LinuxQuestions.org - Problem with dmalloc Library

Hello experts,
I'm trying to use dmalloc (http://dmalloc.com) library to debug a program that I suspect is suffering from some kind of memory leak. To do this, I have wrote a very simple program to see how dmalloc is working!
I have runed this program on 2 platforms 1)Ubuntu 32 bit 2)Suse 64 bit
and it gives completely different results on these two platforms! Ultimately I need to run it on Suse, but I wonder why results are not the same on these platforms , and moreover they are not expected results.
1-Ubuntu:
test.c

Code:

#include <stdio.h>

#include <stdlib.h>

void myfunc();

#ifdef DMALLOC

#include "dmalloc.h"

#endif

int main()

{

int *test,i,j;

test=(int*)malloc(sizeof(int)*2);

for(i=0;i<10;i++) test[i]=i;

for (j=9;j>=0;j--) printf(" %d ",test[j]);

free(test);

myfunc();

return 1;

}

myfunc.c

Code:

#include <stdio.h>

#include <stdlib.h>

void myfunc();

#ifdef DMALLOC

#include "dmalloc.h"

#endif

void myfunc()

{

int *test,i,j;

printf("\n");

test=(int*)malloc(sizeof(int)*2);

for(i=0;i<10;i++)test[i]=i;

for (j=9;j>=0;j--)printf(" %d ",test[j]);

free(test);

printf("\n");

}

makefile:

Code:

CC=g++

CFLAGS=-c -Wall -fpermissive -DDMALLOC -DDMALLOC_FUNC_CHECK 

LDFLAGS=

SOURCES= myfunc.c test.c libdmallocxx.a

OBJECTS=$(SOURCES:.c=.o)

EXECUTABLE=test

all: $(SOURCES) $(EXECUTABLE)        

$(EXECUTABLE): $(OBJECTS)  

        $(CC) $(LDFLAGS) $(OBJECTS) -o $@

.c.o:

        $(CC) $(CFLAGS) $< -o $@

at the beginning I run dmalloc -l logfile ( I already run "function dmalloc { eval `command dmalloc -b $*`; }" as stated in docs)

here is the results after running:

Quote:

amir-laptop_[1]: ./test
Segmentation fault
amir-laptop_[1]: ./test
Segmentation fault
amir-laptop_[1]: ./test
Segmentation fault
amir-laptop_[1]: ./test
Segmentation fault
amir-laptop_[1]: ./test
Segmentation fault
amir-laptop_[1]: ./test
Segmentation fault
amir-laptop_[1]: ./test
Segmentation fault
amir-laptop_[1]: ./test
Segmentation fault
amir-laptop_[1]: ./test
Segmentation fault
amir-laptop_[1]: ./test
Segmentation fault
amir-laptop_[1]: ./test
debug-malloc library: dumping program, fatal error
Error: failed OVER picket-fence magic-number check (err 27)
9 8 7 6 5 4 3 2 1 0 Aborted

As you can see I have runned test 10 times and in these runs it gives a segmentation fault error and does NOT generate a logfile
after that in 11th run it generate the logfile and gives another kind of error, WHAT 's the problem? Why this happen? I expect that it generate a logfile everytime not just by chance

On SUSE-64 bit:
Here the problem is even worse. When I do not use dmalloc the program generate kind of error:
output without dmalloc:

Quote:

euler_[1]: make
g++ -c -Wall -fpermissive myfunc.c -o myfunc.o
g++ -c -Wall -fpermissive test.c -o test.o
test.c: In function ‘int main()’:
test.c:16: warning: ‘test’ may be used uninitialized in this function
g++ myfunc.o test.o -o test
euler_[1]: ./test
*** glibc detected *** free(): invalid pointer: 0x0000002a9566b1c0 ***
9 8 7 6 5 4 3 2 1 0
*** glibc detected *** free(): invalid next size (fast): 0x0000000000501010 ***
9 8 7 6 5 4 3 2 1 0

This is the output with dmalloc:

Quote:

euler_[1]: ./test
9 8 7 6 5 4 3 2 1 0
9 8 7 6 5 4 3 2 1 0

This time we have a logfile but it doen not show any error!!!

Quote:

euler_[1]: cat logfile
1279255144: 4: Dmalloc version '5.5.2' from 'http://dmalloc.com/'
1279255144: 4: flags = 0, logfile 'logfile'
1279255144: 4: interval = 0, addr = 0, seen # = 0, limit = 0
1279255144: 4: starting time = 1279255144
1279255144: 4: process pid = 784
1279255144: 4: ending time = 1279255144, elapsed since start = 0:00:00

What's wrong here?

Thanks,
amir