Doubt regarding asmlinkage

Mulyadi Santosa mulyadi.santosa at gmail.com
Thu Sep 8 00:20:26 EDT 2011


Hi :)

On Thu, Sep 8, 2011 at 10:40, rohan puri <rohan.puri15 at gmail.com> wrote:
> Hi Mulyadi,
>
> Thanks for the response. I do agree with the issue concerning the no.of
> registers available are less for 32 bit to that of 64 bit.
>
> But even in this case if parameters are more than the no of register for 32
> bit, then also before executing int 80h interrupt it stores the parameters
> in the register and after that system call dispatcher puts them on the
> kernel stack of that process. So, how the case where more than no of
> registers are the parameters to the system call is handled.


Please don't top post :)

Regarding passing the parameters when it is more than number of
registers used in x86 32 bit, AFAIK it's using EDX to contain the
address of user space memory that contains the data, later it will be
copied to kernel stack IIRC.

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

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



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