Re: [PATCH v3 05/17] add support for Clang's Shadow Call Stack (SCS)

[Sami Tolvanen]

On Thu, Oct 31, 2019 at 8:51 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> > +/* A random number to mark the end of the shadow stack. */
> > +#define SCS_END_MAGIC        0xaf0194819b1635f6UL
>
> Is 0xaf.... non-canonical for arm64? While "random", it should also
> likely be an "impossible" value to find on the call stack.

Agreed, and yes, this is non-canonical for arm64 and AFAIK all 64-bit
architectures the kernel supports. I'll add a note about it.

Sami