Re: [RFC] prctl: (Please do not!) Deprecate non PR_SET_MM_MAP operations

[Jonathan de Boyne Pollard <J.deBoynePollard-newsgroups@NTLWorld.COM>]

In case you weren't aware, programs can make use of a facility on Linux 
to make their ps listings contain appropriate command-line arguments and 
environment strings. There's also a similar kernel API on FreeBSD.  This 
is used by the built-ins in nosh to good effect, even more so in the 
forthcoming version 1.38, allowing system adminstrators to debug things 
more easily from ps listings by showing them the actually effective 
states of the chained argument and environment vectors rather than what 
they were at the beginning of a chain of built-in commands.

* https://unix.stackexchange.com/a/438007/5132

* https://unix.stackexchange.com/a/432681/5132

The subject of deprecating and removing the API that permits this came 
up recently on the Linux Kernel Mailing List.  I raised my concerns, and 
the Linux Kernel developers have been laudably responsive on the 
subject.  As I said to them, I would welcome a better API, that allows 
setting these things atomically, start and length together as a pair.

* https://lkml.org/lkml/2018/4/3/739

* https://lkml.org/lkml/2018/5/6/127

* https://lkml.org/lkml/2018/5/7/78

* https://lkml.org/lkml/2018/5/7/79

* https://lkml.org/lkml/2018/5/7/80

* https://lkml.org/lkml/2018/5/7/81