linux segment

[Mulyadi Santosa]

Hi Fan...

On Sun, Oct 28, 2012 at 9:02 PM, Fan Yang <lljyangfan at gmail.com> wrote:
>
> [root at shell--box kernel_mod]# dmesg -c
> **********************************
> cs 60 96
> ds 7b 123
> ss 68 104
> es 7b 123
> fs d8 216
> gs e0 224
> **********************************
>
> The cs and ds in the kernel space is 60 and 7b. But the kernel define the
> KERNEL_CS as 60 and the KERNEL_DS as 7b.  Where am I wrong?
>


you print CS and DS twice, once during init and once during exit of
your kernel module. So, which one do you want to confirm?

All in all, I have a guess that you see such number (DS belongs to
user space in kernel module) because IIRC kernel module loading is
done using syscall and with the help of modprobe helper.

Thus, it is important to access user space during that stage, hence DS
still using user space data segment.


-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com