mmap giving Permission Denied error

Sept. 21, 2013

      Hello all,

I tried mmap'ing to address zero after setting */proc/sys/vm/mmap_min_addr*to
* 0*, but mmap is giving Permission Denied error.

My C code is as below -

#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>

int main(void)
{
int *ptr = NULL;
ptr =
mmap(0,4096,PROT_READ|PROT_WRITE,MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED,-1,0);
if(ptr == MAP_FAILED)
{
perror("Error in mapping\n");
exit(1);
}
printf("After mmap\n");
*ptr = 16;
printf("Contents of address 0x%x is :: %d\n",ptr,*ptr);
return 0;
}

Am I doing anything wrong here?

Thank you in advance.

Regards,
Ravi Teja