From mboxrd@z Thu Jan  1 00:00:00 1970
From: Rahul K Patel <rahulk.patel@einfochips.com>
Subject: Re: Linux process...
Date: Mon, 30 Mar 2009 11:45:58 +0530
Message-ID: <49D0639E.3060101@einfochips.com>
References: <34e1241d0903292306m3e879639u4752e821349c84ee@mail.gmail.com>
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To: beginner_h4x3r <nightdecoder@gmail.com>
Cc: linux-c-programming@vger.kernel.org

it's offset address and not absolute address.
base addresses of your parent and child process will be different so
final absolute address (base + offset) will be different for both.

beginner_h4x3r wrote:
> Hi All..
>
> I am a beginner hacker, i want to learn Linux from scratch. I read
> some resources on Linux's process management. Process duplicates it's
> page table to it's child process, right? so i wrote demonstrate code
> to prove this.
>
> #include <stdio.h>
> #include <stdlib.h>
> #include <unistd.h>
> #include <sys/types.h>
> #include <sys/wait.h>
>
> int main (void) {
>   pid_t child;
>   int stack_int;
>
>   child = fork ();
>   if (child == 0) {
>       sleep (1); /* ;p */
>       printf ("child process stack_int value %i, address: %p\n",
> stack_int, &stack_int);
>       exit (0);
>     }
>   if (child == -1) {
>       perror ("fork");
>       return -1;
>     }
>   stack_int = 32;
>   printf ("main process stack_int value %i, address: %p\n", stack_int,
> &stack_int);
>   waitpid (child, NULL, 0);
>
>   return 0;
> }
>
> The output is:
> main process stack_int value 32, address: 0xbf9c66ec
> child process stack_int value 8495092, address: 0xbf9c66ec
>
> stack_int value is different from parent and it's child.
>
> My question: why the stack_int has a same address between parent and
> it's child ?, but confusedly... they have a different value, i was
> though it should be different, since process duplicate it's page to
> child, please explain me. ;)
>
> Thanks before.
>
> --- curious_hacker
> --
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