Re: static inline struct task_struct * get_current(void)

[Ketan Mukadam <kmukadam@neomagic.com>]

You better start reading

Understanding Linux Kernel O'Reiliy....

It gives a good insight.... but i think it explains an older version of 
kernel....[2.2]

ketan

SACHIN PRASAD wrote:
> 
> 
> 
> 
> I was just looking at the code on the link 
> http://www.kernelnewbies.org/faq/ and found a piece of code
> 
> static inline struct task_struct * get_current(void)
> {
>        struct task_struct *current;
>        __asm__("andl %%esp,%0; ":"=r" (current) : "0" (~8191UL));
>        return current;
> }
> 
> 
> 
> i am new to kernel prograaming and want an explantions for :-
> 
> 1. "%0" is a macro that expands to the first input/output specification.
> 
> 2.Basically, the task's task_struct and a task's kernel stack occupy an 
> 8KB block that is 8KB aligned, with the task_struct at the beginning and 
> the stack growing from the end downwards. So you can find the 
> task_struct by clearing the bottom 13 bits of the stack pointer value.
> 
> I am a computer science graduate and have a C programming experience but 
> still these are really proving qutie tuff for me , especially the stack 
> architecture in memory
> 
> any replies and helps appreciated
> 
> regards
> sachin
> 
> 
> 
> 
> 
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