Re: [RFC/PATCH] RLIMIT_ARG_MAX

Jakub Jelinek
2008-02-29T19:14:22Z

On Fri, Feb 29, 2008 at 11:01:38AM -0800, Ollie Wild wrote:
> On Fri, Feb 29, 2008 at 10:12 AM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > So it's not *going* to be exact even with RLIMIT_ARG_MAX, because it's
> > going to have all those other issues to contend with - on a 64-bit
> > architecture, the argument _pointers_ are often within an order of
> > magnitude of the argument strings themselves, and I don't think your patch
> > counted them as part of the argument/environemnt size (I was too lazy to
> > check the sources, but I'm pretty sure argv/env_start/end is just the
> > string space, not the pointers).
>
> This is precisely why I picked 25% as the maximum argument size ratio.
> In practice, that 25% can easily mean 50% or more. If people want to
> increase this, it can probably be tweaked somewhat, but switching it
> to, say, 50% probably isn't a good idea.

I think 50% would be still fine. And, ideally make that
MAX (RLIMIT_STACK / 2, 128KB) to avoid regressions for programs which assume
they can pass ARG_MAX args+env, even if they have say 192KB stack limit.

Jakub