the page directory */
 static	unsigned	malloc_ninfo;
 
-/*
- * Free pages line up here
- */
+/* Free pages line up here */
 static struct pgfree	free_list;
 
-/*
- * Abort() if we fail to get VM ?
- */
+/* Abort(), user doesn't handle problems.  */
 static int malloc_abort;
 
-/*
- * Are we trying to die ?
- */
+/* Are we trying to die ?  */
 static int suicide;
 
 #ifdef MALLOC_STATS
-/*
- * dump statistics
- */
+/* dump statistics */
 static int malloc_stats;
 #endif /* MALLOC_STATS */
 
-/*
- * always realloc ?
- */
+/* always realloc ?  */
 static int malloc_realloc;
 
-/*
- * zero fill ?
- */
+#ifdef __FreeBSD__
+/* pass the kernel a hint on free pages ?  */
+static int malloc_hint;
+#endif
+
+/* zero fill ?  */
 static int malloc_zero;
 
-/*
- * junk fill ?
- */
+/* junk fill ?  */
 static int malloc_junk;
 
-/*
- * my last break.
- */
+#ifdef __FreeBSD__
+/* utrace ?  */
+static int malloc_utrace;
+
+struct ut { void *p; size_t s; void *r; };
+
+#define UTRACE(a, b, c) \
+	if (malloc_utrace) \
+		{struct ut u; u.p=a; u.s = b; u.r=c; utrace(&u, sizeof u);}
+#else /* !__FreeBSD__ */
+#define UTRACE(a,b,c)
+#endif
+
+/* 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 */
+char *malloc_options;
+
 /*
  * 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);
 
 #ifdef MALLOC_STATS
 void
@@ -290,60 +282,63 @@ malloc_dump(fd)
 
     /* print out all the pages */
     for(j=0;j<=last_index;j++) {
-	fprintf(fd,"%08lx %5d ",(j+malloc_origo) << malloc_pageshift,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);
+	    fprintf(fd, ".. %5d not mine\n",	j);
 	} else if (pd[j] == MALLOC_FREE) {
 	    for(j++;j<=last_index && pd[j] == MALLOC_FREE;j++)
 		;
 	    j--;
-	    fprintf(fd,".. %5d free\n", j);
+	    fprintf(fd, ".. %5d free\n", j);
 	} else if (pd[j] == MALLOC_FIRST) {
 	    for(j++;j<=last_index && pd[j] == MALLOC_FOLLOW;j++)
 		;
 	    j--;
-	    fprintf(fd,".. %5d in use\n", j);
+	    fprintf(fd, ".. %5d in use\n", j);
 	} else if (pd[j] < MALLOC_MAGIC) {
-	    fprintf(fd,"(%p)\n", pd[j]);
+	    fprintf(fd, "(%p)\n", pd[j]);
 	} else {
-	    fprintf(fd,"%p %d (of %d) x %d @ %p --> %p\n",
-		pd[j],pd[j]->free, pd[j]->total,
+	    fprintf(fd, "%p %d (of %d) x %d @ %p --> %p\n",
+		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->end,pf->size,pf->prev,pf->next);
+	fprintf(fd, "Free: @%p [%p...%p[ %ld ->%p <-%p\n",
+		pf, pf->page, pf->end, pf->size, pf->prev, pf->next);
 	if (pf == pf->next) {
-		fprintf(fd,"Free_list loops.\n");
++ 		fprintf(fd, "Free_list loops.\n");
 		break;
 	}
     }
 
     /* print out various info */
-    fprintf(fd,"Minsize\t%d\n",malloc_minsize);
-    fprintf(fd,"Maxsize\t%d\n",malloc_maxsize);
-    fprintf(fd,"Pagesize\t%d\n",malloc_pagesize);
-    fprintf(fd,"Pageshift\t%d\n",malloc_pageshift);
-    fprintf(fd,"FirstPage\t%ld\n",malloc_origo);
-    fprintf(fd,"LastPage\t%ld %lx\n",last_index+malloc_pageshift,
+    fprintf(fd, "Minsize\t%d\n", malloc_minsize);
+    fprintf(fd, "Maxsize\t%d\n", malloc_maxsize);
+    fprintf(fd, "Pagesize\t%d\n", malloc_pagesize);
+    fprintf(fd, "Pageshift\t%d\n", malloc_pageshift);
+    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);
+    fprintf(fd, "Break\t%ld\n", (u_long)sbrk(0) >> malloc_pageshift);
 }
 #endif /* MALLOC_STATS */
 
