path: root/kmtrace/ktrace.c

/* More debugging hooks for `malloc'.
   Copyright (C) 1991,92,93,94,96,97,98,99,2000 Free Software Foundation, Inc.
		 Written April 2, 1991 by John Gilmore of Cygnus Support.
		 Based on mcheck.c by Mike Haertel.
		 Hacked by AK
		 Cleanup and performance improvements by
		 Chris Schlaeger <cs@kde.org>

   This 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.

   This 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 this library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.

   The author may be reached (Email) at the address mike@ai.mit.edu,
   or (US mail) as Mike Haertel c/o Free Software Foundation.
*/

#define MALLOC_HOOKS
#define _GNU_SOURCE

#include <pthread.h>
#include <malloc.h>

#include <dlfcn.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <execinfo.h>
#include <unistd.h>

#ifdef USE_IN_LIBIO
# include <libio/iolibio.h>
# define setvbuf(s, b, f, l) _IO_setvbuf (s, b, f, l)
#endif

/* This is the most important parameter. It should be set to two times
 * the maximum number of mallocs the application uses at a time. Prime
 * numbers are very good candidates for this value.  I added a list of
 * some prime numbers for conveniance.
 *
 * 10007, 20011, 30013, 40031, 50033, 60037, 70039, 80051, 90053,
 * 100057, 110059, 120067, 130069, 140071, 150077, 160079, 170081,
 * 180097, 190121, 200131, 210139, 220141, 230143, 240151, 250153,
 * 260171, 270191, 280199, 290201, 300221, 310223, 320237, 330241,
 * 340261, 350281, 360287, 370373, 380377, 390389 */
#define TR_CACHE_SIZE 100057

/* The DELTA value is also a value for the maximum
 * number of iterations during a positive free/realloc
 * search. It must NOT divide TR_CACHE_SIZE without
 * remainder! */
#define DELTA 23

/* The high and low mark control the flushing algorithm.  Whenever the
 * hashtable reaches the high mark every DELTAth entry is written to
 * disk until the low filling mark is reached. A hash table becomes
 * very inefficient when it becomes filled to 50% or more. */
#define TR_HIGH_MARK ((int) (TR_CACHE_SIZE * 0.5))
#define TR_LOW_MARK ((int) (TR_HIGH_MARK - (TR_CACHE_SIZE / DELTA)))

/* Maximum call stack depth. No checking for overflows
 * is done. Adjust this value with care! */
#define TR_BT_SIZE 100

#define PROFILE 1

/* The hash function. Since the smallest allocated block is probably
 * not smaller than 8 bytes we ignore the last 3 LSBs. */
#define HASHFUNC(a) (((((unsigned long) a) << 1) ^ \
                     (((unsigned long) a) >> 3)) % \
                     TR_CACHE_SIZE)

#define TR_HASHTABLE_SIZE	9973

#define TR_NONE		0
#define TR_MALLOC	1
#define TR_REALLOC	2
#define TR_FREE		3

#define TRACE_BUFFER_SIZE 512

typedef struct
{
	void* ptr;
	size_t size;
	int bt_size;
	void** bt;
} tr_entry;

typedef struct CallerNode
{
	void* funcAdr;
	unsigned long mallocs;
	unsigned long mallocsSum;
	unsigned int noCallees;
	unsigned int maxCallees;
	struct CallerNode** callees;
} CallerNode;

void ktrace(void);
void kuntrace(void);

static void addAllocationToTree(void);

// Pointers to real calls
static void* (*real_malloc_ptr)  (size_t size) = NULL;
static void* (*real_realloc_ptr) (void *ptr, size_t size) = NULL;
static void  (*real_free_ptr)    (void *ptr) = NULL;

// This is used to return "allocated" memory until the pointer
// to the real malloc function becomes known.
// It seems about 75k of memory are required before that happens,
// but the buffer provides more space to cater for more if needed
// in other OS.
#define MALLOC_INIT_SIZE (1024 * 256)
static char malloc_init_buf[MALLOC_INIT_SIZE];
static size_t malloc_init_pos = 0;
static pthread_mutex_t malloc_init_lock = PTHREAD_MUTEX_INITIALIZER;

static FILE* mallstream;
static char malloc_trace_buffer[TRACE_BUFFER_SIZE];

static pthread_mutex_t malloc_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t free_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t realloc_lock = PTHREAD_MUTEX_INITIALIZER;

static int tr_malloc_hook_enabled = 0;
static int tr_realloc_hook_enabled = 0;
static int tr_free_hook_enabled = 0;

