[Vol-users] Problem reading mapped ranges in linux address spaces

Hi all, I am having a problem reading certain values in an address space. I know for certain that the range I am trying to read is mapped, i.e. there is a vma for it. The specific range in this case is shown in the vma list as this: 1206 0x00007faf9d98f000 0x00007faf9db4d000 r-x 0x0 8 1 241 /lib/x86_64-linux-gnu/libc-2.17.so The offset in this range that I am trying to read is 0x21e9b = 0x7faf9d9b0e9b the call may look like this: proc_as.read(0x7faf9d9b0e9b, 10) and it will return None, meaning it could not read that address. Using the linux_dump_map I exported the whole range and there's a pretty big empty (inaccessible) chunk in the middle, which appears as 0-bytes in the export. I know for a fact that my libc does not have a big area of 0-bytes, so this is pretty weird. It also works just fine for other processes in the same dump (so using the same libc). For research purposes I make my memory dumps with virtualbox, so I don't think it's an issue with memory corruption; as far as i can tell, virtualbox makes complete snapshots. Does anyone know what might cause this problem? Cheers, Edwin