+static char *malloc_func;
+
 static void
 wrterror(p)
     char *p;
 {
     char *q = "Malloc error: ";
     suicide = 1;
-    write(2,q,strlen(q));
-    write(2,p,strlen(p));
+    write(2, q, strlen(q));
+    write(2, malloc_func, strlen(malloc_func));
+    write(2, p, strlen(p));
 #ifdef MALLOC_STATS
     if (malloc_stats)
 	malloc_dump(stderr);
@@ -358,21 +353,22 @@ wrtwarning(p)
     char *q = "Malloc warning: ";
     if (malloc_abort)
 	wrterror(p);
-    write(2,q,strlen(q));
-    write(2,p,strlen(p));
+    write(2, q, strlen(q));
+    write(2, malloc_func, strlen(malloc_func));
+    write(2, p, strlen(p));
 }
 
 #ifdef EXTRA_SANITY
 static void
 malloc_exit()
 {
-    FILE *fd = fopen("malloc.out","a");
+    FILE *fd = fopen("malloc.out", "a");
     char *q = "malloc() warning: Couldn't dump stats.\n";
     if (fd) {
         malloc_dump(fd);
 	fclose(fd);
     } else
-	write(2,q,strlen(q));
+	write(2, q, strlen(q));
 }
 #endif /* EXTRA_SANITY */
 
@@ -384,14 +380,14 @@ static caddr_t
 map_pages(pages)
     int pages;
 {
-    caddr_t result,tail;
+    caddr_t result, tail;
 
     result = (caddr_t)pageround((u_long)sbrk(0));
     tail = result + (pages << malloc_pageshift);
 
     if (brk(tail)) {
 #ifdef EXTRA_SANITY
-	wrterror("(internal): map_pages fails\n");
+	wrterror("(ES): map_pages fails\n");
 #endif /* EXTRA_SANITY */
 	return 0;
     }
@@ -466,7 +462,7 @@ static int
 extend_pgdir(index)
     u_long index;
 {
-    struct  pginfo **new,**old;
+    struct  pginfo **new, **old;
     int i, oldlen;
 
     /* Make it this many pages */
@@ -520,35 +516,61 @@ extend_pgdir(index)
 static void
 malloc_init ()
 {
-    char *p;
+    char *p, b[64];
+    int i, j;
 
 #ifdef EXTRA_SANITY
     malloc_junk = 1;
 #endif /* EXTRA_SANITY */
 
-    if (issetugid() == 0) {
-        for (p=getenv("MALLOC_OPTIONS"); p && *p; p++) {
+    for (i = 0; i < 3; i++) {
+	if (i == 0) {
+	    j = readlink("/etc/malloc.conf", b, sizeof b - 1);
+	    if (j <= 0)
+		continue;
+	    b[j] = '\0';
+	    p = b;
+	} else if (i == 1) {
+	    p = getenv("MALLOC_OPTIONS");
+	} else if (i == 2) {
+	    p = malloc_options;
+	}
+	for (; p && *p; p++) {
 	    switch (*p) {
-	    case 'a': malloc_abort   = 0; break;
-	    case 'A': malloc_abort   = 1; break;
+		case '>': malloc_cache   <<= 1; break;
+		case '<': malloc_cache   >>= 1; break;
+		case 'a': malloc_abort   = 0; break;
+		case 'A': malloc_abort   = 1; break;
 #ifdef MALLOC_STATS
-	    case 'd': malloc_stats   = 0; break;
-	    case 'D': malloc_stats   = 1; break;
+		case 'd': malloc_stats   = 0; break;
+		case 'D': malloc_stats   = 1; break;
 #endif /* MALLOC_STATS */
-	    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 'z': malloc_zero    = 0; break;
-	    case 'Z': malloc_zero    = 1; break;
-	    default:
-		wrtwarning("(Init): Unknown char in MALLOC_OPTIONS\n");
-		p = 0;
-		break;
+#ifdef __FreeBSD__
+		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;
+#ifdef __FreeBSD__
+		case 'u': malloc_utrace  = 0; break;
+		case 'U': malloc_utrace  = 1; break;
+#endif /* __FreeBSD__ */
+		case 'z': malloc_zero    = 0; break;
+		case 'Z': malloc_zero    = 1; break;
+		default:
+		    j = malloc_abort;
+		    malloc_abort = 0;
+		    wrtwarning("unknown char in MALLOC_OPTIONS\n");
+		    malloc_abort = j;
+		    break;
 	    }
 	}
     }
 
