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From: The Natural Philosopher <tnp@invalid.invalid>
Newsgroups: comp.os.linux.misc
Subject: Re: memory managment and (its) protection under Linux
Date: Wed, 21 Aug 2024 10:56:37 +0100
Organization: A little, after lunch
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On 21/08/2024 05:11, 186282@ud0s4.net wrote:
> On 8/20/24 2:27 PM, The Natural Philosopher wrote:
>> On 20/08/2024 14:09, MarioCCCP wrote:
>>>
>>> partially OT : programming task
>>> Scenario : Debian Bookworm, XFCE4
>>> Very often GUI programs show their results in the form of ListBoxes, 
>>> whose content is mainly textual semantically, but very often cannot 
>>> be copied/pasted as text and neither is easy to export as text. I 
>>> have one case in FreeFileSync, that shows lists of files upwards of 
>>> 500'000 items, and other deduplicators programs.
>>> I am having a general curiosity about this problem in linux.
>>> Can a root user access, in read only mode, to memory associated to 
>>> another (plain user mode) process ? Or the outcome is invariably a 
>>> seg_fault ? Has a root user the right to inquire the memory of non 
>>> root programs ?
>> I believe not.
>> In such cases it is usual to write a daemon to handle *all* requests.
>>
>>   I am not speaking about disk files, but specifically in
>>> physical memory
>>
>> Well thereby hangs a tale. In fact i deliberately created a RAMDISK in 
>> one application purely to handle communications between synchronous 
>> processes.
>>
>> One process writes it, others may read
> 
>    In many Linux distros now, /tmp is a de-facto
>    ramdisk - all disappears on reboot. IF you have
>    the space in your / partition then you need not
>    specifically create a NEW ramdisk to achieve the
>    effect.
> 
Not /tmp oddly, but various other stuff like /run is, yes.



-- 
For every complex problem there is an answer that is clear, simple, and 
wrong.

H.L.Mencken