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To: Fu-hau Hsu <fhsu@ic.sunysb.edu>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Memory maps
In-Reply-To: <Pine.GSO.4.21.0104021611050.24682-100000@sparky.ic.sunysb.edu>
From: ebiederm@xmission.com (Eric W. Biederman)
Date: 03 Apr 2001 06:57:22 -0600
In-Reply-To: Fu-hau Hsu's message of "Mon, 2 Apr 2001 16:25:11 -0400 (EDT)"
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Fu-hau Hsu <fhsu@ic.sunysb.edu> writes:

> Dear freinds:
> 
>  I have following questions about memory maps. I appreciate any
> suggestion.
> 
>  Q. (1)When a process is running, how can I get the range of data, stack,
>        and code segments, say the stack segment is from address 0x..... to
>        0x..... so do data segments and code segments?
>        PS: Under ELF format, there are several seperaed code and data
>            segments, but the process control table has only one pair of
>            pointers for each, Are the pointers still useful?


Sort of, you can currently confuse the elf loader with multiple bss segments.
The stack, and the brk pointer are still used. 

>     (2) /proc/*/maps will show us those info, but how does it get these
>        info? 

This is a reflection of what areas of memory the kernel sees.  In principle
every thing is now handled by mmap, and this /proc/maps is a reflection
of that.  See under the files in mm/*.c

Eric