Re: [GIT PULL] gcc-plugin updates for v4.19-rc1

From: Linus Torvalds
Date: Wed Aug 15 2018 - 15:04:15 EST

On Wed, Aug 15, 2018 at 11:35 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> I swear I'm doing my best. Are you speaking of
> stackleak_check_alloca() or stackleak_erase()? These were both
> discussed on the list, and we weren't able to come up with
> alternatives: in both cases we're off the stack, and recovery is
> seemingly impossible.

Why do you even *test* that thing? Why don't you just allocate stack
and clear it.

Dammit, the whole f*cking point of this patch-set is to clear the
stack used. It is *not* supposed to do anything else. If the process
runs out of stack, that's caught by the vmalloc'ed stack.

And if you don't have vmalloc'ed stack, then clearly you don't care.

I refuse to take this kind of code that does stupid things, and then
*because* it does those initial stupid things it does even more stupid
things to correct for it.

I hated the thing to begin with, told people that there are better
approaches that don't have the downsides, got ignored, and then I'm
pushed crap.