+    UTRACE(0, 0, 0);
+
     /*
      * We want junk in the entire allocation, and zero only in the part
      * the user asked for.
@@ -579,10 +601,6 @@ malloc_init ()
     }
 #endif /* malloc_pageshift */
 
-#ifndef malloc_cache
-    malloc_cache = 100 << malloc_pageshift;
-#endif /* malloc_cache */
-
 #ifndef malloc_minsize
     {
     int i;
@@ -612,7 +630,7 @@ malloc_init ()
     page_dir = (struct pginfo **) mmap(0, malloc_pagesize, PROT_READ|PROT_WRITE,
 				       MAP_ANON|MAP_PRIVATE, -1, (off_t)0);
     if (page_dir == (struct pginfo **) -1)
-	wrterror("(Init) my first mmap failed.  (check limits ?)\n");
+	wrterror("mmap(2) failed, check limits.\n");
 
     /*
      * We need a maximum of malloc_pageshift buckets, steal these from the
@@ -630,7 +648,12 @@ malloc_init ()
      * 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 *) malloc (sizeof *px);
+    px = (struct pgfree *) imalloc (sizeof *px);
+
+    if (!malloc_cache)
+	malloc_cache++;
+
+    malloc_cache <<= malloc_pageshift;
 }
 
 /*
@@ -640,7 +663,7 @@ void *
 malloc_pages(size)
     size_t size;
 {
-    void *p,*delay_free = 0;
+    void *p, *delay_free = 0;
     int i;
     struct pgfree *pf;
     u_long index;
@@ -705,14 +728,14 @@ malloc_pages(size)
 	    page_dir[index+i] = MALLOC_FOLLOW;
 
 	if (malloc_junk)
-	    memset(p, SOME_JUNK,size << malloc_pageshift);
+	    memset(p, SOME_JUNK, size << malloc_pageshift);
     }
 
     if (delay_free) {
 	if (!px)
 	    px = delay_free;
 	else
-	    free(delay_free);
+	    ifree(delay_free);
     }
 
     return p;
@@ -728,7 +751,7 @@ malloc_make_chunks(bits)
 {
     struct  pginfo *bp;
     void *pp;
-    int i,k,l;
+    int i, k, l;
 
     /* Allocate a new bucket */
     pp = malloc_pages(malloc_pagesize);
@@ -744,7 +767,7 @@ malloc_make_chunks(bits)
     if ((1<<(bits)) <= l+l) {
 	bp = (struct  pginfo *)pp;
     } else {
-	bp = (struct  pginfo *)malloc(l);
+	bp = (struct  pginfo *)imalloc(l);
 	if (!bp)
 	    return 0;
     }
@@ -768,12 +791,12 @@ malloc_make_chunks(bits)
 	bp->bits[i / MALLOC_BITS] = (u_long)~0;
 
     for(; i < k; i++)
-	set_bit(bp,i);
+	set_bit(bp, i);
 
     if (bp == bp->page) {
 	/* Mark the ones we stole for ourselves */
 	for(i=0;l > 0;i++) {
-	    clr_bit(bp,i);
+	    clr_bit(bp, i);
 	    bp->free--;
 	    bp->total--;
 	    l -= (1 << bits);
@@ -835,8 +858,8 @@ malloc_bytes(size)
 /*
  * Allocate a piece of memory
  */
-void *
-malloc(size)
+static void *
+imalloc(size)
     size_t size;
 {
     void *result;
@@ -850,36 +873,30 @@ malloc(size)
     if (suicide)
 	abort();
 
