Re: [PATCH 0/2] Make tunable a default feature

[Siddhesh Poyarekar <siddhesh@gotplt.org>]

On 2023-03-20 12:59, Adhemerval Zanella Netto wrote:
> I think it might make sense for tunables that change the program semantic, such
> as security hardening; although I don't think it really fits for performance
> oriented ones (such malloc or pthread tuning).  So maybe we can define a global

Administrative level performance tuning defaults for setuid binaries?

> file format where the administrator can set where setuid binaries can use it,
> and if uses can overwrite it.  My initial idea would be something quite simple,
> similar to sysctl.conf:

Yes, I think Florian suggested reusing ld.so.conf instead.  I don't have 
a strong preference either way so y'all can fight that one out - potato 
potato ;)

> And I was thinking about an DF_1_NODEFLIB analogous so the program can opt-out
> any performance or behavior difference any tunable might incur.  Although with
> your idea of enforceable tunable, I think it does not make much sense.

Yeah an ELF flag to override all tunables seems counter to the whole 
idea, but ELF flags to override specific tunables may make sense.  E.g. 
memory tagging enabled by default in the system and a program built with 
DF_NO_MEMTAG overrides that systemwide setting.

Sid