Re: memory managment and (its) protection under Linux

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.