// Hooks active in this thread
static __thread int tr_malloc_hook_active = 0;
static __thread int tr_realloc_hook_active = 0;
static __thread int tr_free_hook_active = 0;

static int bt_size;
static void *bt[TR_BT_SIZE + 1];
static char tr_offsetbuf[20];
static tr_entry tr_cache[TR_CACHE_SIZE];
static int tr_cache_level;
static int tr_cache_pos;
static int tr_max_offset = 0;
static void *tr_hashtable[TR_HASHTABLE_SIZE];
#ifdef PROFILE
static unsigned long tr_mallocs = 0;
static unsigned long tr_logged_mallocs = 0;
static unsigned long tr_frees = 0;
static unsigned long tr_logged_frees = 0;
static unsigned long tr_current_mallocs = 0;
static unsigned long tr_max_mallocs = 0;
static unsigned long tr_flashes = 0;
static unsigned long tr_failed_free_lookups = 0;
static unsigned long tr_malloc_collisions = 0;
#endif

static CallerNode* CallTree = NULL;
static char* mallTreeFile = NULL;
static FILE* mallTreeStream = NULL;
static long mallThreshold = 2000;

// Get real function pointers on loading
static void __attribute__((constructor)) init(void)
{
	if (!real_malloc_ptr)
	{
		real_malloc_ptr = (void* (*)(size_t))(dlsym(RTLD_NEXT, "malloc"));
		real_realloc_ptr = (void* (*)(void *, size_t))(dlsym(RTLD_NEXT, "realloc"));
		real_free_ptr = (void (*)(void *))(dlsym(RTLD_NEXT, "free")); 
	}
}

__inline__ static void 
tr_backtrace(void **_bt, int size)
{
	int i;
	Dl_info info;
	for (i = 0; i < size; i++)
	{
		long hash = (((unsigned long)_bt[i]) / 4) % TR_HASHTABLE_SIZE;
		if ((tr_hashtable[hash]!= _bt[i]) && dladdr(_bt[i], &info) &&
			info.dli_fname  && *info.dli_fname)
		{
			if (_bt[i] >= (void *) info.dli_saddr)
				sprintf(tr_offsetbuf, "+%#lx", (unsigned long)
						(_bt[i] - info.dli_saddr));
			else
				sprintf(tr_offsetbuf, "-%#lx", (unsigned long)
						(info.dli_saddr - _bt[i]));
			fprintf(mallstream, "%s%s%s%s%s[%p]\n",
					info.dli_fname ?: "",
					info.dli_sname ? "(" : "",
					info.dli_sname ?: "",
					info.dli_sname ? tr_offsetbuf : "",
					info.dli_sname ? ")" : "",
					_bt[i]);
			tr_hashtable[hash] = _bt[i];
		}
		else
		{
			fprintf(mallstream, "[%p]\n", _bt[i]);
		}
	} 
}

__inline__ static void 
tr_log(const void* caller, void* ptr, void* old,
	   size_t size, int op)
{
	int i, offset;

	switch (op)
	{
	case TR_FREE:
		i = HASHFUNC(ptr);
		if ((offset = (i + tr_max_offset + 1)) >= TR_CACHE_SIZE)
			offset -= TR_CACHE_SIZE;
		do
		{
			if (tr_cache[i].ptr == ptr)
			{
				tr_cache[i].ptr = NULL;
				free(tr_cache[i].bt);
				tr_cache_level--;
				return;
			}
			if (++i >= TR_CACHE_SIZE)
				i = 0;
#ifdef PROFILE
			tr_failed_free_lookups++;
#endif
		} while (i != offset);

		/* We don't know this allocation, so it has been flushed to disk
		 * already. So flush free as well. */
		fprintf(mallstream, "@\n");
		bt_size = backtrace(bt, TR_BT_SIZE);
		tr_backtrace(&(bt[1]), bt_size - 2);
		fprintf(mallstream, "- %p\n", ptr);
#ifdef PROFILE
		tr_logged_frees++;
#endif
		return;

	case TR_REALLOC:
		/* If old is 0 it's actually a malloc. */
		if (old)
		{
			i = HASHFUNC(old);
 			if ((offset = (i + tr_max_offset + 1)) >= TR_CACHE_SIZE)
				offset -= TR_CACHE_SIZE;
			do
			{
				if (tr_cache[i].ptr == old)
				{
					int j = HASHFUNC(ptr);
					/* We move the entry otherwise the free will be
					 * fairly expensive due to the wrong place in the
					 * hash table. */
					tr_cache[i].ptr = NULL;
					for ( ; ; )
					{
						if (tr_cache[j].ptr == NULL)
							break;

