Re: [PATCH v1 1/2] Add the initify gcc plugin

Emese Revfy
2016-06-29T18:59:00Z

On Tue, 28 Jun 2016 23:05:56 +0200
Rasmus Villemoes <linux@rasmusvillemoes.dk> wrote:

> On Tue, Jun 28 2016, Emese Revfy <re.emese@gmail.com> wrote:
>
> > The kernel already has a mechanism to free up code and data memory that
> > is only used during kernel or module initialization.
> > This plugin will teach the compiler to find more such code and data that
> > can be freed after initialization.
> > It has two passes. The first one tries to find all functions that
> > can be become __init/__exit. The second one moves string constants
> > (local variables and function string arguments marked by
> > the nocapture attribute) only referenced in __init/__exit functions
> > to the __initconst/__exitconst sections.
> > It reduces memory usage. This plugin can be useful for embedded systems.
>
> May I suggest, as a followup patch, a debug option/plugin parameter to
> put the strings in a section which will not be reaped after init, but
> just marked inaccessible, with graceful handling of bad accesses (print
> a big fat warning, make the page(s) readable, continue)?

I think even better would be to verify the whole init section.
Unfortunately, I won't implement it anytime soon because my project ends this week.

--
Emese