Error reading /dev/mem

[Paddie O'Brien]

Hi,

I have a system call that maps virtual to physical addresses. I have
disabled CONFIG_STRICT_DEVMEM and am reading from /dev/mem to verify
that the contents of the syscall-returned physical address match the
contents of the virtual address. It works fine up to a point. Reading
beyond byte 935321597 in /dev/mem throws a "bad address" error. Not
sure it's relevant but I'm running on virtual box and specifying 1GB
of RAM. Tried with 2GB of RAM and hit the same problem.

Any idea why I can't read beyond the above point?

Thanks.