						if (++j >= TR_CACHE_SIZE)
							i = 0;
					}
					tr_cache[j].ptr = ptr;
					if (ptr)
					{
						tr_cache[j].size = tr_cache[i].size;
						tr_cache[j].bt_size = tr_cache[i].bt_size;
						tr_cache[j].bt = tr_cache[i].bt;
					}
					else
						tr_cache_level--;
					tr_cache[i].size = size;
					return;
				}
				if (++i >= TR_CACHE_SIZE)
					i = 0;
			} while (i != offset);

			fprintf(mallstream, "@\n");
			bt_size = backtrace(bt, TR_BT_SIZE);
			tr_backtrace(&(bt[1]), bt_size - 2);
			fprintf(mallstream, "< %p\n", old);
			fprintf(mallstream, "> %p %#lx\n", ptr,
					(unsigned long) size);
			return;
		}

	case TR_MALLOC:
		if (tr_cache_level >= TR_HIGH_MARK)
		{
			/* The hash table becomes ineffective when the high mark has
			 * been reached. We still need some more experience with
			 * the low mark. It's unclear what reasonable values are. */
#ifdef PROFILE
			tr_flashes++;
#endif
			i = HASHFUNC(ptr);
			do
			{
				if (tr_cache[i].ptr)
				{
#ifdef PROFILE
					tr_logged_mallocs++;
#endif
					fprintf(mallstream, "@\n");
					tr_backtrace(&(tr_cache[i].bt[1]),
								 tr_cache[i].bt_size - 2);
					fprintf(mallstream, "+ %p %#lx\n",
							tr_cache[i].ptr, 
							(unsigned long int)
							tr_cache[i].size);
					tr_cache[i].ptr = NULL;
					tr_cache_level--;
				}
				if ((i += DELTA) >= TR_CACHE_SIZE)
					i -= TR_CACHE_SIZE;
			} while (tr_cache_level > TR_LOW_MARK);
		}

		i = HASHFUNC(ptr);
		for ( ; ; )
		{
			if (tr_cache[i].ptr == NULL)
				break;

			if (++i >= TR_CACHE_SIZE)
				i = 0;
#ifdef PROFILE
			tr_malloc_collisions++;
#endif
		}
		if ((offset = (i  - HASHFUNC(ptr))) < 0)
			offset += TR_CACHE_SIZE;
		if (offset > tr_max_offset)
			tr_max_offset = offset;

		tr_cache[i].ptr = ptr; 
		tr_cache[i].size = size;
		tr_cache[i].bt = (void**) malloc(TR_BT_SIZE * sizeof(void*));
		tr_cache[i].bt_size = backtrace(
			tr_cache[i].bt, TR_BT_SIZE);
		tr_cache[i].bt = realloc(tr_cache[i].bt, tr_cache[i].bt_size * sizeof(void*));
		tr_cache_level++;

		return;

	case TR_NONE:
		if (tr_cache[tr_cache_pos].ptr)
		{
#ifdef PROFILE
			tr_logged_mallocs++;
#endif
			fprintf(mallstream, "@\n");
			tr_backtrace(&(tr_cache[tr_cache_pos].bt[1]),
						 tr_cache[tr_cache_pos].bt_size - 2);
			fprintf(mallstream, "+ %p %#lx\n", 
					tr_cache[tr_cache_pos].ptr, 
					(unsigned long int)
					tr_cache[tr_cache_pos].size);
			tr_cache[tr_cache_pos].ptr = NULL;
			free(tr_cache[tr_cache_pos].bt);
			tr_cache_level--;
		}

		if (++tr_cache_pos >= TR_CACHE_SIZE)
			tr_cache_pos = 0;
		break;
	}
}

void free(void *ptr)
{
	if (ptr == NULL ||
	   (ptr >= (void*)malloc_init_buf && ptr < (void*)(malloc_init_buf + malloc_init_pos)))
	{
		return;
	}

	if (!real_free_ptr)
	{
		// Should never happen!
		return;
	}

	if (!tr_free_hook_enabled || tr_free_hook_active)
	{
		// Real function is called if hooks are not enabled or if
		// free is called recursively while logging data (should
		// probably never happen!)
		return (*real_free_ptr)(ptr);
	}

	pthread_mutex_lock(&free_lock);
	tr_free_hook_active = 1;