-#ifdef  _THREAD_SAFE
-    _thread_kern_sig_block(&status);
-#endif
     if (size <= malloc_maxsize)
 	result =  malloc_bytes(size);
     else
 	result =  malloc_pages(size);
 
     if (malloc_abort && !result)
-	wrterror("malloc(): returns NULL\n");
+	wrterror("allocation failed.\n");
 
     if (malloc_zero)
-	memset(result,0,size);
+	memset(result, 0, size);
 
-#ifdef  _THREAD_SAFE
-    _thread_kern_sig_unblock(status);
-#endif
     return result;
 }
 
 /*
  * Change the size of an allocation.
  */
-void *
-realloc(ptr, size)
+static void *
+irealloc(ptr, size)
     void *ptr;
     size_t size;
 {
     void *p;
-    u_long osize,index;
+    u_long osize, index;
     struct pginfo **mp;
     int i;
 #ifdef  _THREAD_SAFE
@@ -889,37 +906,20 @@ realloc(ptr, size)
     if (suicide)
 	return 0;
 
-    if (!ptr)				/* Bounce to malloc() */
-	return malloc(size);
-
     if (!initialized) {
-	wrtwarning("realloc(): malloc() never got called.\n");
-	return 0;
-    }
-
-    if (ptr && !size) {			/* Bounce to free() */
-	free(ptr);
+	wrtwarning("malloc() has never been called.\n");
 	return 0;
     }
 
-#ifdef  _THREAD_SAFE
-    _thread_kern_sig_block(&status);
-#endif
     index = ptr2index(ptr);
 
     if (index < malloc_pageshift) {
-	wrtwarning("realloc(): junk pointer (too low)\n");
-#ifdef  _THREAD_SAFE
-	_thread_kern_sig_unblock(status);
-#endif
+	wrtwarning("junk pointer, too low to make sense.\n");
 	return 0;
     }
 
     if (index > last_index) {
-	wrtwarning("realloc(): junk pointer (too high)\n");
-#ifdef  _THREAD_SAFE
-	_thread_kern_sig_unblock(status);
-#endif
+	wrtwarning("junk pointer, too high to make sense.\n");
 	return 0;
     }
 
@@ -929,10 +929,7 @@ realloc(ptr, size)
 
 	/* Check the pointer */
 	if ((u_long)ptr & malloc_pagemask) {
-	    wrtwarning("realloc(): modified page pointer.\n");
-#ifdef  _THREAD_SAFE
-	    _thread_kern_sig_unblock(status);
-#endif
+	    wrtwarning("modified (page-) pointer.\n");
 	    return 0;
 	}
 
@@ -943,9 +940,6 @@ realloc(ptr, size)
         if (!malloc_realloc && 			/* unless we have to, */
 	  size <= osize && 			/* .. or are too small, */
 	  size > (osize - malloc_pagesize)) {	/* .. or can free a page, */
-#ifdef  _THREAD_SAFE
-	    _thread_kern_sig_unblock(status);
-#endif
 	    return ptr;				/* don't do anything. */
 	}
 
@@ -953,10 +947,7 @@ realloc(ptr, size)
 
 	/* Check the pointer for sane values */
 	if (((u_long)ptr & ((*mp)->size-1))) {
-	    wrtwarning("realloc(): modified chunk pointer.\n");
-#ifdef  _THREAD_SAFE
-	    _thread_kern_sig_unblock(status);
-#endif
+	    wrtwarning("modified (chunk-) pointer.\n");
 	    return 0;
 	}
 
@@ -964,11 +955,8 @@ realloc(ptr, size)
 	i = ((u_long)ptr & malloc_pagemask) >> (*mp)->shift;
 
 	/* Verify that it isn't a free chunk already */
-	if (tst_bit(*mp,i)) {
-	    wrtwarning("realloc(): already free chunk.\n");
-#ifdef  _THREAD_SAFE
-	    _thread_kern_sig_unblock(status);
-#endif
+	if (tst_bit(*mp, i)) {
+	    wrtwarning("chunk is already free.\n");
 	    return 0;
 	}
 
