Re: [PATCH v5 05/14] add support for Clang's Shadow Call Stack (SCS)

Sami Tolvanen
2019-11-15T18:34:49Z

On Fri, Nov 15, 2019 at 7:37 AM Mark Rutland <mark.rutland@arm.com> wrote:
> > +config SHADOW_CALL_STACK_VMAP
> > + bool
> > + depends on SHADOW_CALL_STACK
> > + help
> > + Use virtually mapped shadow call stacks. Selecting this option
> > + provides better stack exhaustion protection, but increases per-thread
> > + memory consumption as a full page is allocated for each shadow stack.
>
> The bool needs some display text to make it selectable.
>
> This should probably be below SHADOW_CALL_STACK so that when it shows up
> in menuconfig it's where you'd expect it to be.
>
> I locally hacked that in, but when building defconfig +
> SHADOW_CALL_STACK + SHADOW_CALL_STACK_VMAP, the build explodes as below:

Ugh, thanks for pointing this out. I'll fix this in v6.

Sami