#ifdef PROFILE
	tr_frees++;
	tr_current_mallocs--;
#endif

	void *caller = __builtin_return_address(0);
	(*real_free_ptr)(ptr);
	tr_log(caller, ptr, 0, 0, TR_FREE);

	tr_free_hook_active = 0;
	pthread_mutex_unlock(&free_lock);
}

void *malloc(size_t size)
{
	if (!real_malloc_ptr)
	{
		// Return memory from static buffer if available
		pthread_mutex_lock(&malloc_init_lock);
		if ((malloc_init_pos + size) > MALLOC_INIT_SIZE)
		{
			pthread_mutex_unlock(&malloc_init_lock);
			return NULL;
		}
		else
		{
			void *ptr = (void*)(malloc_init_buf + malloc_init_pos);
			malloc_init_pos += size;
			pthread_mutex_unlock(&malloc_init_lock);
			return ptr;
		}
	}

	if (!tr_malloc_hook_enabled || tr_malloc_hook_active)
	{
		// Real function is called if hooks are not enabled or if
		// malloc is called recursively while logging data
		return (*real_malloc_ptr)(size);
	}

	pthread_mutex_lock(&malloc_lock);
	tr_malloc_hook_active = 1;

	void *caller = __builtin_return_address(0);
	void *hdr = (*real_malloc_ptr)(size);
	tr_log(caller, hdr, 0, size, TR_MALLOC);

	/* We only build the allocation tree if mallTreeFile has been set. */
	if (mallTreeFile)
		addAllocationToTree();

#ifdef PROFILE
	tr_mallocs++;
	tr_current_mallocs++;
	if (tr_current_mallocs > tr_max_mallocs)
		tr_max_mallocs = tr_current_mallocs;
#endif

	tr_malloc_hook_active = 0;
	pthread_mutex_unlock(&malloc_lock);

	return hdr;
}

void* realloc(void *ptr, size_t size)
{
	if (ptr >= (void*)malloc_init_buf && ptr < (void*)(malloc_init_buf + malloc_init_pos))
	{
		// Reallocating pointer from initial static buffer, nothing to free. Just call malloc
		return malloc(size);
	}

	if (!real_realloc_ptr)
	{
		// Should never happen
		return NULL;
	}

	if (!tr_realloc_hook_enabled || tr_realloc_hook_active)
	{
		// Real function is called if hooks are not enabled or if
		// realloc is called recursively while logging data
		return (*real_realloc_ptr)(ptr, size);
	}

	pthread_mutex_lock(&realloc_lock);
	tr_realloc_hook_active = 1;

	void *caller = __builtin_return_address(0);
	void *hdr = (*real_realloc_ptr)(ptr, size);
	tr_log(caller, hdr, ptr, size, TR_REALLOC);

#ifdef PROFILE
	// If ptr is 0 there was no previos malloc of this location
	if (ptr == NULL)
	{
		tr_mallocs++;
		tr_current_mallocs++;
		if (tr_current_mallocs > tr_max_mallocs)
			tr_max_mallocs = tr_current_mallocs;
	}
#endif

	tr_realloc_hook_active = 0;
	pthread_mutex_unlock(&realloc_lock);

	return hdr;
}

void
addAllocationToTree(void)
{
	int bt_size;
	int i, j;
	void *bt[TR_BT_SIZE + 1];
	CallerNode* cn = CallTree;
	CallerNode** parent = &CallTree;
	
	bt_size = backtrace(bt, TR_BT_SIZE);
	for (i = bt_size - 1; i >= 4; i--)
	{
		if (cn == NULL)
		{
			*parent = cn = (CallerNode*) malloc(sizeof(CallerNode));
			cn->funcAdr = bt[i];
			cn->mallocs = 0;
			cn->noCallees = 0;
			cn->maxCallees = 0;
			cn->callees = NULL;
		}
		if (i == 4)
			cn->mallocs++;
		else
		{
			int knownCallee = 0;
			for (j = 0; j < cn->noCallees; j++)
				if (bt[i - 1] == cn->callees[j]->funcAdr)
				{
					parent = &cn->callees[j];
					cn = cn->callees[j];
					knownCallee = 1;
					break;
				}
			if (!knownCallee)
			{
				if (cn->noCallees == cn->maxCallees)
				{
					/* Copy callees into new, larger array. */
					CallerNode** tmp;
					int newSize = 2 * cn->maxCallees;
					if (newSize == 0)
						newSize = 4;
					tmp = (CallerNode**) malloc(newSize * sizeof(CallerNode*));
					memcpy(tmp, cn->callees,
						   cn->maxCallees * sizeof(CallerNode*));
					if (cn->callees)
						free(cn->callees);
					cn->callees = tmp;
					memset(&cn->callees[cn->maxCallees], 0,
						   (newSize - cn->maxCallees) * sizeof(CallerNode*));
					cn->maxCallees = newSize;
				}
				parent = &cn->callees[cn->noCallees++];
				cn = 0;
			}
		}
	}
}