@@ -978,33 +966,24 @@ realloc(ptr, size)
 	  size < osize && 		/* ..or are too small, */
 	  (size > osize/2 ||	 	/* ..or could use a smaller size, */
 	  osize == malloc_minsize)) {	/* ..(if there is one) */
-#ifdef  _THREAD_SAFE
-	    _thread_kern_sig_unblock(status);
-#endif
 	    return ptr;			/* ..Don't do anything */
 	}
 
     } else {
-	wrtwarning("realloc(): wrong page pointer.\n");
-#ifdef  _THREAD_SAFE
-	_thread_kern_sig_unblock(status);
-#endif
+	wrtwarning("pointer to wrong page.\n");
 	return 0;
     }
 
-    p = malloc(size);
+    p = imalloc(size);
 
     if (p) {
 	/* copy the lesser of the two sizes, and free the old one */
 	if (osize < size)
-	    memcpy(p,ptr,osize);
+	    memcpy(p, ptr, osize);
 	else
-	    memcpy(p,ptr,size);
-	free(ptr);
+	    memcpy(p, ptr, size);
+	ifree(ptr);
     } 
-#ifdef  _THREAD_SAFE
-    _thread_kern_sig_unblock(status);
-#endif
     return p;
 }
 
@@ -1019,22 +998,22 @@ free_pages(ptr, index, info)
     struct pginfo *info;
 {
     int i;
-    struct pgfree *pf,*pt=0;
+    struct pgfree *pf, *pt=0;
     u_long l;
     void *tail;
 
     if (info == MALLOC_FREE) {
-	wrtwarning("free(): already free page.\n");
+	wrtwarning("page is already free.\n");
 	return;
     }
 
     if (info != MALLOC_FIRST) {
-	wrtwarning("free(): freeing wrong page.\n");
+	wrtwarning("pointer to wrong page.\n");
 	return;
     }
 
     if ((u_long)ptr & malloc_pagemask) {
-	wrtwarning("free(): modified page pointer.\n");
+	wrtwarning("modified (page-) pointer.\n");
 	return;
     }
 
@@ -1045,11 +1024,16 @@ free_pages(ptr, index, info)
 
     l = i << malloc_pageshift;
 
-    tail = (char *)ptr + l;
+#ifdef __FreeBSD__
+    if (malloc_hint)
+	madvise(ptr, l, MADV_FREE);
+#endif
+
+    tail = (char *)ptr+l;
 
     /* add to free-list */
     if (!px)
-	px = malloc(sizeof *pt);	/* This cannot fail... */
+	px = imalloc(sizeof *pt);	/* This cannot fail... */
     px->page = ptr;
     px->end =  tail;
     px->size = l;
@@ -1065,7 +1049,7 @@ free_pages(ptr, index, info)
     } else {
 
 	/* Find the right spot, leave pf pointing to the modified entry. */
-	tail = (char *)ptr + l;
+	tail = (char *)ptr+l;
 
 	for(pf = free_list.next; pf->end < ptr && pf->next; pf = pf->next)
 	    ; /* Race ahead here */
@@ -1103,7 +1087,7 @@ free_pages(ptr, index, info)
 	    pf = px;
 	    px = 0;
 	} else {
-	    wrterror("messed up free list");
+	    wrterror("freelist is destroyed.\n");
 	}
     }
     
@@ -1132,7 +1116,7 @@ free_pages(ptr, index, info)
 	/* XXX: We could realloc/shrink the pagedir here I guess. */
     }
     if (pt)
-	free(pt);
+	ifree(pt);
 }
 
 /*
@@ -1154,16 +1138,16 @@ free_bytes(ptr, index, info)
     i = ((u_long)ptr & malloc_pagemask) >> info->shift;
 
     if (((u_long)ptr & (info->size-1))) {
-	wrtwarning("free(): modified pointer.\n");
+	wrtwarning("modified (chunk-) pointer.\n");
 	return;
     }
 