static int
removeBranchesBelowThreshold(CallerNode* root)
{
	int i;
	int max;

	if (!root)
		return (0);
	for (i = 0; i < root->noCallees; i++)
	{
		if (removeBranchesBelowThreshold(root->callees[i]))
		{
			free(root->callees[i]);
			if (root->noCallees > 1)
			{
				root->callees[i] = root->callees[root->noCallees - 1];
				root->callees[root->noCallees - 1] = 0;
			}
			else if (root->noCallees == 1)
				root->callees[i] = 0;
			
			root->noCallees--;
			i--;
		}
	}
	if (root->noCallees == 0 && root->mallocs < mallThreshold )
		return (1);

	return (0);
}

static void
dumpCallTree(CallerNode* root, char* indentStr, int rawMode)
{
	int i;
	Dl_info info;
	char* newIndentStr;
	size_t indDepth;

	if (!root || !mallTreeStream)
		return;

	if (rawMode)
	{
		fprintf(mallTreeStream, "-");
	}
	else
	{
		newIndentStr = (char*) malloc(strlen(indentStr) + 2);
		strcpy(newIndentStr, indentStr);
		if (root->noCallees > 0)
			strcat(newIndentStr, "+");
		indDepth = strlen(newIndentStr);
		fprintf(mallTreeStream, "%s- ", newIndentStr);
	}

	if (dladdr(root->funcAdr, &info) && info.dli_fname  && *info.dli_fname)
	{
		if (root->funcAdr >= (void *) info.dli_saddr)
			sprintf(tr_offsetbuf, "+%#lx", (unsigned long)
					(root->funcAdr - info.dli_saddr));
		else
			sprintf(tr_offsetbuf, "-%#lx", (unsigned long)
					(info.dli_saddr - root->funcAdr));
		fprintf(mallTreeStream, "%s%s%s%s%s[%p]",
				info.dli_fname ?: "",
				info.dli_sname ? "(" : "",
				info.dli_sname ?: "",
				info.dli_sname ? tr_offsetbuf : "",
				info.dli_sname ? ")" : "",
				root->funcAdr);
	}
	else
	{
		fprintf(mallTreeStream, "[%p]", root->funcAdr);
	}
	fprintf(mallTreeStream, ": %lu\n", root->mallocs);
	if (indDepth > 1 && !rawMode)
	{
		if (newIndentStr[indDepth - 2] == '+')
			newIndentStr[indDepth - 2] = '|';
		else if (newIndentStr[indDepth - 2] == '\\')
			newIndentStr[indDepth - 2] = ' ';
	}

	for (i = 0; i < root->noCallees; i++)
	{
		if (rawMode)
			dumpCallTree(root->callees[i], "", 1);
		else
		{
			if (i == root->noCallees - 1)
				newIndentStr[indDepth - 1] = '\\';
			dumpCallTree(root->callees[i], newIndentStr, rawMode);
		}
	}
	if (rawMode)
		fprintf(mallTreeStream, ".\n");
	else
		free(newIndentStr);
	
}

#ifdef _LIBC
extern void __libc_freeres (void);

/* This function gets called to make sure all memory the library
 * allocates get freed and so does not irritate the user when studying
 * the mtrace output.  */
static void
release_libc_mem (void)
{
	/* Only call the free function if we still are running in mtrace
	 * mode. */
	/*if (mallstream != NULL)
		__libc_freeres ();*/

	kuntrace();
        write(2, "kuntrace()\n", 11); 
}
#endif

/* We enable tracing if either the environment variable MALLOC_TRACE
 * or the variable MALLOC_TREE are set */
void
ktrace()
{
#ifdef _LIBC
	static int added_atexit_handler;
#endif
	char* mallfile;

	/* Don't panic if we're called more than once.  */
	if (mallstream != NULL)
		return;

#ifdef _LIBC
	/* When compiling the GNU libc we use the secure getenv function
	 * which prevents the misuse in case of SUID or SGID enabled
     * programs.  */
	mallfile = __secure_getenv("MALLOC_TRACE");
	mallTreeFile = __secure_getenv("MALLOC_TREE");
	if( __secure_getenv("MALLOC_THRESHOLD") != NULL )
	    mallThreshold = atol(__secure_getenv("MALLOC_THRESHOLD"));
#else
	mallfile = getenv("MALLOC_TRACE");
	mallTreeFile = getenv("MALLOC_TREE");
	if( getenv("MALLOC_THRESHOLD") != NULL )
	    mallThreshold = atol(getenv("MALLOC_THRESHOLD"));
#endif
	if (mallfile != NULL || mallTreeFile != NULL)
    {
		mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null", "w");
		if (mallstream != NULL)
		{
			char buf[512];
            
			/* Be sure it doesn't malloc its buffer!  */
			setvbuf (mallstream, malloc_trace_buffer, _IOFBF,
					 TRACE_BUFFER_SIZE);
			fprintf (mallstream, "= Start\n");
			memset(buf, 0, sizeof(buf));
			readlink("/proc/self/exe", buf, sizeof(buf));
			if(*buf)
				fprintf (mallstream, "#%s\n", buf);

			// Enable hooks
			tr_malloc_hook_enabled = 1;
			tr_realloc_hook_enabled = 1;
			tr_free_hook_enabled = 1;

			tr_cache_pos = TR_CACHE_SIZE;
			do
			{
				tr_cache[--tr_cache_pos].ptr = NULL;
			} while (tr_cache_pos);
			tr_cache_level = 0;

			memset(tr_hashtable, 0, sizeof(void*) * TR_HASHTABLE_SIZE);
#ifdef _LIBC
			if (!added_atexit_handler)
			{
				added_atexit_handler = 1;
				atexit (release_libc_mem);
			}
#endif
		}
	}
}

void
kuntrace()
{
	// Disable hooks
	tr_malloc_hook_enabled = 0;
	tr_realloc_hook_enabled = 0;
	tr_free_hook_enabled = 0;

	if (mallstream == NULL)
		return;

	if (removeBranchesBelowThreshold(CallTree))
		CallTree = 0;
	if (mallTreeFile)
	{
		if (mallTreeStream = fopen(mallTreeFile, "w"))
		{
			dumpCallTree(CallTree, "", 0);
			fclose(mallTreeStream);
		}
	}

	/* Flush cache. */
	while (tr_cache_level)
		tr_log(NULL, 0, 0, 0, TR_NONE);

	fprintf (mallstream, "= End\n");
#ifdef PROFILE
	fprintf(mallstream, "\nMax Mallocs:    %8ld   Cache Size:   %8ld"
			"   Flashes:      %8ld\n"
			"Mallocs:        %8ld   Frees:        %8ld   Leaks:        %8ld\n"
			"Logged Mallocs: %8ld   Logged Frees: %8ld   Logged Leaks: %8ld\n"
			"Avg. Free lookups: %ld  Malloc collisions: %ld  Max offset: %ld\n",
			tr_max_mallocs, (long int)TR_CACHE_SIZE, tr_flashes,
			tr_mallocs, tr_frees, tr_current_mallocs,
			tr_logged_mallocs, tr_logged_frees,
			tr_logged_mallocs - tr_logged_frees,
			tr_frees > 0 ? ( tr_failed_free_lookups / tr_frees ) : 0,
			tr_malloc_collisions, (long int)tr_max_offset);
#endif
	fclose (mallstream);
	mallstream = NULL;
	write(2, "kuntrace()\n", 11);
}

int fork()
{
  int result;
  if (mallstream)
     fflush(mallstream);
  result = __fork();
  if (result == 0)
  {
    if (mallstream)
    {
      close(fileno(mallstream));
      mallstream = NULL;
    }
  }
  return result;
}


static int my_mcount_lock = 0;
void mcount()
{
   Dl_info info;
   int i = 1;
   if (my_mcount_lock) return;
   my_mcount_lock = 1;
   bt_size = backtrace(bt, TR_BT_SIZE);
#if 0
for(i = 1; (i < 5) && (i < bt_size); i++)
{
#endif
   if (dladdr(bt[i], &info) &&	info.dli_fname  && *info.dli_fname)
   {
	fprintf(stdout, "%s\n", info.dli_sname ? info.dli_sname : "");
   }
   else
   {
	fprintf(stdout, "[%p]\n", bt[i]);
   }
#if 0
}
   fprintf(stdout, "\n");
#endif   
   my_mcount_lock = 0;
}