-    if (tst_bit(info,i)) {
-	wrtwarning("free(): already free chunk.\n");
+    if (tst_bit(info, i)) {
+	wrtwarning("chunk is already free.\n");
 	return;
     }
 
-    set_bit(info,i);
+    set_bit(info, i);
     info->free++;
 
     mp = page_dir + info->shift;
@@ -1198,12 +1182,12 @@ free_bytes(ptr, index, info)
     page_dir[ptr2index(info->page)] = MALLOC_FIRST;
     vp = info->page;		/* Order is important ! */
     if(vp != (void*)info) 
-	free(info);
-    free(vp);
+	ifree(info);
+    ifree(vp);
 }
 
-void
-free(ptr)
+static void
+ifree(ptr)
     void *ptr;
 {
     struct pginfo *info;
@@ -1217,7 +1201,7 @@ free(ptr)
 	return;
 
     if (!initialized) {
-	wrtwarning("free(): malloc() never got called.\n");
+	wrtwarning("malloc() has never been called.\n");
 	return;
     }
 
@@ -1225,35 +1209,102 @@ free(ptr)
     if (suicide)
 	return;
 
-#ifdef  _THREAD_SAFE
-    _thread_kern_sig_block(&status);
-#endif
     index = ptr2index(ptr);
 
     if (index < malloc_pageshift) {
-	wrtwarning("free(): junk pointer (too low)\n");
-#ifdef  _THREAD_SAFE
-	_thread_kern_sig_unblock(status);
-#endif
+	wrtwarning("junk pointer, too low to make sense.\n");
 	return;
     }
 
     if (index > last_index) {
-	wrtwarning("free(): junk pointer (too high)\n");
-#ifdef  _THREAD_SAFE
-	_thread_kern_sig_unblock(status);
-#endif
+	wrtwarning("junk pointer, too high to make sense.\n");
 	return;
     }
 
     info = page_dir[index];
 
     if (info < MALLOC_MAGIC)
-        free_pages(ptr,index,info);
+        free_pages(ptr, index, info);
     else
-	free_bytes(ptr,index,info);
-#ifdef  _THREAD_SAFE
-    _thread_kern_sig_unblock(status);
+	free_bytes(ptr, index, info);
+    return;
+}
+
+/*
+ * These are the public exported interface routines.
+ */
+
+#ifdef _THREAD_SAFE
+#include <pthread.h>
+#include "pthread_private.h"
+static int malloc_lock;
+#define THREAD_LOCK() _thread_kern_sig_block(&malloc_lock);
+#define THREAD_UNLOCK() _thread_kern_sig_unblock(&malloc_lock);
+#else
+#define THREAD_LOCK() 
+#define THREAD_UNLOCK()
 #endif
+
+static int malloc_active;
+
+void *
+malloc(size_t size)
+{
+    register void *r;
+
+    malloc_func = "malloc():";
+    THREAD_LOCK();
+    if (malloc_active++) {
+	wrtwarning("recursive call.\n");
+        malloc_active--;
+	return (0);
+    }
+    r = imalloc(size);
+    UTRACE(0, size, r);
+    malloc_active--;
+    THREAD_UNLOCK();
+    return (r);
+}
+
+void
+free(void *ptr)
+{
+    malloc_func = "free():";
+    THREAD_LOCK();
+    if (malloc_active++) {
+	wrtwarning("recursive call.\n");
+        malloc_active--;
+	return;
+    }
+    ifree(ptr);
+    UTRACE(ptr, 0, 0);
+    malloc_active--;
+    THREAD_UNLOCK();
     return;
 }
+
+void *
+realloc(void *ptr, size_t size)
+{
+    register void *r;
+
+    malloc_func = "realloc():";
+    THREAD_LOCK();
+    if (malloc_active++) {
+	wrtwarning("recursive call.\n");
+        malloc_active--;
+	return (0);
+    }
+    if (!ptr) {
+	r = imalloc(size);
+    } else if (ptr && !size) {
+	ifree(ptr);
+	r = 0;
+    } else {
+        r = irealloc(ptr, size);
+    }
+    UTRACE(ptr, size, r);
+    malloc_active--;
+    THREAD_UNLOCK();
+    return (r);
+}